{"id": "10.4202/app.01067.2023", "title": "The holotype of the basal archosauromorph Prolacerta broomi revisited", "abstract": "Prolacerta broomi is one of the most important of fossil reptiles. First considered as one of the earliest members of squamates, this basal archosauromorph has been used as a model for diapsid morphological evolution ever since its discovery, playing a pivotal role in hypotheses on the origin of diapsid reptiles. The holotype of Prolacerta broomi (UCMZ 2003.41R) is known from a mostly complete skull, but the original description is limited to the superficial features of the skull roof and palate. Since then, many other specimens of Prolacerta broomi have been recovered that potentially account for this limited access to anatomical information, but it remains unclear whether these aspects correspond well to the known material of the holotype. Here, the skull morphology of the holotype of Prolacerta broomi is revisited through the use of \u03bcCT scans. The identifications of some cranial elements have been corrected, such as the left prefrontal and lacrimal, and several new elements are revealed, including the epi- and ectopterygoids, prearticular, coronoid, and braincase bones. The orbitonasal region is described in detail and significantly shows a contribution of the lacrimal to the dorsal alveolar canal. Finally, the addition of the holotype as an independent OTU in recently published analyses indicate conflicts with the current knowledge on Prolacerta broomi phylogenetic affinity and taxonomy. First, it points to potential taxonomic inconsistency since the holotype does not form a monophyletic group with other Prolacerta broomi OTUs in any of the analyses and, second, it suggests a more basal position for the holotype than that recovered in some studies, more basal than rhynchosaurs and close to the origin of Crocopoda. Together, these findings indicate areas of future research interest in the study of early evolving archosauromorphs.", "keyphrases": ["reptilia", "diapsida", "archosauromorpha", "crocopoda", "triassic", "south africa"]}
{"id": "10.4202/app.01038.2022", "title": "Biomechanical analysis and new trophic hypothesis for Riojasuchus tenuisceps, a bizarre-snouted Late Triassic pseudosuchian from Argentina", "abstract": "Ornithosuchids are a Late Triassic pseudosuchian archosaur group, consisting of four species (three from South America, and one from Scotland). All of them have triangular skulls with a protruding premaxilla, large nostrils, an extensive diastema in their narrow snout, a short jaw that does not reach the anterior end of the skull, and serrated posteriorly curved teeth. For this clade, carnivorous and scavenger habits have been previously proposed. Within the Ornithosuchidae, Riojasuchus tenuisceps (from Argentina) has the most morphologically extreme characteristics. Based on CT scans of the preserved skulls we generated a 3D model, and over this, we estimated the volumes of the adductors and abductor muscles and the force exerted by each. From these data we built the finite element model and measured the bite force (1.8\u20132.3 kN). Lateral, tractive, and torsional forces were applied to the end of the snout to evaluate the structural response of the skull during feeding. The results show that R. tenuisceps could resist tractive and torsional stresses better than lateral stress. Additionally, we analysed the peculiar morphological characteristics of the skull and their functional implications. We observed that the upper and lower dental rows were laterally separated from each other, preventing the generation of a cutting line during occlusion, and therefore, R. tenuisceps would have fed on small-sized prey that it could swallow whole. The curved premaxilla and the short mandible would not allow it to bite with the tip of the snout (ruling out the scavenging hypothesis), but were instead more adequate to capturing prey suspended in a fluid. This set of results allows us to propose that R. tenuisceps could have had a zoophagous diet and a wading habit, being able to feed on fish, amphibians, or any small animals that they could catch from the shoreline.", "keyphrases": ["archosauria", "biomechanics", "feeding habits", "finite element model", "bite force estimation"]}
{"id": "10.4202/app.01080.2023", "title": "New artiopodan euarthropods from the Chengjiang fauna (Cambrian, Stage 3) at Malong, Yunnan, China", "abstract": "The artiopodans, consisting of trilobites and their relatives, were a major euarthropod group in the Paleozoic. Since the first discovery of Naraoia from the Chengjiang fauna, a significant number of artiopodans have been subsequently found in China. Here we describe three new artiopodan species from the lower Cambrian Chengjiang fauna (Cambrian Series 2, Stage 3) at Malong, Yunnan, China. Zhugeia acuticaudata gen. et sp. nov. is defined by a semielliptical cephalon with long genal spines, nine overlapping thoracic tergites, and a pygidium with an elongated needle-like median spine. Its cephalic shield covers multiple anterior thoracic tergites. Tonglaiia bispinosa gen. et sp. nov. is defined by a suboval cephalon, seven thoracic tergites, and a micropygous pygidium with a pair of parallel posteriormost spines. Sidneyia malongensis sp. nov., a new occurrence of Sidneyia from South China, is defined by a crescent-shaped cephalon, eight imbricated tergites, and an abdomen consisting of two cylindrical segments and a tail fluke. The evolutionary affinities of these new taxa are reconstructed and discussed in a phylogenetic context. Phylogenetic analyses resolve Z. acuticaudata among the xandarellids and T. bispinosa gen. et sp. nov. as a trilobitomorph with an uncertain placement, The discovery of three new species improves the biodiversity of artiopodans from the Cambrian and the Chengjiang fauna.", "keyphrases": ["arthropoda", "trilobitomorpha", "vicissicaudata", "burgess shale-type fossils", "exceptional preservation", "lagerst\u00e4tten", "cambrian", "yu\u2019anshan formation", "chengjiang"]}
{"id": "10.4202/app.01078.2023", "title": "Parmalean and other siliceous nannofossils from the Oligocene of Polish Flysch Carpathians", "abstract": "Well-preserved fossil assemblages provide valuable insights into the evolutionary history of biota and their environments. Here, we report on Rupelian (early Oligocene) siliceous nanoeukaryotes from diatomites in the Carpathian Mountains, southeastern Poland. These sediments yielded novel forms of parmaleans and parmalean-like fossils. Their cell wall structure differs from that of described genera. Instead of the generically specific separate dorsal plate and set of girdle plates, some of our taxa contain one upended, hollow, subspherical, perforated cup. To accommodate these differences, we propose a new division Parmaphyta, a new family Parmoligocenaceae, a new genus Parmoligocena and a new species Parmoligocena janusii. Other remains are reminiscent of the extant genus Pentalamina and for this we propose a new genus and species, Pentalaminamorpha radiata. The taxonomic affinity is less certain for other nannofossils found, as they are only somewhat similar to parmaleans, and so we only tentatively associate them with this group. All these fossils occur together with a diverse assemblage of diatoms (mostly from Leptocylindrales, Rhizosoleniales, Coscinodiscales, Cymatosirales, and Hemiaulales), silicoflagellates (mostly species from the genus Corbisema) and archaeomonads. Together they suggest the palaeoenvironmental context for the parmaleans, a neritic marine environment, thus similar to where silicified parmaleans can be found today.", "keyphrases": ["parmoligocena", "pentalaminamorpha", "diatomites", "siliceous nannofossils", "parmaleans", "oligocene", "polish flysch carpathians"]}
{"id": "10.4202/app.01057.2023", "title": "New records of marsupials from the Miocene of Western Amazonia, Acre, Brazil", "abstract": "The Amazonian region covers a significant part of the South American continent and harbors outstanding biodiversity. However, much of its history is still unknown. This situation has begun to change with paleontological field efforts over the last decades, which have been proving that fossils can be common in this region. Despite their great current species richness and abundance in the area today, marsupials have a sparse fossil record, restricted to a few specimens from handful Cenozoic Amazonian localities. Here we present new records of fossil marsupial teeth from the Solim\u00f5es Formation (lower Eocene\u2013Pliocene), on the Juru\u00e1 and Envira riverbanks (Acre, Northwestern Brazil). The localities investigated yield at least four distinct didelphid didelphimorphians at PRE 06 (Ponto Rio Envira: Marmosini ?Marmosa sp., Didelphis cf. D. solimoensis, Thylamys? colombianus, plus unidentified didelphids), and two paucituberculatans from the Juru\u00e1 River localities (Ponto Rio Juru\u00e1: the palaeothentid Palaeothentinae indet. at PRJ 25 and PRJ 33\u2019, and Abderitidae indet. from PRJ 33). In agreement with the associated mammalian faunas, most of the didelphids, except for Thylamys? colombianus from PRE 06, indicate a (?early) Late Miocene age for this locality. Conversely, the abderitid specimens found in situ at PRJ 33 would match a Middle Miocene age. The palaeothentids found at PRJ 25 and PRJ 33\u2019 localities cannot be considered for biostratigraphic inferences, since they were found outside a stratigraphic context. Nevertheless, these paucituberculatans considerably add to our knowledge, as they are the first ever recorded in Brazilian Amazonia.", "keyphrases": ["mammalia", "metatheria", "didelphimorphia", "paucituberculata", "systematics", "historical biogeography", "miocene", "brazil"]}
{"id": "10.4202/app.01076.2023", "title": "A new diminutive fossil ziphiid from the deep-sea floor off northern Chile and some remarks on the body size evolution and palaeobiogeography of the beaked whales", "abstract": "The evolutionary history of the beaked whales (Ziphiidae), odontocetes nowadays adapted to deep diving, is well known thanks to a significant fossil record mainly from the deep ocean floors. A partial cranium of a ziphiid recovered from Plio-Pleistocene deep sea deposits (about 1000 m) off the port of Pisagua, northern Chile, during fishing activity is here described and referred to the new species Ihlengesi changoensis. Ihlengesi changoensis differs from the type species Ihlengesi saldanhae, from the sea floor off South Africa, by having a more elongated premaxillary sac fossa and consequently a more anteriorly located premaxillary foramen; dorsal margin of each premaxillary crest sloping markedly ventrolaterally and generating an acute dorsal profile of the vertex in anterior view; less anterolateral extension of the right nasal forming part of the premaxillary crest; lateral margins of the nasals not anteriorly diverging but weakly convex; nasofrontal suture anteriorly pointed. The phylogeny supports a sister-taxon relationship between I. changoensis and I. saldanhae, both members of the crown ziphiids Hyperoodontinae. Ihlengesi changoensis shares with I. saldanhae and other fossil ziphiids a small body size (estimated length 3.5 m) supporting the hypothesis that in the past small beaked whales (<4 m) were more common than today. Such recent shift of the ziphiids towards a larger size could be the result of a progressive change of diet from fish to cephalopods, to the competition with the delphinids, and the predatory impact of the white shark Carcharodon carcharias and/or of the killer whale Orcinus orca. This new Chilean ziphiid further supports the hypothesis that crown beaked whales originated and firstly dispersed in the oceanic waters of the Southern Hemisphere. Their radiation and geographical distribution could have been driven by the southern oceanic circulation and related localized concentration of trophic resources in high productivity upwelling areas.", "keyphrases": ["mammalia", "cetacea", "ziphiidae", "cenozoic", "southeastern pacific", "south america"]}
{"id": "10.4202/app.01058.2023", "title": "A comparison of teeth in Tithonian, Late Jurassic, predatory actinopterygian fishes from Owad\u00f3w-Brzezinki L\u00e4gerstatte and its palaeoecological implications", "abstract": "The Owad\u00f3w-Brzezinki palaeontological site is known for its very well-preserved fossils of Late Jurassic vertebrates, such as numerous fossil fish teeth and occasional dental bones. Some of these represent well-studied taxa, including the most common large predatory fish, with notable examples of caturoids (such as Strobilodus sp.) and pachycormids (Orthocormus teyleri). The current study presents the microstructure and histological features of the teeth of the selected specimens of the above taxa. They are determined through examinations of tooth cross-sections under thin microscopic observations and by the usage of scanning electron microscopy (SEM). The above inspections, combined with aspects of external tooth morphology, allowed us to determine the palaeoecology of the aforementioned taxa of large predatory fish. It is concluded that examined Caturoidea displayed a rather homogenous dentition belonging to the intermediate cut/slash guild, characterized by an internal orthodentin histology with prominent incremental Andresen growth lines of differing form, indicating living in a highly variable, unstable environment. The teeth of pachycormid specimen (O. teyleri) can be characterized as having denteon-based orthodentin histology, with a rapid rate of tooth eruption and a heterodont, elongated specialist dentition of the piercing guild. The observed structural differences in the teeth suggest a different niche distribution between the taxa studied. They help to explain how these predatory ray-finned fishes may have coexisted both in the local environment of the Owad\u00f3w-Brzezinki and in the wider, more global context of Late Jurassic shallow marine environments. In addition, the tooth samples are characterised by pronounced surface bioerosion with traces of Mycellites ossifragus durophagous fungal activity, indicating an intense bioerosion caused by these microorganisms after the death of the fish.", "keyphrases": ["key words: actinopterygii", "caturoidea", "teeth", "predatory", "microstructure", "histology", "niches", "late jurassic", "poland", "owad\u00f3w-brzezinki quarry"]}
{"id": "10.4202/app.01075.2023", "title": "A new Early Devonian antiarch placoderm from Belarus, and the phylogeny of Asterolepidoidei", "abstract": "A new asterolepidoid antiarch, Sherbonaspis talimaae sp. nov., is described based on the disarticulated skeletal elements from several boreholes in Belarus, from the Lepel Beds of the Vitebsk Formation, which has been assigned to an Early Devonian, late Emsian age. New information is provided on the structure of the paranuchal plate previously unknown in Sherbonaspis. Data on the remains of the other fossil vertebrates, and the characteristics of the fossil-bearing rocks are provided. These data add information on the taxonomic composition of the late Emsian\u2013early Eifelian fish fauna from the western part of the East European Platform. The new cladistic analysis of the Euantiarcha provides results more reliable in comparison with the analysis of all antiarchs together, and supports traditional subdivision of the group into Bothriolepidoidei and Asterolepidoidei. However, further analysis demonstrates unresolved polytomy close to the base of the Asterolepidoidei, and supports the hypothesis that the family Pterichthyodidae is polyphyletic. Until the phylogenetic relationships of Asterolepidoidei are more clearly resolved, Sherbonaspis is attributed to Pterichthyodidae. Comparison of the sections of the Lepel Beds of Belarus with the age-equivalent deposits in Estonia, Lithuania, and Latvia supports a late Emsian or possibly early Eifelian age for the Lepel Beds.", "keyphrases": ["placodermi", "asterolepidoidei", "phylogeny", "devonian", "belarus"]}
{"id": "10.4202/app.01088.2023", "title": "The tarphyceratid cephalopod Trocholites in the Middle\u2013Upper Ordovician of the Prague Basin \u2014the Baltican element in peri-Gondwana", "abstract": "The vast majority of cephalopods of the order Tarphyceratida are known from regions that were located at mid- or low palaeolatitudes during the Ordovician (mainly Baltica, Laurentia, and Chinese palaeoblocks). Only a handful of tarphyceratid specimens are known from high palaeolatitude regions of peri-Gondwana and Gondwana. Here, we describe the two best-preserved trocholitid cephalopods known to date from the Ordovician of the Prague Basin. The first is from the late Darriwilian/early Sandbian Dobrotiv\u00e1 Formation and is assigned to Trocholites fugax, a species previously recorded from roughly coeval strata of Iberia, France, and Bohemia. The specimen thus strengthens previous hypotheses regarding the interchange of non-benthic faunas between Baltica and different regions of peri-Gondwana during the Middle/ Late Ordovician boundary interval. The second specimen, assigned to a new species of Trocholites chaloupkai sp. nov., is from the late Sandbian\u2013early Katian Zaho\u0159any Formation and thus represents one of the stratigraphically youngest Trocholites in the Ordovician of peri-Gondwana. Internal structures of the shell of the holotype of the new species were studied using micro-CT tomography. This revealed that T. chaloupkai sp. nov. closely resembles the stratigraphically older (Darriwilian) species Trocholites depressus from Estonia.", "keyphrases": ["tarphyceratida", "trocholites", "micro ct", "darriwilian", "sandbian/katian", "prague basin", "baltica", "peri-gondwana", "bohemia"]}
{"id": "10.4202/app.01087.2023", "title": "On Triassic Murchisonia-like gastropods\u2014surviving the end-Permian extinction to become extinct in the Late Triassic", "abstract": "High-spired Murchisonia-like slit-band gastropods are an important component of late Paleozoic gastropod faunas. Twenty-seven genera of such gastropods have been reported from the Permian, most of which representing the caenogastropod family Goniasmatidae. Only four genera, Trypanocochlea, Wannerispira, Laschmaspira, and Altadema crossed the Permian/Triassic boundary. Based on the study of newly collected specimens and material from natural history collections, we studied the surviving genera as well as the Triassic recovery of this group. Two new species (Laschmaspira lirata sp. nov. and Altadema hausmannae sp. nov.) and one new subfamily (Cheilotomoninae) are introduced. Murchisonia-like caenogastropods, chiefly Goniasmatidae, were diverse and abundant until the Permian, barely survived the end-Permian extinction, regained a certain generic diversity within the Triassic with the evolution of several new genera but failed by far to regain their Permian generic diversity. This once successful and diverse group shares a similar fate (surviving the end-Permian extinction, a reduced Triassic diversity and extinction during Late Triassic crises) as conodonts, orthoceratids, conulariids, and others. This diversity pattern does not qualify for the \u201cDead Clade Walking\u201d phenomenon, i.e., the extinction shortly after a major mass extinction event (survival without recovery) because they have survived for ca. 30 Ma (at least until the Norian) and even produced a number of new genera. The exact time of their extinction is unknown but there are no safe Rhaetian occurrences. Their extinction is part of a long-term selective trend against the character \u201cshell-slit\u201d.", "keyphrases": ["gastropoda", "goniasmatidae", "diversity", "recovery", "end-permian extinction", "triassic", "italy", "austria"]}
{"id": "10.4202/app.01108.2023", "title": "Palaeoclimate and fossil woods\u2014is the use of mean sensitivity sensible?", "abstract": "The growth rings of fossil wood provide valuable data on tree ecology. As many of the parameters controlling width are climatic, it is tempting to use these rings as an indicator of climate. This is what has been done, with great success, by dendrochronological studies of archaeological wood. For wood dating from before the Pleistocene, however, the task is more uncertain. Since around 1980, researchers have relied mainly on a statistical parameter, the mean sensitivity, an average of the difference in width between two consecutive rings. However, there has never been a critical examination of utility and significance of this parameter for fossil wood. I compiled 63 studies that used mean sensitivity for palaeoclimatological inferences. An analysis of this compilation is presented here. Despite its ups and downs since the 1980\u2019s, mean sensitivity is increasingly used by palaeobotanists. However, it has been used in very different ways. The values obtained for the same fossil can vary greatly from one researcher to another, but also according to the radii of the woody axis considered. Within fossil wood assemblages, average sensitivity varies widely, but rarely consistently. Overall, mean sensitivity values are continuously, normally and unimodally distributed, and therefore are unsuitable for characterising discrete climate classes. Finally, it seems that the most recent studies are also the least cautious when it comes to interpreting the values obtained.", "keyphrases": ["climate proxy", "growth ring", "palaeobotany", "palaeoecology", "tree"]}
{"id": "10.4202/app.01107.2023", "title": "A new thalassematid echiuran worm from the Middle Ordovician Castle Bank Biota of Wales, UK", "abstract": "Echiurans (spoonworms) are a very distinctive group of polychaete annelids that had long been considered to constitute a separate phylum. Their fossil record is extremely limited, although trace fossils that have been suggested to be attributable to them date back as far as the Cambrian Period. The oldest body fossils are from the Carboniferous Mazon Creek Biota, and preserve only limited morphological detail. New material from the Middle Ordovician (Darrivilian, Didymograptus murchisoni Biozone) Castle Bank Biota of Wales shows fine detail of the morphology of a new taxon, Llwygarua suzannae gen. et sp. nov., including several details that indicate an assignment to the derived family Thalassematidae, allied to the speciose genus Ochetostoma. These details include proboscis morphology, anterior setae, and muscle organisation within the trunk. An additional specimen is described in open nomenclature, as it may be either a distinct species, or a juvenile of Llwygarua suzannae gen. et sp. nov. with a relatively elongated proboscis. These worms demonstrate a very early and previously unrecognised diversification of the echiuran grown group, further supporting an early diversification of Annelida as a whole.", "keyphrases": ["annelida", "echiura", "thalassematidae", "darriwilian", "middle ordovician", "united kingdom"]}
{"id": "10.4202/app.01103.2023", "title": "Early Tremadocian cephalopods from Santa Rosita Formation in NW Argentina: the oldest record for South America", "abstract": "We describe early Tremadocian (Kainella meridionalis Biozone) cephalopods from the Cordillera Oriental, Jujuy, NW Argentina. They consist of numerous small specimens collected at the Quebrada de Arenal, Trancas section, near the town of Tilcara, in the Alfarcito Member of the Santa Rosita Formation. All but three specimens were assigned to a new species of Ellesmeroceras (Family Ellesmeroceratidae), E. humahuacaensis sp. nov., based on its slightly endogastric curvature, the characteristics of the siphuncle and chambers dimensions. Micro CT scanning of one specimen aided in the description of the apex and facilitated the construction of a 3D model of the species. A single, similar specimen was assigned to Ellesmeroceras sp. pending the availability of additional material. Two specimens differ from the rest, being exogastric with a lower angle of expansion. They are tentatively assigned to Bassleroceras sp. This material indicates that Cambrian and early Tremadocian cephalopods are not as different as previously thought. \u201cDiversification\u201d and \u201cextinction\u201d events during the late Cambrian may be attributed to taxonomic \u201cover-splitting\u201d and taphonomic and/or sampling biases, respectively. These specimens are currently the oldest recorded in the Central Andean Basin and of West Gondwana, and probably represent the first migration of cephalopods into the region, when the water column was still poorly colonized. During the middle Tremadocian, subsequent immigrations and originations of several cephalopod orders accounted for a rise in diversity and expansion into new niches during this interval. Some of these taxa persisted into the middle Floian, at which time, a second increase in diversity is recorded. Ellesmeroceras humahuacaensis sp. nov. is interpreted as a sub-vertical nektobenthic organism.", "keyphrases": ["cephalopoda", "ellesmeroceratidae", "ellesmeroceras", "stem cephalopods", "tremadocian", "ordovician", "santa rosita formation", "cordillera oriental"]}
{"id": "10.4202/app.01060.2023", "title": "Enamel microstructure and dental histology in a heterodontosaurid dinosaur: Heterodontosaurus tucki", "abstract": "Among non-avian dinosaurs, Heterodontosaurus tucki is unique for possessing complex dental features including both morphological and proportional heterodonty, sub-hypsodonty, tooth occlusion, and extensive low-angled wear facets\u2014a collection of derived traits made additionally noteworthy by their appearance in one of the earliest-branching ornithischian lineages. In many taxa with similar dental characteristics, complex suites of modified dental tissues shape functional occlusal surfaces through wear. It remains unknown if H. tucki possesses similar histological complexity. Here, we investigate the histology and enamel microstructure of H. tucki maxillary cheek teeth from the Early Jurassic upper Elliot Formation of South Africa. Despite possessing a superficially complex dentition, the maxillary teeth exhibit a thin, relatively simple, three-layered enamel schmelzmuster (basal unit, columnar unit, and parallel crystallite) with enamel tubules. On the labial face, the enamel thins out drastically (<6 \u03bcm) and is discontinuous with a more simplified enamel microstructure. Surprisingly, a thick band of wear-resistant, histologically distinct dentine arises concurrent with the thinning enamel and appears to form the primary cutting crest of the functional occlusal surface, a role typically filled by enamel. This represents both the phylogenetically and chronologically earliest known acquisition of this form of modified dentine within Ornithischia.", "keyphrases": ["dinosauria", "heterodontosauridae", "heterodontosaurus tucki", "enamel", "microstructure", "histology"]}
{"id": "10.4202/app.01091.2023", "title": "New Pleistocene bird fossils in Taiwan reveal unexpected seabirds in East Asia", "abstract": "The island of Taiwan, with its diverse microclimates and key position on the East Asian-Australasian Flyway, attracts numerous bird enthusiasts due to its diverse avian fauna. Nevertheless, due to the scarcity of fossil records, there is a significant knowledge gap between modern and ancient avifaunas in Taiwan. Currently, there is only a single described Pleistocene fossil; it is attributed to Phasianidae. To address this gap, this study describes two new bird fossils, a left humerus and a left tibiotarsus, and discusses them in detail herein. The fossils were collected from the Liuchungchi Formation (Early Pleistocene, 1.95\u20131.35 Ma) in Niubu, Chiayi, southwestern Taiwan, which represents a neritic environment. The fossils are identified as from species of Gaviidae (loons), with the humerus belonging to an undetermined species of Gavia and the tibiotarsus to Gavia stellata. Loons are seabirds that are primarily distributed in high- and middle latitudes of the Northern Hemisphere. In addition, these birds are extremely rare in modern Taiwan: records are scarce and most are limited to northern and northeastern Taiwan since the 1860s, indicating that the modern Gavia birds only occasionally visit Taiwan. All known Pleistocene fossils of species of Gavia from the northern West Pacific come from Japan. The Taiwan fossils of Gavia provide valuable bird evolutionary and paleobiogeographic information for the subtropical West Pacific and may imply the presence of a distinct avifauna in the region during the Early Pleistocene.", "keyphrases": ["aves", "gavia", "loon", "seabird", "early pleistocene", "taiwan"]}
{"id": "10.4202/app.01101.2023", "title": "Muscle attachment scars in helcionelloids from Denmark cast light on mollusc evolution in the Cambrian", "abstract": "Multiple, small (diameter <20 \u03bcm) swellings on the apex of internal moulds of the laterally compressed helcionelloids Eotebenna viviannae and the new species Eotebenna danica from the middle Cambrian (Miaolingian) of Bornholm, Denmark, are interpreted as a muscle attachment scars. The scar pattern is unique amongst currently known helcionelloids both in the abundance of attachment sites and in crossing the median plane of symmetry on the supra-apical (dorsal) surface. Sites of typically two pairs of dorsal muscle scars in other helcionelloids are distributed symmetrically on the dorso-lateral areas. The recognition of four groups of muscle scar patterns in helcionelloids suggests a degree of anatomical diversity within the group that is obscured by the morphological simplicity of the enclosing cap-shaped shells, although evolutionary links to mollusc crown groups are unresolved. In addition to the muscle scars, traces of shell micro\u2011structure are described.", "keyphrases": ["mollusca", "helcionelloida", "muscle scars", "miaolingian", "cambrian", "denmark"]}
{"id": "10.4202/app.01081.2023", "title": "Dimorphism in Late Cretaceous ammonites\u2014evidence from early Turonian ammonite faunas of the Brie\u00dfnitz Formation in Saxony, Germany", "abstract": "Systematic palaeontological and biometric-statistical analyses (classical clustering and linear discriminant analysis) of statistically significant populations of three early Turonian ammonite species from offshore marls of the Brie\u00dfnitz Formation (Saxonian Cretaceous Basin, eastern Germany) were used to evaluate a formerly just visually suspected hypothesis of a size dimorphism within the taxa. The studied faunas can in fact be regarded as contemporaneous late early Turonian fossil assemblages derived from a palaeobiogeographic and depositional entity. However, only one of the three species passed the statistical tests. Neither in Lewesiceras peramplum nor in Mammites nodosoides can a dimorphism be proven. In both taxa, no other features than size can be recognised that differ significantly between the overlapping groups. Furthermore, adulthood cannot be proven due to the absence of unequivocal mature modifications. Thus, a combination of large intraspecific variability and commonly incompletely preserved (i.e., small) specimens dissembles dimorphic populations at a first glance. On the other hand, the suspected dimorphism in Spathites (Jeanrogericeras) reveliereanus was confirmed by the statistical analyses of numerous biometric parameters. Not only the maximum diameters but also the distinct apertural cross-sections and ornament show significant differences between the statistically clearly separated two groups. Furthermore, a decline in ornament and widening of the body chamber in fully grown macroconch specimens, regarded as a mature modification of the shell, demonstrate that the antidimorphs really differed in adult morphology. Thus, it can be shown that there are in fact two forms in the fossil assemblage of S. (J.) reveliereanus that, based on their morphological differences and lack of any overlap, represent micro- and macroconchs (inferred males and females) of an evidently dimorphic ammonite species. Finally, we conclude that simple visual inspection is commonly insufficient for the reliable proof of dimorphism in ammonoids.", "keyphrases": ["ammonitina", "biometric-statistical analyses", "dimorphic pairs", "elbtal group", "cretaceous"]}
{"id": "10.4202/app.01095.2023", "title": "In vivo and post-mortem bioerosion traces in solitary corals from the upper Pliocene deposits of Tunisia", "abstract": "The polychaete borings Caulostrepsis taeniola, Caulostrepsis cretacea, Caulostrepsis avipes, Caulostrepsis penicillus isp. nov., Maeandropolydora elegans, Maeandropolydora sulcans, Sulcichnus sigillum, the bryozoan boring Pinaceocladichnus onubensis and the phoronid boring Talpina cf. hackberryensis occur in coralla of the solitary scleractinian coral Ceratotrochus (Edwardsotrochus) duodecimcostatus in the upper Pliocene middle/lower neritic to upper bathyal fine-grained deposits of NE Tunisia. This very rich assemblage of borings is produced in vivo as suggested by (i) their occurrence close to the surface and mostly in the upper part of coralla (Caulostrepsis ispp., M. elegans), even if they are known to penetrate deeply in the substrate, or (ii) evidence of corallum deformation in response to the boring action (Sulcichnus sulcans). The remaining borings were probably produced post mortem; they penetrate deeply into the corallum (M. sulcans) or always occur shallowly in the substrate (Talpina) and, in addition, cross cut other borings (Pinaceocladichnus). The polychaete borings are dominant. The abundance of the borings is probably caused by ecological pressure from shallower zones in subtropical waters. This resulted in the colonization of hard, small-sized substrates located in relatively deep (offshore) waters. The interpretation of age and palaeoenvironment was elucidated by the analysis of benthic and planktonic foraminifers.", "keyphrases": ["anthozoa", "palaeoecology", "ichnotaxonomy", "commensalism", "pliocene", "mediterranean basin"]}
{"id": "10.4202/app.01102.2023", "title": "Floian, Early Ordovician, trilobites from the Olongbluk Terrane, northwest China", "abstract": "Floian, Early Ordovician trilobites are systematically described and revised based on new material from the middle part of the Duoquanshan Formation of the Shihuigou area, northern Qinghai Province, northwest China. The fauna that lived on the shallow-water carbonate platform comprises three species belonging to two families, i.e., Tsaidamaspis diarmatus, Zhiyia tsinghaiensis, and Liexiaspis sp. indeterminate. It exhibits a strong endemicity to the Olongbluk terrane. The new isoteline genus Zhiyia is established on the basis of the material from the Olongbluk terrane and South China palaeoplate, and is characterized by its: (i) almost obsolete cephalic and pygidial axial furrows; (ii) flattened anterior border and narrow (sag., exsag.) occipital ring; (iii) bilobed hypostome with a shallow median notch and a small triangular median projection; (iv) subsemicircular pygidium with wide pygidial axis and border. Faunal evidence indicates that the palaeogeographic position of the Olongbluk terrane may have been situated closer to the South China palaeoplate rather than the North China palaeoplate during the Floian.", "keyphrases": ["trilobita", "palaeogeography", "floian", "ordovician", "olongbluk terrane", "northwest china"]}
{"id": "10.4202/app.01083.2023", "title": "An early Eocene pan-gekkotan from France could represent an extra squamate group that survived the K/Pg extinction", "abstract": "In this paper we describe a new lizard from the early Eocene of the Cos locality in the Quercy region (near the Caylus village, Southwest France). The age of the Cos deposit has been proposed as the MP 10\u201311 interval, close to the transition of the late Ypresian to early Lutetian. The fossil material includes a nearly complete right maxilla and a large section of the right dentary, both elements attributed to Pan-Gekkota. These specimens are morphologically different from crown gekkotans, therefore, we describe them as a new species. Some aspects of the maxilla are very atypical regarding geckos (e.g., the shape of the facial process). The posterior margin of the facial process slopes down gradually dorsoventrally towards the jugal facet, reaching the posterior end of the maxilla, in contrast to gekkotans, where the facial process ends anterior to the posterior end of the maxilla. A similar maxilla is present in the Late Jurassic\u2013Early Cretaceous pan-gekkotan genus Eichstaettisaurus. This suggests that the new fossil taxon represents either a lineage that persisted from the Mesozoic to the early Eocene in Europe, or perhaps a morphology otherwise unrepresented in crown gekkotans. We allocate this taxon provisionally to Pan-Gekkota, and contribute to increase the diversity of this clade in Western Europe during the Paleogene, which now includes the stratigraphically similarly aged Laonogekko lefevrei from France (MP 10), and older Dollogekko from Belgium (MP 7).", "keyphrases": ["squamata", "pan-gekkota", "mesozoic", "k/pg extinction", "paleogene", "phosphorites du quercy", "france"]}
{"id": "10.4202/app.01105.2023", "title": "Novel pneumatic features in the ribs of the sauropod dinosaur Brachiosaurus altithorax", "abstract": "Pneumatic dorsal ribs are known for many sauropods, but to date costal pneumaticity has received relatively little attention. In particular, the pneumatic ribs of the holotype specimen of Brachiosaurus altithorax have been largely overlooked, although they present a unique configuration of pneumatic features. One rib, with a pneumatic foramen some distance down the shaft, was briefly described and illustrated in the early 20th century by Elmer S. Riggs. A second rib with a pneumatic foramen in the tuberculum of the rib has not previously been described or illustrated. This previously undescribed foramen is similar in location to those in some dorsal ribs of Brontosaurus excelsus and Giraffatitan brancai, but differs from them in both size and shape. The contrasting sites of costal pneumaticity in the holotype individual of Brachiosaurus altithorax emphasize the generally opportunistic mode of postcranial pneumatization, in both sauropods and other ornithodirans, but conform to models of pneumatization following vascularization.", "keyphrases": ["sauropoda", "dinosauria", "brachiosauridae", "pneumaticity", "costal pneumaticity"]}
{"id": "10.4202/app.01086.2023", "title": "A new gigantic titanosaurian sauropod from the early Late Cretaceous of Patagonia (Neuqu\u00e9n Province, Argentina)", "abstract": "A new gigantic titanosaur Bustingorrytitan shiva gen. et sp. nov. is described. The four specimens upon which this species is erected come from Neuqu\u00e9n Province, Argentina, from levels of the Huincul Formation (Cenomanian). Bustingorrytitan shiva gen. et sp. nov. exhibits some autapomorphic characters such as posterior dorsal vertebrae with spinodiapophyseal laminae bifurcated in two, very well developed anterior and posterior spinodiapophyseal lamina rami, which limit a deep, vertical, socket-like fossa; posterior dorsal neural arches with forked centropostzygapophyseal laminae; hyposphene in anterior caudal vertebrae; humerus with deltopectoral crest strongly expanded distally; and femur with a low longitudinal crest on the lateromedial half of the anterior face, bifurcated in two minor crests, which are directed to their respective condyles. The phylogenetic analysis performed recovers B. shiva gen. et sp. nov. as a lithostrotian, the sister taxon of Saltasauridae. The estimated body mass is 67.297 metric tons (with a standard error of \u00b117.228), which makes B. shiva gen. et sp. nov. one of the largest sauropods ever recorded. The record of this new sauropod corroborates the idea that gigantism (evolution of forms over the 50 metric tons) would have evolved many times within Eutitanosauria.", "keyphrases": ["dinosauria", "sauropoda", "titanosauria", "cretaceous", "neuqu\u00e9n", "patagonia"]}
{"id": "10.1016/j.cretres.2023.105680", "title": "A new Baurusuchidae (Notosuchia, Crocodyliformes) from the Adamantina Formation (Bauru Group, Upper Cretaceous), with a revised phylogenetic analysis of Baurusuchia", "abstract": "Baurusuchidae is a group of notosuchian crocodyliforms ubiquitous to South American Upper Cretaceous deposits. They are distinguished by having dog-faced skulls, reduced tooth rows, and hypertrophied caniniforms. Here, we describe a new baurusuchid from the Adamantina Formation (Bauru Group), in Southeast Brazil. The new taxon consists of a right portion of the skull, cranial roof elements, fragments of the secondary palate and the lower jaw, as well as six isolated teeth. The specimen is assigned to the genus Aphaurosuchus due to the presence of a posterior depression on the nasal and upturned infraorbital jugal ridge. A new species, Aphaurosuchus kaiju, was erected based on characters that distinguish it from Aph. escharafacies, such as a large and deep depression occupying most of the dorsal surface of the frontal, a midline longitudinal depression on the anteriormost portion of the frontal, a well-developed crest concealed in the frontal depression, and a smooth parietal near the supratemporal fenestrae. We investigated the affinities of Aphaurosuchus kaiju and recently described/revised putative baurusuchians by performing an updated phylogenetic analysis that combined information from the three most up to date datasets available. We recovered the two main lineages of Baurusuchidae, Pissarrachampsinae and Baurusuchinae, with its traditional subset of taxa, but also recovered Ogresuchus furatus (Maastrichtian of Europe) and Razanandrongobe sakalavae (Batesian of Madagascar) as non-baurusuchid baurusuchians. In the light of our results, the inclusion of these two taxa in an otherwise well stablished Baurusuchia suggests that this clade had much broader spatial and temporal distributions than initially thought.", "keyphrases": ["aphaurosuchus", "baurusuchidae", "baurusuchia", "adamantina formation", "bauru basin"]}
{"id": "10.1016/j.cretres.2023.105689", "title": "Redescription of the key specimen MACN-Pv-N 35: Laminar anatomy and hyposphene\u2013hypantrum in an early rebbachisaurid (Dinosauria, Sauropoda) from Patagonia, Argentina", "abstract": "The purported basal rebbachisaurid MACN-Pv-N 35 specimen from the La Amarga Formation (Lower Cretaceous) is re-described. It is represented by a single mid to posterior dorsal neural arch and it was considered as a basal rebbachisaurid based on the well-developed hyposphene. Here I provided a re-description and a phylogenetic analysis including a new combination of morphological characters. The peculiar ovoidal hollow hyposphene, particularly recognizable in this specimen, is completely different from the massive and rhomboidal hyposphene present in Diplodocidae or Histriasaurus. The presence of a laterodiapophyseal fenestra on the transverse process recover the specimen MACN-Pv-N 35 as a Rebbachisaurinae closely related to Katepensaurus. The reassessment of the specimen MACN-Pv-N 35 as a Rebbachisaurinae improves our knowledge about the evolutionary history of Rebbachisauridae, opening the field for future investigations into how hyposphene evolved within the group.", "keyphrases": ["sauropoda", "diplodocoidea", "rebbachisauridae", "la amarga formation", "argentina"]}
{"id": "10.1016/j.cretres.2023.105696", "title": "Integrated biostratigraphy (orbitolinids, calcareous nannofossils, and palynomorphs) of the Lower Cretaceous Sarcheshmeh Formation, western Koppeh-Dagh Basin, NE Iran", "abstract": "An integrated biostratigraphy using orbitolinids, calcareous nannofossils, and dinoflagellate cysts was conducted on the Lower Cretaceous Sarcheshmeh Formation in two stratigraphic sections from the western Koppeh-Dagh Basin (NE Iran). The analyzed successions consist mainly of deep-marine shales and marlstones with intercalations of thin-bedded orbitolinid-bearing limestones. These strata yielded common to abundant and fairly well to well-preserved calcareous nannofossil assemblages. The aforementioned assemblages led to the identification of parts of the NC6 and NC7a biozones that can be correlated with parts of the CC7a and CC7b zones. The organic-walled dinoflagellate cysts also show well-preserved and relatively diverse assemblages in the studied sections that corresponded to the Odontochitina operculata Zone. Additionally, within the limestone intercalations of the Sarcheshmeh Formation, two index species of orbitolinids, Praeorbitolina cormyi Schroeder, and P. wienandsi Schroeder, were recorded, indicating the presence of the Praeorbitolina cormyi Zone. According to the literature, these recognized biozones are compatible with the ammonite zones of Deshayesites forbesi, Deshayesites deshayesi, and Dufrenoyia furcata, as well as the Globigerinelloides blowi and Leupoldina cabri planktonic foraminiferal zones. By the compilation of all acquired data, an age of late early Aptian (late Bedoulian) is deduced for the Sarcheshmeh Formation in the studied sections.", "keyphrases": ["aptian", "orbitolinids", "calcareous nannofossils", "dinoflagellate cysts", "biostratigraphy", "koppeh-dagh basin"]}
{"id": "10.1016/j.cretres.2023.105710", "title": "Stratigraphic distribution and importance of some imperforate benthic foraminifera from the upper Campanian\u2013Maastrichtian of the Tauride Carbonate Platform, T\u00fcrkiye", "abstract": "Many parts of the Tauride Carbonate Platform were exposed to subaerial exposure from the Turonian to the Santonian. However, the record of the upper Campanian\u2013Maastrichtian in shallow-marine facies is relatively continuous, except for short-term platform emergences. The present study focuses on the stratigraphic distribution and importance of some selected benthic foraminifera from the upper Campanian\u2013Maastrichtian of the Tauride Carbonate Platform. Mainly Accordiella conica, Moncharmontia apenninica, Fleuryana adriatica, Murciella cuvillieri, Pseudocyclammina sphaeroidea, Rhapydionina liburnica and Pachycolumella acuta recorded from different parts of the TCP were studied. On a local and/or regional scale, some of these benthic foraminifera can be regarded as chronostratigraphically significant. Murciella cuvillieri, whose first occurrence is in the upper Campanian, and Rhapydionina liburnica, which has a narrow stratigraphic range (upper Maastrichtian), are two examples. Their occurrences and abundance vary throughout the upper Campanian\u2013Maastrichtian. The presence of Accordiella conica, which is represented by a small number of specimens, and Moncharmontia apenninica, of which numerous characteristic specimens have been found, characterizes the upper Campanian strata. The upper Maastrichtian is marked by Rhapydionina liburnica, which co-exists with Pachycolumella acuta, known from the upper Maastrichtian\u2013Paleocene interval. Murciella cuvillieri, Fleuryana adriatica, and Pseudocyclammina sphaeroidea occur throughout the upper Campanian\u2013Maastrichtian strata. Fleuryana adriatica is represented by larger, typical specimens in the upper Maastrichtian but by smaller, atypical ones in the older strata. The stratigraphical importance of these species for the Campanian\u2013Maastrichtian intervals in the Tauride Carbonate Platform is discussed.", "keyphrases": ["upper cretaceous", "platform carbonates", "benthic foraminifera", "stratigraphic ranges", "taurides"]}
{"id": "10.1016/j.cretres.2023.105711", "title": "First discovery of large-bodied dromaeosaurid fossil materials (Dinosauria: Theropoda) from the Upper Cretaceous Quantou Formation, Songliao Basin, Northeast China", "abstract": "This paper reports the first discovery of large-bodied dromaeosaurid fossil materials (Dinosauria: Theropoda) from the lower Upper Cretaceous Quantou Formation, in Changchun area, Jilin Province. The specimens include a manual ungual and a pedal penultimate phalanx. The manual ungual is the larger of the two and laterally flattened, curved and sickle-shaped from the middle to the distal end; the pedal penultimate phalanx is strongly constricted centrally with the subcircular fossae on both sides of the trochlea located in the upper part of the geometric center of the articular arc. The available evidence indicates that these specimens likely belong to an eudromaeosaur. This new discovery provides important reference materials for studies of dromaeosaurid evolution and distribution, as well as a deeper understanding of the paleocommunity and diversity of northeast Asia during the Cretaceous Period.", "keyphrases": ["theropoda", "large-bodied dromaeosaurid", "cretaceous", "songliao basin", "jilin province"]}
{"id": "10.1016/j.cretres.2023.105682", "title": "Paleobiology of Rinconsaurus caudamirus and Muyelensaurus pecheni (Sauropoda, Titanosauria) from the Neuqu\u00e9n Group, Upper Cretaceous of Argentina: inferences from long bone histology", "abstract": "Titanosauria is the most successful and diverse clade of sauropodomorph dinosaurs, with some of the largest and smallest sauropod species known to date. Rinconsaurus caudamirus and Muyelensaurus pecheni were two small-sized titanosaurs recollected from the Neuqu\u00e9n Group (Upper Cretaceous) of Argentina. The bone remains of both specimens include axial and appendicular elements corresponding to several individuals. These taxa have been anatomically and phylogenetically studied, but did not analyzed from paleohistological viewpoint yet. This contribution focuses on the description of the long bone histology of both species including several aspects of its paleobiology. For this, thin transverse sections were made at the diaphysis level and were analyzed under microscope. The histology of M. pecheni and R. caudamirus shows a uniform bone microstructure similar to other titanosaurs, with changes in bone tissue types being mostly related to the different life story. The major difference between the taxa is in the type of bone matrix. Whereas woven fibered bone predominates in the cortex of M. pecheni, R. caudamirus shows parallel-fibered bone. The presence of this last primary tissue is consistent with the reduced size of R. caudamirus. The long bone histology of M. pecheni resembles that of large basal neosauropods. Contrary to the reported for other noesauropods, the data obtained in this study does not reveal a correlation between the ontogenetic stage and the body size in R. caudamirus and M. pecheni. Finally, as was mentioned previously to others titanosaurs, both specimens show a high rate of secondary remodeling.", "keyphrases": ["osteohistological study", "life history", "rinconsauria", "south america"]}
{"id": "10.1016/j.cretres.2023.105705", "title": "The problem of landscape evolution across the Cretaceous/Paleogene boundary revisited at Madrid East, southeastern Colorado, U.S.A.", "abstract": "Faulting at the well-known Madrid East K/Pg boundary locality in the Raton Basin of southeastern Colorado, U.S.A., recently has been interpreted to be the result of remote triggering by the Chicxulub impact in the Yuc\u00e1tan Peninsula, Mexico. However, a similar fault at the neighboring, correlative Madrid West locality recently has been attributed to overloading by a rapidly or catastrophically deposited crevasse splay in a sedimentological study. Therefore, this investigation seeks to provide additional insight on this problem. By focusing primarily on the timing of faulting and deposition of the crevasse splay at Madrid East and neighboring localities, this study presents evidence that faulting at Madrid East and neighboring localities post-dated the K/Pg boundary.", "keyphrases": ["seismicity", "k/pg boundary", "chicxulub", "asteroid impact", "crevasse splay"]}
{"id": "10.1016/j.cretres.2023.105706", "title": "Pachytraga gracilis sp. nov. (Hippuritida, Caprinidae) from the Barremian of the Sub-Alpine region (SE France). Evolutionary and biogeographic implications for the genus Pachytraga Paquier", "abstract": "A new species of Pachytraga (family Caprinidae) is described from the For\u00eat de Coulmes (Northern Vercors, Subalpine region of SE France) and dated from the Taveraidiscus hugii- Nicklesia nicklesi ammonite Zones (lowermost Barremian). Pachytraga gracilis sp. nov. has an undivided posterior myocardinal cavity on the left valve and an anterior myophore supported by a single row of rectangular canals. The right valve bears a row of anterior canals, a partitioned posterior perimyophoral cavity and a network of minute pallial canals on the dorsal side. The new species represents an evolutionary link in between the Hauterivian Pachytraga tubiconcha and the Late Barremian\u2013early Aptian Pachytraga paradoxa, so shortening the West European Barremian Lazarus phase of the genus Pachytraga. The possibility of a Barremian p.p. ecological rather than geographical refuge is proposed. We consider the new species as a potential biostratigraphic marker of the West European lowermost Barremian. It is the oldest member of canaliculated Caprinidae. Number of traits of Pachytraga gracilis sp. nov. (shape, mode of canaliculation), are absent in its assumed descendant P. paradoxa, but present in other advanced taxa, Praecaprina, Caprina, hence the new taxon was a precursor in more ways than one.", "keyphrases": ["rudists", "lower cretaceous", "se france", "new species", "caprinidae"]}
{"id": "10.1016/j.cretres.2023.105720", "title": "Farlowichnus rapidus new ichnogen., new ichnosp.: A speedy and small theropod in the Early Cretaceous Botucatu paleodesert (Paran\u00e1 Basin), Brazil", "abstract": "The Botucatu Formation (Paran\u00e1 Basin, Brazil and the southern neighboring countries) comprises one of the richest tetrapod ichnological deposits of the Lower Cretaceous in South America. The ichnofossils are found in reddish sandstones lithofacies -interpreted to be dune and interdune deposits. The sandstones of Botucatu Formation originally covered a surface estimated in at least 1,300,000 km2, the largest known fossil desert in the Earth's history. The distribution area of the Botucatu paleodesert presents one of the world's largest megatracksites. The tetrapod ichnofauna from the Botucatu Formation comprises minor bipedal dinosaur tracks (almost all attributable to theropods, with one exception, a doubt ornithopod trackway) along with many thousands of footprints of early mammals, and a single trackway of a lacertiform reptile. Among the bipedal dinosaur footprints, the most common and typical are considered theropod tracks, with long strides and high step angle and always with an acuminate termination. These trackways are straight and very narrow, with long strides and step angles showing high values. The footprints have a relatively large and very wide III digit and small, short, pointed, bladelike outer digits. The most special characteristic is that the II digit is longer and more important than the IV digit. Because of this morphology, the general outline of the footprint often reminds that of a waterdrop and, although it is structurally tridactyl, it usually looks like functionally monodactylous. These tracks are herein assigned to small theropods adapted to desert life with a prevalently cursorial gait, probably ancestors of clades such as noasaurs and velocisaurs. Due its unique morphological aspects it is defined a new ichnogenus and ichnospecies, Farlowichnus rapidus new ichnogen., new ichnosp.", "keyphrases": ["farlowichnus rapidus new ichnogen.", "new ichnosp.", "botucatu formation", "paran\u00e1 basin", "brazil", "lower cretaceous", "dinosaur tracks"]}
{"id": "10.1016/j.cretres.2023.105709", "title": "A new Mesozoic record of the pseudoscorpion family Garypinidae from Upper Cretaceous (Santonian) Ajkaite amber, Ajka area, Hungary", "abstract": "Pseudoscorpions have a sparse fossil record although they are among the oldest terrestrial lineages with origins extending to the Devonian (ca. 390 Ma). Amongst the 25 extant families of pseudoscorpions, only 14 are known from fossils, most of which are preserved in European ambers from the Eocene. Fossil pseudoscorpions from the Cretaceous of Europe have only been reported from three localities, Archingeay amber (France), from the Rhenish Massif (Germany), and from \u00c1lava and Teruel amber (Spain), but only one of these has ever been formally described. Here we add a new fossil pseudoscorpion genus and species, Ajkagarypinus stephani gen. et sp. nov., from an Upper Cretaceous (Santonian, ca. 86.3\u201383.6 Ma) amber deposit in the Ajka Coal Formation (Ajka area, Hungary), the so-called Ajkaite. This fossil extends the spatial range of the pseudoscorpion family Garypinidae and suggests that they might have been widespread in the whole Eurasian landmasses under humid, subtropical climatic conditions.", "keyphrases": ["santonian", "ajkagarypinus", "pseudoscorpiones", "amber inclusion", "late cretaceous"]}
{"id": "10.1016/j.cretres.2023.105715", "title": "New evidence on the previously unknown gynoecium of Araripia florifera (Araripiaceae, fam. nov.), a magnoliid angiosperm from the Lower Cretaceous (Aptian) of the Crato Konservat-Lagerst\u00e4tte (Araripe Basin), northeastern Brazil", "abstract": "The angiosperm Araripia florifera was originally described based on a fossil specimen including a few lobed leaves and floral buds. Although nothing was known of the internal structure of the flowers, based on the external similarity of the flower buds, it was compared with Calycanthaceae (Laurales). A new fossil from the type locality provides the first morphological evidence for the gynoecium of A. florifera. An androecium was not found, but new evidence is still needed to determine whether the flowers are unisexual. The gynoecium of this fossil species is syncarpous or monomerous, the ovary is superior, globose and distinctly stipitate, and the style is elongated and relatively thick. This new floral information disagrees with suggestions that Araripia belonged to the family Calycanthaceae, because this extant family is characterized by perigynous flowers, with apocarpous gynoecium and ovaries that are never stipitate. We also question the leaf arrangement, originally proposed as opposite, but alternate in this new fossil. We provide a phylogenetic hypothesis combining morphological and DNA sequence data using Bayesian inference. Our phylogenetic analyses indicate that A. florifera is more likely an extinct lineage of Laurales, and is hereby placed in its own family Araripiaceae.", "keyphrases": ["araripiaceae", "calycanthaceae", "crato formation", "gynoecium", "laurales"]}
{"id": "10.1016/j.cretres.2023.105716", "title": "Report on the 7th International Meeting of the IUGS Lower Cretaceous Ammonite Working Group, the Kilian Group (Warsaw, Poland, 21st August 2022): State of the art on the current Standard Ammonite Zonation of the Western Tethyan Mediterranean Province,", "abstract": "The 7th meeting of the IUGS Lower Cretaceous Ammonite Working Group the \u2018Kilian Group (KG)\u2019 was held in Warsaw, Poland, on 21st August 2022. Need of major changes for the Jurassic/Cretaceous transition, namely to the uppermost Tithonian and lower Berriasian, and for the upper Aptian and Albian schemes is a long-known issue, which are finally conceptualized and hereby introduced into the Standard Mediterranean Ammonite Zonation (SMAZ, Western Tethys). Besides, refinements were added to the Valanginian and Hauterivian stages, discussion on some zonal indices and units are also provided. The KG highlights again the exclusive use of interval zones and subzones. Most important changes of the uppermost Tithonian\u2013Berriasian stages are the followings: i) use of two folded Berriasian is agreed, to be in better accordance with ammonite turnovers and microfossil framework; ii) uppermost Tithonian Lopeziceras chaperi, top-uppermost Tithonian to lowermost Berriasian Praedalmasiceras progenitor and lower Berriasian Pseudosubplanites grandis Zones are accepted to be introduced into the SMAZ, these three zones to cover the former \u2018Berriasella\u2019 jacobi Zone auctorum which is formally abandoned; iii) lower Berriasian Delphinella delphinensis Subzone is accepted as a reliable marker level of the upper Praedalmasiceras progenitor Zone; iv) Strambergella jacobi Zone is established and discussed. Tirnovella occitanica Zone and Tirnovella subalpina Subzone are discussed. Modifications on the Valanginian zonation are the followings: i) Neocomites premolicus Subzone is re-defined, ii) Neolissoceras (Vergoliceras) salinarium Subzone is introduced; iii) Neocomites neocomiensiformis Zone is divided into two subzones, the lower N. neocomiensiformis and the upper Busnardoites campylotoxus Subzones. Modifications on the Hauterivian stage are the followings: i) all horizons are deleted; ii) Olcostephanus (Olcostephanus) variegatus Subzone is introduced; iii) Balearites angulicostatus Subzone is introduced; iv) all subzonal index-species of the B. balearis Zone are assigned to genus Balearites; v) Pseudothurmannia mortilleti is considered as a senior synonym of P. catulloi, therefore its nominal subzone also changed its name to mortilleti. No change in the Barremian scheme, however the base of Toxancyloceras vandenheckii Subzone and Zone is defined by the first appearance of the genus Toxancyloceras. Most important changes of the upper Aptian zonation are the followings: i) Nolaniceras nolani and 'Hypacanthoplites jacobi' zones are retained from the SMAZ; ii) re-introduction of Diadochoceras nodosocostatum Zone is given. For the Aptian\u2013Albian transition interval, introduction of \u2018Hypacanthoplites\u2019 elegans Zone is accepted, where the Aptian/Albian boundary lies within. Most important zonal changes of the Albian stage are: i) the Leymeriella-based succession is abandoned from the SMAZ and replaced by the cosmopolitan Douvilleiceras-based succession; ii) Douvilleiceras leightonense Zone is introduced; iii) middle Albian Hoplites dentatus, Euhoplites loricatus, Euhoplites lautus Zones and Hoplites spathi Subzone are retained from the SMAZ and restricted to the Boreal ammonite scheme; iv) Lyelliceras lyelli Subzone arisen to zonal rank defining the basal middle Albian; v) Oxytropidoceras (Oxytropidoceras) roissyanum Zone is introduced; vi) upper Albian zonation based on the phyletic lineage of Mortoniceratids is kept, however generic names of the indices are modified to Pervinquieria; vii) Pervinquieria pricei Zone is divided into three subzones of Hysteroceras varicosum, H. binum and H. choffati from the oldest to youngest; viii) Pervinquieria inflata Zone is divided into two subzones of Hysteroceras bucklandi and Cantabrigites spp. The KG tributes to our recently deceased ammonitologist colleagues in the Supplement, a discussion on the future work is provided. The next Kilian Group meeting will be held in Hannover, prior to the first day of the 12th International Symposium on the Cretaceous System.", "keyphrases": ["lower cretaceous", "ammonites", "mediterranean standard zonation", "berriasian", "aptian", "albian"]}
{"id": "10.1016/j.cretres.2023.105722", "title": "Evolution of the Upper Jurassic and Lower Cretaceous vulcano-sedimentary record \u2013 Southeast portion of the Paran\u00e1 Basin, Brazil", "abstract": "The period between the Late Jurassic and Early Cretaceous on the southernmost part of the Paran\u00e1 Basin was characterized by the accumulation of the aeolian system from the Botucatu Formation, which was entirely preserved by the volcanic flows of the Serra Geral Formation. To a lesser extent, intense basic and acid magmas covered an extensive aeolian continental environment. However, in the central region of the state of Rio Grande do Sul, in the southernmost part of the Paran\u00e1 Basin, data from 29 outcrops, 13 vertical stratigraphic profiles, and 334 paleocurrent measurements exposed fluvial\u2013aeolian deposits of the Guar\u00e1 Formation in contact with volcanic rocks of the Serra Geral Formation. This study considers new temporal and spatial relationships between the fluvial\u2013aeolian, aeolian, and volcanic systems developed in this temporal range. For this purpose, facies analysis and architectural elements were used to reconstruct the evolution of this volcano-sedimentary record. Nineteen facies grouped into five facies associations (braided fluvial channel, ephemeral braided fluvial channel, aeolian sand sheets, aeolian dunes, and volcanic plain) were identified according to their architectural elements in the Guar\u00e1, Botucatu, and Serra Geral formations. The contacts between the deposits of the Guar\u00e1 and Botucatu Formations and their boundaries between Serra Geral Formation flows demonstrate that these sedimentary environments remained active during the onset of volcanism, and there was no hiatus between these units. Therefore, the Guar\u00e1 and Botucatu Formations present ages between Late Jurassic and Early Cretaceous.", "keyphrases": ["botucatu formation", "serra geral formation", "guar\u00e1 formation", "fluvial\u2013aeolian systems", "aeolian systems"]}
{"id": "10.1016/j.cretres.2023.105713", "title": "Upper Cenomanian caprinulid-radiolitid rudists (Bivalvia) from the Gattar Member of Jebel el Kebar (central Tunisia): Stratigraphical implications and palaeobiogeographical relationships with coeval rudist-assemblages from carbonate platforms of the southern Tethyan margin", "abstract": "The Gattar Member (upper part of the Zebbag Formation) is a prominent dolomitic limestone unit in Tunisia, the age of which was ascribed either to the Turonian, the Cenomanian, or the Cenomanian\u2212Turonian. Here, we present the discovery of a Caprinulidae-Radiolitidae rudist asssemblage in the Gattar Member of Jebel el Kebar (central Tunisia). This consists of Caprinula cf. boissyi, Sauvagesia cf. sharpei, Durania arnaudi, Neocaprina sp. and Eoradiolites sp. The detailed description of two sections of the Gattar Member in Jebel el Kebar allows us to define the sedimentological and palaeoecological attributes of the rudist-bearing carbonates and their sequential relationships with the Zebbag and Rouana stratigraphical units respectively. The caprinulid-radiolitid assemblage is age-calibrated, based on the ammonite standard zonation of the Cenomanian stage from Portugal, South-Eastern France, and Oman, where rudist, benthic foraminifera and ammonite Zones have been correlated. Its age is late Cenomanian. The correlations of the Gattar Member between central Tunisia and the Gafsa-Chotts area are established on the base of ammonite and rudist biostratigraphical markers. The age of the Gattar Member of southern Tunisia and of its stratigraphical counterpart in western Libya is discussed. At last, we analyze the palaeobiogeographical distribution of the upper Cenomanian caprinulid-radiolitid assemblages from coeval carbonate platforms of the North African margin (Algeria, Morocco) and of the North Arabian margin (Levant region: Syria, Jordan, Lebanon, Israel, North Sinai).", "keyphrases": ["rudists", "stratigraphy", "cenomanian-turonian", "carbonate platforms", "tunisia", "north africa", "levant"]}
{"id": "10.1016/j.cretres.2023.105708", "title": "Caenagnathids (Theropoda, Oviraptorosauria) from the uppermost Maastrichtian of the Scollard Formation of Alberta, Canada", "abstract": "Recent work has greatly improved our understanding of the diversity and paleobiogeography of caenagnathids in North America. However, the late Maastrichtian caenagnathid record remains poorly understood, with only two species established from this time interval. Here we describe three isolated elements of caenagnathids recovered from the base of the upper Maastrichtian portion of the Scollard Formation of Alberta, Canada. Two specimens, a metatarsal II and a pedal ungual, represent large-bodied species and are most similar to the same elements in Anzu wyliei (upper Maastrichtian Hell Creek Formation) and Caenagnathus collinsi (upper Campanian Dinosaur Park Formation). The third specimen, a pedal ungual from an immature individual, is most similar to Leptorhynchos gaddisi (upper Campanian Aguja Formation). Preservation of only isolated elements from the Scollard Formation and a scarcity of relevant comparative specimens from the upper Maastrichtian in general, hinders taxonomic assignment of these specimens to the genus level. Regardless, these specimens provide evidence for the widespread and northerly occurrence of caenagnathids, including large-bodied forms, in North America during the last one million years of the Cretaceous.", "keyphrases": ["theropoda", "caenagnathidae", "maastrichtian", "biogeography", "biodiversity"]}
{"id": "10.1016/j.cretres.2023.105714", "title": "Bite traces of a large, mosasaur-type(?) vertebrate predator in the lower Turonian ammonite Mammites nodosoides (Schl\u00fcter, 1871) from the Czech Republic", "abstract": "A specimen of the acanthoceratid ammonite Mammites nodosoides from the lower Turonian of the Bohemian Cretaceous Basin shows signs of having been preyed upon by a reptile, probably with a mosasaur-like dentition. Based on these traces, a new ichnotaxon, Nihilichnus quadripertitus Mikul\u00e1\u0161, isp. nov., is erected. Several bite traces are arranged into two convergent, straight rows, which would rule out sauropterygian reptiles or fishes as agents. Jaw margins appear to contour the ammonite aperture, suggesting an attack directed at the apertural part with the head and arm crown. The lethal nature of the bite(s) inflicted is supported by the crushed anterior, albeit not anteriormost, portion of the body chamber. Spacing, size and angle of these traces, as well as the angle of convergence between both rows would suggest that the agent was a medium-sized (up to 6 m) member of the marine lizard family Mosasauridae, and more specifically, of the subfamily Tethysaurinae. However, a representative of another closely related subfamily, the Yaguarasaurinae (which includes the genus Romeosaurus), cannot be ruled out. The bite marks on the present ammonite shell contribute to a palaeoecological evaluation of tethysaurines (in particular with regard to food adaptations) and to a better picture of the palaeogeographical distribution of early Turonian mosasauroids across central European shelves.", "keyphrases": ["amniote predation", "upper cretaceous", "central europe", "new ichnotaxon", "cephalopods"]}
{"id": "10.1016/j.cretres.2023.105702", "title": "A new genus of whip scorpion (Arachnida: Thelyphonida: Thelyphonidae) from mid-Cretaceous Kachin amber of northern Myanmar", "abstract": "Familiar animals today, whip scorpions are rather rare in the Mesozoic and only three species are recognized from the Cretaceous. Here we describe a new genus and species, Crethypoctonus kachinus gen. et sp. nov. from mid-Cretaceous Kachin amber, clearly belonging to Thelyphonidae. It is characterized by its stout and long patellar apophysis of the pedipalps with attached microteeth and setae, and the absence of an ommatoid on tergite XII of the opisthosoma. Significantly, it lacks a keel and its abdomen is not divided. It not only augments the rare Mesozoic occurrence of whip scorpions with their distinct morphology, but reveals the long history of their evolution.", "keyphrases": ["kachin amber", "cretaceous", "whip scorpions", "thelyphonidae"]}
{"id": "10.1016/j.cretres.2023.105704", "title": "Changes in bivalve assemblages at the onset of the OAE2 event in the Peri-Tethyan area (Bohemian Cretaceous Basin)", "abstract": "The Ocean Anoxic Event (OAE2) at the Cenomanian-Turonian boundary presents a unique record of gradual global warming and its effects on benthic organisms. The present research considers a palaeoecological, systematical and statistical evaluation of bivalve assemblages from the Pec\u00ednov Member in the Bohemian Cretaceous Basin. The well-exposed succession of Cenomanian through lower Turonian strata contains one of the most complex records of the OAE2 in central Europe. In total, 392 specimens have been studied and assigned to 24 genera within 21 families and 9 orders. The bivalve association prior to the positive shift of the \u03b413Corg (peak \u201ca\u201d sensu global carbon curve; lower part of the Metoicoceras geslinianum Zone) is strongly dominated by infaunal suspension feeders, followed by semi-infaunal suspension feeders. The near-absence of free-living epifaunal bivalves may be linked to a very fine, muddy substrate and water turbidity, a limiting factor for many epifaunal species. Infaunal deposit feeders are also present but comparatively rare, indicating a nutrient-rich environment with energy levels sufficiently high to keep organic matter in suspension. The Cucullaea glabra \u2013 Pseudoptera anomala assemblage of this level is considered to have formed during normal, shallow (15\u201320 m, supported by abundant material of Pinna) marine conditions. The association inhabiting the area above this level (upper part of the M. geslinianum Zone, S. gracile/E. septemseriatum Subzone) is characterized by the Panopea gurgitis \u2013 Rhynchostreon suborbiculatum assemblage suggesting considerably shallower depths and higher energy. Clusters of Modiolus and small oysters characterize the upper parts directly prior to the prominent positive \u03b413Corg peak \u201cb\u201d (the major peak of OAE2 CIE; ? base/lower part of the N. juddii Zone). No benthic fauna occurs above this level.", "keyphrases": ["late cenomanian", "central europe", "bivalves", "palaeoecology"]}
{"id": "10.1016/j.cretres.2023.105703", "title": "Discovery of a new species of Eomysmauchenius from mid-Cretaceous Kachin amber (Araneae: Archaeidae)", "abstract": "Maybe extant Archaeidae are only distributed in southern hemisphere, but all of their fossils are from the northern hemisphere. Here, we report a new well-preserved fossil specimen from Kachin amber, which was identified to be a new species, Eomysmauchenius cretaceominimus, through a series of morphological characteristics comparison, including a strongly raised cephalic part, a sclerotized ring around the spinnerets and a pedipalpal-cheliceral stridulatory organ absence, cheliceral peg teeth in an irregular position, the distal lateral margin of chelicera with a small triangular projection, length and height almost equal opisthosoma. The discovery of this new species once again increases fossil record diversity of the family Archaeidae in the Cretaceous, and unique palp structure enrich our knowledge of juvenal male pedipalps.", "keyphrases": ["archaeidae", "new species", "eomysmauchenius", "kachin amber", "cretaceous"]}
{"id": "10.1016/j.cretres.2023.105712", "title": "New amber records of Burmusculidae (Hymenoptera) from mid-Cretaceous Myanmar", "abstract": "Two new species, Burmusculus flexus sp. nov. and Burmusculus mutatus sp. nov. of Burmusculus Zhang and Rasnitsyn, 2018 in Burmusculidae, are described from the mid-Cretaceous amber of northern Myanmar. A key to all seven species of Burmusculus and detailed comparisons among the species are provided. Veins 1-Rs, 1-M, 1cu-a, 2m-cu and 2-Rs with different states suggest interspecific diagnostic characters within Burmusculus.", "keyphrases": ["taxonomy", "new taxa", "apocrita"]}
{"id": "10.1007/s12549-023-00594-y", "title": "Middle Miocene trace fossils from the Tenes area (NW Algeria) and their palaeoenvironmental implications", "abstract": "The Miocene succession (Allala River Sandstones and Tenes Blue Marls Formation) that crops out in the Tenes area, situated in the northeast of the Lower Chelif Basin in NW-Algeria, contains a low-diversity assemblage of trace fossils. Fifteen (15) ichnogenera were identified: Arenicolites, Beaconites, Cylindrichnus, Diplocraterion, Macaronichnus, Ophiomorpha, Palaeophycus, Parahaentzschelinia, Planolites, Rosselia, Skolithos, Taenidium, Teichichnus, Thalassinoides and Zoophycos. Ethologically, these ichnogenera chiefly display dwelling and feeding activities. The presence of thick, deep-tier, scattered, mainly vertical dwelling burrows attributed to the Skolithos ichnofacies indicates high energy conditions, normal oxygenation and soft substrate. Moreover, elements of the Cruziana ichnofacies show more varied behavioural strategies and higher inchnodiversity with the dominance of horizontal burrows of deposit-feeders. This ichnological study supports the palaeoenvironmental interpretation based on sedimentological analysis of a wave-dominated siliciclastic platform (backshore to offshore), allowing a more precise zonation of the shoreface zone (middle/upper and lower shoreface). In addition, this study allows evaluation of variable degrees of storm influence in response to the contrasting palaeogeomorphology of the coastline.", "keyphrases": ["ichnology", "tenes", "lower chelif basin", "shallow-marine", "storm influence"]}
{"id": "10.1007/s12549-023-00591-1", "title": "Fringing reef growth in the Mid-Devonian: An example from the southern Rhenish Massif, Germany", "abstract": "The Givetian Balduinstein Reef developed upon mixed felsic lavas and volcaniclastic tuffs. The Givetian age of the reef is proven by conodonts (Polygnathus rhenanus/varcus Zone to the Polygnathus ansatus Zone) and the occurrence of the brachiopod Stringocephalus burtini. Remains of land plants and subaerially ejected volcanic bombs in the vicinity of the outcrops document that the volcano was an emerged island surrounded by a fringing reef in an unstable tectonic environment. Reef development is characterised by a complex interaction of volcanism, erosion and the rate and pattern of sea-level change, which resulted in a variety of facies settings and rock-types. Microfacies analysis and rock-types prove that the fringing reef was backed by a shallow lagoon. A lime mudstone/alkali rhyolitic breccia represents a lava flow, or more probably a dome collapse breccia, which flowed into the lagoonal mud and confirms a contemporaneous occurrence of volcanism and reef growth. Reefs flourished during several episodes of inactivity of the volcano, particularly in the upper part of the sections, suggesting that the reef development kept up with sea-level changes and/or local events. Lithofacies of the upper part of the youngest section point to a regressive phase. The distinctive depositional architecture and evolution of the Balduinstein Reef are interpreted as having been controlled mainly by regional tectonics and volcanism with contributions from eustasy.", "keyphrases": ["middle devonian", "fringing reef", "lahn syncline", "microfacies", "volcanism"]}
{"id": "10.1007/s12549-023-00596-w", "title": "Early Cretaceous Equisetites from Slovakia", "abstract": "A new find of terrestrial plant Equisetites cf. lyellii is reported from the Early Cretaceous of Slovakia. It comes from the Mr\u00e1znica Formation of the Rajec Basin in Fatricum, Zby\u0148ov locality, Rajeck\u00e9 Teplice (\u017dilina district). The presence of a 53 mm long horsetail axis provides good evidence of terrestrial environments during sedimentation of the studied strata. According to our interpretation, such a plant strongly indicates a moist to wet habitat (even swampy environments) on the presumed dryland from where it was transported. This dryland could represent an isolated unknown small island(s) in the vicinity, or the Vindelician-Bohemian Massif that was active as a dryland for the entire period of time from the Triassic through the Late Cretaceous. However, the exact palaeogeographic position of the Fatricum during the Mesozoic in relation to the Vindelician Landmass is not entirely clear, and such an interpretation needs a bit of caution.", "keyphrases": ["equisetites", "terrestrial fossil plants", "early cretaceous", "slovakia"]}
{"id": "10.1007/s12549-023-00595-x", "title": "Benthic graptolites (Graptolithina, Pterobranchia) in the Miaolingian (Cambrian Series 3)", "abstract": "Benthic graptolites (Graptolithina) were surprisingly common and diverse in the Miaolingian (Cambrian), but have rarely been described in detail. Encrusting and erect growing colonies already evolved and can be differentiated in early Miaolingian faunas. The Rhabdopleuridae with their encrusting colonies provide few fossils, but members of the erect growing, bushy colonies of the Dithecodendridae are more common, at least as fragments indicating considerable fragmentation and transport. In the Wuliuan, the benthic graptolites reached a considerable diversity at the genus level with at least 6 genera appearing in this interval. The most common taxon is the encrusting genus Sphenoecium with its robust colonies, showing a worldwide distribution. Most taxa, however, are known from few records and their biostratigraphical and palaeogeographical distribution cannot be established yet. Erroneously, the widely distributed Tarnagraptus with its conical thecae has often been misidentified as the Ordovician Mastigograptus, but differs considerably in its tubarium construction and both might not be closely related.", "keyphrases": ["graptolites", "cambrian", "miaolingian", "rhabdopleuridae", "dithecodendridae", "evolution", "diversity"]}
{"id": "10.1007/s12549-023-00593-z", "title": "First evidence of the Upper Jurassic deposits in the Middle Atlas (Marmoucha syncline, Morocco) and connections to the Tethyan Domain", "abstract": "The Marmoucha syncline is located in the eastern part of the Middle Atlas. In this syncline, the \"Gypsum marls\" (Bathonian-Callovian) are covered by red detrital deposits which outcrop in Ait Bazza locality. The upper limit of these detrital deposits is below the transgressional unconformity of the Albian-Cenomanian marine series. The present work introduces a synthesis of stratigraphical, sedimentological and micropalaeontological studies, which has led to new dating and to the identification of different depositional environments. These results have allowed us to define a new chrono-lithostratigraphic unit, the \"Ait Bazza Formation\", which comprises three superimposed members AB1-3 separated by two sedimentary discontinuities. This formation, exceeding 300 m in thickness, is formed by conglomerate, sandstone, sand and varicoloured marls. Micropalaeontological bulk sampling in marly horizons revealed associations of charophytes and ostracods, particularly in Member AB2. The charophytes are represented by oogonia of small Porocharaceae, Clavatoraceae such as Hemiglobator rectispirale, Dictyoclavator ramalhoi, and Nodosoclavator bradleyi that characterise the Tithonian. The ostracod microfauna is diverse, consisting of non-marine and lagoonal- shallow marine species at several horizons, associated with sea urchin spines and rare foraminifera, which indicate fluvio-deltaic sedimentary environments subjected to marine influences. This new age constraints of AB2 Mb to the Late Jurassic, and the discovery of marine influences in this eastern part of the folded Middle Atlas, consequently indicates the existence of palaeogeographical connections with the Tethyan domain located to the NE in the Rif foreland.", "keyphrases": ["charophytes", "ostracods", "tithonian", "marmoucha syncline", "middle atlas", "morocco"]}
{"id": "10.1007/s12549-023-00592-0", "title": "Euboeus mimonti Boieldieu, 1865, the oldest record of an extant species of Tenebrionidae (Coleoptera) and notes on other species identified as darkling beetles from the Late Pliocene of Willershausen (Germany)", "abstract": "Several fossil beetles from the Late Pliocene (Piacenzian) of Willershausen (Lower Saxony, Germany) previously identified as Tenebrionidae and Staphylinidae are reviewed. One species, formerly determined as \u201cStaphylinoidea\u201d is identified as Euboeus mimonti Boieldieu, 1865 (Tenebrionidae: Helopini). This species is the oldest record of an extant species of darkling beetles, which occurs now in the Balkans and Anatolia. The discovery of Euboeus mimonti in the Late Pliocene of Germany indicates that the range of this species was much wider, and the climate in the Late Pliocene in the modern territory of Lower Saxony was much milder. One species formerly determined as \u201cAlleculidae gen. sp.\u201d belongs to the subfamily Alleculinae (Tenebrionidae) and it is identified here as Pseudocistela aff. ceramboides. Two species, misidentified by a previous author as Tenebrionidae belong to Elateridae and Cerambycidae respectively. Generic and species composition, as well as the ratio of extinct and extant beetle taxa in the Willershausen Fossil Lagerst\u00e4tte are discussed.", "keyphrases": ["tenebrionid beetles", "elateridae", "cerambycidae", "fossil", "willershausen lagerst\u00e4tte", "piacenzian"]}
{"id": "10.1007/s12549-023-00590-2", "title": "Environmental, vegetational and climatic investigations during the Plio-Pleistocene in SW-Anatolia: A case study from the fluvio-lacustrine deposits in U\u015fak-Karahall\u0131 area", "abstract": "The Plio-Quaternary fluvio-lacustrine sediments located in the U\u015fak-Karahall\u0131 area (SW- Anatolia) have been investigated with multidisciplinary approaches to highlight their depositional processes and palaeovegetational history. For this purpose, samples from seven different core sites drilled in the area have been used besides field observations. According to sedimentological analysis, three depositional environments were determined: alluvial fan, fluvial and lacustrine. The first two of them are mainly composed of Pliocene aged coarse-medium grained clastics. In the meantime, lacustrine deposits mainly composed of Pliocene aged fine-grained clastics (mudstone, coal), and carbonates (clayey limestone, marl) were deposited. Later, (?)Early-Middle Pleistocene aged clayey limestone, marl, and travertines were precipitated in this lacustrine system. The 230Th measurements on travertines obtained from core samples indicate that these terrestrial carbonates continued to precipitate during the Middle Pleistocene (~288 ka). Moreover, Pliocene palynoflora is mainly represented by hydrophytic plants and gymnosperms, according to palynological investigations. These palynomorph association could be indicated the swamp environment and low-middle altitude area souround the deposition area. The Middle Pleistocene (MIS 10) microflora unlike the Pliocene palynoflora is characterised by widespread open vegetation areas consisted of herb plants in general. The palaeoclimatic signals in the U\u015fak-Karahall\u0131 area during the Middle Pleistocene show that temperate climate mainly prevailed, and also the humidity has changed from dry to wet. All findings suggest that the sedimentation of clastic and carbonate deposits is influenced by topography, tectonic activity, and climate. Tectonic structures such as growth faults have very important role in the lake infill, causing subsidence, which affected the sedimentation rate. Additionally, hydrothermal water influx played an important role in forming travertine precipitation and this could be strongly concerned with the active fault systems in the study area.", "keyphrases": ["plio-pleistocene", "palynology", "depositional systems", "u\u015fak-karahall\u0131", "sw-anatolia"]}
{"id": "10.1007/s12549-023-00589-9", "title": "Global palaeobiogeographic distribution patterns of the Cenozoic pleurotomariid gastropods (Family: Pleurotomariidae Swainson, 1840)", "abstract": "The palaeobiogeographic distributions of the pleurotomariid gastropods (Family Pleurotomariidae) are investigated from Maastrichtian (Latest Cretaceous) to Holocene to understand the global distribution patterns of this gastropod group during the Cenozoic. Although the diversity of the pleurotomariids considerably declined during the Late Cretaceous, they survived the K-Pg mass extinction and thrived in the Cenozoic. The Tethyan group of localities hosted the greatest diversity and thus, can be considered the central hub for the pleurotomariid gastropods throughout the Paleogene. However, with the closure of the Tethyan seaway during the early Neogene, their abundance significantly dropped in the Mediterranean. In the present times, this group has entirely disappeared from the Mediterranean Sea. The distribution became bicentric from the Middle Miocene onwards with one cluster in the Caribbean group of localities and the other in the Western Pacific group of localities. Latitudinal distribution of the fossil pleurotomariids shows that during the end-Cretaceous and Paleocene these gastropods were mostly confined to the polar and temperate latitudinal zones. However, they become more abundant in the temperate latitudinal zone during the Eocene and gradually expanded their habitat towards the tropical latitudinal zone from the Pleistocene onwards. Thus, a typical unidirectional shift from higher to lower latitudes is observed during the Cenozoic revealing habitat tracking in pleurotomariid gastropods.", "keyphrases": ["pleurotomariidae", "palaeobiogeography", "cenozoic", "latitudinal distribution", "habitat tracking"]}
{"id": "10.1007/s12549-023-00584-0", "title": "Organic carbon isotope stratigraphy of Devonian-Carboniferous boundary sections in the Rhenish Mountains", "abstract": "The boundary between the Devonian and the Carboniferous has been drawn using ammonoids, conodonts and miospores, while geochemical data have only rarely been used. The sampling of eight sections (Aprath, Apricke, Effenberg, Wocklum, Stockum, Drewer WJ, Drewer WA, Marsberg) at the northern margin of the Rhenish Mountains demonstrates the potential of the isotope ratio of organic carbon to regionally correlate sections in different facies areas. With the help of the carbon isotopes, a distinct stratigraphic succession is documented, which is characterised by several positive and negative excursions; this succession was recorded in all examined sections. The carbon isotopes can therefore make a significant contribution to the stratigraphic subdivision of sections and complement the biostratigraphic methods.", "keyphrases": ["devonian-carboniferous boundary", "hangenberg event", "rhenish mountains", "organic carbon isotopes", "stratigraphy"]}
{"id": "10.1007/s12549-023-00585-z", "title": "Lithofacies variability and facies analysis of a Givetian reef in the southwestern Lahn Syncline (Rhenish Massif, Germany)", "abstract": "A 200 m thick drill core penetrating the Givetian Hahnst\u00e4tten Reef in the southwestern Lahn Syncline (Rhenish Massif) was investigated. A range of different depositional environments is described based on lithofacies and microfacies analysis. All in all, nine lithofacies types (FTs) are distinguished, which can include subfacies types. The majority of lithofacies of these ultrapure carbonates is represented by lime mudstone and fenestral microbialites, all pointing to shallow subtidal, intertidal to even supratidal low-energy palaeoenvironments. In contrast, more high-energy parts of the reef were dominated by bioclastic rubble deposits (e.g. rudstone). Autochthonous, reef-building carbonates are represented by bafflestone and framestone. Diversity of reef building organisms (stromatoporoids and corals) is low and is dominated by Stachyodes, Actinostroma, Stromatopora, and Thamnopora and alveolitids, respectively. Other bioclasts are brachiopods, gastropods, ostracods, foraminifera, echinoderms, trilobites, and conodonts in descending order. Development of the Hahnst\u00e4tten Reef is interpreted as having been controlled mainly by synsedimentary tectonics and volcanism with contributions from eustasy. The occurrence of Stringocephalus burtini in the entire section and conodont findings, which provide more precise biostratigraphic data confirm an early to middle Givetian age (Polygnathus rhenanus/varcus Zone to Polygnathus ansatus Zone) of the succession. The average quality of the ultrapure carbonates lies at 97.68% CaO (excl. loss of ignition), with 70% of the core ranging between 98% and 99% CaO. This extremely high purity makes it difficult to identify correlations between lithofacies and geochemical data.", "keyphrases": ["middle devonian", "rhenish massif", "reef limestone", "facies", "biostratigraphy"]}
{"id": "10.1007/s12549-023-00588-w", "title": "Where\u2019s dinner? Variation in carnivoran distributional responses to the mid-Vallesian faunal turnover", "abstract": "The Catalan locality of Can Llobateres 1 (early Vallesian, MN9) shows a remarkably rich diversity just prior to the mid-Vallesian crisis, including 23 species of Carnivora. Similarity maps using the Raup-Crick index and covering the Middle to Late Miocene (16\u20135.3 Ma) show that the origin of this carnivoran chronofauna lies to the north of the Iberian Peninsula, gradually making its way south. The chronofauna built up through migrations during the Aragonian, but shows a major influx during the early Vallesian, leading to a biodiversity hotspot. At the end of MN9, the mid-Vallesian turnover, the chronofauna collapses. This is mainly because of the extinction of parts of the fauna, and the retraction of some species to the north, disappearing from Spain. Thus, the rich fauna is an amalgamation of persisting older elements, northern elements having a brief temporary presence and new elements coming in. All these were supported by the unique rich ecosystem of the Vall\u00e8s-Pened\u00e8s Basin during the early Vallesian.", "keyphrases": ["late miocene", "palaeobiogeography", "carnivora", "vallesian crisis", "mammals", "iberian peninsula"]}
{"id": "10.1007/s12549-023-00586-y", "title": "Early Paleogene precipitation patterns over East Asia: Was there a monsoon after all?", "abstract": "Early Paleogene latitudinal precipitation gradients and patterns along the Pacific coast of Eurasia are studied in time and space using the Coexistence Approach, for the first time applied on an extensive regional palaeobotanical record. The palaeobotanical data used in this reconstruction are compiled from literature resources on 110 reasonably well-dated floras, including terrestrial deposits of 73 sites located in the Far East of Russia, Eastern Siberia, China, and Japan, and covering the early Palaeocene to early Eocene. Our reconstructions of precipitation for the Pacific side of Eurasia in the early Paleogene demonstrate a clear division (especially pronounced in the early Eocene) into two zones at ca. 50\u00b0 N palaeolatitude on all precipitation parameters. Our results reveal very weak latitudinal precipitation gradients during the early and late Palaeocene. In the early Eocene, the gradient became more clearly pronounced, and a larger \u201carid\u201d zone can be distinguished in the mid-latitudes. Our data suggest that in the early Paleogene, the global atmospheric circulation consisted of two well-defined cells, Hadley and Ferrell, while the polar cell was either absent or located over the Arctic Ocean and was very weak. Based on our reconstructions, the records could not be interpreted in terms of a monsoonal type of climate. The regional distribution of hygrophilous and xerophilous taxa in our early Eocene record largely coincides with the reconstructed precipitation pattern and generally corresponds to the distribution of coals and/or oil shales and red beds and/or evaporites, respectively.", "keyphrases": ["coexistence approach", "spatial precipitation gradient", "temporal climatic trends", "precipitation seasonality", "monsoon", "global atmospheric circulation"]}
{"id": "10.1007/s12549-023-00587-x", "title": "The identity of the Silurian retiolitine genera Paraplectograptus and Sagenograptoides (Graptoloidea, Retiolitinae)", "abstract": "The genus Paraplectograptus includes a small number of retiolitine species with an identical development of the main thecal and ancora sleeve lists. A complete virgella-virga-nema development with connecting lists is formed on the obverse side of the tubarium, while the only thecal lists on the reverse side are the lateral apertural lists, connected through the pleural lists of the ancora sleeve. Obverse and reverse sides of the tubarium are connected by the thecal lips on the ventral sides. The characteristic zigzag thecal lists of the reverse side of many early retiolitines are not present in the genus. The development and extent of the reticular ancora sleeve lists on the obverse and reverse sides of the tubarium are quite variable and range from lacking entirely to dense. The genus Pseudoplectograptus is regarded as a junior synonym of Paraplectograptus. Pseudoplectograptus sagenus is transferred to the genus Sagenograptoides. Its type species \u2018Sagenograptoides arctos\u2019 was known only from small, immature or fragmentary specimens of the associated Sagenograptoides sagenus. This species bears a characteristic reticulum on the ventral thecal walls, not found in the genus Paraplectograptus, but which is present in other Cyrtograptus lundgreni Biozone retiolitines.", "keyphrases": ["graptolites", "retiolitinae", "paraplectograptus", "pseudoplectograptus", "sagenograptoides", "tubarium construction", "biostratigraphy"]}
{"id": "10.1007/s12549-023-00583-1", "title": "Late Early to late Middle Pleistocene medium-sized deer from the Italian Peninsula: implications for taxonomy and biochronology", "abstract": "The taxonomy of Quaternary medium-sized deer from Europe rests mainly on antler morphology, while adequate dental and postcranial diagnostic features are lacking. When complete antlers are not available, the taxonomic identifications are often attempted on chronological ground. A considerable number of mostly unpublished craniodental and postcranial remains of fallow deer from selected Italian sites from the late Early Pleistocene to the late Middle Pleistocene is here presented and discussed. The aim of this work is to test the validity of the diagnostic characters proposed in literature and to explore the variability of the fallow deer taxa. In addition, the analysis of the two reference samples from Riano and Ponte Molle allows to refine the features of Dama clactoniana. Finally, biometric comparison has been performed in order to investigate possible oscillations across time and/or differences among taxa.", "keyphrases": ["early-middle pleistocene transition", "mediterranean area", "morphology", "cervids"]}
{"id": "10.1007/s12549-023-00582-2", "title": "The shark and ray teeth of the Lower Miocene (Upper Marine Molasse) from Ballendorf, Baden-W\u00fcrttemberg, Southern Germany", "abstract": "In an abandoned sand pit near Ballendorf (Alb-Donau District, Baden-W\u00fcrttemberg), sediments of the Upper Marine Molasse (Lower Miocene) are present. In these sediments, 39 shark and ray species belonging to 29 genera were identified (Aetobatus, Alopias, Araloselachus, Carcharhinus, Carcharias, Centrophorus, Chaenogaleus, Dasyatis, Galeocerdo, Hemipristis, Iago, Isistius, Keasius, Notorynchus, Pachyscyllium, Paragaleus, Physogaleus, Pristiophorus, Raja, Rhinobatos, Rhinoptera, Rhizoprionodon, Rhynchobatus, Scyliorhinus, Sphyrna, Squalus, Squatina, Taeniurops, Triakis). However, in this paper we only illustrate and describe the 23 taxa not already discussed in previous publications on the Upper Marine Molasse deposits of \u00c4pfingen, Rengetsweiler and Ursendorf, apart from two exceptions: teeth from jaw positions not previously illustrated, and specimens that are better preserved than those in previous publications. Specimens only determined as \u201csp.\u201d were illustrated because it cannot be ruled out that they represent different species to the ones published earlier. Nearly all of the taxa found have Recent relatives; only Araloselachus, Keasius and Physogaleus are extinct. Most of the recovered taxa lived on or near the bottom in the shelf region. Alopias and possibly also Keasius lived higher in the water column. With Isistius, a taxon living in the oceanic realm was present, and the Recent representatives of Centrophorus live in deeper waters. Nearly all taxa fed on invertebrates and/or fishes; Isistius also fed as an ectoparasite. Additionally, two generalist feeders (Galeocerdo, Notorynchus) and one filter feeder (Keasius) were identified. The species Carcharias crassidens, which is not common in the Upper Marine Molasse, was also verified. Other fossils found in this deposit include remnants of odontocete cetaceans, molluscs, balanid barnacles, algae, and teeth of terrestrial mammals. The palaeoenvironment was a warm, shallow-water habitat. Based on greater proximity to the palaeo-coastline, the water depth was probably less than in other Upper Marine Molasse deposits.", "keyphrases": ["elasmobranchii", "teeth", "lower miocene", "upper marine molasse", "paratethys"]}
{"id": "10.1007/s12549-023-00577-z", "title": "Eocene sediments and a fresh to brackish water biota from the early rifting stage of the Upper Rhine Graben (west of oil field Landau, southwest Germany): implications for biostratigraphy, palaeoecology and source rock potential", "abstract": "The Eocene biota from the pre-rifting stage of the Upper Rhine Graben (southwest Germany) is, with exception of the world-famous fossil sites Messel and Bouxwiller, poorly known. While from these localities exclusively terrestrial and freshwater fossils were recovered, here we present floral and faunal assemblages from the middle Upper Rhine Graben which clearly indicate a temporarily brackish water environment and consist of a diverse palynomorph association, calcareous nannoplankton, foraminifers, ostracods and some fish and reptile remains. Based on the occurrence of Trochastrites hohnensis, a Lutetian age is assumed. Organic-walled dinoflagellate cysts, in particular Phthanoperidinium comatum, Phthanoperidinium echinatum, Apectodinium homomorphum and Apectodinium quinquelatum, suggest a late Ypresian to Lutetian age. The pollen and spores assemblage includes typical mid Eocene species, such as Tegumentisporis villosoides, Tricolporopollenites crassostriatus and representatives of Bombacaceae, but a late Ypresian to Priabonian age cannot be excluded. Foraminifers and ostracods do not further refine the biostratigraphical assignment. Hence, a Lutetian age is most probable. The mass occurrence of Neocyprideis, various foraminifer taxa and an organic-walled dinoflagellate cyst assemblage of very low diversity are indicative of a brackish water environment. Disarticulated vertebrate remains include fish teeth of Lepisosteidae, turtle plates and alligatoroid teeth of Diplocynodon and Hassiacosuchus. The present palaeogeographical scenarios do not consider a connection from the Upper Rhine Graben to the North Sea Basin, Alpine Sea/Paratethys or Paris Basin during the mid Eocene. Provided that the middle Upper Rhine Graben was land-locked and definitely not reached by a marine ingression during this time interval, we tentatively suggest that the brackish water taxa may have been accidentally introduced into a brackish inland sea by wind (anemochory), rain, highly mobile insects or vertebrates such as fish, birds and mammals (endozoochory/ectozoochory). The presumably freshwater calcareous nannoplankton species Nannoserratolithus minutus Martini is newly described.", "keyphrases": ["calcareous nannoplankton", "palynomorphs", "microfossils", "vertebrate remains", "palaeoecology", "organic geochemistry", "paleogene"]}
{"id": "CUI2024111875", "title": "Chronological features of Heinrich Stadial 2 based on a high-resolution analysis of \u03b418O stalagmite records from China, and possible links to changes in Atlantic Meridional Overturning Circulation", "abstract": "The Heinrich Stadial 2 (HS2) event is poorly defined in the Greenland \u03b418O ice core record; however, it can be identified in stalagmite records from China. In this paper, we reconstruct an absolutely-dated and high-resolution calcite \u03b418O record from Shima Cave, central China, covering the interval from 26.0 to 23.9 ka BP, with a temporal resolution of \u00a016 years. By integrating our newly reported record with all available \u03b418O records of Marine Isotope Stage 2 from China, which are securely 230Th/U-dated, we calculate the timing of the onset, termination and duration of HS2. The statistical results show that the prominent HS2a phase started at \u00a024.4 \u00b1 0.1 ka BP and ended at \u00a023.6 \u00b1 0.1 ka BP, lasting approximately 0.8 \u00b1 0.3 ka. If the onset of the Dansgaard-Oeschger 2 event in the Greenland \u03b418O record is synchronous with the termination of HS2a, then the GICC05 chronology should be adjusted by +230 years to align it with stalagmite results. Further investigation of HS2 shows that Chinese cave records exhibit a distinct two-fold structure, corresponding to HS2a and HS2b, as observed in marine sediment cores, particularly those recovered around the Atlantic Ocean. These records show comparable changes in relative amplitudes during the HS2a and HS2b phases, which could possibly be related to different weakening episodes in the Atlantic Meridional Overturning Circulation.", "keyphrases": ["east asian summer monsoon", "stalagmite", "th/u dating", "heinrich stadial 2"]}
{"id": "ZHAO2024111877", "title": "Mid-Miocene terrestrial carbon isotope shift driven by atmospheric CO2 in the Xining Basin, NE Tibetan Plateau", "abstract": "The Mid-Miocene Climatic Optimum (MMCO; \u00a017\u201315 Ma) was a relatively recent warming event unrelated to human activity that provides an ideal analogue for our global warming future. However, the terrestrial ecosystem response to the MMCO remains unclear because of limited records. Continuous sedimentation from the Tashan Borehole (TSB) in the Xining Basin, northeastern Tibetan Plateau (NETP) spans the entire MMCO, with dates of 18.5\u201313.5 Ma from high-resolution paleomagnetic studies. Here, we explore the organic carbon isotope (\u03b413CTOC) record of TSB to investigate the NETP terrestrial ecosystem response to the MMCO. The sediments are typical floodplain deposits with \u03b413CTOC values ranging from \u221228.03\u2030 to \u221225.16\u2030, indicating terrestrial C3 plants were the dominant NETP terrestrial vegetation during MMCO. Further, an obviously negative shift of 0.6\u2030 occurred in TSB \u03b413CTOC during \u00a017.6\u201314.2 Ma. TSB \u03b413CTOC values show the opposite trend to global benthic \u03b413C values, both in the long-term Monterey Excursion event and short-term carbon maxima events. Increased atmospheric CO2 during the MMCO enhanced the carbon isotope fractionation through photosynthesis by terrestrial plants and resulted in more 12C-enriched organic matter. Similar processes on a global scale subsequently accounted for part of the Monterey carbon isotope excursion. Therefore, in warm and humid conditions, the carbon isotope cycle of terrestrial C3 plants in the Xining Basin was mainly controlled by atmospheric CO2 concentration, with superimposition of effects of enhanced East Asian summer monsoon precipitation.", "keyphrases": ["carbon isotope", "palaeoecology", "mid-miocene climatic optimum", "monterey carbon isotope excursion", "tibetan plateau"]}
{"id": "RAHMAN2024111865", "title": "Transport pathways of black carbon to a high mountain Himalayan lake during late Holocene: Inferences from nitrogen isotopes of black carbon", "abstract": "Historically, forest fires have played a significant role in the production and distribution of black carbon (BC), including its deposition in water bodies. BC can reach to water bodies through two main pathways: (i) wet and dry atmospheric deposition and (ii) transportation of soil BC via surface runoff. Identifying the transport pathways of BC after fire has proven to be a challenging endeavour. This study aimed to decipher the pathway of BC transportation to a lake (Wular Lake, Kashmir Valley, India) by utilizing nitrogen isotopic composition of BC (\u03b415NBC) from a sediment core spanning 3744 years. The \u03b415NBC record demonstrate that terrestrial N dynamics in the Kashmir Valley were predominantly influenced by shifts in climate condition during the late Holocene. The observed variations indicated lower \u03b415NBC, indicative of dominance of atmospheric transportation of BC to the lake, during relatively drier periods with higher forest fire activity. In contrast, higher \u03b415NBC, suggesting a dominance of soil BC transportation via runoff, aligned with relative wetter periods of low forest fire activity.", "keyphrases": ["himalaya", "lake", "black carbon", "nitrogen isotopes", "forest fire", "transportation"]}
{"id": "HILLMAN2024111904", "title": "Holocene hydroclimate stability in three lake sediment records from the southeastern United States", "abstract": "Many Holocene paleoclimate records from the southeastern United States (SE US) have limited chronological constraints and/or low sedimentation rates and consequently low resolution; this presents challenges in discerning the relative importance of synoptic\u2013scale drivers of past hydroclimate. In this study we summarize three lake sediment records that are uniquely located to test hypotheses regarding the importance of the Pacific North American (PNA) pattern and the North Atlantic Oscillation (NAO) over the last 5000 years. At Pigeon Marsh, Buck Pond, and Halls Pond, we used sedimentological (radiocarbon dating of transect cores), physical (grain size), geochemical (carbon and nitrogen ratios and isotopes), and biological (palynomorphs) proxies to reconstruct lake level and lake environment. Moderate lake and environmental changes occur around 2000 cal yr BP at Buck and Halls Pond, which is regionally consistent with other paleorecords and may suggest that the NAO was an important control. However, our results generally indicate fairly stable hydroclimate conditions up until historical European settlement when land clearance caused vegetational and lake hydrologic balance changes that were unprecedented in both magnitude and rate compared to the middle/late Holocene.", "keyphrases": ["lake sediment", "southeastern united states", "north atlantic oscillation", "sedimentology", "human impacts"]}
{"id": "DONG2024111898", "title": "Atmospheric CO2 controls on the MIS 6 glaciation: 10Be chronology of moraines in the Haizishan area, southeastern Tibetan Plateau", "abstract": "A unifying theory interpreting the cause of ice-age cycles remains elusive, in view of the near-synchronous interhemispheric major climate shifts but anti-phased summer solar insolation signatures between hemispheres. Determining the timing and magnitude of mountain glaciations helps in shedding new light on this long-standing unsolved puzzle. Yet, robust glacial chronologies are limited for the pre-Last Glaciation time periods, impeding a full understanding of glacial histories and climatic mechanisms behind them in mountainous regions, such as the Tibetan Plateau (TP). Here, we report thirty-five new 10Be exposure-ages from moraine boulders in the Niqingqu Valley, eastern Haizishan Plateau, which adds to the existing glacial chronologies of the Hengduan Mountains, southeastern TP. The dating results indicate that four centennial to millennial-scale glacial activities occurred around 168.4 ka in the studied valley. Despite being indistinguishable in age, these high-frequency glacial fluctuations allow us to draw a conclusion that glaciers in the studied valley achieved the marine isotope stage 6 (MIS 6) glacial maximum prior to the Penultimate Glacial Maximum (PGM), inconsistent with Northern Hemisphere. We attribute the MIS 6 glacial maximum identified here to the response of glaciers to a combination of low-level atmospheric CO2 content and low northern high-latitude summer solar insolation/high summer-monsoon precipitation. The consistent local PGM and low CO2 levels suggest that low atmospheric CO2 contents are likely a necessary prerequisite for the MIS 6 glaciation.", "keyphrases": ["be exposure dating", "penultimate glacial maximum", "atmospheric co", "summer solar insolation", "east asian summer monsoon"]}
{"id": "XIE2024111879", "title": "Stromatolites from the Majiagou Formation in the Ordos Basin, Northwestern China", "abstract": "Stromatolites declined remarkably in the Middle Ordovician, which has been speculatively related to the concomitant proliferation of metazoan reefs during the Great Ordovician Radiation Event, however, they are flourish and widely distributed in the Middle Ordovician (Darriwilian) Majiagou (Machiakou) Formation in the Ordos Basin, northwestern China. The stromatolites in the Ma-5 Member of the Majiagou Formation in the Ordos Basin exhibit significant morphological diversity, and are ready to be divided into wavy and domal stromatolites from the south and west part, columnar in the Northeast part, accompanied with rarely hemispheroid and conical ones. The stromatolites in the Ma-5 Member distribute in a subcircular ring belt, which can be subdivided into three sedimentary divisions, mostly near the boundary between the gypsum-bearing dolomite flat and gypsum salt lake, of which, the north-central division, with its thicker stromatolite-bearing strata and more complex stromatolite morphologies, was the most favorable for the establishment of stromatolites, where grazing animals were absent and burrowing animals few. Some calcified microorganisms were recovered from the stromatolites, which substantially increases their known diversity for this interval and suggestive of a severe undersampling of the middle Ordovician calcified cyanobacteria fossil record in the Ordos Basin.", "keyphrases": ["stromatolites", "ma-5 member", "middle odovician (darriwilian) majiagou formation", "ordos basin"]}
{"id": "DONG2024111902", "title": "Impact of water level change on shifts in subsistence regimes revealed by anthropogenic fire in the lower Yangtze basin during the Mid-Holocene", "abstract": "The lower Yangtze is one of the regions of origin of rice agriculture but it is unclear if environmental change drove the transition from hunting-gathering to agriculture. Long-term and continuous lacustrine records of anthropogenic fire are a more effective means of addressing this problem than the fragmentary terrestrial records available for the lower Yangtze region. We constructed a Holocene fire history revealed by records of black carbon content (BCC) and grain size of the sediments of Lake Nanyi in the lower Yangtze. Our results show the following: 1) Peaks in fire activity occurred during \u223c8400\u20136500 (fire peak P1) and \u223c 1100\u20130 cal BP (fire peak P2), while weaker fire activity occurred during \u223c6500\u20131100 cal BP (S2). 2) This temporal pattern of fire activity, with a double peak (P1-S2-P2), was asynchronous from east to west across the lower Yangtze. The warm and humid climate would not have caused intense fires and the reduction of forest during \u223c8400\u20136500 and \u223c 1100\u20130 cal BP. Therefore, we suggest that anthropogenic ignitions, corresponding to pronounced population fluctuations after 8400 cal BP, dominated the regional fire activity. Combined with archaeological evidence, the inverse relationship between the agricultural and population levels and fire intensity during the mid-Holocene suggests that fire intensity at this time was the result of the diversity of landscape types associated with prehistoric subsistence patterns, rather than the magnitude of anthropogenic activity. Combined with sea level, rainfall and archaeological evidence, we propose a mechanism whereby asynchronous water-level rise during \u223c8400\u20136500 cal BP forced the migration of humans to the foothills where they often used fire to modify the landscape as part of a broad-spectrum subsistence pattern. Whereas, water-level fall after 6500 cal BP expanded the area of open ground for human settlement, and in this less diverse landscape, less use was made of fire in agricultural subsistence. Overall, our study reveals how regional water-level, driven by sea-level rise and extreme rainfall, delayed the transition from hunting-gathering to agriculture in the lower Yangtze region.", "keyphrases": ["water level", "anthropogenic fire", "subsistence", "mid-holocene", "lower yangtze"]}
{"id": "MENEZES2024111881", "title": "Pedogenic processes and climatic conditions from Cretaceous (Albian) tropical paleosols of the Itapecuru Formation, Parna\u00edba Basin, northeast Brazil", "abstract": "Paleosols are an under-utilized tool for paleoenvironmental and paleoclimatic reconstruction in Brazilian intracontinental basins. The Itapecuru Formation, from the Lower Cretaceous of the Parna\u00edba Basin, consists of a 600-m-thick succession of interbedded very fine-to-fine-grained sandstone, mudstone, and paleosols containing rich fossil assemblages. This paper provides a detailed description of the macro and microscopic pedogenic features of a hydromorphic paleosol profile whithin the Itapecuru Formation. Analyses of clay mineralogy and whole-rock geochemistry in the hydromorphic paleosols at the Prata locality are used to infer pedogenic processes, paleoclimate, paleohumidity and paleovegetation. Estimates of paleoprecipitation and paleotemperature using climofunctions, chemical index of alteration without potassium, and paleosol weathering index proxies (PWIs) show values ranging from 810 to 1042 mm/yr (SE = \u00b178.1 mm/yr) and 10.9 to 11.8 \u00b0C (SE = \u00b10.23 \u00b0C), respectively. Climofunction values (MAP and MAT), paleohumidity, K\u04e7ppen aridity index, and pedogenic clay mineral content suggest a humid paleoclimate during soil-forming and weathering processes. Based on these climate data and previously published paleogeographic and palynological studies, the Cretaceous (Albian) Prata pedotype was formed within the equatorial humid belt with vegetation of wet tropical forests.", "keyphrases": ["itapecuru formation", "ultisols", "redoxmorphic features", "tropical paleosols"]}
{"id": "DEPUYDT2024111884", "title": "Last Glacial \u2013 Holocene variability of the European Slope Current, NE Atlantic", "abstract": "The upper branch of the Atlantic Meridional Overturning Circulation (AMOC) in the mid-latitudes of the Northeast Atlantic remains poorly studied. This study provides a complete overview of the glacial, deglacial and Holocene dynamics of the easternmost portion of the AMOC upper branch, namely the European Slope Current (ESC) and its glacial equivalent known as the Glacial Eastern Boundary Current (GEBC). This is achieved through the study of the sediment core SU81\u201344 retrieved from the southern Bay of Biscay (BoB) (\u223c1000 m water depth), and by using a multiproxy approach (i.e. benthic foraminiferal assemblage, grain size proxies, oxygen and carbon stable isotopes, and neodymium isotopic composition of foraminiferal shells). During the glacial period and the onset of the deglaciation, the grain size proxies at SU81\u201344 fluctuate significantly. These fluctuations are coherent with changes in relative densities of benthic foraminiferal indicator species of current strength and ventilation, thus highlighting significant changes in the GEBC vigor through time. The SU81\u201344 data confirm the Dansgaard-Oeschger interstadial/faster-stadial/slower flow pattern previously observed in northern BoB. Our results also provide new constraints on the strength of the slope current during the late deglaciation and Holocene period with a significant reinvigoration of the ESC, and by extension the upper branch of the AMOC during the B\u00f8lling-Aller\u00f8d warming. This seems to confirm the crucial role of the ESC in deep water formation at high northern latitudes, as it is the case today. Finally, our data show a progressive weakening of the ESC during the Holocene. We hypothesize a link with a long-term decrease in the density gradient between low and high latitudes that can be attributed to long term changes in insolation and the strength of the subpolar gyre dynamics.", "keyphrases": ["late glacial", "heinrich stadials", "b\u00f8lling\u2013aller\u00f8d", "holocene", "european slope current", "northeast atlantic", "amoc"]}
{"id": "XIE2024111908", "title": "Orbitally-forced meridional shifts of the westerlies modulated the hydroclimate of northeast China during the late Eocene", "abstract": "The mid-latitude westerlies are a fundamental component of the global climate system. There has been extensive research about how meridional shifts of the westerlies influenced the wet-dry paleoclimate regimes of mid-latitude Asia during the Quaternary. However, how the westerlies operated in much older geological times, such as the late Eocene, particularly on an orbital time scale, is not fully understood. Here, we conducted detailed cyclostratigraphic and palynological analyses on a late Eocene (41.2\u201337.8 Ma) mudstone-shale sedimentary sequence from the Fushun Basin in northeast China, which uniquely records orbitally-forced meridional shifts of the westerlies. Cyclostratigraphic analyses reveal that the mudstone-shale rhythms exhibit a prominent short eccentricity cycle, with a modest expression of obliquity cycles and a weak expression of precession cycles. The palynological results show that the vegetation experienced frequent alternations between semi-desert and swamp forest, and the climate exhibited periodic oscillations between warm-dry and cold-wet climates. We propose that a combination of eccentricity-modulated low-latitude summer insolation and obliquity-forced high-latitude incipient ice sheet and meridional temperature gradient variations drove cyclical vegetation and hydroclimate fluctuations in northeast China during the late Eocene by regulating the intensity and displacement of the westerlies and the subtropical high. Our results imply that continued poleward movement of the westerlies and the subtropical high will lead to increased aridification along the southern margin of the westerlies under a continuous global warming scenario.", "keyphrases": ["orbital forcing", "late eocene", "westerlies", "subtropical high", "fushun basin", "palynological record"]}
{"id": "LIN2024111900", "title": "Organic matter enrichment in shale deposited proximal to paleo-uplifts and its impact on shale gas exploration", "abstract": "Much of the global exploration and development of shale gas is focused on organic-rich shale deposited in basin or slope/basin margin settings. There is a clear need to assess the degree to which organic-rich shale deposited in other settings, notably proximal to paleo-uplifts, are promising shale gas prospects. Organic-rich sediments that accumulated proximal to paleo-uplifts are recognized globally and include the Cambrian Niutitang Formation, Ordovician-Silurian transition \u201chot shales\u201d, and modern sediments of the Black Sea. Though the subject of recent research efforts, much remains to be learned of the mechanisms of organic matter enrichment of fine-grained sediment deposited adjacent to paleo-uplifts. Our study focuses on the Ordovician Wufeng Formation that accumulated proximal to uplifted areas of the Upper Yangtze platform. Though the TOC content of the analyzed Wufeng Formation samples recovered from near the paleo-uplifts is less than that of Wufeng samples collected from basin or slope/basin margin settings, average TOC value of the former can still reach more than 2", "keyphrases": ["paleo-uplift", "upper yangtze platform", "shale gas", "organic matter", "sedimentary environment"]}
{"id": "MAJCHRZYK2024111876", "title": "Modern-type reef in ancient time - Palaeoecology of a Middle Devonian coral community from Mad\u00e8ne el Mrakib (Anti-Atlas, Morocco)", "abstract": "The southernmost Devonian reefs formed along the north-western margin of Gondwana. One of the best-preserved reefal palaeoecosystems of this area is found in the Givetian of Mad\u00e8ne el Mrakib (Anti-Atlas, Morocco), exposing a vast, at least \u223c1.2 km2 area of reef strata. This contribution documents the ecological succession, taxonomical structure and palaeoecology of this exceptionally diverse reef community. Combined evidence from the sedimentary succession and faunal changes records a trend of progressive shallowing. The ecological succession is characterised by an upsection increase in the abundance and diversity of the reef-building biota, accompanied by a shift in the dominant morphotypes of tabulate corals from platy (pioneering and diversification stages) to branching and massive forms (climax stage). The exceptionally rich, shallow-water reef community occurs in the uppermost part of the succession. The climax community is dominated by extraordinarily large, branching tabulate corals (mostly Thamnopora), with the notable role of massive alveolitid, heliolitid and favositid tabulates, as well as large, solitary rugose corals. A surprising feature of this assemblage is the rather subordinate role of stromatoporoids, generally regarded as a main component of the shallow-water Devonian reefs. Remarkably, the observed community structure is closer to that typical of modern shallow-water reefs, dominated by branching scleractinian corals from the family Acroporidae, than to the archetypal Paleozoic reefs. These distinctive traits of the Mad\u00e8ne el Mrakib community make it particularly suitable for comparative studies between Devonian and modern reef ecosystems, showing that these communities shared notable similarities in terms of their ecological successions, zonation patterns, dominance of branching corals and high morphological variability in shallow-water environments, and adaptations of corals to turbulent conditions.", "keyphrases": ["devonian", "shallow-water reef", "branching corals", "tabulate corals", "photosymbiosis", "gondwana"]}
{"id": "WU2024111882", "title": "Meteoric diagenesis influenced by East Asian Summer Monsoon: A case study from the Pleistocene carbonate succession, Xisha Islands, South China Sea", "abstract": "The East Asian Monsoon (EAM) has significantly influenced various depositional and diagenetic processes in carbonate sediments in much of East and South Asia during the Cenozoic. The relationship between the EAM and marine carbonate platforms, which are widely developed in this region, however, remains largely unknown. Based on petrographic, mineralogical, and geochemical analyses of the carbonate succession (\u223c237 m thick) on the Xisha Islands, South China Sea, meteoric diagenesis and its relationship with the East Asian Summer Monsoon (EASM) during the Pleistocene were studied. Various petrographic features, stable isotopes (\u03b413C, \u03b418O), and trace elements (Sr, Fe, Mn, Rare Earth Elements and Y) indicate that this succession was extensively altered by meteoric diagenesis, producing four exposed surfaces embedded in the shallow coral reef sediments. Given this data, we suggest that the meteoric diagenesis that affected this succession occurred during periods of low sea-level, and was potentially related to the relative intensity of the EASM. During strong EASM periods, particularly during the Mid-Pleistocene Transition \u223c0.9 Ma, meteoric diagenesis was intense, as suggested by the complete alteration of unstable minerals, extreme dissolution, the presence of reddish-brown iron oxides, and a large negative excursion of \u03b413C (\u22126.2\u2030). The influence of the EASM on meteoric diagenesis of Pleistocene carbonate platforms can be identified throughout the South China Sea. This study sheds light on the relationship between meteoric diagenesis and paleo-climate conditions in carbonate platform regions that are influenced by monsoons.", "keyphrases": ["meteoric diagenesis", "east asian monsoon", "carbonate rocks", "pleistocene", "xisha islands"]}
{"id": "LIU2024111903", "title": "Evolution of Silurian phytogeography, with the first report of Aberlemnia (Rhyniopsida) from the Pridoli of West Junggar, Xinjiang, China", "abstract": "The development of phytogeography is an essential aspect of floral evolution. The Silurian is considered a pivotal period for the development of early land vegetation based on both macrofossil and microfossil evidence; however, the evolution of phytogeographic zonation at that time remains controversial. In this paper, we describe a new species of the rhyniopsid, Aberlemnia junggaria sp. nov., from the Pridoli (upper Silurian) of West Junggar, Xinjiang, China. The new plant consists of at least three orders of axes, an oval to reniform terminal sporangium bearing in sparse ultimate axes and sporangium with a nearly enclosed dehiscence line. A dataset of global Silurian macrofossil records was compiled, including 30 species within 24 genera from 38 localities covering 8 main paleogeographic blocks. Using these data, the spatial-temporal distribution of Silurian plant macrofossils was mapped. Biogeographic evolution is revealed for the first time by means of network analysis and cluster analysis, and two phytogeographic realms, the West Junggar-Vietnam and Laurussia-North Gondwana realms are provisionally recognized during the Pridoli Epoch. Considering the widespread microfossil evidence for land plant diversification and dispersal, this global phytogeographic zonation might have onset at an even earlier time.", "keyphrases": ["paleobotany", "biogeography", "embryophyte", "sporophyte", "spores"]}
{"id": "QUAMAR2024111844", "title": "Hydroclimatic changes in the Core Monsoon Zone of India since the Last Glacial Maximum: An overview of the palynological data and correlation with the marine and continental records", "abstract": "The Indian Summer Monsoon (ISM) is one of the major components of the Asian Monsoon System that exhibits a complex ocean-atmospheric-coupled mechanism of the tropics, which is indispensable in inter-hemispheric heat transfer on Earth. The ISM causes \u223c80", "keyphrases": ["indian summer monsoon (ism)", "inter-tropical convergence zone (itcz)", "last glacial maximum (lgm)", "holocene", "palaeoclimate", "core monsoon zone", "india"]}
{"id": "CASTROLOPEZ2024111897", "title": "Holocene climate variability and the effect of anthropogenic activities on the vegetation landscape of western-central Mexico", "abstract": "Atmospheric forcings control climate variability and at the same time control vegetation distribution and forest fires during the Holocene. Paleoenvironmental studies are scarce in western Mexico, particularly those documenting vegetation change, landscape dynamics, and fire regimes. This study presents a vegetation and fire occurrence reconstruction in the Etzatl\u00e1n-Magdalena paleolake, western Mexico, during the Holocene. The reconstruction relies on fossil pollen, macrocharcoal and microcharcoal analyses of a clay sediment core. In the early Holocene (10\u20135.8 ka), climatic conditions were humid between 10 and 9 ka, represented by cloud forest of Liquidambar, Juglans, and Betulaceae. After 9 ka Quercus forest expanded and a trend towards warm conditions was detected, associated with high fire activity, suggesting the presence of a dry forest. Fire episodes at local and regional scale had a long-term negative effect on temperate and cloud forests. In the middle Holocene (5.8\u20132.1 ka), temperate forest was replaced by dry forest, indicating a drier climate. In the late Holocene (2.1\u20130.3 ka), the expansion of disturbance taxa and the low local fires indicated an open landscape and dry conditions. Human activity was documented by an increase of Cheno-Amaranthaceae, Poaceae and microcharcoal concentration after 3.5 ka. This research provides relevant information on the vegetation dynamics in a region with a long history of human settlement.", "keyphrases": ["paleoclimate", "pollen", "fire history", "human perturbation", "biodiversity"]}
{"id": "WEI2024111905", "title": "Diversity dynamics, faunal turnover and radiation pattern of the Middle Ordovician trilobites in South China", "abstract": "Available data on the temporal and geographical distribution of Middle\u2013early Late Ordovician trilobites in South China were reviewed under a high-resolution biostratigraphical framework to investigate the diversity dynamics and explain the faunal turnover and radiation pattern of trilobites during the Middle Ordovician. Three macroevolutionary phases are recognized on the basis of the diversity changes at taxonomic levels. Cluster analysis shows three trilobite groups, two distinct trilobite faunas and three faunal turnovers through nine time slices. Three trilobite groups (Groups A, B and C) are coupled with three macroevolutionary phases, and characterized by different proportions of the Whiterock Fauna. Two distinct trilobite faunas (Early\u2013Middle Ordovician and Late Ordovician Trilobite Faunas) and three faunal turnovers could be recognized at different similarity coefficients, their replacements were mainly affected by changes of sea level and substrate conditions. The trilobite radiation was manifested by the development, expansion and domination of the Whiterock Fauna (part of the Paleozoic Evolutionary Fauna) through the Middle Ordovician. The first diversity acme of trilobites occurred during the Dapingian\u2013early Darriwilian, while the radiation centre gradually shifted from inner platform to outer platform environments. From the end Darriwilian onwards, elements of the Whiterock Fauna had further developed and dominated all environmental settings from the inner platform to the lower slope, coinciding with the second and more extensive radiation of trilobites in South China. Two phases of radiation may have been directly triggered by two major transgressions during the late Dapingian\u2013early Darriwilian and the late Darriwilian\u2013early Sandbian respectively. In addition, climate cooling and various substrate conditions, as well as the increased oxygen levels in the atmosphere and marine water, nutrients and tectonic movements during the Middle Ordovician may have provided essential conditions for the trilobite radiation.", "keyphrases": ["middle ordovician trilobites", "whiterock fauna", "south china", "macroevolution", "environmental changes", "great ordovician biodiversification event"]}
{"id": "SONG2024111899", "title": "Editorial preface to special issue: Recovery of marine ecosystem after the Permian-Triassic mass extinction: New progress from South China", "abstract": "The end Permian to Middle Triassic interval (\u223c252\u2013242 Ma) witnessed the largest marine mass extinction and the most delayed recovery in the Phanerozoic. The nature and mechanism of these biotic and environmental changes remain unclear. This special issue focuses on the Triassic marine sediments in South China, which provide unique documentation of the collapse and recovery of marine ecosystems. Six papers focus on biotic changes and their ecological significance in Early and Middle Triassic times, documenting evidence from bivalves, marine reptiles, stromatolites, hybodontid teeth, vertebrate coprolites, and other putative fossils. Two papers study conodont biostratigraphy across the Permian-Triassic boundary (PTB) and Induan-Olenekian boundary. Two papers reconstruct the palaeoenvironments of the Early Triassic Chaohu Fauna and Middle Triassic Luoping Biota. Two further papers present new marine \u03b413C records and biomarker data and link them to volcanic eruptions in Early Triassic times. These new findings are important for understanding the co-evolution between biotic and environmental changes in the aftermath of Permian-Triassic boundary mass extinction.", "keyphrases": ["mass extinction", "recovery", "triassic", "south china", "ocean anoxia", "volcanisms"]}
{"id": "ZHANG2024111896", "title": "Evolution of sedimentary environment in the Eastern Henan Basin since the Late Pliocene", "abstract": "The Eastern Henan Basin is situated within the downstream alluvial plain of the Yellow River, harboring an impressive accumulation of over 500 m of fluviolacustrine strata since the Pliocene. However, the evolutionary characteristics and driving factors of the sedimentary environment in this region remain unclear due to a lack of reliable chronological constraints on the sedimentary sequence. Here, two cores were retrieved from Hangkonggang (HKG, 303.5 m) and Baisha (BS, 320.2 m) in the Eastern Henan Basin for comprehensive analyses of chronology and sedimentology. A combination of paleomagnetism, electron spin resonance (ESR), and optically stimulated luminescence (OSL) dating results indicates that sediments of two boreholes were accumulated spanning the last \u223c3.48 Ma. Grain size distributions (GSDs) of typical sedimentary facies show that the boreholes predominantly encompass three types of sedimentary facies: riverbed, levee, and floodplain. Downcore variations of mean grain size (MGS) reveal that the sedimentary environment in this basin evolved from a dominant riverbed setting during the late Pliocene (3.48\u20132.72 Ma) to alternations between the floodplain and levee facies during the early Pleistocene (2.72\u20131.25 Ma) and subsequently between the riverbed, levee, and floodplain after 1.25 Ma. It was closely associated with the decrease in East Asian monsoon precipitation at \u223c2.72 Ma and the increase at 1.25 Ma. Notably, the abrupt coarsening of MGS after \u223c1.25 Ma was synchronized with the formation of the Sanmenxia terraces, implying the significant influence of the evolution of the Yellow River. Our results suggest that the sedimentary environment of the Eastern Henan Basin was predominantly affected by the stepwise evolution of the East Asian monsoon since \u223c3.48 Ma and complementary landform transformation of the Yellow River since at least \u223c1.25 Ma.", "keyphrases": ["plio-pleistocene", "fluvial deposits", "grain size", "sedimentary environment", "east asian monsoon", "magnetic stratigraphy"]}
{"id": "PARK2024111878", "title": "Re-Os geochronology of the Middle to Upper Jurassic marine black shales in the Agardhfjellet Formation, Central Spitsbergen, Svalbard: A cornerstone for global faunal correlation and Os isotopic change", "abstract": "Ammonite provincialism makes it difficult to link the Boreal and Tethyan realms during the Late Jurassic to Early Cretaceous time. Absolute ages through radiometric dating offer new age information that is independent and complementary to relative ages based on biostratigraphy. In this study, we report seven new Re-Os ages for black shales from the Agardhfjellet Formation, Svalbard. We also report pyrolysis results, carbon and sulfur stable isotopic data, and initial 187Os/188Os ratios to evaluate the paleoenvironment during organic-rich shale deposition. Re-Os ages are derived from three Boreal ammonite zones: (1) 159.2 and 160.1 Ma from the shale intervals containing Cadoceras sp.; (2) 149.6, 149.9, 150.8, and 151.9 Ma from the Rasenia cymodoce Zone in the Early Kimmeridgian, which is the equivalent of the Sutneria platynota and Ataxioceras hypselocyclum zones in the Tethyan realm; (3) 146.8 Ma from an upper Volgian interval above the occurrence of Laugeites sp.. Within this 14.5 Myr interval, the initial Os profile shows a gradually increasing trend from 0.335 (one of the lowest shale values throughout the Phanerozoic) to 0.529, consistent with previous initial Os studies and Sr isotopic ratio chemostratigraphic studies. The trend of increasing initial Os ratios indicates an increase in continental runoff relative to unradiogenic Os input from mantle sources, such as seafloor hydrothermal activity or ultramafic source rocks. We provide new Re-Os geochronological anchors in the Late Jurassic with new Re-Os ages and propose correlations of specific Late Jurassic ammonite zones between the Tethyan and Boreal realms. In turn, the gradual increase in seawater Os isotopic ratios may signal climate change in the Late Jurassic, indicating the increase of radiogenic Os or decrease of unradiogenic Os, induced by high continental runoff or less hydrothermal/volcanic activity.", "keyphrases": ["black shale", "late jurassic", "agardhfjellet formation", "re-os ages", "initial os/os ratio"]}
{"id": "ZHANG2024111880", "title": "Significance of site-specific factors to peat accumulation indicated by differences in Holocene histories of dust delivery and peat deposition at two neighboring locations in the Altai Mountains, northwestern China", "abstract": "Peatlands can archive exceptional paleoenvironmental histories of dust delivery because of their uninterrupted and elevated accumulation rates, yet long-term records of dust deposition and its effect on peat accumulation are rare in the arid and semiarid Asian regions that can be major dust sources. We present here high-resolution Holocene peat accumulation and paleodust records from the Tielishahan (TLSH) and Halashazi (HLSZ) peatlands in the Altai Mountains of northwestern China. We find that although the two peatlands share common histories of external climate forcing and dust delivery, they have significantly different long-term rates of peat accumulations. Peat deposition initiated \u00a02 kyr earlier in the HLSZ peatland than in the TLSH peatland, exhibiting higher peat accumulation rates and greater mineral dust fluxes during the early Holocene, but it has constantly smaller values from the mid-Holocene to the present. The TLSH peatland has a higher peat accumulation rate and mineral dust flux during the early Holocene, lower values during the mid-Holocene, and increasing values during the latest Holocene. The elemental proxies in the two peat cores indicate that atmospheric deposition is the major factor in controlling delivery of mineral elements in HLSZ peatland, whereas elemental delivery in the TLSH peat record is affected by both the regional atmospheric dust flux and the water table under this sequence. We also find that peat accumulation is closely related to mineral dust deposition, as most Asian locations generally share similar patterns in long-term peat accumulation and dust deposition. We postulate that increased aridity in the dust sources of arid central Asia and stronger westerly winds induced by negative NAO variations are key drivers on greater dust deliveries. We further postulate that local factors, such as site-specific differences in permafrost thawing, the areas of the peatlands, and their hydrology are the main reasons for the asynchronous Holocene histories of these two neighboring peatlands. These local factors should be considered when interpreting long-term paleoclimate records from rates of peat accumulation and paleodust delivery.", "keyphrases": ["peatlands", "peat accumulation", "dust deposition", "holocene", "the altai mountains of northwest china"]}
{"id": "YU2024111895", "title": "Holocene geomorphological evolution of a sediment-starved coastal embayment in response to sea level change: Insights from the Qing'ao Embayment, southern China", "abstract": "Aiming to gain a better understanding of the response of sediment-starved coastal systems to the climate-driven sea level change, this study examines the Holocene evolution history of Qing'ao Embayment, southern China, as a case study. Results suggest three distinct stages of the evolution history: Stage 1 (8400\u20136000 cal yr BP) records an initial sedimentation phase associated with the early Holocene marine transgression into the embayment. Stage 2 (6000\u20133000 cal yr BP) records early sediment deposition under relatively strong hydrodynamic inshore/open-bay environment during early marine regression. Stage 3 (3000 cal yr BP to present) records two substages: Stage 3a relates to the semi-enclosed bay, intertidal and lagoonal salt marsh facies between 3000 and 1300 cal yr BP, and Stage 3b records the final infilling of the embayment into a lagoonal plain. This evolution model suggests that the rates of sea level change and sediment accretion are the two major controlling factors for the Holocene geomorphological evolution of sediment-starving coastal systems. Comparison of the evolution of Qing'ao embayment with sediment-supply rich large-river estuary/deltas reveals unique features in the response to Holocene sea level change of this sediment-starved embayment: During the early Holocene marine transgression, sediment starts to accumulate in the small embayment around 8400 cal yr BP, hundreds of years later than in large river estuaries. During 8400\u20136000 cal yr BP, sediment accretion rate remains dramatically lower than sea level rise rate, which results in the quick growth of sediment accommodation space during this stage. Around 6000 cal yr BP, though sea level has remained relatively stable and large-river deltas have been growing for about 1000 years, the sediment-starved embayment was still under shallow marine and/or open bay conditions. At 3000 cal yr BP, shoreline started to prograde in sediment-starved embayment, which is about 3000 years later than large river deltas. Finally, agricultural activity started around 1300 cal yr BP in the embayment, thousands of years later than large river deltas. Limited or minimal fluvial sediment supply to the small embayment has constrained the land expansion during the sea level stabilization since mid-Holocene, and the limited living space might result in the much later agricultural activity in such coastal system. Due to the different balances between sea level change and sediment flux, sediment-starved coasts are expected to be under higher risks than large river deltas. However, earlier and more extensive human activities in large river basins have resulted in the reduction of sediment discharge that heighten the risks of large river deltas against future sea level rise. Thus, more attention should be paid to the coastal sediment supply budgets in the context of the background of rising sea level.", "keyphrases": ["sediment-starved coastal embayment", "sedimentary environment", "sea level change", "holocene", "sediment supply"]}
{"id": "TIAN2024111901", "title": "Back-reef and lagoonal communities, Givetian (Middle Devonian) in Guangdong, South China: Their role in global Devonian reef development", "abstract": "Back-reef and lagoonal communities played an important role in the construction of global reef ecosystems and shallow water carbonate factories during the Devonian Period, but their reef-building significance is not fully understood. This study describes a previously undocumented Givetian stromatoporoid biostromal sequence, 12 m thick and comprising 7 biostromes, in the Tangjiawan Formation of Yaozhai, Guangdong Province, Southeast China. Large bulbous or columnar stromatoporoid Actinostroma and delicate dendroid stromatoporoid Amphipora are abundant, with a comparatively smaller presence of tabulate corals, rugose corals, brachiopods, gastropods, calcimicrobes, and tubeworms. The dominant Actinostroma-Amphipora assemblage, together with leperditicopid ostracods, parathuramminid foraminifers, and calcispheres, indicates a shallow, low-energy back-reef to lagoonal setting. Taphonomic analysis shows a common occurrence of overturned skeletons, and the deposit is interpreted as a parabiostrome constructed in a low-energy environment and affected by episodic high-energy events. Statistical data of similar global assemblages from the Lochkovian to the Famennian based on 153 localities show a relatively rare occurrence of back-reef and lagoonal communities from the Lochkovian to the Eifelian, peaking during the Givetian and Frasnian together with metazoan reefs then declining sharply in the Famennian after the Kellwasser Event. Although autobiostromes have rarely been documented, the densely packed reworked bulbous/domical and dendroid stromatoporoids justify the existence of low-diversity but highly abundant metazoan ecosystems in back-reef to lagoonal settings. This study thus highlights our understanding of the back-reef and lagoonal facies and the important role they played in the expansion of large-scale carbonate factories and reef ecosystems during the Middle to Late Devonian.", "keyphrases": ["stromatoporoids", "biostromes", "back-reef to lagoon", "devonian", "reef expansion"]}
{"id": "FOURNIER2024111883", "title": "Eocene-Oligocene large-scale circulation of the East Asian summer monsoon recorded in neritic carbonates of the proto-South China Sea", "abstract": "When the modern features of large-scale Asian monsoonal circulation were set-up is poorly constrained and pre-Neogene monsoonal archives are rare. This study investigates the temporal evolution of neritic carbonates in the proto-South China Sea to reconstruct East Asian monsoonal currents and winds during the middle to late Paleogene. Analysis of three-dimensional seismic and well core data from the North-West Palawan block reveals the occurrence of a set of thick (>125 m), aggrading Halimeda bioherms, early Oligocene in age. By analogy with Holocene green algal buildup counterparts, they are interpreted to form in nutrient-rich areas subject to upwelling currents and reflect the early presence of a strong coastal jet in the Proto-South China Sea, as seen today during the summer monsoonal season. The analysis of the underlying mixed carbonate\u2013siliciclastic ramp shows that mesotrophic conditions already prevailed during the late Eocene, thus suggesting that modern-like summer East Asian Monsoon large-scale circulation was possibly active as early as the late Eocene in the Proto-South China Sea. Evidence for upwelling currents vanishes in late early Oligocene carbonate-producing biota, that are characterized by the significant development of euphotic hermatypic coral communities reflecting lower nutrient concentrations. This turnover coincides with the opening of the modern South China Sea and is interpreted to result from the southward drift of the North-West Palawan block which placed the area away from the Chinese margin and the coastal jet. Our results highlight therefore that many of the features of the summer East Asian Monsoon large-scale circulation are rooted in the middle Paleogene.", "keyphrases": ["monsoon", "carbonates", "paleogene", "southeast asia", "coastal jet"]}
{"id": "BALESTRIERI2024111885", "title": "Recurrent E - W oscillations of the ice flow confluence of the East and West Antarctic ice sheets in the central Ross Sea, Antarctica, from the Middle Miocene to the present day", "abstract": "We present a multidisciplinary provenance study on legacy cores drilled in the 1970s during DSDP Leg 28 at sites 271 and 272, in the central Ross Sea, Antarctica. The two sites combined provide a discontinuous glaciomarine sedimentary record covering 18 myr, from the Middle Miocene to the present day. The two boreholes are located on the continental shelf and near the edge of the Ross Ice Shelf, in the middle of the Ross Sea, at a key site close at 180\u00b0 longitude that is considered to represent the present confluence between ice flows fed by West Antarctica and East Antarctica. The study employs UPb dating of detrital zircons and apatites, coupled with apatite fission-track dating and trace element and REE compositions. Based on the sedimentary provenance, our data show a recurrent E-W oscillation of the confluence of the West Antarctica and East Antarctica ice flows, allowing phases of advance and retreat of the West Antarctic Ice Sheet to be inferred.", "keyphrases": ["provenance study", "apatite and zircon upb dating", "antarctica", "middle miocene-quaternary glaciomarine sediments", "ice-sheet flows", "dsdp site 271", "site 272"]}
{"id": "TIAN2024111944", "title": "Basin-scale reconstruction of late Pleistocene-Holocene fluvial landform evolution and its mechanisms in transitional areas between Taihang Mountain and North China Plain", "abstract": "The processes and mechanisms of fluvial landform evolution, especially in the transitional zones between mountains and plains, are of great significance for predicting future regional sustainability and ecosystem stability in the basin. As a region of significant cultural and ecological importance, the transitional area between Taihang Mountain and North China Plain still has a limited understanding of the fluvial landform evolution. With detailed field surveys and 39 optically stimulated luminescence (OSL) ages of 14 sections, we reconstruct fluvial landform evolution in the southern piedmont of the Taihang Mountain since the late Pleistocene. The results show that two major fluvial processes occurred during 18\u201310 ka BP and 9\u20133 ka BP. Meanwhile, the late Pleistocene-Holocene can be divided into 5 intervals in the alluvial fan and floodplain areas, with corresponding ages of 3 ka BP, 9\u20133 ka BP, 10\u20139 ka BP, 18\u201310 ka BP, and before 20 ka BP, respectively. The results also indicate that the regional fluvial processes primarily result from climate change and tectonic activities, and secondarily result from sea level fluctuation. Additionally, the prehistoric settlement pattern was also shaped by the evolution of regional rivers. Our research is significant for understanding the evolution and mechanisms of fluvial landforms in transitional zones.", "keyphrases": ["taihang mountain", "fluvial landform evolution", "holocene", "transitional zones between mountains and plains", "climate change", "sea level change"]}
{"id": "KNAUST2024111913", "title": "The trace fossil Thalassinoides paradoxicus Kennedy, 1967 revisited from its type locality (Albian-Cenomanian chalk, SE England)", "abstract": "The trace fossil Thalassinoides includes ichnospecies that have been recognised for a long time and widely used in the interpretation of depositional systems. Despite its broad occurrence, the ichnotaxonomic status of this important ichnogenus is far from being unmistakable, which in turn hampers its application in palaeoenvironmental reconstructions. One of the most common ichnospecies is Thalassinoides paradoxicus, originally described from the Paradoxica Bed of the Lower Chalk in the Hunstanton Cliff in SE England. To demarcate this characteristic form from similar ichnospecies, T. paradoxicus is reexamined and described from its type locality. It is characterised by an \u2018irregular, very extensive horizontal burrow network, occurring at several levels, connected by vertical shafts\u2019 (Kennedy), but its morphological variability also includes a range of significant architectural elements as well as burrow portions with a laminated wall, scratches and pellets. A series of colonisation events along omission surfaces can be reconstructed based on the occurrence of several burrow generations. T. paradoxicus is an important constituent of shallow-marine environments and subtle variations in morphology may help to constrain facies interpretations. Based on modern analogues and finds of body fossils within their burrows, decapod crustaceans (foremost callianassid shrimp) are known producers of T. paradoxicus from the Mesozoic onwards, whereas older records can be attributed to other malacostracans but also trilobites.", "keyphrases": ["cretaceous", "chalk", "burrow", "ichnotaxonomy", "decapoda", "callianassidae", "mud shrimp"]}
{"id": "WU2024111912", "title": "Quaternary evolution of the Meiji Atoll (Mischief Reef) in the southern South China Sea", "abstract": "This paper describes the Quaternary evolution of Meiji Atoll (also known as Mischief Reef) in the southern South China Sea. Findings are based on a sedimentological and paleontological investigation of the uppermost 150 m of core NK-1. Through the Quaternary, open-lagoon sediments initially developed from ca. 2.6 to 1.6 Ma, which were succeeded by backreef sediments from 1.6 to 1.1 Ma, and subsequently by reef-flat sediments from 1.1 Ma to present, as the atoll evolved. The deepest depositional environments occurred between 2.0 and 1.6 Ma as a result of significant rates of subsidence in the Dangerous Grounds area. Coral abundance steadily increased during the Quaternary due to the secular eustatic sea-level drop and continuous high temperatures in the southern South China Sea. After the start of the Mid-Pleistocene Transition from 1.25 Ma, there was an increase in the amplification of short-eccentricity glacio-eustatic cycles, which resulted in two impacts. First, more frequent exposure horizons developed over the atoll due to an increase in amplitude of short-term sea-level fall events. Second, the occurrence of the thickest coral framestone units developed at around 0.8 Ma, perhaps linked to prominent short-term sea-level highstands (i.e., 125-ka cycle) and moderate subsidence rates. In summary, we document the Quaternary evolution of the Meiji Atoll, and show how variations in sea surface temperature, eustatic sea level, and tectonics have influenced its development. These findings have broader implications for understanding the Quaternary evolution of similar tropical carbonate atolls in the region.", "keyphrases": ["carbonate sediments", "coral reef", "quaternary", "meiji atoll", "south china sea"]}
{"id": "PINERO2024111935", "title": "Multiproxy approach to reconstruct the climate and environment of a new late Middle Pleistocene vertebrate site in northwestern Italy", "abstract": "The Moleto site (Ottiglio, AL, Piemonte, Italy) was discovered in the 1990s in an abandoned quarry carved into a Burdigalian\u2013Langhian carbonate succession called Pietra da Cantoni. Sediment collection in three closely spaced fissures provided a rich vertebrate association whose age can be constrained to the late Middle Pleistocene on the basis of the presence of the extinct water vole Arvicola mosbachensis and its enamel characteristics (SDQ values ranging from 100 to 130). The very similar faunal content, evidenced by the common presence of Arvicola mosbachensis and its similar SDQ values, is indicative of a coeval deposition of the fillings of the three fissures. The vertebrate assemblage is represented by 30 taxa, including amphibians, squamate reptiles, birds, and mammals. Interestingly, a diverse fish assemblage from the embedded sediments of the Miocene Pietra da Cantoni has been found in the fissure fillings. We present here a multi-method approach using the small vertebrate assemblages (rodents, insectivores, amphibians, and squamate reptiles) from Moleto to characterize the environment and climate of the site. In order to reconstruct the palaeoenvironmental and palaeoclimatic conditions, we applied the Mutual Ecogeographic Range using UDA-ODA technique, the Bioclimatic Model, the Habitat Weightings, and the Quantified Ecology methods. The results revealed a landscape dominated by woodland habitats with presence of open humid meadows, under temperate and moist climatic conditions, although somewhat colder and drier than today. According to all evidence, the associations from Moleto would correspond to the interglacial MIS 7.", "keyphrases": ["vertebrate assemblage", "mutual ecogeographic range", "bioclimatic model", "quantified ecology", "habitat weightings", "marine isotope stage 7"]}
{"id": "MATEOS2024111926", "title": "Sabretooths, giant hyenas, and hominins: Shifts in the niche of Early Pleistocene scavengers in Iberia at the Epivillafranchian-Galerian transition", "abstract": "The Epivillafranchian and the transition to the Galerian (1.2\u20130.9 Ma) was a period marked by environmental fluctuations and faunal turnover. Homo arrived into Europe around 1.4 Ma. ago, and was established in Iberia during the Epivillafranchian, as evidenced by the oldest sites with hominin fossils located in the Iberian Peninsula. The Iberian ecosystems offered a variety of trophic resources to hominins, including the opportunity to scavenge carcasses of large ungulates killed by a diverse predatory guild, especially due to the presence of two sabre-toothed cats. It has been claimed that the presence of Pachycrocuta brevirostris, a strong competitor for carrion, prevented hominins from exploiting abandoned carcasses as a reliable meat and fat resource. However, computer simulation experiments suggest that the coexistence of P. brevirostris and hominins competing for carrion was ecologically viable in the Epivillafranchian. Nevertheless, the faunal turnover of the Epivillafranchian-Galerian transition drastically changed the composition of the large carnivore fauna. The changes include the extinction of the sabre-toothed felid Megantereon, frequently considered a key provider of partially consumed carcasses, and the demise of the hyperscavenger P. brevirostris. All these changes modified the ecological scenario and the opportunities for hominins and other facultative scavengers. Computer simulation experiments using the agent-based model SCAVCOMP-ABM are used here to evaluate the viability of the coexistence of hominins and giant hyenas in the Epivillafranchian-Galerian transition. Different ecological scenarios defined by the composition of the predatory guild, ecosystem productivity, and competition pressure from other scavengers are evaluated. Results suggest that hominins and giant hyenas could coexist during the Epivillafranchian with different carnivore guilds, but a disruption of the scavenging niche likely occurred in the transition to the Galerian, coinciding with the extinction of P. brevirostris. A low ecosystem productivity during the cold intervals, maintenance of a high competition for carrion with other facultative scavengers, and a hypothetical social behaviour of the sabre-toothed cat Homotherium latidens appear as key factors to explain the changes in the scavenger guild at the Epivillafranchian-Galerian transition.", "keyphrases": ["pleistocene", "palaeoecology", "western europe", "computer simulation", "trophic ecology"]}
{"id": "ROTHNEBELSICK2024111932", "title": "Diversity of leaf architecture and its relationships with climate in extant and fossil plants", "abstract": "In this contribution, the diversity of functional leaf architecture and its association with climate is studied for extant woody dicot species of North America and Europe/South West Asia. The results are compared to fossil leaves of seventeen locations in Central Europe ranging from the Paleogene to Neogene. Four functional leaf traits, lobation, margin, type of primary and secondary venation, were selected as defining sixteen basic functional architectures (Trait Combination Types, TCT). Diversity of leaf architecture was studied as Shannon diversity (meaning frequency and evenness of TCT occurrence) as realized by site-specific species composition. The extant data indicate significant positive correlations of Shannon diversity of leaf architecture with temperature particularly for North America. After having reached a peak at about 18 \u00b0C MAT, functional diversity of leaf architecture then declines in North America with rising MAT. This decline occurs mostly for drier sites, probably because humidity becomes more influential at higher MAT, with low water availability driving selective pressure towards adaptive convergence. The data indicate that warm environments are able to accommodate a higher variety of leaf types than colder environments, unless water supply is scarce. The fossil data essentially agree with the recent data, with the exception of sites harbouring fossil leaves preserved in marine sediments. Here, the diversity of leaf architecture is lower which is probably due to taphonomic bias. Highest leaf architecture diversity was found for the Pliocene sites, although no distinct relationship with stratigraphic age could be identified. The results of this study indicate that diversity of leaf architecture may be a useful source of information for palaeoecology and palaeoclimate and merits further study.", "keyphrases": ["functional diversity", "shannon diversity", "functional traits", "leaf venation", "leaf margin", "leaf lobation"]}
{"id": "ZHANG2024111958", "title": "Natural and anthropogenic forcing on the fate of sedimentary organic matter in the South Yellow Sea during the Holocene", "abstract": "Long-term organic matter (OM) burial in the ocean is essential to the global carbon cycle. Mud deposits, such as South Yellow Sea mud deposit (SYSMD) located in the central South Yellow Sea (SYS), are ideal for the study of long-term OM burial. A sediment core YS-A from the SYSMD was analyzed for lignin phenols and bulk OM properties to reveal the driving forces of sedimentary OM (SOM) fate during the Holocene. SOM burial was found to be dominantly influenced by sea level rise and increased East Asian summer monsoon during 11.0\u20137.0 ka BP. During 7.0\u20131.0 ka BP, the fate of SOM was controlled by El Ni\u00f1o Southern Oscillation on the millennial time scale, and correlated with East Asian winter monsoon variability on the centennial time scale. Remarkably, anthropogenic perturbation has gradually overwhelmed long-term climate control on the fate of SOM since 1.0 ka BP, and this phenomenon became more evident after 0.4 ka BP.", "keyphrases": ["sedimentary organic matter", "south yellow sea", "holocene", "climate change", "human activities"]}
{"id": "DUXBURY2024111928", "title": "Holocene climate and catchment change inferred from the geochemistry of Lashmars Lagoon, Kangaroo Island (Karti/Karta), southern Australia", "abstract": "We present a continuous \u223c7000-year sedimentary record from Lashmars Lagoon, Kangaroo Island (Karti/Karta), southern Australia, a region heavily impacted by drought and bushfires in recent decades. Records such as this are vital to contextualise current climatic and environmental shifts, particularly regarding the interplay between hydroclimate and fire-related disturbances in this ecologically sensitive area. We use high-resolution \u03bcX-ray fluorescence core scanning, complemented by bulk organic geochemistry and X-ray diffraction mineralogy of catchment soil and lake sediments to reconstruct past climate and catchment processes. Phases of elevated sediment organic matter content (inferred from high Br and total organic carbon) suggest increased lake freshening and productivity, and coincide with increased chemical weathering (inferred from high Al/K and kaolinite/illite and feldspars), likely reflecting the influence of wetter climates. Conversely, periods of high Ca correlate with biogenic carbonate inputs typical of brackish conditions, which we attribute to drier climates or a marine influence. From 7.0 ka, at the mid-Holocene sea level highstand, until 5.7 ka, we suspect Lashmars Lagoon was under virtually continuous influence from the sea. At 5.7 ka, we interpret the abrupt increase in sediment total organic carbon to reflect the severance of the connection to the sea, allowing organic material to accumulate. This, coupled with evidence of high inferred chemical weathering, suggests the climate was relatively wet at the time. After 5.4 ka, our data point to the establishment of drier conditions until the commencement of wetter climates again at 4.5 ka. From 2.5 ka, however, drier climates prevailed again until present. Notably, the climate changes recorded in the sedimentary sequence at Lashmars Lagoon seem to be linked to the strength of the Leeuwin Current, a current that brings warm tropical waters to southern Australia and demonstrates a teleconnection with the El Ni\u00f1o Southern Oscillation, and may well have been an important driver of rainfall on Kangaroo Island (Karti/Karta) over the past \u223c7000 years.", "keyphrases": ["lake sediment", "itrax", "x-ray diffraction (xrd)", "x-ray fluorescence (xrf)", "weathering", "hydroclimate"]}
{"id": "DING2024111947", "title": "Reconstruction of the topographic evolution of the Nanling Range in South China and its implications for the East Asian Monsoon evolution", "abstract": "The East Asian monsoon is the largest periodic airflow on Earth and significantly affects the climate of East Asia. However, considerable controversy exists about the onset timing of the East Asian monsoon. As one of the southern barriers blocking the northward movement of the warm and humid airflow, the Nanling Range has likely recorded key topographic information related to the East Asian monsoon onset and development. We used apatite and zircon (UTh)/He data obtained from the Shaoguan\u2013Guidong horizontal cross-section to reconstruct the two-dimensional (2-D) paleotopography of the Nanling Range on a long-term scale. Four vertical profiles in Shulouqiu, Erjian, Sanfenshi, and Leiwangdian were used to constrain the exhumation history of the Nanling Range. The result revealed the following: 1) The drainage divide began to move from south to north at 80 Ma. At 80 Ma, the south segment of the cross-section reached a peak elevation of \u223c3.6 km. The asymmetric topography experienced a rapid elevation (and relief) decrease from 80 Ma to 40\u201330 Ma. The four vertical profiles also experienced increased cooling and high exhumation rates from 100 Ma to 40\u201330 Ma. 2) The south segment experienced more rapid exhumation than the north segment from 80 Ma to 40\u201330 Ma. The rapid exhumation of the south segment during the Late Cretaceous\u2013Paleocene is probably related to the activity of the Nanxiong Fault, and the rapid exhumation of the south segment during the Eocene probably results from the onset of the East Asian Monsoon.", "keyphrases": ["low-temperature thermal history", "topographic evolution", "(uth)/he dating", "nanling range", "south china"]}
{"id": "MONEDEROCONTRERAS2024111953", "title": "Redox geochemical signatures in Mediterranean sapropels: Implications to constrain deoxygenation dynamics in deep-marine settings", "abstract": "Global warming and anthropogenic activity are boosting marine deoxygenation in many regions around the globe. Deoxygenation is a critical ocean stressor with profound implications for marine ecosystems and biogeochemical cycles. Understanding the dynamics and evolution of past deoxygenation events can enhance our knowledge of present-day and future impacts of climate change and anthropogenic pressure on marine environments. Many studies have reconstructed the evolution redox conditions of past deoxygenation events using geochemical proxies. In this regard, the present work focuses on understanding the paleoenvironmental significance of geochemical redox signals derived from the onset, evolution and termination of regional-scale deoxygenations in deep-marine settings, with a specific focus on sapropels in the Eastern Mediterranean (EM). Sapropels, rhythmic organic-rich sediments deposited in EM, offer a unique opportunity to investigate recent deoxygenation events linked to past climate changes. Sapropels serve as paleo-archives of past deoxygenation events and can provide insights into the potential impacts of ongoing climate change on marine ecosystems and biogeochemical cycles. By integrating previous sapropel geochemical studies with a detailed analysis of new geochemical data from five Quaternary sapropels (S1, S5, S6, S7 and S8) in three different EM deep-marine settings, this study enhances our understanding of the paleoenvironmental significance of geochemical redox signals produced by deoxygenation dynamics and postdepositional processes in different deep-marine settings. The study supports that certain trace elements, such as Mo, V, U, Co, and Ni, are identified as more reliable redox proxies compared to Cr, Cu, Pb, and Zn. Four recurrent geochemical intervals attributed to specific redox conditions and postdepositional processes have been identified. Moreover, internal calibration of redox proxies thresholds has been performed and demonstrates how local environmental conditions (e.g., productivity rate) and hydrogeographic features (e.g., water-depth, particulate-shuttling intensity, deep-water renewal and fluvial input) play crucial roles in controlling the authigenic uptake rates of redox-sensitive trace metals, and subsequently, redox thresholds values of geochemical redox proxies. The results also emphasize the importance of postdepositional processes to accurately interpret geochemical signals in paleoenvironmental studies. This research enhances our overall understanding of geochemical signals associated with regional-scale deoxygenation events in deep-marine settings, offering new insights into predicting biogeochemical changes in marine environments undergoing a transition towards anoxia. By comprehending the dynamics of past and present deoxygenation, we acquire valuable knowledge regarding the potential effects of climate variability in marine ecosystems.", "keyphrases": ["mediterranean", "sapropel", "deoxygenation", "paleoredox", "trace metal", "inorganic geochemistry"]}
{"id": "NGUYEN2024111925", "title": "Monsoon influence on plant diversity in northern Indochina: Evidence from the late Miocene Yen Bai flora, northern Vietnam", "abstract": "Indochina, as a global biodiversity hotspot, offers the potential for understanding the evolution of biodiversity. However, the historical narrative of plant diversity in this region remains enigmatic due to limited fossil records. Here, we report a newly discovered megafossil flora from the late Miocene of the Yen Bai Basin, northern Vietnam. This megafossil flora suggests that the late Miocene vegetation in northern Vietnam comprised mixed tropical evergreen and deciduous broadleaved forest components mainly characterized by Fabaceae, Fagaceae, and Lauraceae bearing strong resemblance to the modern vegetation in northern Vietnam. Paleoclimate reconstruction for this plant fossil assemblage using the Coexistence Approach indicates a mean annual temperature (MAT) of 18.5\u201323.0 \u00b0C and a mean annual precipitation (MAP) of 1183.1\u20132078.5 mm. Similarly, employing the Climate-Leaf Analysis Multivariate Program yields an MAT of 21.3 \u00b1 2.3 \u00b0C and a growing season precipitation (GSP) of 1328.6 \u00b1 606.0 mm. The length of the growing season was about eleven months. Overall these results indicate a modern-like warm and humid tropical monsoon climate in northern Vietnam during the late Miocene. Climatic comparison of the Yen Bai with other fossil floras in northern Vietnam and southern China reveals the relative stability of temperature seasonality since the middle Eocene but obvious long-term variation in precipitation seasonality, particularly in respect of precipitation during the three consecutive driest months (X3.DRY). This suggests the Asian monsoon in northern Vietnam underwent important changes from the middle Eocene to the late Miocene, and intensified significantly during the middle and late Miocene. Our results show the modernization of plant diversity in northern Indochina had its origin in the Paleogene and further developed in the late Miocene, and was linked to the evolution of the Asian monsoon mainly in terms of changes in dry season precipitation.", "keyphrases": ["asian monsoon", "indochina", "neogene", "paleoclimate", "red river fault zone", "yen bai basin"]}
{"id": "HALL2024111927", "title": "Intensive chemical weathering in the Arctic during the Miocene Climatic Optimum", "abstract": "The Arctic today has shallow, chemically immature, and frost-dominated weathering regimes. At Sokli, Finland (68\u00b0N), a 70 m deep palaeo-weathering profile is developed in a Devonian carbonatite pipe that represents fundamentally different past weathering environments. Formation of the apatite-francolite P-ore likely began under Palaeogene warm, humid climates. Later, cryptomelane (K-Mn oxide) crusts developed within the ore that have yielded peak 40Ar/39Ar ages of 16.20 \u00b1 0.13 Ma (2\u03c3)., The crusts formed at the redox front during the Miocene Climatic Optimum (\u223c16.9\u201314.7 Ma) under mean annual temperatures \u223c12\u201314 \u00b0C warmer than today. The presence of the cryptomelane crust at shallow depth (15 m) indicates very low erosion rates since formation, consistent with its position on a tectonically stable Archaean craton and in the cold-based ice-divide zone of successive Fennoscandian ice sheets. The Miocene Climatic Optimum triggered a pulse of intensive weathering in mid- and low latitudes; the Sokli cryptomelane ages demonstrate that intensive chemical weathering extended into the Arctic.", "keyphrases": ["miocene climatic optimum", "weathering", "arctic", "cryptomelane", "climate change"]}
{"id": "BASSI2024111916", "title": "Porcelaneous larger foraminiferal responses to Oligocene\u2013Miocene global changes", "abstract": "Sea surface temperatures (SST) have been identified as a main controlling factor on larger benthic foraminifera (LBF) living in tropical to sub-tropical shallow-water carbonate and mixed siliciclastic\u2011carbonate platforms. Changes in SST, along with those in ocean acidification and nutrient content recorded in the global oceans throughout their history will not only continue but also be amplified in the future at an unprecedented rate of change possibly reaching levels found in the geological record. This study focuses on the Oligocene (mean SST 8 \u00b0C higher than present) and the Miocene (SST 5\u20138 \u00b0C higher than present) epochs which were characterized by a higher richness in porcelaneous LBF (pLBF) than today. A systematic re-assessment and comprehensive literature survey of stratigraphic ranges and palaeogeographic distribution in the Western Tethyan (Mediterranean) and Indo-Pacific regions are used to evaluate the impact of changes in SST, seawater pCO2 and pH on the biodiversity of the Oligocene\u2013Miocene pLBF Alveolinella, Austrotrillina, Borelis, Bullalveolina, Flosculinella, and Praebullalveolina. Two peaks in species richness were identified during the Aquitanian and Langhian\u2013Serravallian. These peaks occurred when SST was \u223c29 \u00b0C, with pCO2 of \u223c400 ppm and pH > 7.8. These values are comparable to those of today. The minima in species richness recorded in the Rupelian\u2013early Chattian, in the Burdigalian and from the Tortonian onward can be correlated to the detrimental effects of both minimum (< 26 \u00b0C) and maximum (> 31 \u00b0C) SST thresholds. High pCO2 (> 600 ppm) values, which are limited to the Rupelian\u2013early Chattian, are also detrimental to species richness. Seawater pH higher than 7.7 did not negatively affect species richness. These historical trends have serious implications for the future diversity of pLBFs with the increasing likely scenario of rising SST and pCO2 and lowering of pH values in the near future. These developments can potentially lead to diversity decrease and even extinction of pLBFs. However, the resilience of present-day pLBF species to rising SST and pCO2 levels is underpinned by the evolutionary histories of their fossil counterparts during climate variations, albeit at much different rates of change.", "keyphrases": ["oligocene\u2013miocene", "larger foraminifera", "western tethys", "mediterranean", "indo-pacific", "ocean acidification", "marine biodiversity"]}
{"id": "SANZPEREZ2024111917", "title": "Paleoenvironment and paleoecology associated with the early phases of the Great American Biotic Interchange based on stable isotope analysis of fossil mammals and new U\u2013Pb ages from the Pampas of Argentina", "abstract": "The analysis of stable isotopes in fossil mammals is useful for reconstructing paleoenvironmental and paleoecological conditions, but has been rarely applied to the Neogene of South America. In this study, we perform an integrative analysis (including U\u2013Pb zircon dates and mammalian stable isotopes data) for the Late Miocene\u2013Early Pliocene of central Argentina. We provide radioisotopic ages for some classic fossiliferous localities in this region, including an age of 9.7 \u00b1 0.3 Ma for Arroyo Chasic\u00f3 and 4.5 \u00b1 0.2 Ma for Farola Monte Hermoso, and address the interval covering the Chasicoan (Late Miocene), Huayquerian (Late Miocene\u2013Early Pliocene), and Montehermosan (Early Pliocene) stages/ages. In the Chasicoan Stage/Age, taxa with mixed C3\u2013C4 diets are recorded, suggesting the existence of favorable conditions for the C4 photosynthetic pathway before its full expansion. However, taxa represented across most of the Huayquerian Stage/Age show a preference for C3\u2013based diets, which changes in the latest Huayquerian\u2013Montehermosan stages/ages when an increase in the percentage of C4 plants in the diet of notoungulates, rodents, and xenarthrans is recorded, coinciding with the global expansion of C4 plants. For the first time, the dietary behavior of two South American endemic sparassodont metatherians (Lycopsis and Thylacosmilus) has been evaluated from using stable isotope; analysis of these hypercarnivores show differences in \u03b413C values, suggesting prey partitioning, partly due to the difference in body size. The fossiliferous sites studied, and the new isotopic and chronological information obtained, provide more detailed paleoecological and paleoenvironmental contexts for the Argentine Pampas during the last stages of the isolation of South America and the first pulses of the Great Biotic American Interchange. In addition, the new ages allow to better adjust the arrival of the first Holarctic immigrants in the region.", "keyphrases": ["carbon", "oxygen", "radiometric dating", "miocene", "pliocene", "south america"]}
{"id": "ZHANG2024111946", "title": "Contrasting patterns of Last-deglacial and Holocene precipitation between the southern and northern portions of Arid Central Asia", "abstract": "The north-south migration of prevailing westerly system shapes the seasonality of modern precipitation in Arid Central Asia (ACA). The temperate continental climate with warm-season precipitation dominates the northern ACA and the Mediterranean climate with cold-season precipitation dominates the southern ACA. However, the north-south contrasts of precipitation/moisture for longer time scales remain unknown. In this study, we quantitatively reconstructed the precipitation sequence covering the past \u00a014.4 cal. kyr BP based on pollen data obtained from Shayan loess section in southern ACA using MAT (Modern Analogue Technique) method. Our reconstruction shows that the precipitation had an increasing trend from \u00a014.4 to \u00a08.2 cal. kyr BP and a decreasing trend from \u00a08.2 to \u00a01.5 cal. kyr BP with the past 1500 years being characterized by an averagely high precipitation. The precipitation trend in southern ACA was rather different from that in northern ACA where the precipitation has increased more or less constantly since the late deglaciation. The contrast between southern and northern ACA appears to have been associated with the south-north migration of westerlies that was accompanied with alterations of NAO (North Atlantic Oscillation) phases and also with changes in strengths of Siberian High and ENSO (El Nino-southern Oscillation).", "keyphrases": ["loess", "pollen", "modern analogue techniques", "precipitation", "last deglaciation", "arid central asia"]}
{"id": "COLETTI2024111914", "title": "Barnacle-rich facies as a tool for palaeoenvironmental reconstructions", "abstract": "Palaeoenvironmental data are fundamental in determining the manifold impacts of climate change. This paper argues that sessile barnacles are an excellent palaeoenvironmental proxy: they are present in nearly all nearshore environments, and their shell consists of diagenetically stable low-magnesium calcite and grows fast enough to record short-term variations. To demonstrate their utility, specimens from several Western Mediterranean Pliocene and Pleistocene barnacle-rich deposits are analysed herein, using for the first time a combination of sedimentology, taphonomy, stable isotope geochemistry and detailed comparisons with modern counterparts. Within shelf carbonate systems, barnacle diversity is highest in the shallow, nearshore waters and decreases moving offshore, thus providing a good proxy for the reconstruction of water depth and distance from the coastline. Barnacle taphonomy is also informative. Well-preserved complete specimens are characteristic of protected areas, whereas less well-preserved specimens occur in high-energy areas. The presence/absence of opercular plates is also particularly relevant for evaluating hydrodynamic conditions. As regards the C and O stable isotope ratios, due to the porous and coarse-grained nature of the deposits in which barnacle remains are usually found, the shells are often exposed to meteoric water percolation during diagenesis. Among the analysed specimens, only those collected from fine-grained deposits display no evidence of alteration and have isotopic ratios in line with those of their modern counterparts. These fossils display intra-shell variations that in modern barnacles have been related to short-term environmental changes (e.g., seasonal cycles). These results demonstrate that barnacles can always be useful for detailed palaeoenvironmental reconstructions based on skeletal assemblages. Furthermore, with further research aimed at gathering more data and assessing potentially interfering signals, they could become useful proxies for palaeoseasonality.", "keyphrases": ["pliocene", "pleistocene", "stable isotope geochemistry"]}
{"id": "ZHANG2024111931", "title": "Fluctuations of aquatic macrophytes in a shallow lake in eastern China over the last 1800 years: Evidence from n-alkanes", "abstract": "To address the threats of global warming and human activities to freshwater shallow lake ecosystems, it is imperative to comprehend the long-term evolutionary history of lake ecosystems under external forces. However, short-term records are insufficient to distinguish the effects of climate change and human activities. This study applied n-alkanes in a sediment core retrieved from Lake Nvshan in the Huai River basin in eastern China to investigate ecological changes over the past 1800 years. Carbon isotope compositions of long-chain (C27\u201331) n-alkanes revealed that they were mainly derived from floating and submerged plants, which enabled us to monitor the evolution of aquatic macrophytes in lake sediments. Prior to the Little Ice Age, the growth of floating and submerged plants in Lake Nvshan declined steadily, but underwent a significant expansion afterwards. Before \u223c1400 CE, the development of aquatic macrophytes was controlled by the hydrological condition, which regulated nutrient supply from the watershed. After 1700 CE, however, anthropogenic activities became the dominant factor influencing the evolution of lake macrophytes, leading to an increase in erosion and nutrient input, potentially resulting in a shift from submerged plants to a system dominated by floating plants and algae. This research emphasizes the effect of various stressors on the long-term development of lake macrophytes, and provides insight into how freshwater shallow lakes can be safeguarded in the face of global changes.", "keyphrases": ["lake ecosystem", "-alkanes", "macrophytes", "paleolimnology", "compound-specific carbon isotope"]}
{"id": "DU2024111909", "title": "Sedimentary evidence for the diversion of the Yellow River onto the North China Plain 3000\u20132600 years ago", "abstract": "The lower Yellow River is characterized by frequent channel avulsion and flooding during the late Holocene, which not only shaped the geomorphic landscape of the North China Plain, but also modified the preexisting drainage network and affected human settlement pattern. The channel evolution of the lower Yellow River during historical periods of China has been well known from documentary records. However, it is still unclear about the drainage pathway of the river during the archaic period of Chinese history. Here we show sedimentary evidence for a dramatic channel displacement of the lower Yellow River about 3000\u20132600 years ago. Our multi-proxy analyses indicate that the first prehistoric diversion of the Yellow River occurred around 3000 yr B.P. and the river flowed northward into the Bohai Sea through the foreland depression along the eastern foothill of the Taihang Mountains. Frequent floods thereafter not only led to the widespread infilling of depressions in the lower reaches of the Yellow River and thus accelerated the formation of the North China Plain, but also drove humans to migrate from the piedmont area of the Taihang Mountains to the hinterland of the central North China Plain.", "keyphrases": ["yellow river", "channel avulsion", "drainage pattern", "north china plain", "late holocene"]}
{"id": "LYU2024111915", "title": "Upper Triassic (middle Norian) conodont biostratigraphy succession from Qamdo, eastern Tibet", "abstract": "The Late Triassic is a critical period that witnessed major biological and environmental events. The geographic range and taxonomic diversity of conodonts were significantly changed during the Late Triassic, with the geographic range contracting prior to complete extinction of the group near the end of the Triassic. In the present study, we recognize for the first time a continuous middle Norian (Upper Triassic) conodont succession from the Qamdo (Changdu) area, eastern Tibet (Xizang), which was part of the North Qiangtang and Qamdo-Simao Block (NQ-QSB) located in the northeastern Tethys Ocean during the Late Triassic. Four conodont zones are established from the middle Norian (Alaunian) of the Chaiwei section in Qamdo, and in ascending order these are: the Epigondolella spiculata Zone, the Orchardella elongata Zone, the Mockina postera Zone, and the E. serrulata Zone; the neighboring Tuoba section also records these four zones, in addition to the upper lower Norian (upper Lacian) Ancyrogondolella uniformis Zone. All of these zones (except for the M. postera Zone) have been recognized for the first time in eastern Tibet. The Lacian-Alaunian boundary is tentatively placed at the level of sample CW-3 at the Chaiwei section and at the level of sample TBL-36 at the Tuoba section by the first occurrence (FO) of E. spiculata in each section. The position of the Alaunian-Sevatian boundary (ASB) is uncertain since the conodont assemblage from the top of the Bolila Formation at the study sections lacks age-diagnostic elements. The conodonts recovered from the Qamdo area have not only dated the Bolila Formation but also refined the conodont biostratigraphic zonation of the Alaunian in the study area. This allows improved correlation between the faunas of Qamdo and their counterparts elsewhere in Tibet and Europe, although the conodont zonations from these regions display lower precision than those established from North America. The Alaunian conodont faunas at Chaiwei and Tuoba appear to be dominated by juvenile specimens; this often appears to be the case in the Alaunian of the Tethyan Realm, but seems not occur in North America. This may suggest that the conodonts living in these two realms may have inhabited different ecological environments. The faunal turnover around the Lacian-Alaunian transition, with the evolution of Epigondolella, Orchardella, and Mockina from Ancyrogondolella, can be recognized in both study sections, although it is more remarkable in the Tuoba section. Although the lack of previous detailed studies of Norian conodont biostratigraphy from Tibet hampers correlation in this region and beyond, this study demonstrates the possibility of establishing high-resolution conodont biostratigraphic successions from Tibet in the future, since the conodont faunas recognized from Tibet and adjacent areas (e.g., Baoshan) suggest that relatively complete Norian strata exist in these regions. Overall, this study also provides new data to improve our understanding of conodont evolution during the Alaunian, and is significant in providing palaeontological data for studying the palaeogeographic evolution of eastern Tethyan ocean basins in the Late Triassic.", "keyphrases": ["late triassic", "conodont biostratigraphy", "changdu basin", "north qiangtang", "tethys"]}
{"id": "MULLER2024111906", "title": "Phosphorus cycling during the Hirnantian glaciation", "abstract": "Unlike other mass extinctions of the Phanerozoic, the Late Ordovician mass extinction took place during an icehouse interval, accompanied by the glaciation of Gondwana. Ice sheets reached their maximum during the Hirnantian and global sea-level dropped substantially. Consequently, the shallow tropical shelf environments of Laurentia and Baltica became subaerially exposed or remaining submerged shelves were characterized by very shallow water-depths. Redox proxies suggest that most shallow shelf settings were well oxygenated to that time, while the global extent of anoxic environments increased, implying that deoxygenation was confined to the open ocean. We speculate that the burial rate of the nutrient phosphorus (P) on shelves was minimal during the Hirnantian glacial maximum (HGM) due to bypass of the shelves in respect to the incoming riverine dissolved load. Hence, a large excess of bioavailable P entering the open ocean would have stimulated phytoplankton production which lowered oxygen concentrations by aerobic respiration. In order to test this hypothesis, we determined reactive P (Preact) contents in two low-latitude carbonate successions (Anticosti Island and Estonia) spanning the HGM. Moreover, we measured total organic carbon (C) concentrations and calculated C/P ratios to evaluate the burial efficiency of P. Samples from both sites are characterized by overall low Preact contents. We observe a decreasing trend in Preact towards the HGM, reaching a minimum during the initial transgression thereafter. C/P ratios suggest efficient P-burial throughout the study interval and, hence, Preact contents are assumed to be a direct measure of primary productivity, P-availability, and P-burial. Using the Preact concentrations, we modeled shelf P-burial fluxes with estimates for global shelf area and sedimentation rates. The model suggests that shelf P-burial fluxes around the HGM were approximately halved due to a reduced shelf area and minimum Preact contents. With the assumption of a constant P-input to the ocean, the proposed scenario serves as a plausible explanation for the observed redox gradients.", "keyphrases": ["phosphorus cycle", "hirnantian", "glaciation", "primary productivity", "sea level", "anoxia"]}
{"id": "ADDANTE2024111907", "title": "Climate-induced surface water variability at Monte San Nicola type-section (Sicily, southern Italy): New data across the Gelasian GSSP", "abstract": "We present the first high-resolution results on planktonic foraminiferal stable oxygen isotopes and calcareous plankton assemblages at the Monte San Nicola GSSP section (near Gela, Sicily), the type-section for the Lower Pleistocene Gelasian Stage. The oxygen isotope profile is remarkably similar to the Eastern Mediterranean oxygen isotope record and indicates that the studied section, extending from marine isotope stage (MIS) G4 to MIS 103, clearly records glacial-interglacial variability. Cyclic changes of calcareous plankton assemblages (calcareous nannofossils and foraminifera) indicate that warmer and stratified surface waters occurred during interglacials, while cooler and unstable conditions developed during glacial phases. Signatures of further increase in surface water stratification are also captured by our surface water proxies and are coeval with enhanced monsoon run-off, developed during precession minima/insolation maxima. The surface water changes recorded at the Monte San Nicola section are in phase with North Atlantic climate variability, even at suborbital scale, and reveal evidence of the first significant southward migration of the Subarctic Front in the mid-latitudes during MIS 104, slightly below the GSSP. The overall dataset provides precise alignment of the Gelasian GSSP within MIS 103 as well as new climatostratigraphic constraints, close to the GSSP, thus improving its correlation potential outside the type-area.", "keyphrases": ["lower pleistocene gssp", "mediterranean area", "stable oxygen isotope", "calcareous plankton", "paleoclimate", "north hemisphere glaciation"]}
{"id": "XU2024111930", "title": "Permian post-orogenic terrestrial successions in the western and northern peripheral orogens of the Junggar Basin: Records of sedimentary provenance, paleogeographic and tectonic changes", "abstract": "The Permian terrestrial successions were deposited in peripheral orogens of the main Junggar Basin, including the West Junggar and Chinese Altai orogens. These successions probably marked the termination of the Paleozoic orogeny in the SW Central Asian Orogenic Belt and document paleogeographic and tectonic changes during that time. However, comprehensive research of these successions is still lacking. This study investigated representative sections and outcrops of Permian successions in West Junggar and Chinese Altai, and we present a detailed sedimentological comparison in the specific chronological framework according to new zircon U-Pb ages of syn-depositional volcanics. This comparison shows that the Lower Permian successions consist of almost equal amounts of sedimentary rocks (46\u201356", "keyphrases": ["post-orogenic sedimentation", "permian terrestrial succession", "provenance analysis", "paleogeographic pattern", "west junggar", "chinese altai"]}
{"id": "10.26879/1294", "title": "Miocene ant species of the genus Forelius Emery, 1888 (Hymenoptera: Formicidae: Dolichoderinae) from Mexico", "abstract": "The first fossil ant species of the New World genus Forelius (Formicidae: Dolichoderinae) is described. The type material is a Miocene amber inclusion from the Montecristo mine near Simojovel, Chiapas, southwestern Mexico. The new species is named Forelius chenpauch sp. nov. It differs from its congeners by having a unique combination of characters: antennal scapes reaching the posterior margin of the head; pronotum with six erect hairs; mesonotum with four erect hairs; propodeum with four erect hairs; front and dorsum of head, dorsum of pronotum, dorsum of mesonotum and propodeum covered with a fine striation. Forelius chenpauch sp. nov. has a rounded spiracle, which could be considered a plesiomorphic character closely related to the Forelius group from the north of the Amazon basin. Accordingly, the current divergence estimates of Forelius as a single genus from the Leptomyrmex + Forelius + Dorymyrmex clade (ca. 27 Ma) and the occurrence of Forelius chenpauch sp. nov. in the fossil record (ca. 23 Ma), may suggest that the rounded spiracle is a plesiomorphic state probably widespread since the Miocene from southern Mexico to northern South America.", "keyphrases": ["ant fossil", "amber-lagerst\u00e4tte", "chiapas amber", "leptomyrmecini tribe", "new species"]}
{"id": "10.26879/1268", "title": "Two exceptional Balaenomorpha (Cetacea: Mysticeti) from the Biemenhorst Subformation (middle/late Miocene) of Bocholt (W M\u00fcnsterland, Germany) with a critical appraisal on the anatomy of the periotic bone", "abstract": "Here we present two new Miocene basal balaenomorph mysticetes recognized by periotic bones with a unique combination of characters. The fossil periotics originated from former shallow marine sediments and were discovered in a suburban quarry of Bocholt in the German M\u00fcnsterland holding a number of remains of a multispecies community of mysticetes. A detailed accompanying analysis of the internal and external structures of mysticete periotics resulted in a critical review and revision of two important characteristics of the pars cochlearis. The partition between the openings for the facial nerve and the vestibulocochlear nerve, named here \u2018bony septum\u2019 for baleen whales, has been developed so prominently during mysticete evolution that the crista transversa is no longer recognizable in derived forms, as it lies deep inside the inner ear canal and within the fundus of the internal acoustic meatus where it separates the cochlear nerve from the inferior vestibular nerve. We show that the designation of the opening for the superior vestibular nerve as \u2018foramen singulare\u2019 is misleading since this term describes the opening for the nerve to the posterior semicircular canal within the fundus of the internal acoustic meatus.", "keyphrases": ["diorocetidae", "breda formation", "iam", "bony septum", "crista transversa"]}
{"id": "10.26879/1258", "title": "Miocene decapod crustacean faunas from Cyprus \u2013 Part 1. Geographical-stratigraphical setting and Anomura", "abstract": "Study of high-diversity Miocene decapod crustacean faunas has resulted in the recognition of several new species from a range of localities across Cyprus. Anomuran taxa collected comprise Paguristes joecollinsi, Dardanus cyprioticus sp. nov., Dardanus plevrotos sp. nov., Galathea weinfurteri, Palmunidopsis muelleri, Petrolisthes haydni, Petrolisthes magnus and Petrolisthes mitseroensis sp. nov. The presence of Petrolisthes magnus in upper Chattian-middle Burdigalian strata documents the oldest stratigraphical occurrence of that species to date. Anomuran taxa recognised in the lower Miocene are also present in upper Miocene reefal facies; the latter illustrate the highest anomuran diversity.", "keyphrases": ["mediterranean sea", "cenozoic", "paguroidea", "galatheoidea", "new species"]}
{"id": "10.26879/1319", "title": "Report from the 8th Symposium on Fossil Decapod Crustaceans, Zaragoza (Spain), June 2022", "abstract": "Decapod crustaceans are an important component in modern ecosystems with a rich fossil record spanning more than 400 million years. Last summer (19th-24th June 2022) the 8th Symposium on Fossil Decapod Crustaceans took place in Zaragoza (Spain), a meeting covering all aspects of studies on fossil decapod crustaceans, including information from modern representatives. The Symposium was organized by the Spanish Research Council (CSIC) and the University of Zaragoza with collaboration of organizers from universities of the Basque Country, Alabama, and Barcelona, and the support of the regional Government of Arag\u00f3n.", "keyphrases": ["decapoda", "mesozoic", "cenozoic", "evolution", "field trip"]}
{"id": "10.26879/1315", "title": "Bioerosion traces on the Campanian turtle remains: New data from the lagoonal deposits of the Quseir Formation, Kharga Oasis, Egypt", "abstract": "The uppermost part of the Campanian Quseir Formation of Kharga Oasis, Egypt, contains a concentration of turtle skeletal remains in a lagoon setting. They appear as three successive horizons (I\u2012III), alternated between the variegated shales and the glauconitic mudstones and conglomeratic layers within the Hindaw Member. However, bones recovered in horizon III present a higher preservation potential than the others. Therein, turtle remains are represented by mostly complete shells, partial shells and many scattered and weathered shell fragments. The studied turtles lived in small ponds and marshes and were deposited as autochthonous to parautochthonous relics. Their bones display significant bioerosion signatures on both carapace and plastron. The morphological analysis of the bioerosion structures preserved revealed 11 ichnospecies, belonging to nine ichnogenera. Eight of these ichnotaxa are recorded for the first time in turtle bones of Egypt. The recognised bioerosional structures appear as borings, shallow chambers, grooves, and punctures produced by ticks, beetles, polychaete worms, fishes/crocodile, and gastropods. They were attributed to the ichnogenera Karethraichnus, Cubiculum, Osteocallis, Radulichnus, Osteichnus, Osedacoides, Sulculites, and Machichnus. In addition, some bite marks assigned to Nihilichnus also occur on a carapace peripheral. This grade of bioerosion was likely caused by relatively long exposure time before the final deposition or burial. In some cases, borings may be produced during the host\u2019s lifetime. The new material considerably expands the stratigraphic and geographic distribution of this trace fossil assemblage and reveals that their producers may have been able to survive in other palaeoenvironmental conditions.", "keyphrases": ["turtles", "bioerosion", "trace fossils", "campanian", "kharga oasis", "egypt"]}
{"id": "10.26879/1289", "title": "Forelimb motion and orientation in the ornithischian dinosaurs Styracosaurus and Thescelosaurus, and its implications for locomotion and other behavior", "abstract": "The range of motion (ROM) in the forelimb has previously been studied in many saurischian dinosaur species but only a few ornithischian dinosaur species. Here, we fill in some of the blanks in current knowledge of ornithischian forelimb function by investigating the range of shoulder motion and the orientation of the humerus, radius, and ulna in the centrosaurine ceratopsid Styracosaurus albertensis and the basal ornithopod Thescelosaurus sp. Manual manipulation of forelimb bones, using the margins of bony articular surfaces to delimit the range of motion, shows that humeral ROM and forearm orientation in S. albertensis resemble those previously found in chasmosaurine ceratopsians. Locomotion occurred with the elbows tucked in at the sides and with the radius anterior to the ulna, without pronation. The animal was also capable of splaying its forelimbs with the elbows strongly everted, so that elbow flexion and extension produced side-to-side or up-and-down movements of the torso and head. Thescelosaurus sp. had limited humeral ROM and could not swing its humerus forward through the parasagittal plane as far as a vertical orientation. While being swung upward through the transverse plane, the humerus could not move as high as a horizontal position. Skeletal proportions and spinal curvature indicate that the forelimbs of Thescelosaurus could contact the ground while the animal stood. However, the animal is unlikely to have used quadrupedal locomotion, because its palms faced medially, and its fingers would have flexed through the transverse plane and therefore would not have provided forward propulsion.", "keyphrases": ["styracosaurus", "thescelosaurus", "ceratopsia", "ornithopoda", "ornithischia", "forelimb"]}
{"id": "10.26879/1290", "title": "An overview of crawling water beetle larvae and a first possible record from 100-million-years-old Myanmar amber", "abstract": "The group Coleoptera contributes heavily to the modern-day species diversity and biomass. Most individuals in the modern fauna are present as larvae, since these live for quite long in some cases, and a lot of individuals never reach adulthood. Despite this fact, the larval stages often get less attention compared to the adults. The group of crawling water beetles, Haliplidae, is an ingroup of Adephaga, living mainly in freshwater as adults. The larvae also live in water, but do not swim like the adults; instead, they move over the surface of the ground and climb on water plants. The larvae develop through three larval stages; all have an elongated shape, and in most species the trunk end is strongly elongated, bearing numerous setae. Herein, we review the entire record of water crawling beetle larvae, report possible fossils, and compare the shape of their overall body outlines using an elliptic Fourier analysis. The fossils show a lower variation in comparison to modern fauna; the shapes of the fossils are well represented in the modern fauna. A minor difference is rather elongate thorax segments of the fossils in comparison to their extant counterparts. The new fossils expand the record of fossil adephagan larvae.", "keyphrases": ["haliplidae", "coleoptera", "cretaceous", "diversity", "burmese amber", "larva"]}
{"id": "10.26879/1130", "title": "A fossil locality predictive model using weighted suitability analysis for the Early Cretaceous Cedar Mountain Formation, Utah, USA", "abstract": "Hard work and chance are nearly always among the deciding factors in finding new, important, and productive paleontological localities. Fossil locality predictive models have the potential to maximize field time and increase chances to find important localities. This study uses remotely sensed data to design and test a fossil locality predictive model for the Early Cretaceous Cedar Mountain Formation. Landsat 8 OLI/TIRS data from known localities were summarized, reclassified, and used in a weighted suitability analysis to categorize fossil locality potential of the study area. Field work was conducted to test model functionality. Field observations were used to refine the weighted suitability analysis. Landsat 8 OLI/TIRS data alone offers a less accurate prescription of fossil locality potential. Additional physical and environmental factors play a role in determining the chance of finding fossils. Slope degree and aspect data from known localities were summarized and analyzed to further refine the model. Forty percent of existing fossil localities within the final model boundaries were located on areas having the highest fossil locality potential as identified by the model. The usefulness of fossil locality predictive models is dependent upon the quality of input data and methods used to determine fossil locality potential. To fully determine the quality of a fossil locality predictive model, field testing is ideal.", "keyphrases": ["cedar mountain formation", "gis", "predictive model", "landsat 8", "remote sensing", "weighted suitability analysis"]}
{"id": "10.26879/1269", "title": "Rogueus belgodereae, a new raninoid crab (Crustacea: Brachyura: Raninoidea) from the Upper Palaeocene (Thanetian) of Southern France, with comments on early palaeocene decapod crustacean faunules", "abstract": "Palaeocene crabs are rare globally; crab faunules of this period are mostly described from reefal environments, and little is reported about non-reefal environments. A new raninoid crab is described and formally named from Thanetian (upper Palaeocene) non-reefal deeper water deposits of Boussens, southern France. The new species is assigned to the genus Rogueus, from which only two species were previously known, and this new record suggests the genus was widespread in the European Palaeocene. A rich Palaeocene brachyuran assemblage of this locality is preliminarily presented and briefly discussed. It appears that eubrachyuran crabs dominated this palaeoenvironment. Based on the global fossil record, it appears that brachyuran crabs quickly recovered after the K/Pg extinction event and were able to restock both reefal and non-reefal environments, prior to the explosive diversification of decapods during the Early Eocene Climatic Optimum.", "keyphrases": ["decapoda", "gymnopleura", "lyreididae", "palaeocene", "france"]}
{"id": "10.26879/1233", "title": "Trophic relationships in the Early Miocene Upper Marine Molasse of Baden-W\u00fcrttemberg, Southwest Germany, with special emphasis on the elasmobranch fauna", "abstract": "The Early Miocene Upper Marine Molasse (OMM) in south-western Germany contains a diverse fossil ecosystem in which elasmobranch teeth are especially abundant. However, the scarcity of outcrops and sometimes poor preservation of fossils resulted in scant recent literature about the OMM. Here, we focus on the elasmobranch fauna to determine the trophic relationships within the OMM, using fossil teeth as proxies for diet and trophic levels based on functional morphology and an actualistic species- or genus-level approach. Herein we present a fresh and comprehensive palaeoecological reconstruction of the OMM ecosystem in Baden-W\u00fcrttemberg. All five outcrop areas available for the present analysis (Baltringen, Me\u00dfkirch-Rengetsweiler, Me\u00dfkirch-Walbertsweiler, Ulm-Ermingen, and Ursendorf) exhibit a similar faunal composition, with the apex predator being Otodus (Megaselachus) sp. Among the other elasmobranchs, there are mostly piscivorous and malacophagous species; taxa that feed on a variety of other invertebrates or amniotes (including marine mammals) are also present. The OMM sediments deposited in shallow-water settings, but there are fossils of more oceanic species that might, at times, have approached the shore. With a soft bottom, partly covered by sea grass, the OMM environment would have been like the present-day warm-waters settings of the Mediterranean.", "keyphrases": ["dental morphology", "elasmobranchii", "obere meeresmolasse", "omm", "palaeoecology", "palaeoenvironment"]}
{"id": "10.26879/1322", "title": "Wear-dependent molar morphology in hypsodont rodents: The case of the spalacine Pliospalax", "abstract": "Studying the dental pattern of micromammals has proven to be a valuable tool in classifying and identifying extinct species, but problems may arise when dental morphology changes with wear. This holds particularly true for the high-crowned rodents, such as the Spalacinae. X-ray microtomography provides new opportunities to document the changes in dental morphology of the species with wear. Combining this technology with visualization and analysis software enables the examination of virtual occlusal surfaces of the molars mimicking the various wear stages. In this paper, we apply this technology on Pliospalax macoveii from the locality of \u00c7alta in Turkey, P. tourkobouniensis and P. sotirisi from the Greek localities of Tourkobounia-1 and Maritsa, and the recent species Spalax microphthalmus from Hungary and Romania. This method enables the effective comparison between the spalacine species. As a result, we consider P. sotirisi as a junior synonym of P. macoveii.", "keyphrases": ["variation", "rodentia", "microtomography", "wear stage", "pliocene"]}
{"id": "10.26879/1177", "title": "Dental ecomorphology and macroevolutionary patterns of North American Late Cretaceous metatherians", "abstract": "Metatherian mammals were taxonomically rich and abundant in Late Cretaceous faunas of North America. Although much attention has been paid to metatherian taxonomy, a comprehensive, quantitative study on the ecomorphology of this clade is lacking. Here, we predict the diets of a large sample of metatherians using three-dimensional dental topographic analysis, with the aim to better understand macroevolutionary patterns in dental morphology and dietary diversity. Contrary to their taxonomic diversity patterns, our results show that dental disparity and dietary diversity did not significantly change throughout the Late Cretaceous and that most metatherians were invertivorous (diets of insects and soft-bodied invertebrates). Nevertheless, we also found that metatherians occupied a wide range of dietary niches and were arguably the most dietarily diverse of any mammalian clade of the Late Cretaceous. Regarding the timing of metatherian ecomorphological diversification, our results indicate that it began by the mid-Cretaceous in-step with the Cretaceous Terrestrial Revolution and the taxonomic diversification of angiosperms, prior to the ecological diversifications of multituberculates and eutherians that began in the latest Cretaceous and Paleocene.", "keyphrases": ["metatheria", "cretaceous", "ecomorphology", "dental topographic analysis"]}
{"id": "10.26879/1308", "title": "First report of rodents from the Miocene Siwalik locality of Dunera, Pathankot District, Punjab, India", "abstract": "Although there have been a few reports of macromammals from the Siwalik site of Dunera, no micromammals have yet been described. Recently, a diverse micromammal fossil assemblage represented by isolated teeth has been recovered from Dunera. The specimens are identified as a murine similar to Progonomys hussaini (Progonomys cf. hussaini , the ctenodactylid Sayimys sivalensis, the cricetid Democricetodon fejfari, and a sciurid, cf. Tamias urialis. These rodents are documented for the first time from this region of the Indian Siwaliks. Based on the biostratigraphic ranges of these rodents from well-dated localities in the Siwaliks of Pakistan along with previously collected magnetostratigraphic data, Dunera locality best correlates to between ~11-10 Ma (early Late Miocene), approximately equivalent to the lower half of the Nagri Formation. Previous magneto-stratigraphic data suggests that an age closer to ~11 Ma is more likely, perhaps sampling a temporal gap in the known Siwaliks micromammal record and extending the age ranges of P. hussaini and T. urialis by a few hundred thousand years.", "keyphrases": ["dunera (punjab, india)", "micromammals", "middle siwalik", "miocene", "nagri formation"]}
{"id": "10.26879/1306", "title": "An Early Cretaceous Sphenophyllum or a hatchling turtle?", "abstract": "Correctly identifying fossil specimens from parautochtonous deposits where marine and terrestrial organisms co-occur can be challenging due to the abundance of rare and obscure specimens with unclear morphologies. In this study, we reviewed fossils from the Lower Cretaceous La Paja Formation (Ricaurte Alto, Villa de Leyva, Colombia) that were originally described as the plant \u201cSphenophyllum colombianum\u201d based on an apparent resemblance to the upper Paleozoic genus. We determined that the type specimen corresponds to the carapace of a hatchling turtle. In addition, a second specimen of \u201cS. colombianum\u201d although less well-preserved, also exhibits similar features of a hatchling turtle. The two fossil specimens are significant as they represent the first report of hatchling marine turtles from the Aptian of northwestern South America and provide evidence of the exceptional preservation of the Marine Reptile Lagerst\u00e4tte of Ricaurte Alto.", "keyphrases": ["aptian", "testudines", "pan-chelonioidea", "south america", "colombia"]}
{"id": "10.26879/1330", "title": "Morphospace dynamics and intraspecies variety of Sorex araneus and S. tundrensis according to recent and fossil data", "abstract": "Several patterns were revealed in a temporal study on morphological variety of Sorex araneus and S. tundrensis (Soricidae, Mammalia). We examined samples from 18 modern and three fossil Early-Late Holocene Uralian localities. We analyzed shape variation of the first lower molar and hemimandible using two-dimensional geometrical landmarks; size differences were estimated by means of three linear measures. A separate purpose was estimation of the measurement error that arose during the data acquisition. We found that the modern samples of both species share underestimated similarity in both size and shape of morphological structures. Regression analysis revealed different phenotypic traits of the mandibular proportion in the large and small shrews regardless of species attribution. A size decrease of S. araneus and conversely a size increase of S. tundrensis both drive the mandibular shape toward phenotypic convergence. This pattern, however, is violated in the fossil samples, where the largest S. tundrensis from a Late Holocene Sim III locality (South Ural) showed a well-distinguishable mandibular shape located in a separate part of the morphospace. In this work, we found that the m1 shape has only weak resolving power as compared to the mandibular or especially skull shape. Nonetheless, even the moderate resolving power of the mandibular shape allowed us to uncover phenotypic changes during the Holocene that have not been noticed by previous researchers at Uralian late Quaternary localities.", "keyphrases": ["soricidae", "sorex", "paleocommunity", "morphospace dynamics", "holocene", "geometric morphometrics"]}
{"id": "10.26879/1334", "title": "An intriguing new species of dabbling duck (Aves: Anseriformes) from the middle Miocene of Austria", "abstract": "Several dozen species of Miocene anatids are known worldwide, but few are known from abundant finds and even fewer from nearly complete specimens. Most fossil ducks have been described from very scant fragmentary remains, making it very difficult or impossible to compare them with one another. In Austria, only a few heavily damaged remains of Miocene anatids have been found so far. Here, we describe a new genus and species of a nearly complete medium-sized duck preserved on four slabs from the middle Miocene of Lavanttal, southern Austria. A number of features on various parts of the skeleton including the coracoid, humerus and pelvis indicate that it was a dabbling duck in an ecological sense, and exclude the option of it being a diving duck. The new species shows a unique mosaic of features typical of different groups of ducks and some features specific to it. Its more precise systematic position is uncertain, pending future finding of more fossil specimens.", "keyphrases": ["new species", "new genus", "miocene", "fossil dabbling duck", "anseriformes", "lavanttal, austria"]}
{"id": "10.26879/1305", "title": "Diversification events of the shield morphology in shore crabs and their relatives through development and time", "abstract": "The group of shore crabs and their relatives, Carcinidae, are first known from the Eocene (56\u201333.9 mya). Since the group\u2019s first appearance, its representatives have evolved a variety of lifestyles and morphologies. The exact evolutionary steps resulting in these morphologies are still a matter of debate. Here, we analyse the changes of morphology within Carcinidae over time. We also investigate the change of morphology through ontogeny to see how it relates to the evolutionary changes. We focus on the outline of the shield as a proxy for morphology, as it has a strong effect on the appearance of the crab and yields the largest sample size of all body parts. Using an elliptic Fourier transformation of the shield outline and a principal component analysis, we create a morphospace for the shields of Carcinidae. Using the morphospace as input data and a new phylogenetic tree based on a molecular and a morphological character matrix from literature, we reconstruct ancestral states for the shield. Combining data of fossil and extant specimens and reconstructed ancestral states, we analyse changes of the shield shape through time. From the morphospace, we find that the morphological diversity of the shield is strongly influenced by ontogeny, but not so much by ecology. Yet, the shields of the adults show a large diversity, corresponding to adaptations to different lifestyles. The reconstruction of ancestral states showed that the earliest representatives of Carcinidae had quasi-hexagonal shields, which could correspond to an epibenthic lifestyle. From these forms, different shapes evolved, significantly during the Oligocene (ca. 33 mya) and Pliocene (ca. 5 mya).", "keyphrases": ["ancestral state reconstruction", "brachyura", "carcinidae", "elliptic fourier transformation", "geometric morphometrics", "quantitative morphology"]}
{"id": "10.26879/1275", "title": "Achieving kinematic identity across shape diversity in musculoskeletal modeling", "abstract": "Musculoskeletal modeling is emerging as a powerful approach to investigate the locomotor biomechanics of extinct taxa. These models rely on bony morphology to define joint locations and muscle geometry. Using different motion profiles to drive models of extinct and extant taxa complicates comparisons because results reflect both morphological and kinematic differences. Here we report on an approach that permits changes in shape while maintaining model kinematics. Using a human musculoskeletal model, we carried out walking simulations of ten humans. Next, we morphed the model pelvis and proximal femur to match a reconstructed australopithecine pelvis and proximal femur. Using the kinematic results from the human walking simulations, we created new motion files based on the positions of joint centers and tracked anatomical locations. These files were used to drive simulations of the same walking trials with the australopithecine model. Joint centers and axes of the human and australopithecine models were compared for each walking trial simulation. We found that joint centers in the australopithecine simulations were typically within ~1\u00b5m of their locations in human simulations, and joint axes differed by less than 0.005 degrees. Such small differences have negligible effects on external joint moments calculated during inverse dynamics analyses. This conservative comparison will serve as a baseline for more complex simulations. Although this work focuses on one taxon, the approach outlined is applicable to a wide variety of extinct animals.", "keyphrases": ["hominin", "biomechanics", "locomotion", "hip", "pelvis"]}
{"id": "10.26879/1220", "title": "Fossil snakes of the Penny Creek Local Fauna from Webster County, Nebraska, USA, and the first record of snakes from the Early Clarendonian (12.5-12 Ma) of North America", "abstract": "The Penny Creek Local Fauna in southern Webster County, Nebraska, is an early Clarendonian fossil locality within the Ash Hollow Formation. Undescribed fossils from previously collected Penny Creek material represent the first record of snakes from this time interval and confirm the presence of multiple taxa immediately following the Mid-Miocene Climatic Optimum. We identified eight taxa from the locality, including one booid (Charina), three colubrines (Pantherophis, Lampropeltis, and Salvadora), a dipsadid (Heterodon/Paleoheterodon), and several natricids (Neonatrix elongata, Neonatrix magna, and Nerodia). Of these snakes, only Neonatrix is an extinct genus, Charina and Salvadora are presently extirpated from the area, and all other genera are represented in the Central Great Plains today. Habitats occupied by extant members of genera represented in the Penny Creek snake assemblage suggest a relatively open environment with loose substrates and plentiful ground cover near a permanent water source. This further corroborates previous geological and mammalian paleoecological assessments of the Penny Creek area as a somewhat open, woodland-prairie ecotone environment near a permanent, high-energy fluvial water source. Finally, the snakes of Penny Creek help contribute to our understanding of the modernization of North American snake assemblages in the Central Great Plains by providing data for a poorly understood time within the evolution of North American snakes.", "keyphrases": ["neogene", "miocene", "clarendonian", "snakes", "central great plains", "nebraska", "climate envelope models"]}
{"id": "10.26879/1323", "title": "Miocene and Pliocene amphibians from Hambach (Germany): new evidence for a late Neogene refuge in northwestern Europe", "abstract": "The Hambach lignite mine in northwestern Germany is a renowned fossil locality, which has yielded remains of several vertebrates dated back to the Middle Miocene and the Late Pliocene. Among these is a recently-described and peculiar proteid urodele, Euronecturus grogu, currently known only from the Middle Miocene level in Hambach. Here, we provide detailed descriptions and identifications of the remaining fossil amphibians (both urodeles and anurans) from the Hambach mine, in total identifying at least 12 Middle Miocene taxa (Cryptobranchidae indet., Palaeoproteus cf. miocenicus, E. grogu, Chelotriton sp., Lissotriton sp., Triturus sp., Latonia sp., ?Palaeobatrachidae indet., Pelobatidae indet., Hyla sp., Pelophylax sp., Rana sp.) and at least nine Late Pliocene ones (Palaeoproteus cf. miocenicus, Mioproteus cf. wezei, Lissotriton sp., Latonia sp., Palaeobatrachus eurydices, cf. Eopelobates sp., Hyla sp., Bufo gr. bufo, Ranidae indet.). The high diversity of amphibians in both Miocene and Pliocene levels at Hambach supports a very humid climate persisting in the area for most of the Neogene, possibly originating a refugium for these animals in northwestern Europe that persisted until the Late Pliocene (and possibly even the Early Pleistocene). Urodeles such as Palaeoproteus and Mioproteus and anurans such as Latonia, the palaeobatrachids, and possibly Eopelobates are all significant occurrences in such a northern latitude at the end of the Pliocene, a period when southward withdrawal of thermophilic animals as well as the first effects of a deteriorizing climate ultimately leading to the Quaternary glaciation had already started in the European continent.", "keyphrases": ["urodela", "anura", "middle miocene", "late pliocene", "lower rhine embayment", "rhine-meuse system"]}
{"id": "10.26879/1312", "title": "Late Oligocene decapod crustaceans from the Trbovlje Formation of Slovenia, with a description of two new species of hymenosomatid crabs", "abstract": "From the Oligocene (Chattian) marls of the Trbovlje Formation, exposed at the Ne\u017ea locality, Slovenia, a brachyuran crab (Malacostraca: Brachyura) association consisting of three taxa is described. The material presented here includes as many as 15 near-complete crab specimens from the Upper Oligocene of Slovenia does not only allow direct comparison with extant hymenosomatids, but the identification of important diagnostic characters permit classification of the fossils in question within extant genera, i.e., Halicarcinus White, 1846, and Lucascinus Poore, Guinot, Komai, and Naruse, 2016. The newly erected species, Halicarcinus popeius sp. nov. and Lucascinus trifailensis sp. nov., are considered herein the first reliable occurrences of the family Hymenosomatidae MacLeay, 1838, in the fossil record. Previously reported occurrence of hymenosomatid crabs from the Cretaceous of Brazil is disputed herein. The hymenosomatid association from the Ne\u017ea locality is accompanied with the portunid crab, Necronectes cf. michelini A. Milne-Edwards, 1860, documented by an incomplete claw.", "keyphrases": ["chattian", "malacostraca", "brachyura", "hymenosomatidae", "portunidae palaeoecology"]}
{"id": "10.1111/pala.12678", "title": "Limited convergence in the postcranium of aquatic Crocodylomorpha", "abstract": "Thalattosuchia (Early Jurassic to Early Cretaceous) and Dyrosauridea (Late Cretaceous to Early Eocene) are crocodylomorph archosaurs which diversified in fluvial and marine environments and endured extinction events (i.e. Jurassic\u2013Cretaceous boundary for Thalattosuchia; Cretaceous\u2013Palaeogene for Dyrosauridea). Their postcrania remain globally undervalued in anatomical descriptions and diagnoses, shrouding the locomotive adaptations that possibly underpinned their radiations and longevity. We thoroughly surveyed the postcranial morphology of Dyrosauridea and Thalattosuchia, recreated their girdles in three-dimensions using tens of high-precisions 3D scans, and analysed their shape using geometric morphometrics. Dyrosauridea and Thalattosuchia have clearly distinct postcrania, even when found within similar environments, suggesting the existence of clade-specific features limiting the strength of evolutionary convergence. Moreover, the range of postcranial morphologies evolved by dyrosaurids and thalattosuchians is large compared to extant crocodylians, making the latter unsatisfactory functional analogues for every group of extinct crocodylomorphs. Our work reveals the previously unsuspected potential of postcranial anatomy as an abundant source of phylogenetic and taxonomic characters to assess the relationships within Crocodylomorpha. Incorporation of postcranial anatomy therefore appears crucial to fully assess the ecology, disparity, and relationships of crocodylomorphs.", "keyphrases": ["archosauria", "postcranium", "phylogenetic signal", "thalattosuchia", "dyrosauroidea", "appendicular morphology"]}
{"id": "10.1111/pala.12679", "title": "Putting the F into FBD analysis: tree constraints or morphological data?", "abstract": "The fossilized birth\u2013death (FBD) process provides an ideal model for inferring phylogenies from both extant and fossil taxa. Using this approach, fossils are directly integrated into the tree, leading to a statistically coherent prior on divergence times. Since fossils are typically not associated with molecular sequences, additional information is required to place fossils in the tree. We use simulations to evaluate two different approaches to handling fossil placement in FBD analyses: using topological constraints, where the user specifies monophyletic clades based on established taxonomy, or using total-evidence analyses, which use a morphological data matrix in addition to the molecular alignment. We also explore how rate variation in fossil recovery or diversification rates impacts these approaches. We find that the extant topology is well recovered under all methods of fossil placement. Divergence times are similarly well recovered across all methods, with the exception of constraints which contain errors. We see similar patterns in datasets which include rate variation, however, relative errors in extant divergence times increase when more variation is included in the dataset, for all approaches using topological constraints, and particularly for constraints with errors. Finally, we show that trees recovered under the FBD model are more accurate than those estimated using non-time calibrated inference. Overall, we show that both fossil placement approaches are reliable even when including uncertainty. Our results underscore the importance of core taxonomic research, including morphological data collection and species descriptions, irrespective of the approach to handling phylogenetic uncertainty using the FBD process.", "keyphrases": ["fossilized birth\u2013death", "total-evidence", "taxonomy", "morphological data", "topological constraints", "phylo-genetic inference"]}
{"id": "10.1111/pala.12681", "title": "Dental microwear texture analysis reveals a likely dietary shift within Late Cretaceous ornithopod dinosaurs", "abstract": "Dinosaurs were the dominant megaherbivores during the Cretaceous when angiosperms, the flowering plants, emerged and diversified. How herbivorous dinosaurs responded to the increasing diversity of angiosperms is largely unknown due to the lack of methods that can reconstruct diet directly from body fossils. We applied dental microwear texture analysis (DMTA), an approach that quantifies microtopography of diet-induced wear marks on tooth surfaces, to ornithopods, the dinosaur clade that includes taxa with the most sophisticated masticatory system. We found that Late Cretaceous ornithopods have significantly rougher dental microwear texture (DMT) compared to pre-Late Cretaceous ornithopods, and DMT variation increased in hadrosaurids, a derived Late Cretaceous ornithopod clade. These changes indicate a likely temporal dietary shift towards more abrasive foodstuffs within ornithopods, probably due to the increased ingestion of phytoliths (amorphous silica bodies in plants). Phytoliths are a main source of rough DMT in modern herbivores, along with exogenous dust and grit, and were generally more concentrated in Late Cretaceous angiosperms than in other major plant groups. Our results show that DMTA of the occlusal enamel surface can be used to reconstruct the diets of herbivorous dinosaurs, with a resolution superior to conventional methods.", "keyphrases": ["dental microwear texture analysis", "ornithopoddinosaurs", "angiosperm", "cretaceous", "dietary reconstruction"]}
{"id": "10.1111/pala.12684", "title": "Machine-learning-based morphological analyses of leaf epidermal cells in modern and fossil ginkgo and their implications for palaeoclimate studies", "abstract": "Leaf stomata form an essential conduit between plant tissue and the atmosphere, thus presenting a link between plants and their environments. Changes in their properties in fossil leaves have been studied widely to infer palaeo-atmospheric-CO2 in deep time, ranging from the Palaeozoic to the Cenozoic. Epidermal cells of leaves, however, have often been neglected for their usefulness in reconstructing past-environments, as their irregular shape makes the manual analyses of epidermal cells a challenging and error-prone task. Here, we used machine-learning (using the U-Net architecture, which evolved from a fully convolutional network) to segment epidermal cells automatically, to efficiently reduce artificial errors. We furthermore applied minimum bounding rectangles to extract length-to-width ratios (RL/W) from the irregularly shaped cells. We applied this to a dataset including over 21000 stomata and 170000 epidermal cells in 114 Ginkgo leaves from 16 locations spanning three climate zones in China. Our results show negative correlations between the RL/W and specific climatic parameters, suggesting that local temperature and precipitation conditions may have affected the RL/W of epidermal cells. We subsequently tested this methodology and the observations from the modern dataset on 15 fossil ginkgoaleans from the Lower to the Middle Jurassic (China). It suggested that the RL/W values of fossil ginkgo generally had a similar negative response to warmer climatic backgrounds as modern G. biloba. The automated analyses of large palaeo-floral datasets provide a new direction for palaeoclimate reconstructions and emphasize the importance of hidden morphological characters of epidermal cells in ginkgoaleans.", "keyphrases": ["ginkgo", "epidermal cell", "micro-character", "machine learning", "palaeoclimate parameter"]}
{"id": "10.1111/pala.12675", "title": "Taxic and morphological diversification during the early radiation of Clupeomorpha (Actinopterygii, Teleostei)", "abstract": "Evolutionary radiation is a problematic concept whose definition and classification have recently changed. Radiations can be defined as the pattern of abrupt increase in diversity of a lineage. It is relevant to evaluate the presence and interaction of different types of radiation in extant and fossil organisms to adequately delimitate the radiation types and to know the diversity in the context of Earth's history. Here, we employed the superorder Clupeomorpha at the Early\u2013Late Cretaceous boundary as a study case to investigate radiation types and their interactions, using both taxic and morphological approaches. Clupeomorpha is an extensively studied, diverse and ancient teleostean superorder with wide geographical and ecological distributions. We propose a model for calculating rates of origination in order to analyse the taxic diversification and employ geometric morphometrics to analyse the morphological diversification that occurred at the temporal boundary. The results suggest the absence of taxic radiation due to a constant increase in taxon origination. However, the expansion of the phylomorphospace occupation and the disparity increase suggest the presence of a \u2018climatic\u2013geographical\u2019 or \u2018broad diversification-like\u2019 disparity, according to current classifications. This illustrates the incompatibility of current radiation classifications with this case study.", "keyphrases": ["origin rate", "phylomorphospace", "disparity", "clupeiformes", "ellimmichthyiformes", "diversification"]}
{"id": "10.1111/pala.12677", "title": "Quantifying the gastral mass in Early Cretaceous ornithuromorphs (Aves, Ornithothoraces) from the Jehol avifauna", "abstract": "Some birds intentionally ingest stones to facilitate digestion of hard foodstuffs, a behaviour inherited from non-avian dinosaurs and present in some of the earliest birds, as evidenced by clusters of gastroliths preserved within the abdominal cavity of a wide range of dinosaurs and Cretaceous birds. For the first time, high-resolution computed laminographic and computed tomographic scans were used to reconstruct the gastral mass in two species of non-neornithine ornithuromorph birds from the Lower Cretaceous Jehol Group. Four specimens of each taxon were analysed. Preservation of the gastral mass in most of these specimens is in situ and regarded as complete or nearly so. The number of gastroliths, their total volume, and their total mass relative to the estimated body mass were calculated for each specimen. The resultant gastral mass to body mass ratios fall within the range observed in extant birds, supporting previous inferences that the digestive system in non-neornithine ornithuromorphs was comparable to that of extant taxa. Compared to available data for non-volant non-avian theropods, the gastral mass is proportionately smaller in birds suggesting that the evolution of flight constrained gastral mass size in the theropod lineage. Currently available data on gastral mass characteristics suggests that Iteravis ate larger food particles compared to Archaeorhynchus but cannot be used to determine diet more precisely. Better understanding of the relationship between gastral mass characteristics and food items across a broader range of extant taxa may provide an indirect but important method through which to infer diet and digestive function in archosaurs.", "keyphrases": ["ornithuromorpha", "aves", "gastrolith", "digestive system", "ct reconstruction", "diet"]}
{"id": "10.1111/pala.12650", "title": "Cranial endocast of Anagale gobiensis (Anagalidae) and its implications for early brain evolution in Euarchontoglires", "abstract": "Anagalids are an extinct group of primitive mammals from the Asian Palaeogene thought to be possible basal members of Glires. Anagalid material is rare, with only a handful of crania known. Here we describe the first virtual endocast of an anagalid, based on the holotype of Anagale gobiensis (AMNH 26079; late Eocene, China), which allows for comparison with published endocasts from fossil members of modern euarchontogliran lineages (i.e. primates, rodents, lagomorphs). The endocast displays traits often observed in fossorial mammals, such as relatively small petrosal lobules and a low neocortical ratio, which would be consistent with previous inferences about use of subterranean food sources based on heavy dental wear. In fact, Anagale gobiensis has the lowest neocortical ratio yet recorded for a euarchontogliran. This species was olfaction-driven, based on the relatively large olfactory bulbs and laterally expansive palaeocortex. The endocast supports previous inferences that relatively large olfactory bulbs, partial midbrain exposure and low encephalization quotient are ancestral for Euarchontoglires, although the likely fossorial adaptations of Anagale gobiensis may also partly explain these traits. While Anagale gobiensis is a primitive mammal in many aspects, some of its derived endocranial traits point towards a new, different trajectory of brain evolution within Euarchontoglires.", "keyphrases": ["anagalidae", "eocene", "china", "endocast", "brain evolution", "mammal"]}
{"id": "10.1111/pala.12642", "title": "Did the Late Ordovician mass extinction event trigger the earliest evolution of \u2018strophodontoid\u2019 brachiopods?", "abstract": "\u2018Strophodontoid\u2019 brachiopods represented the majority of strophomenide brachiopods in the Silurian and Devonian periods. They are characterized by denticles developed along the hinge line. The evolution of denticles correlated with the disappearance of dental plates and teeth and were already present when the clade originated in the Late Ordovician. Specimens of Eostropheodonta parvicostellata from the Kuanyinchiao Bed (early\u2013middle Hirnantian, uppermost Ordovician) in the Hetaoba Section, Meitan, Guizhou Province, South China, display clear fossil population variation, during a process of loss of dental plates and the development of denticles. Three phenotypes of E. parvicostellata are recognized in a single fossil bed, likely heralding a speciation process. Non-metric multidimensional scaling (NMDS) based on five key characters of genera of the Family Leptostrophiidae shows a much wider morphospace for Silurian genera than for those in the Devonian. Phylogenetic analysis of the Family Leptostrophiidae supports the NMDS analysis and mostly tracks their geological history. The fossil population differentiation in E. parvicostellata discovered between the two phases of the Late Ordovician mass extinction event (LOME) linked to a major glaciation, suggests a Hirnantian origination of the \u2018strophodontoid\u2019 morphology, and links microevolutionary change to a macroevolutionary event.", "keyphrases": ["brachiopod", "late ordovician mass extinction", "leptostrophiidae", "microevolution", "morphospace", "speciation"]}
{"id": "10.1111/pala.12646", "title": "Three-dimensional anatomy of the Tully monster casts doubt on its presumed vertebrate affinities", "abstract": "Tullimonstrum gregarium, also known as the Tully monster, is a well-known phylogenetic enigma, fossils of which have been found only in the Mazon Creek Lagerst\u00e4tte. The affinities of Tullimonstrum have been debated since its discovery in 1966, because its peculiar morphology with stalked eyes and a proboscis cannot easily be compared with any known animal morphotypes. Recently, the possibility that Tullimonstrum was a vertebrate has attracted much attention, and it has been postulated that Tullimonstrum might fill a gap in the fossil record of early vertebrates, providing important insights into vertebrate evolutionary history. With the hope of resolving this debate, we collected 3D surface data from 153 specimens of Tullimonstrum using a high-resolution laser 3D scanner and conducted x-ray micro-computed tomographic (\u03bcCT) analysis of stylets in the proboscis. Our investigation of the resulting comprehensive 3D morphological dataset revealed that structures previously regarded as myomeres, tri-lobed brain, tectal cartilages and fin rays are not comparable with those of vertebrates. These results raise further doubts about its vertebrate affinities, and suggest that Tullimonstrum may have been either a non-vertebrate chordate or a protostome.", "keyphrases": ["tully monster", "mazon creek", "problematica", "vertebrate", "lagerst\u00e4tten"]}
{"id": "10.1111/pala.12636", "title": "Thecate stem medusozoans (Cnidaria) from the early Cambrian Chengjiang biota", "abstract": "Cnidarians are phylogenetically located near the base of the \u2018tree of animals\u2019, and their early evolution had a profound impact on the rise of bilaterians. However, the early diversity and phylogeny of this \u2018lowly\u2019 metazoan clade has hitherto been enigmatic. Fortunately, cnidarian fossils from the early Cambrian could provide key insights into their evolutionary history. Here, based on a scrutiny of the purported hyolith Burithes yunnanensis Hou et al. from the early Cambrian Chengjiang biota in South China, we reveal that this species shows characters distinct from those typical of hyoliths, not least a funnel-shaped gastrovascular system with a single opening, a whorl of tentacles surrounding the mouth, and the lack of an operculum. These characters suggest a great deviation from the original definition of the genus Burithes, and a closer affinity with cnidarians. We therefore reassign the material to a new genus: Palaeoconotuba. Bayesian inference of phylogeny based on new anatomical traits identifies a new clade, including Palaeoconotuba and Cambrorhytium, as a stem group of sessile medusozoan cnidarians that are united by the synapomorphies of developing an organic conical theca and a funnel-like gastrovascular system. This study unveils a stem lineage of medusozoans that evolved a lifelong conical theca in the early Cambrian.", "keyphrases": ["cambrian", "cnidaria", "medusozoa", "burithes", "palaeoconotuba", "cambrorhytiu"]}
{"id": "10.1111/pala.12637", "title": "An early Cambrian polyp reveals a potential anemone-like ancestor for medusozoan cnidarians", "abstract": "Cnidarians form a disparate phylum of animals and their diploblastic body plan represents a key step in animal evolution. Cnidarians are split into two main classes; anthozoans (sea anemones, corals) are benthic polyps, while medusozoans (hydroids, jellyfishes) generally have alternating life cycle stages of polyps and medusae. A sessile polyp is present in both groups and is widely regarded as the ancestral form of their last common ancestor. However, the nature and anatomy of the ancestral polyp, particularly of medusozoans, is controversial, owing to the divergent body plans of the extant lineages and the scarcity of medusozoan soft tissues in the fossil record. Here, we redescribe Conicula striata Luo & Hu from the early Cambrian Chengjiang biota, south China, which has previously been interpreted as a polyp, lophophorate or deuterostome. Through re-examination of the holotype and 51 exceptionally preserved specimens, we show that C. striata possessed features of both anthozoans and medusozoan polyps. A conical, annulated organic skeleton (periderm) fully encasing a polyp is found in fossil and living medusozoans, while a tubular pharynx extending from the mouth into a gut partitioned by c. 28 mesenteries, resembling the actinopharynx of anthozoans. Our phylogenetic analyses recover C. striata as a stem-group medusozoan, implying that the wealth of medusozoan diversity derived, ultimately, from an anemone-like ancestor.", "keyphrases": ["cnidaria", "medusozoan polyp", "evolution", "early cambrian", "chengjiang biota"]}
{"id": "10.1111/pala.12639", "title": "Morphological disparity and evolutionary rates of cranial and postcranial characters in sloths (Mammalia, Pilosa, Folivora)", "abstract": "Sloth morphological evolution has been widely studied qualitatively, with comparative anatomy and morpho-functional approaches, or through quantitative assessments of morphological variation using morphometrics. Only recently, however, have folivoran morphological disparity and evolutionary rates begun to be evaluated using discrete character data. Nonetheless, patterns of morphological evolution in separate character partitions have not been investigated, neither the relative influence of, on the one hand, phylogeny, and on the other, dietary and locomotory adaptations of sloths. Here we evaluate those patterns using a phylomorphospace approach, quantifying morphological disparity and evolutionary rates, and investigating possible drivers of morphological evolution for cranial and postcranial characters in Folivora. The evolution of the morphology in those partitions is associated with distinct patterns of disparity among clades and ecological groups, even though the two partitions do not differ substantially in overall evolutionary tempo. Historical processes shaped the morphological evolution of sloths more consistently than ecological ones, although changes in postcranial characters also seem to be associated with locomotory adaptations, in which morphological convergences were much more common. We also discuss important methodological trade-offs in investigations of partitioned datasets mostly composed of fossil taxa.", "keyphrases": ["sloth", "morphology", "partition", "phylomorphospace", "diet", "locomotion"]}
{"id": "10.1111/pala.12640", "title": "An efficient method for estimating vein density of Glossopteris and its application", "abstract": "Glossopteris-type leaves are the most abundant floristic element from the Gondwanan continent and are recorded throughout the Permian, which was a period of extreme icehouse-to-hothouse climatic global change. Fossil leaf traits can be useful for the reconstruction of palaeoenvironments and identification of climatic changes throughout geological time, but the conservative morphology of Glossopteris leaves has thus far made them difficult to use for this purpose. If the characters of Glossopteris can be better quantified then it should make them useful for tracking environmental changes over a wide geographical area and over a long time interval. Venation density is a highly variable leaf trait that might be useful for this purpose. This trait can be calculated, usually as vein length per centimetre squared, but this can be a time-consuming procedure. In this paper we propose a new rapid method to estimate venation density in a conical sector of Glossopteris leaf lamina using an accurate linear model whose predictors are three linear venation densities, measured as veins per centimetre. In addition to substantially reducing the data collection time, it is less biased and more reproducible than methods applied previously with this leaf type. Using this more robust method, preliminary results significantly distinguish the venation densities of leaves produced in wet and drier ecosystems, matching a pattern similar to modern plants. This is the first survey using a large sample size to reveal that environmental stress controlled the vein architecture of Palaeozoic plants, in a manner similar to plants in modern ecosystems.", "keyphrases": ["gondwana", "palaeoecology", "permian", "palaeobotany", "glossopteris"]}
{"id": "https://doi.org/10.1111/pala.12651", "title": "Associations between trilobite intraspecific moulting variability and body proportions: Estaingia bilobata from the Cambrian Emu Bay Shale, Australia", "abstract": "Abstract Trilobites were notably flexible in the moulting behaviours they employed, producing a variety of moult configurations preserved in the fossil record. Investigations seeking to explain this moulting variability and its potential impacts are few, despite abundant material being available for study. We present the first quantitative study on moulting in a single trilobite species using a dataset of almost 500 moult specimens of Estaingia bilobata from the Cambrian (Series 2, Stage 4) Emu Bay Shale, South Australia. Specimens were categorized by moulting mode (Salter's or Sutural Gape) and their associated configurations, and their body proportions measured from both a museum collection (including a bycatch sample) and a randomly-collected field sample. This enabled analysis of the proportion of E. bilobata specimens displaying the Sutural Gape and Salter's modes of moulting and their different configurations, and tests for association between moulting behaviour and body proportions. The results show a wide range of E. bilobata moulting configurations in all samples, suggesting that configurations represent definable instances in a largely continuous spectrum of variation. Analyses comparing body proportions of specimens showing the two modes of moulting were non-significant, suggesting there is no true association between moulting behaviour and body proportion, except for a single significant result for body length. All results were relatively consistent between the museum and field samples. However, removing accessioned specimens from the museum sample brought results even further in line with the field sample, supporting the need for consideration of museum collection bias in palaeontological analyses.", "keyphrases": ["moulting", "emu bay shale", "behaviour", "trilobite", "cambrian", "collection bias"]}
{"id": "https://doi.org/10.1111/pala.12650", "title": "Cranial endocast of Anagale gobiensis (Anagalidae) and its implications for early brain evolution in Euarchontoglires", "abstract": "Abstract Anagalids are an extinct group of primitive mammals from the Asian Palaeogene thought to be possible basal members of Glires. Anagalid material is rare, with only a handful of crania known. Here we describe the first virtual endocast of an anagalid, based on the holotype of Anagale gobiensis (AMNH 26079; late Eocene, China), which allows for comparison with published endocasts from fossil members of modern euarchontogliran lineages (i.e. primates, rodents, lagomorphs). The endocast displays traits often observed in fossorial mammals, such as relatively small petrosal lobules and a low neocortical ratio, which would be consistent with previous inferences about use of subterranean food sources based on heavy dental wear. In fact, Anagale gobiensis has the lowest neocortical ratio yet recorded for a euarchontogliran. This species was olfaction-driven, based on the relatively large olfactory bulbs and laterally expansive palaeocortex. The endocast supports previous inferences that relatively large olfactory bulbs, partial midbrain exposure and low encephalization quotient are ancestral for Euarchontoglires, although the likely fossorial adaptations of Anagale gobiensis may also partly explain these traits. While Anagale gobiensis is a primitive mammal in many aspects, some of its derived endocranial traits point towards a new, different trajectory of brain evolution within Euarchontoglires.", "keyphrases": ["anagalidae", "eocene", "china", "endocast", "brain evolution", "mammal"]}
{"id": "https://doi.org/10.1111/pala.12654", "title": "Unique dentition of rhynchosaurs and their two-phase success as herbivores in the Triassic", "abstract": "Abstract Rhynchosaurs were key herbivores over much of the world in the Middle and Late Triassic, often dominating their faunas ecologically, and much of their success may relate to their dentition. They show the unique ankylothecodont mode of tooth implantation, with deep roots embedded in the bone of the jaw and low crowns that were rapidly worn down in use. During growth, the main area of oral food processing, located in the middle and posterior portions of the occlusal surfaces of the jaws, moved posteriorly relative to the anterior tips of the jaws, which curved up. As the maxilla and dentary grew by addition of new bone posteriorly, the dental lamina fed in new teeth at the back of the tooth rows. CT scanning of the holotype skull of Bentonyx sidensis from the Middle Triassic of England reveals previously concealed details of the dentition. Together with new dentary material from the same location, this has enabled us to examine the tooth replacement process and elucidate ontogenetic changes in dentition and jaw morphology as the animals aged. There were major changes in rhynchosaur anatomy and function through their evolutionary history, with the early forms of the Middle Triassic dying out before or during the Carnian Pluvial Episode (233\u2013232 Ma), and the subclade Hyperodapedontinae, with broad skulls and adaptations to chop tough vegetation, subsequently diversifying worldwide in a successful ecological expansion until their global extinction 227\u2013225 Ma.", "keyphrases": ["dentition", "rhynchosaur", "tooth replacement", "herbivory", "triassic", "carnian pluvial episode"]}
{"id": "https://doi.org/10.1111/pala.12652", "title": "Decoding the drivers of deep-time wetland biodiversity: insights from an early Permian tropical lake ecosystem", "abstract": "Abstract Wetlands are important to continental evolution, providing both arenas and refugia for emerging and declining biotas. This significance and the high preservation potential make the resulting fossiliferous deposits essential for our understanding of past and future biodiversity. We reconstruct the trophic structure and age of the early Permian Manebach Lake ecosystem, Germany, a thriving wetland at a time when the tropical biosphere faced profound upheaval in the peaking Late Palaeozoic Icehouse. Nine excavations, high-resolution spatiotemporal documentation of fossils and strata, and U\u2013Pb radioisotopic dating of tuffs allow us to distinguish autogenic and allogenic factors shaping the limnic biocoenosis. The Manebach Lake was an exorheic, oxygen-stratified, perennial water body on the 101\u2013102 km2 scale, integrated into the catchment draining much of the European Variscides. Lake formation paralleled an Asselian regional wet climatic interval and benefited from rising base level due to post-Variscan half-graben tectonics. Stromatolite-forming cyanobacteria, bivalves, several crustaceans, amblypterids and xenacanthid sharks formed a differentiated biocoenosis in the lake. Fossil stomach remains and teeth prove the rare presence of acanthodians, branchiosaurs and large amphibians. The results indicate woody-debris-bearing lake littorals devoid of semi-aquatic and aquatic plants as places suitable for stromatolites to grow, underpin the model of declining freshwater-shark diversity in most Permian Variscan basins, demonstrate fish/amphibian ratios in limnic assemblages to measure lake perenniality and reveal taphonomic biases in lake taphocoenoses. Our outcomes call for more knowledge about the diversity, ecology and fossilization pathways of past limnic biotas, particularly microorganisms and actinopterygian fishes, to reconstruct deep-time continental ecosystems.", "keyphrases": ["limnic sedimentology", "palaeobotany", "permineralization", "silica", "stromatolite", "vertebrate palaeontology"]}
{"id": "https://doi.org/10.1111/pala.12653", "title": "Early Cenozoic increases in mammal diversity cannot be explained solely by expansion into larger body sizes", "abstract": "Abstract A prominent hypothesis in the diversification of placental mammals after the Cretaceous\u2013Palaeogene (K/Pg) boundary suggests that the extinction of non-avian dinosaurs resulted in the ecological release of mammals, which were previously constrained to small body sizes and limited species richness. This \u2018dinosaur incumbency hypothesis\u2019 may therefore explain increases in mammalian diversity via expansion into larger body size niches, that were previously occupied by dinosaurs, but does not directly predict increases in other body size classes. To evaluate this, we estimate sampling-standardized diversity patterns of terrestrial North American fossil mammals within body size classes, during the Cretaceous and Palaeogene. We find strong evidence for post-extinction diversity increases in all size classes. Increases in the diversity of small-bodied species (less than 100 g, the common body size class of Cretaceous mammals, and much smaller than the smallest non-avialan dinosaurs (c. 400 g)) were similar to those of larger species. We propose that small-bodied mammals had access to greater energetic resources or were able to partition resources more finely after the K/Pg mass extinction. This is likely to be the result of a combination of widespread niche clearing due to the K/Pg mass extinctions, alongside a suite of biotic and abiotic changes that occurred during the Late Cretaceous and across the K/Pg boundary, such as shifting floral composition, and novel key innovations among eutherian mammals.", "keyphrases": ["mammal", "diversity", "body size", "cretaceous\u2013palaeogene mass extinction", "adaptive radiation"]}
{"id": "https://doi.org/10.1111/pala.12667", "title": "Exceptions to the temperature\u2013size rule: no Lilliput Effect in end-Permian ostracods (Crustacea) from Aras Valley (northwest Iran)", "abstract": "Abstract The body size of marine ectotherms is often negatively correlated with ambient water temperature, as seen in many clades during the hyperthermal crisis of the end-Permian mass extinction (c. 252 Ma). However, in the case of ostracods, size changes during ancient hyperthermal events are rarely quantified. In this study, we evaluate the body size changes of ostracods in the Aras Valley section (northwest Iran) in response to the drastic warming during the end-Permian mass extinction at three taxonomic levels: class, order, species. At the assemblage level, the warming triggers a complete species turnover in the Aras Valley section, with larger, newly emerging species dominating the immediate post-extinction assemblage for a short time. Individual ostracod species and instars do not show dwarfing or a change in body size as an adaptation to the temperature stress during the end-Permian crisis. This may indicate that the ostracods in the Aras Valley section might have been exceptions to the temperature\u2013size rule (TSR), using an adaptation mechanism that does not involve a decrease in body size. This adaptation might be similar to the accelerated development despite constant instar body sizes that can be observed in some recent experimental studies of ostracod responses to thermal stress.", "keyphrases": ["permian\u2013triassic", "ostracoda", "body size", "mass extinction", "aras valley section"]}
{"id": "https://doi.org/10.1111/pala.12669", "title": "The evolutionary origin of the durophagous pelagic stingray ecomorph", "abstract": "Abstract Studies of the origin of evolutionary novelties (novel traits, feeding modes, behaviours, ecological niches, etc.) have considered a number of taxa experimenting with new body plans, allowing them to occupy new habitats and exploit new trophic resources. In the marine realm, colonization of pelagic environments by marine fishes occurred recurrently through time. Stingrays (Myliobatiformes) are a diverse clade of batoid fishes commonly known to possess venomous tail stings. Current hypotheses suggest that stingrays experimented with a transition from a benthic to a pelagic/benthopelagic habitat coupled with a transition from a non-durophagous diet to extreme durophagy. However, there is no study detailing macroevolutionary patterns to understand how and when habitat shift and feeding specialization arose along their evolutionary history. A new exquisitely preserved fossil stingray from the Eocene Konservat-Lagerst\u00e4tte of Bolca (Italy) exhibits a unique mosaic of plesiomorphic features of the rajobenthic ecomorph, and derived traits of aquilopelagic taxa, that helps to clarify the evolutionary origin of durophagy and pelagic lifestyle in stingrays. A scenario of early evolution of the aquilopelagic ecomorph is proposed based on new data, and the possible adaptive meaning of the observed evolutionary changes is discussed. The body plan of \u2020Dasyomyliobatis thomyorkei gen. et sp. nov. is intermediate between the rajobenthic and more derived aquilopelagic stingrays, supporting its stem phylogenetic position and the hypothesis that the aquilopelagic body plan arose in association with the evolution of durophagy and pelagic lifestyle from a benthic, soft-prey feeder ancestor.", "keyphrases": ["durophagy", "ecomorph", "evolution", "myliobatiformes", "pelagic lifestyle", "stingray"]}
{"id": "https://doi.org/10.1111/pala.12668", "title": "Preservational modes of some ichthyosaur soft tissues (Reptilia, Ichthyopterygia) from the Jurassic Posidonia Shale of Germany", "abstract": "Abstract Konservat-Lagerst\u00e4tten, such as the Toarcian (Early Jurassic) Posidonia Shale of southwestern Germany, are renowned for their spectacular fossils. Ichthyosaur skeletons recovered from this formation are frequently associated with soft tissues; however, the preserved material ranges from three-dimensional, predominantly phosphatized structures to dark films of mainly organic matter. We examined soft-tissue residues obtained from two ichthyosaur specimens using an integrated ultrastructural and geochemical approach. Our analyses revealed that the superficially-looking \u2018films\u2019 in fact comprise sections of densely aggregated melanosome (pigment) organelles sandwiched between phosphatized layers containing fibrous microstructures. We interpret this distinct layering as representing condensed and incompletely degraded integument from both sides of the animal. When compared against previously documented ichthyosaur fossils, it becomes readily apparent that a range of preservational modes exists between presumed \u2018phosphatic\u2019 and \u2018carbonized\u2019 soft-tissue remains. Some specimens show high structural fidelity (e.g. distinct integumentary layering), while others, including the fossils examined in this study, retain few original anatomical details. This diversity of soft-tissue preservational modes among Posidonia Shale ichthyosaurs offers a unique opportunity to examine different biostratinomic, taphonomic and diagenetic variables that potentially could affect the process of fossilization. It is likely that soft-tissue preservation in the Posidonia Shale was regulated by a multitude of factors, including decay efficiency and speed of phosphatic mineral nucleation; these in turn were governed by a seafloor with sustained microbial mat activity fuelled by high organic matter input and seasonally fluctuating oxygen levels.", "keyphrases": ["holzmaden", "ichthyosaur", "jurassic", "skin", "soft tissue", "taphonomy"]}
{"id": "https://doi.org/10.1111/pala.12670", "title": "What's inside a sauropod limb? First three-dimensional investigation of the limb long bone microanatomy of a sauropod dinosaur, Nigersaurus taqueti (Neosauropoda, Rebbachisauridae), and implications for the weight-bearing function", "abstract": "Abstract Various terrestrial tetrapods convergently evolved to gigantism (large body sizes and masses), the most extreme case being sauropod dinosaurs. Heavy weight-bearing taxa often show external morphological features related to this condition, but also adequacy in their limb bone inner structure: a spongiosa filling the medullary area and a rather thick cortex varying greatly in thickness along the shaft. However, the microanatomical variation in such taxa remains poorly known, especially between different limb elements. We highlight for the first time the three-dimensional microstructure of the six limb long bone types of a sauropod dinosaur, Nigersaurus taqueti. Sampling several specimens of different sizes, we explored within-bone, between-bones, and size-related variations. If a spongiosa fills the medullary area of all bones, the cortex is rather thin and varies only slightly in thickness along the shaft. Zeugopod bones appear more compact than stylopod ones, whereas no particular differences between serially homologous bones are found. Nigersaurus' pattern appears much less extreme than that in heavy terrestrial taxa such as rhinoceroses, but is partly similar to observations in elephants and in two-dimensional sauropod data. Thus, microanatomy may have not been the predominant feature for weight-bearing in sauropods. External features, such as columnarity (shared with elephants) and postcranial pneumaticity, may have played a major role for this function, thus relaxing pressures on microanatomy. Also, sauropods may have been lighter than expected for a given size. Our study calls for further three-dimensional investigations, eventually yielding a framework characterizing more precisely how sauropod gigantism may have been possible.", "keyphrases": ["bone microanatomy", "graviportal", "sauropodomorpha", "x-ray microtomography", "functional morphology", "biomechanics"]}
{"id": "https://doi.org/10.1111/pala.12671", "title": "Palaeobiology and taphonomy of the rangeomorph Culmofrons plumosa", "abstract": "Abstract The deep marine Ediacaran fossil record of Avalonia is dominated by the Rangeomorpha, a clade characterized by up to four orders of fractal-like branching. Despite their abundance, morphological diversity and the recent increase in Ediacaran studies, aspects of their palaeobiology, palaeoecology and phylogenetic position in the tree of life are still hotly debated. The clade has traditionally been interpreted as consisting of organisms that lived erect in the water column and tethered to the seafloor, based on the intuitive interpretation of their frondose body plan. However, recent work has challenged this view and instead proposes a reclining mode of life for several rangeomorphs, possibly in symbiosis with chemoautotrophic bacteria. Here, we offer a detailed description of exceptionally preserved specimens of Culmofrons plumosa from the Discovery UNESCO Global Geopark in Newfoundland, Canada. We suggest that Culmofrons plumosa should be reinterpreted as a reclining organism based on taphonomic and morphological evidence. Additionally, reproductive modes and a growth model of the species are here inferred, and they appear to be most consistent with a reclining mode of life, offering a novel palaeobiological reconstruction of the species.", "keyphrases": ["rangeomorph", "avalon assemblage", "palaeobiology", "taphonomy", "reproduction", "ontogeny"]}
{"id": "https://doi.org/10.1111/pala.12672", "title": "A new method for extracting conodonts and radiolarians from chert with NaOH solution", "abstract": "Abstract Microfossils are important components of sedimentary rocks used for palaeontological, biostratigraphic, palaeoenvironmental and palaeoclimatic investigations. They are usually extracted from rocks using an acid solution, which might vary depending on the embedding rock lithology. Here we propose a new method using common NaOH (sodium hydroxide; soda) to digest cherts (micro- and cryptocrystalline quartz) instead of the standard technique based on HF (hydrofluoric acid). This new method allows the collection of undamaged specimens of different kinds of microfossils, such as conodonts, radiolarians, teeth and dermal scales, the minerology of which is still preserved (e.g. biogenic apatite in conodonts). The use of soda is thus recommended, as it is less dangerous, less expensive, and it better preserves the extracted microfossils both in shape and mineralogy.", "keyphrases": ["chert", "soda", "conodont", "radiolarian", "chemical method", "dissolution technique"]}
{"id": "https://doi.org/10.1111/pala.12673", "title": "Rise and fall of the phacopids: the morphological history of a successful trilobite family", "abstract": "Abstract Phacopidae were a successful family of the Silurian\u2013Devonian period. Although their diversity trends are well identified, their shape evolution is unknown; their morphology often considered to be conservative. We have quantified these morphologies using geometric morphometrics (landmarks) and investigated their evolution using morphological disparity indices. Results identified morphological variations between the genera, and through time. Phacopids differ from each other by the position of the facial suture linked to the size of the visual complex, the shape of the genal angle and the elongation of both cephalon and pygidium. The morphological disparity of cephala was high from the Silurian, contrary to that of pygidia. Subsequently, the morphological disparity increased in the Early Devonian with the development of narrow cephala and triangular pygidia. Morphological disparity was greater in the Emsian for both cephala and pygidia, more than 50 myr after the origination of phacopids. It constituted a perfect example illustrating that a peak of biodiversity does not necessarily happen in the early history of a clade. Subsequently, a strong decrease of morphological disparity occurred in the Middle Devonian, in conjunction with sea-level changes and anoxic events. Taxonomic richness and morphological disparity declined strongly in the Givetian, in a non-random extinction affecting particularly blind genera. The morphological disparity remained low in the Frasnian despite progressive eye reduction influenced by environmental changes. An extensive recovery occurred in the Famennian with an important increase of both taxonomic and morphological diversity. The Hangenberg event caused the final extinction of phacopids.", "keyphrases": ["phacopidae", "palaeozoic", "morphological disparity", "diversification", "extinction"]}
{"id": "https://doi.org/10.1111/pala.12675", "title": "Taxic and morphological diversification during the early radiation of Clupeomorpha (Actinopterygii, Teleostei)", "abstract": "Abstract Evolutionary radiation is a problematic concept whose definition and classification have recently changed. Radiations can be defined as the pattern of abrupt increase in diversity of a lineage. It is relevant to evaluate the presence and interaction of different types of radiation in extant and fossil organisms to adequately delimitate the radiation types and to know the diversity in the context of Earth's history. Here, we employed the superorder Clupeomorpha at the Early\u2013Late Cretaceous boundary as a study case to investigate radiation types and their interactions, using both taxic and morphological approaches. Clupeomorpha is an extensively studied, diverse and ancient teleostean superorder with wide geographical and ecological distributions. We propose a model for calculating rates of origination in order to analyse the taxic diversification and employ geometric morphometrics to analyse the morphological diversification that occurred at the temporal boundary. The results suggest the absence of taxic radiation due to a constant increase in taxon origination. However, the expansion of the phylomorphospace occupation and the disparity increase suggest the presence of a \u2018climatic\u2013geographical\u2019 or \u2018broad diversification-like\u2019 disparity, according to current classifications. This illustrates the incompatibility of current radiation classifications with this case study.", "keyphrases": ["origin rate", "phylomorphospace", "disparity", "clupeiformes", "ellimmichthyiformes", "diversification"]}
{"id": "https://doi.org/10.1111/pala.12677", "title": "Quantifying the gastral mass in Early Cretaceous ornithuromorphs (Aves, Ornithothoraces) from the Jehol avifauna", "abstract": "Abstract Some birds intentionally ingest stones to facilitate digestion of hard foodstuffs, a behaviour inherited from non-avian dinosaurs and present in some of the earliest birds, as evidenced by clusters of gastroliths preserved within the abdominal cavity of a wide range of dinosaurs and Cretaceous birds. For the first time, high-resolution computed laminographic and computed tomographic scans were used to reconstruct the gastral mass in two species of non-neornithine ornithuromorph birds from the Lower Cretaceous Jehol Group. Four specimens of each taxon were analysed. Preservation of the gastral mass in most of these specimens is in situ and regarded as complete or nearly so. The number of gastroliths, their total volume, and their total mass relative to the estimated body mass were calculated for each specimen. The resultant gastral mass to body mass ratios fall within the range observed in extant birds, supporting previous inferences that the digestive system in non-neornithine ornithuromorphs was comparable to that of extant taxa. Compared to available data for non-volant non-avian theropods, the gastral mass is proportionately smaller in birds suggesting that the evolution of flight constrained gastral mass size in the theropod lineage. Currently available data on gastral mass characteristics suggests that Iteravis ate larger food particles compared to Archaeorhynchus but cannot be used to determine diet more precisely. Better understanding of the relationship between gastral mass characteristics and food items across a broader range of extant taxa may provide an indirect but important method through which to infer diet and digestive function in archosaurs.", "keyphrases": ["ornithuromorpha", "aves", "gastrolith", "digestive system", "ct reconstruction", "diet"]}
{"id": "https://doi.org/10.1111/pala.12674", "title": "The dentary of hadrosauroid dinosaurs: evolution through heterochrony", "abstract": "Abstract The near-global distribution of hadrosaurid dinosaurs during the Cretaceous has been attributed to mastication, a behaviour commonly recognized as a mammalian adaptation. Its occurrence in a non-mammalian lineage should be accompanied by the evolution of several morphological modifications associated with food acquisition and processing. This study investigated morphological variation in the dentary, a major element of the hadrosauroid lower jaw. Eighty-four hadrosauroid dentaries were subjected to geometric morphometric and statistical analyses to investigate their taxonomic, ontogenetic, and individual variation. Results suggest increased food acquisition and processing efficiency in saurolophids through a complex pattern of evolutionary and growth-related changes. The edentulous region grew longer relative to dentary length, allowing for food acquisition specialization anteriorly and processing posteriorly, and became ventrally directed, possibly associated with foraging low-growing vegetation, especially in younger individuals. The saurolophid coronoid process became anteriorly directed and relatively more elongate, with an expanded apex, increasing moment arm length, with muscles pulling the jaw more posteriorly, increasing mechanical advantage. During growth, all hadrosauroids underwent anteroposterior dental battery elongation by the addition of teeth, and edentulous region ventralization decreased. The dental battery became deeper in saurolophids by increasing the number of teeth per tooth family. The increased coronoid process anterior inclination and relative edentulous region elongation in saurolophids are hypothesized to have evolved through hypermorphosis and/or acceleration, peramorphic heterochronic processes; the development of an anteroposteriorly shorter but dorsoventrally taller saurolophid dentary, is probably due to post-displacement in dental battery elongation and edentulous region decreased ventral orientation, a paedomorphic heterochronic process.", "keyphrases": ["hadrosaur", "dentary", "geometric morphometrics", "heterochrony", "paedomorphosis", "peramorphosis"]}
{"id": "https://doi.org/10.1111/pala.12676", "title": "Bridging the extant and fossil record of planktonic foraminifera: implications for the Globigerina lineage", "abstract": "Abstract We conducted a morphometric study and wall texture analysis on extant and fossil specimens of the planktonic foraminifera Globigerina falconensis plexus. Our global data reveal morphological inconsistencies between fossil and extant populations. Our results are significant as G. falconensis is widely used in palaeoceanographic studies in conjunction with its sister taxon G. bulloides. Morphologically these two species are similar, with the main difference being the distinctive apertural lip present in G. falconensis. We selected cores covering the entire stratigraphic range of G. falconensis, from the early Miocene to current day, spanning sites from high latitudes in the North Atlantic Ocean and the southern Indian Ocean to sites in equatorial regions. The morphology found in the modern ocean is not consistent with the Miocene holotype of Globigerina falconensis Blow described from lower Miocene sediments in Venezuela. A more lobate morphology evolved in the late Miocene, thus, a new name is required for this morphotype, coexisting in the modern oceans with G. falconensis s.s. We thus describe the new morphospecies, G. neofalconensis for the more lobate forms which evolved in the late Miocene and inhabit the modern oceans. Additionally, we report a pseudocancellate wall texture present in the G. falconensis plexus. We use the molecular sequences from the PR2 database to explore the generic attribution of the G. falconensis lineage, confirming its close relationship with G. bulloides and its retention in the genus Globigerina.", "keyphrases": ["planktonic foraminifera", "extant", "globigerina", "taxonomy", "genetic", "morphometric"]}
{"id": "https://doi.org/10.1111/pala.12678", "title": "Limited convergence in the postcranium of aquatic Crocodylomorpha", "abstract": "Abstract Thalattosuchia (Early Jurassic to Early Cretaceous) and Dyrosauridea (Late Cretaceous to Early Eocene) are crocodylomorph archosaurs which diversified in fluvial and marine environments and endured extinction events (i.e. Jurassic\u2013Cretaceous boundary for Thalattosuchia; Cretaceous\u2013Palaeogene for Dyrosauridea). Their postcrania remain globally undervalued in anatomical descriptions and diagnoses, shrouding the locomotive adaptations that possibly underpinned their radiations and longevity. We thoroughly surveyed the postcranial morphology of Dyrosauridea and Thalattosuchia, recreated their girdles in three-dimensions using tens of high-precisions 3D scans, and analysed their shape using geometric morphometrics. Dyrosauridea and Thalattosuchia have clearly distinct postcrania, even when found within similar environments, suggesting the existence of clade-specific features limiting the strength of evolutionary convergence. Moreover, the range of postcranial morphologies evolved by dyrosaurids and thalattosuchians is large compared to extant crocodylians, making the latter unsatisfactory functional analogues for every group of extinct crocodylomorphs. Our work reveals the previously unsuspected potential of postcranial anatomy as an abundant source of phylogenetic and taxonomic characters to assess the relationships within Crocodylomorpha. Incorporation of postcranial anatomy therefore appears crucial to fully assess the ecology, disparity, and relationships of crocodylomorphs.", "keyphrases": ["archosauria", "postcranium", "phylogenetic signal", "thalattosuchia", "dyrosauroidea", "appendicular morphology"]}
{"id": "https://doi.org/10.1111/pala.12679", "title": "Putting the F into FBD analysis: tree constraints or morphological data?", "abstract": "Abstract The fossilized birth\u2013death (FBD) process provides an ideal model for inferring phylogenies from both extant and fossil taxa. Using this approach, fossils are directly integrated into the tree, leading to a statistically coherent prior on divergence times. Since fossils are typically not associated with molecular sequences, additional information is required to place fossils in the tree. We use simulations to evaluate two different approaches to handling fossil placement in FBD analyses: using topological constraints, where the user specifies monophyletic clades based on established taxonomy, or using total-evidence analyses, which use a morphological data matrix in addition to the molecular alignment. We also explore how rate variation in fossil recovery or diversification rates impacts these approaches. We find that the extant topology is well recovered under all methods of fossil placement. Divergence times are similarly well recovered across all methods, with the exception of constraints which contain errors. We see similar patterns in datasets which include rate variation, however, relative errors in extant divergence times increase when more variation is included in the dataset, for all approaches using topological constraints, and particularly for constraints with errors. Finally, we show that trees recovered under the FBD model are more accurate than those estimated using non-time calibrated inference. Overall, we show that both fossil placement approaches are reliable even when including uncertainty. Our results underscore the importance of core taxonomic research, including morphological data collection and species descriptions, irrespective of the approach to handling phylogenetic uncertainty using the FBD process.", "keyphrases": ["fossilized birth\u2013death", "total-evidence", "taxonomy", "morphological data", "topological constraints", "phylogenetic inference"]}
{"id": "https://doi.org/10.1111/pala.12680", "title": "Inaccurate fossil placement does not compromise tip-dated divergence times", "abstract": "Abstract Time-scaled phylogenies underpin the interrogation of evolutionary processes across deep timescales, as well as attempts to link these to Earth's history. By inferring the placement of fossils and using their ages as temporal constraints, tip dating under the fossilized birth\u2013death (FBD) process provides a coherent prior on divergence times. At the same time, it also links topological and temporal accuracy, as incorrectly placed fossil terminals should misinform divergence times. This could pose serious issues for obtaining accurate node ages, yet the interaction between topological and temporal error has not been thoroughly explored. We simulate phylogenies and associated morphological datasets using methodologies that incorporate evolution under selection, and are benchmarked against empirical datasets. We find that datasets of 300 characters and realistic levels of missing data generally succeed in inferring the correct placement of fossils on a constrained extant backbone topology, and that true node ages are usually contained within Bayesian posterior distributions. While increased fossil sampling improves the accuracy of inferred ages, topological and temporal errors do not seem to be linked: analyses in which fossils resolve less accurately do not exhibit elevated errors in node age estimates. At the same time, inferred divergence times are biased, probably due to a mismatch between the FBD prior and the shape of our simulated trees. While these results are encouraging, suggesting that even fossils with uncertain affinities can provide useful temporal information, they also emphasize that palaeontological information cannot overturn discrepancies between model priors and the true diversification history.", "keyphrases": ["tip dating", "time calibration", "morphological clock", "fossilized birth\u2013death model"]}
{"id": "https://doi.org/10.1111/pala.12681", "title": "Dental microwear texture analysis reveals a likely dietary shift within Late Cretaceous ornithopod dinosaurs", "abstract": "Abstract Dinosaurs were the dominant megaherbivores during the Cretaceous when angiosperms, the flowering plants, emerged and diversified. How herbivorous dinosaurs responded to the increasing diversity of angiosperms is largely unknown due to the lack of methods that can reconstruct diet directly from body fossils. We applied dental microwear texture analysis (DMTA), an approach that quantifies microtopography of diet-induced wear marks on tooth surfaces, to ornithopods, the dinosaur clade that includes taxa with the most sophisticated masticatory system. We found that Late Cretaceous ornithopods have significantly rougher dental microwear texture (DMT) compared to pre-Late Cretaceous ornithopods, and DMT variation increased in hadrosaurids, a derived Late Cretaceous ornithopod clade. These changes indicate a likely temporal dietary shift towards more abrasive foodstuffs within ornithopods, probably due to the increased ingestion of phytoliths (amorphous silica bodies in plants). Phytoliths are a main source of rough DMT in modern herbivores, along with exogenous dust and grit, and were generally more concentrated in Late Cretaceous angiosperms than in other major plant groups. Our results show that DMTA of the occlusal enamel surface can be used to reconstruct the diets of herbivorous dinosaurs, with a resolution superior to conventional methods.", "keyphrases": ["dental microwear texture analysis", "ornithopod dinosaurs", "angiosperm", "cretaceous", "dietary reconstruction"]}
{"id": "https://doi.org/10.1111/pala.12683", "title": "Uncovering a phylogenetic signal in plant biopolymer chemistry: a comparison of sporopollenin isolation approaches for use in palynological research", "abstract": "Abstract Sporomorphs (pollen and spores) are a mainstay of research into past vegetation, and increasingly sporomorph chemistry is being used as a palaeoecological tool. To make extant sporomorphs directly comparable to fossil specimens, fresh material is processed to remove labile compounds and isolate the sporopollenin wall. A range of processing approaches are currently in use, but the chemistries produced by these different techniques have not yet been compared across a range of taxa. It is therefore not clear how they compare in terms of efficiently isolating sporopollenin without changing its chemical structure, and what impact they have on relative chemical similarities and differences among taxa (i.e. whether more closely related species will always appear chemically more similar, regardless of how they have been processed). Here, we test this by applying five different processing approaches to sporomorphs from 15 taxa from across the vascular plant phylogeny. We show that each approach has its own idiosyncrasies in terms of impacts on sporomorph chemistry. For the most part a common pattern of among-taxon chemical variability is uncovered, and a phylogenetic signal within sporopollenin chemistry is supported. Working with spectral derivatives generally increases agreement among the different processing approaches, but decreases the strength of the phylogenetic signal. No one processing approach is ideal, and the choice of which to use is likely to depend on the goal of the study, the type and quantity of material being processed, and the laboratory facilities available for processing.", "keyphrases": ["sporopollenin", "phylogeny", "chemistry", "biopolymer", "fourier transform infrared (ftir) microspectroscopy"]}
{"id": "https://doi.org/10.1111/pala.12682", "title": "Developmental models shed light on the earliest dental tissues, using Astraspis as an example", "abstract": "Abstract Fossils of extinct jawless vertebrates are pivotal to deciphering the evolutionary paths that led to the various forms of the vertebrate skeleton. For example, Pteraspidomorphs (stem-gnathostomes), such as the Ordovician Astraspis, display some of the oldest remains of bony and \u2018dental\u2019 (dentine and enameloid) tissues. However, the identification of the very nature of these early mineralized tissues has been hampered by a lack of unambiguous diagnostic characters. As development is key to identifying the derivation of these tissues, we developed an integrative and generic histogenetic model, testing several ontogenetic scenarios. We illustrate our approach on the basis of the well-preserved Astraspis samples and show how this can be used to infer key developmental features from extinct species. This study suggests that in the odontodes of Astraspis: (1) the initial curvature of the epithelium was close to the shape of the final external surface; (2) the mesenchymal cells differentiate synchronously in the whole inner periphery; and (3) the capping tissue was produced by both mesenchymal and epithelial cells (enameloid rather than enamel). Astraspis specimens also provide evidence of a dual growth periodicity, possibly homologous to Andresen and von Ebner growth lines observed in amniotes, suggesting this type of dual periodicity may be shared by most vertebrates. We estimated that an Astraspis odontode grew up in around 60\u201370 days at a rate of 0.5\u20135 \u03bcm/day. The new developmental approach proposed in this study could be a robust framework for critically evaluating the tissues of extinct taxa in the future.", "keyphrases": ["developmental model", "dental tissue", "odontode", "enameloid", "palaeohistology", "early vertebrate"]}
{"id": "https://doi.org/10.1111/pala.12684", "title": "Machine-learning-based morphological analyses of leaf epidermal cells in modern and fossil ginkgo and their implications for palaeoclimate studies", "abstract": "Abstract Leaf stomata form an essential conduit between plant tissue and the atmosphere, thus presenting a link between plants and their environments. Changes in their properties in fossil leaves have been studied widely to infer palaeo-atmospheric-CO2 in deep time, ranging from the Palaeozoic to the Cenozoic. Epidermal cells of leaves, however, have often been neglected for their usefulness in reconstructing past-environments, as their irregular shape makes the manual analyses of epidermal cells a challenging and error-prone task. Here, we used machine-learning (using the U-Net architecture, which evolved from a fully convolutional network) to segment epidermal cells automatically, to efficiently reduce artificial errors. We furthermore applied minimum bounding rectangles to extract length-to-width ratios (RL/W) from the irregularly shaped cells. We applied this to a dataset including over 21 000 stomata and 170 000 epidermal cells in 114 Ginkgo leaves from 16 locations spanning three climate zones in China. Our results show negative correlations between the RL/W and specific climatic parameters, suggesting that local temperature and precipitation conditions may have affected the RL/W of epidermal cells. We subsequently tested this methodology and the observations from the modern dataset on 15 fossil ginkgoaleans from the Lower to the Middle Jurassic (China). It suggested that the RL/W values of fossil ginkgo generally had a similar negative response to warmer climatic backgrounds as modern G. biloba. The automated analyses of large palaeo-floral datasets provide a new direction for palaeoclimate reconstructions and emphasize the importance of hidden morphological characters of epidermal cells in ginkgoaleans.", "keyphrases": ["ginkgo", "epidermal cell", "micro-character", "machine learning", "palaeoclimate parameter"]}
{"id": "https://doi.org/10.1111/pala.12685", "title": "Macroscopic fossils from the Chuanlinggou Formation of North China: evidence for an earlier origin of multicellular algae in the late Palaeoproterozoic", "abstract": "Abstract Multicellular algae are the core topic for understanding the early life evolution on Earth. The timing of origin and cellular differentiation of multicellular algae, however, remains poorly constrained. The Palaeoproterozoic to early Mesoproterozoic is a critical period during which multicellular algae began to occur and evolve in marine environments. This paper reports well-preserved multicellular fossils from shales of the Chuanlinggou Formation (c. 1.64 Ga) in North China, with emphasis on their holdfast and putative cellular structures. These macroalgal fossils are reasonably diversified and include Chuaria circularis, Tawuia sinensis, Tawuia robusta, Glossophyton ovalis, Glossophyton sp., Tuanshanzia sp. and Changchengia sp.; mainly preserved as carbonaceous compressions, with a few sideritized forms. Field emission scanning electron microscope (FESEM) observation revealed multicellular structures in Chuaria, confirming its biological attributes of a multicellular eukaryote and providing direct evidence that multicellular algae had already originated by the terminal Palaeoproterozoic, earlier than previously speculated. Tuanshanzia sp. and Changchengia sp. developed with a bare rhizome holdfast, suggesting that they had a benthic sessile lifestyle in their late Palaeoproterozoic oceanic habitat.", "keyphrases": ["palaeoproterozoic", "multicellular macroalgal fossil", "holdfast structure", "chuanlinggou formation", "north china platform"]}
{"id": "https://doi.org/10.1111/pala.12686", "title": "Quantitative ichnology: a novel framework to determine the producers of locomotory trace fossils with the ichnogenus Gordia as a case study", "abstract": "Abstract Trace fossils record the interactions between organisms and their surroundings, and can therefore provide unique insights into the coevolution of trace makers and the environment. However, identifying the producers of trace fossils is challenging because different animals can create very similar traces and many ichnotaxa can therefore only be attributed to broad morphological grades. For example, simple horizontal traces like Gordia are generally suggested to have been produced by vermiform organisms, potentially encompassing a range of animal phyla. This uncertainty makes it difficult to decipher their palaeobiological significance through major evolutionary events and episodes of environmental change. We have developed new mathematical approaches for identifying previously unrecognized signatures left by the trace makers of simple marine locomotory traces. We calculated the deviation angle series of self-crossing traces made by extant isopods, polychaetes, gastropods and nematodes, computing the frequency spectrum and autocorrelation function in each case. The results reveal that each of these taxa left unique markers during the trace-making process, reflecting differences in their anatomy and locomotory behaviour. We were able to identify the possible trace makers of several early Palaeozoic Gordia specimens, demonstrating that ichnospecies within the same ichnogenus can be created by distantly related animals with very different morphologies and/or behaviours. This novel mathematical framework has great potential for identifying the possible producers of diverse trace fossils through deep time, helping to uncover the earliest evidence of certain animals or behaviours. It also has great potential for quantifying ichnotaxonomy, consolidating the link between ichnology and palaeobiology.", "keyphrases": ["trace fossil", "locomotory trace", "gordia", "repeating pattern", "frequency spectrum", "autocorrelation function"]}
{"id": "https://doi.org/10.1111/pala.12687", "title": "Germ-soma differentiation and reproduction in a new species of early Cambrian acritarch", "abstract": "Abstract As a significant evolutionary innovation, multicellularity has independently evolved multiple times throughout the evolutionary history of eukaryotes, making a substantial contribution to their diversity. In retracing the multicellularity of eukaryotes, deep-time fossil records play an irreplaceable role. In this paper, we report a new acritarch Concavaesphaera ornata gen. et sp. nov. from the early Cambrian Kuanchuanpu biota (535 Ma). These fossils are generally spherical, with diameters ranging from 450 to 950 \u03bcm, and feature an envelope with complex ornament. Inside, there are two groups of cells varying in size. Larger cells are relatively fewer in number and each resides within a sac-like cavity distributed along the inner wall of the envelope. Statistical data show a positive correlation between the diameter and cavity volume during the development of large cells. Small cells are numerous, have a diameter of about 15 \u03bcm, and fill the entire interior of the specimens. We interpret the large cells as reproductive cells and the small cells as somatic cells. These observations show that Concavaesphaera evolved multicellular complexity equivalent to that of modern Volvox, with germ-soma differentiation and separation. Available evidence suggests that the similarities between Concavaesphaera and Volvox are more likely to be the result of convergent evolution. Therefore, Concavaesphaera may represent an extinct multicellular eukaryote which evolved during the Cambrian explosion and probably documented an independent innovation of multicellularity in eukaryotic evolutionary history. This implies that multicellularity evolved many more times in eukaryotes than previously estimated.", "keyphrases": ["concavaesphaera ornata", "germ-soma differentiation", "multicellularity", "cambrian", "acritarch", "kuanchuanpu biota"]}
{"id": "https://doi.org/10.1002/spp2.1513", "title": "Adult branchiosaurid temnospondyls: the life cycle of Xerodromeus gracilis", "abstract": "Abstract The Branchiosauridae form a clade of tiny newt-like, extinct amphibians of overall larval appearance. Although their status as neotenic (perennibranchiate) forms had long been universally accepted, adult specimens are known from only one taxon that was hitherto referred to as Melanerpeton (Apateon) gracile. Here we study this life cycle in depth, which includes the only well-documented metamorphosis-like transformation in an early tetrapod outside Lissamphibia. Based on various newly recognized features, Melanerpeton gracile is attributed to a new genus, Xerodromeus. Xerodromeus gracilis is characterized by a short postorbital skull table, wide supratemporal, quadrate condyles well posterior to the occipital ones, ossified endocranial elements, carpals, coracoid and pelvis as well as wedge-shaped intercentra and cylindrical pleurocentra, of which the latter are identified for the first time in branchiosaurids. The studied size classes are referred to four phases: (A) integration of jaw and cheek, longer snout; (B) stronger teeth, robust limbs, incipient ossification of exoccipital, coracoid and pelvis, change in dermal ornament; (C) larger gape, wider skull, polygonal ornament; and (D) quadrate, coracoid, carpals and vertebral centra ossified, during which a probably terrestrial adult morph developed. Adult X. gracilis is more massively built than amphibamids, and its non-pedicellate dentition indicates that it was probably feeding on different prey.", "keyphrases": ["amphibamiformes", "development", "dissorophoidea", "phylogeny", "temnospondyli"]}
{"id": "https://doi.org/10.1002/spp2.1514", "title": "The last horned armadillos: phylogeny and decline of Peltephilidae (Xenarthra, Cingulata)", "abstract": "Abstract Peltephilidae (Xenarthra, Cingulata) is an ancient lineage of medium\u2013large-sized \u2018armadillos\u2019 from South America, characterized by chisel-shaped molariforms, a U-shaped dental arcade, and cephalic osteoderms modified into hornlike structures. Although the biochron of the group extends from the early Eocene to the Late Miocene, the most abundant and complete records come from the Early Miocene of Patagonia. Remains from the Late Miocene are very scarce, and the last records of the group are from the Chasicoan Stage (Tortonian). The only taxon known from this interval is Epipeltephilus kanti from the Arroyo Chasic\u00f3 Formation (9.23 \u00b1 0.09 Ma; Buenos Aires Province, Argentina), a species previously represented only by a few isolated osteoderms. Here we report new remains assigned to E. kanti from the Late Miocene of Loma de Las Tapias Formation (c. 9.0\u20137.8 Ma; San Juan Province, Argentina), including a hemimandible and several fixed and mobile osteoderms. These new specimens constitute the youngest record of Peltephilidae. The inclusion of E. kanti within Epipeltephilus and the monophyly of the genera Peltephilus and Epipeltephilus are corroborated for the first time through a cladistic analysis. The decline and eventual disappearance of this \u2018armadillo\u2019 group in the Late Miocene is chronologically coincident with the replacement of subtropical/tropical environments by more open and arid ones and with the proliferation of other large armadillos such as Vetelia, Macrochorobates, and Macroeuphractus.", "keyphrases": ["cenozoic", "epipeltephilus", "evolutionary history", "miocene", "peltephilus", "xenarthra"]}
{"id": "https://doi.org/10.1002/spp2.1512", "title": "The dental system of \u2020Kazanichthys viatkensis (Actinopterygii, Acrolepididae) from the middle Permian of European Russia: palaeobiological and palaeoecological inferences", "abstract": "Abstract Among ray-finned fishes (Actinopterygii), the crushing, durophagous feeding strategy first evolved in the early Carboniferous period, with the \u2020Eurynotiformes possessing dentitions with single layers of partially to fully fused blunt teeth. In the \u2020\u2018Platysomidae\u2019 (Permian), a new form of crushing dentition evolved (phyllodonty), in which multiple layers of superimposed crushing teeth developed intraosseously, within the jaw. The phyllodont durophagous dentition is also recovered from later-occurring taxa originating mainly in the Mesozoic, such as the \u2020Bobastraniiformes, the neopterygians \u2020Pycnodontiformes and Ginglymodi, and in the teleost group \u2020Phyllodonta. By comparison, \u2020Kazanichthys viatkensis, an actinopterygian from the middle Permian of European Russia, is characterized by a third, putatively durophagous dentition, with anterior conical teeth and closely packed molariform teeth on the buccal dental plates (a potential similarity with eurynotiforms). Whereas the conical teeth are similar to those of basal actinopterygians, the molariform teeth superficially resemble teeth of some teleosts (Characiformes, Tetraodontiformes), but are unique among known fossil and living Actinopterygii in being crowned by anastomosing, sharp apical ridges. Teeth are ankylosed to the jaw and acrodont in implantation. There is neither evidence of plicidentine, nor cavities corresponding to intraosseous crypts. Most replacement teeth formed extraosseously, differing from the phyllodont dentition, but similar to several more phylogenetically basal actinopterygians. The dental system morphologically resembles recent Sparidae (Teleostei; Perciformes), possibly indicating a similar trophic adaptation. Based on these comparisons and patterns of wear, we propose that \u2020K. viatkensis was a generalist durophagous feeder, with the ability to switch prey types with its unique and complex dentition.", "keyphrases": ["actinopterygii", "permian", "durophagy", "evolution"]}
{"id": "https://doi.org/10.1002/spp2.1515", "title": "New insights into the sea spider fauna (Arthropoda, Pycnogonida) of La Voulte-sur-Rh\u00f4ne, France (Jurassic, Callovian)", "abstract": "Abstract Three species of sea spider (Arthropoda, Pycnogonida) have been described from the Middle Jurassic (Callovian) Konservat-Lagerst\u00e4tte of La Voulte-sur-Rh\u00f4ne: Palaeopycnogonides gracilis, Colossopantopodus boissinensis and Palaeoendeis elmii. These fossils were initially attributed to three extant families or superfamilies, justifying their use as calibration points in a recent tree-dating analysis. However, their taxonomic affinities are still debated. Our knowledge of the morphology of these Jurassic sea spiders is limited by prior investigation with only light microscopy and radiographs, such that further morphological details such as cephalic appendages (chelifores, palps, ovigers) remain poorly documented. Here, we reinvestigate the La Voulte-sur-Rh\u00f4ne fossils using x-ray microtomography and reflectance transformation imaging. A new specimen, tentatively attributed to P. gracilis, was found using x-ray microtomography, while another fossil initially interpreted as Palaeoendeis elmii may also be related to this species. We attribute all fossils to Pantopoda, crown-group Pycnogonida. Palaeopycnogonides gracilis had ovigers in at least one sex and had chelifores and palps that were either reduced or absent. Together, the cephalic appendage set and the structure of the ovigers are unique among Pantopoda, and this species is reassigned to the new family Palaeopycnogonididae. Colossopantopodus boissinensis lacked chelifores but had palps and ovigers, the latter with the typical structure shown by extant Colossendeinae, to which we attribute the fossil. The absence of chelifores and palps in Palaeoendeis elmii and the structure of its ovigers indicate affinities with Endeidae. The impact of these new taxonomic assignments on the way Jurassic sea spiders can be used as fossil calibrations is discussed.", "keyphrases": ["pycnogonida", "pantopoda", "konservat-lagerst\u00e4tte", "jurassic", "reflectance transformation imaging", "x-ray microtomography"]}
{"id": "https://doi.org/10.1002/spp2.1519", "title": "Cryptic moulting behaviour of some Carboniferous Ostracoda", "abstract": "Abstract Monospecific accumulations of ostracods, represented by spine-bearing Janischewskya? sp. and a smooth-shelled Cavellina? sp., were detected inside the body chamber, siphuncle and camerae of three cephalopod specimens (a nautiloid and two goniatites) from the Carboniferous (Mississippian) Cracoean reefs of North Yorkshire, UK. The ostracods occur as isolated valves packed together and are well-preserved, with delicate spines of Janischewskya? sp. still intact on numerous specimens. Such a mode of ostracod preservation inside the cephalopod conchs and their paucity in the surrounding matrix outside the shells indicate that the valves were not concentrated due to sedimentary processes. Rather, the ostracods deliberately entered the empty cephalopod shells in order to seek sheltered habitats for moulting. In the case of the smooth-shelled Cavellina? sp., the ostracod valves preserved inside a camera of the nautiloid have similar size, indicating that a synchronized mass moulting took place in this species. Additionally, the presence of putative eggs closely associated with the spine-bearing Janischewskya? sp. valves inside a siphuncle of the nautiloid shows that the empty conchs could have also served as safe places for egg deposition. The present finds are thus the first examples of cryptic moulting behaviour in ostracods. They also imply that such behaviour in this group of arthropods has a long evolutionary history, at least since the Carboniferous, and potentially may persist in present day ostracods.", "keyphrases": ["arthropoda", "ostracoda", "ecdysis", "palaeoecology", "mississippian", "palaeozoic"]}
{"id": "https://doi.org/10.1002/spp2.1518", "title": "Eucera bees (Hymenoptera, Apidae, Eucerini) preserved in their brood cells from late Holocene (middle Neoglacial) palaeosols of southwest Portugal", "abstract": "Abstract The c. 100 myr extensive fossil record of bee brood nests and cells (calichnia) in siliciclastic sedimentary deposits, or palaeosols, is virtually devoid of the presence of their producers. The absence of a more specific assignment to a producer of the different ichnogenera of the ichnofamily Celliformidae precludes their use in phylogenetic and palaeobiogeographic studies. Omission surfaces developed in incipient carbonate palaeosols during the late Holocene (middle Neoglacial), c. 2975 yr cal BP, on the southwest coast of mainland Portugal show insect calichnia in dense ichnofabrics dominated by shallow discrete cells (Palmiraichnus castellanosi) and cells at the terminus of vertical shafts. At Carreira Brava, one of the studied sites, bees ready to abandon their cells were found in an exceptional state of preservation inside the sealed brood chambers. The chambers also preserve the inner cell hydrophobic polymerized membrane and remains of the monospecific Brassicaceae-type pollen provision. Although the cause of mass mortality remains a mystery, oxygen depletion due to sudden flooding of the nesting substrate and consequent or overnight temperature drop, just before emergence, are plausible causes. The anaerobic conditions and later rapid carbonate diagenetic lithification are the likely causes of the preservation of the bees and the inner cell organic membrane. The favourable climate conditions for the development of successive, dense ichnofabrics from an omission suite dominated by bee brood cells may be the result of slightly colder and higher-precipitation winters during the Neoglacial interval.", "keyphrases": ["brood cell", "palmiraichnus castellanosi", "eucera", "palaeosol", "neoglacial", "portugal"]}
{"id": "https://doi.org/10.1002/spp2.1517", "title": "The siphonotretide brachiopod Schizambon from the Early Ordovician of South China: ontogeny and affinity", "abstract": "Abstract Schizambon is one of the earliest and most distinctive genera in the Order Siphonotretida. However, current knowledge of siphonotretide phylogeny and early evolution requires understanding of their earliest ontogeny. In this study, the new species Schizambon tongziensis from the Tungtzu Formation at Honghuayuan section in Guizhou Province, South China is described; it is also the first record of Schizambon in South China. The new well-preserved specimens shed light on the ontogeny, palaeobiogeographical distribution, phylogeny and early evolution of siphonotretide brachiopods. Characters of metamorphic shells on both valves, outlined by distinct halos, show that Schizambon had a planktotrophic \u2018paterinide-type\u2019 larva, typical of many early Palaeozoic brachiopods. Based on the newly obtained data it is inferred that the free-swimming larva of Schizambon settled directly on the ventral side of the body, and this type of ontogeny is probably true for other siphonotretides. The divergence of Schizambon from the main siphonotretide lineage probably happened prior to the Guzhangian Age, well before the occurrence of major biodiversification within the order.", "keyphrases": ["linguliformea", "siphonotretida", "tremadocian", "ontogeny", "evolution", "planktotrophic larva"]}
{"id": "https://doi.org/10.1002/spp2.1520", "title": "Healed injuries, ontogeny and scleritome construction in a Late Ordovician machaeridian (Annelida, Aphroditiformia)", "abstract": "Abstract Machaeridians are armoured annelids that were morphologically diverse during the Palaeozoic. The scleritome developed from fleshy protrusions at the base of each parapodium, with alternating segments giving rise to differentiated inner and outer shell plates. The elytra-like anatomy of the shell-bearing soft tissues and distinctive jaw apparatus support an affinity of machaeridians with aphroditacean scaleworms. While frequently found as disarticulated remains, whole scleritomes of machaeridians are rare. Only a few species are represented by multiple articulated individuals, rendering many aspects of our knowledge of scleritome construction and growth uncertain. Here we describe a collection of articulated scleritomes of the plumulitid machaeridian Plumulites tafennaensis Chauvel from the Upper Ordovician (Katian) Upper Tiouririne Formation of Morocco that includes individuals representing both adult and juvenile stages. These scleritomes shed light on the morphology of the anterior region in plumulitids and show an increase in the number of shell plates with increasing size, suggesting that unlike some derived lepidocoleids, at least some plumulitids added segments repeatedly during ontogeny. Shell plates with a distinctive umbo have previously been assigned exclusively to the anterior region, but our material shows that they are present along the scleritome, with corresponding sclerites on the opposite side of the skeleton showing normal morphologies. We suggest that these plates are abnormal and best explained as healed injuries, replacing plates that had been previously removed from the body, demonstrating the capacity for machaeridians to regenerate lost body parts, a feature that is widespread in living annelids.", "keyphrases": ["machaeridia", "plumulites", "katian", "annelida"]}
{"id": "https://doi.org/10.1002/spp2.1526", "title": "A review of the glacial environment arthropod trace fossils Umfolozia and Warvichnium with the description of new ichnotaxa", "abstract": "Abstract Trace fossils are important records of the presence and behaviour of animals in the past, especially in deposits where few body fossils are preserved. They tend to provide the main palaeobiological record for past glacial environments, and are thus very important for understanding the ecology of these palaeoenvironments. Two ichnogenera are common in glacial sediments: Umfolozia and Warvichnium. Both Umfolozia and Warvichnium are attributed to arthropods; the former occurs across the Late Palaeozoic Ice Age (LPIA) and the latter occurs during both the LPIA and the Quaternary glacial event. Here, we review the stratigraphic record, ichnotaxonomy, palaeoecology, palaeoenvironments and possible tracemakers of these two ichnogenera. In addition to assessing morphological ichnotaxobases, we use multivariate morphometric analysis and inferential statistical tests to support our ichnotaxonomic revisions. The diagnosis of Umfolozia is revised, with the description of a new ichnospecies, Umfolozia terere, and the emendation of Umfolozia riojana (formerly Umfolozia longula). We revised Warvichnium, maintaining the original Warvichnium ulbrichi and allocating two morphologies to the ichnogenus Irichnus: Irichnus saltatorius and I. paripinnatus isp. nov. These trace fossils record several behaviours, and have implications for palaeoenvironmental interpretations and the evolution of invertebrate ecosystems. Using Umfolozia and Warvichnium as case studies, we demonstrate the application of morphometric analysis in ichnotaxonomy and highlight this as a tool that may be applied to other trace-fossil groups.", "keyphrases": ["arthropod trackway", "ichnotaxonomy", "crustacean trace fossil", "statistics", "morphometrics"]}
{"id": "https://doi.org/10.1002/spp2.1521", "title": "A description of the palate and mandible of Youngina capensis (Sauropsida, Diapsida) based on synchrotron tomography, and the phylogenetic implications", "abstract": "Abstract The late Permian reptile Youngina capensis (c. 254 Ma) is a non-saurian neodiapsid whose anatomy has been used to represent the reptilian condition prior to the divergence of Sauria (crown-group reptiles). However, despite being first described over 100 years ago, the anatomy of Youngina remains incompletely documented. Here we use synchrotron x-ray micro-computed tomography to document new features of the palate, braincase and mandible of Youngina. New observations include an anteriorly bifurcating vomer, dentition on the ventral surface of the parasphenoid body and cultriform process, and a strongly convex coronoid eminence. Our anatomical observations suggest that Youngina may represent a more stemward lineage among non-saurian neodiapsids and this is supported by our phylogenetic analysis, which places Youngina as an early diverging neodiapsid. Our research will benefit future studies on saurian origins by providing improved constraints on neodiapsid anatomy prior to the divergence of the reptilian crown group.", "keyphrases": ["neodiapsida", "sauria", "phylogeny", "synchrotron tomography", "reptile evolution", "permian"]}
{"id": "https://doi.org/10.1002/spp2.1522", "title": "A micromorphological analysis of Bolonia lata Meunier from the Cretaceous of the Neuqu\u00e9n Basin (Patagonia, Argentina): new insights into the tracemaker", "abstract": "Abstract Polychaetes, echinoids and gastropods have been proposed as tracemakers for Bolonia Meunier, an elongate positive epirelief trace fossil characterized by two lobes composed of biserial, subtriangular pads and a mostly heart-shaped cross-section. Here, the internal structure and micromorphology of Bolonia are described for the first time using serial thin sections from shallow-marine Lower Cretaceous intervals of the Agrio Formation (Neuqu\u00e9n Basin, Argentina). In vertical thin sections, a conical structure of variable width extends centrally from the base to the top of the trace. In horizontal thin sections, grains are reoriented and reworked, forming a central zigzag structure. The organic matter and clays form grain aggregates representing the internal structure of individual pads of the trace fossil. The sediment has mostly been reoriented, with grains making up subcircular pods. We interpret the central conical structure as the collapse of the medial zone of the trace fossil, which could have destroyed drain tubes, especially in the absence of early cementation. Studying horizontal thin sections, we reconstruct the diagnostic biserial pads as biserial concave structures. These are interpreted as backfilling structures produced by the aboral and lateral spines of irregular echinoids, which worked together to compact the sediment anteroposteriorly and moved alternatively, explaining the zigzag pattern in the menisci. We propose Spatangoidea or Cassiduloidea (or a closely related group) with a similar burrowing ability and spine movement as tracemakers of these Bolonia specimens.", "keyphrases": ["patagonia", "palaeoecology", "ichnology", "echinoderm", "early cretaceous", "thin section"]}
{"id": "https://doi.org/10.1002/spp2.1524", "title": "First report of silicified wood from a late Pennsylvanian intramontane basin in the Pyrenees: systematic affinities and palaeoecological implications", "abstract": "Abstract The first anatomically preserved wood specimens of an upland Carboniferous flora from the Iberian Peninsula are reported from the Erillcastell Basin (Eastern Pyrenees, Catalonia, Spain). Two taxa are described, a calamitacean Equisetales (Arthropitys sp.) and a Cordaitales (Dadoxylon sp.). The Arthropitys specimen has fusiform multiseriate rays composed of square parenchyma cells with conspicuous uniseriate or multiseriate simple pits. These pits are located near the transverse walls and occasionally in the tangential walls. The tracheids vary in lumen size, with scalariform-bordered pits on their radial walls and multiseriate pits in their cross-field areas. The Dadoxylon specimen commonly has uniseriate fusiform rays. The tracheids are long, with a square shape in transverse section. Their radial walls bear araucarian pitting with a uniseriate to triseriate arrangement. The pits are circular with a spindle-shaped aperture. Comparison of the Erillcastell specimens with coeval species from Europe indicates that they could belong to new species. The good preservation of the new fossil wood yields significant palaeoenvironmental information. The lack of marked growth rings in both specimens and the presence of tyloses in Dadoxylon suggest that the climate in the intramontane basins of the Pyrenees was slightly seasonal towards the end of the Carboniferous. This contrasts with the marked seasonality of coeval lowland basins. Such upland habitats may have enhanced the survival of plants adapted to humid conditions in a global context of increasing aridity.", "keyphrases": ["cordaites", "calamites", "silicified wood", "upland flora", "pyrenees", "iberian peninsula"]}
{"id": "https://doi.org/10.1002/spp2.1516", "title": "Trilobites of Thailand's Cambrian\u2013Ordovician Tarutao Group and their geological setting", "abstract": "Abstract Tuff-bearing upper Cambrian to lowermost Ordovician strata on Ko Tarutao island, Satun province, southernmost peninsular Thailand, contain a rich trilobite fauna relevant to global biostratigraphy, peri-Gondwanan palaeogeography and shifting evolutionary mode. This area of Sibumasu, a lower Palaeozoic marginal Gondwanan terrane, is shown to have been closely associated with Australia, North China (Sino-Korea) and other continental fragments from the supercontinent's northern equatorial sector, including South China at that time. Shared faunas also suggest a Kazakhstani and Laurentian association. Collections from eight sections yielded 10 newly discovered species and one new genus from ancient shoreface and inner shelf siliciclastic deposits. With the new taxa and revision of taxa known previously, we refine the age of the upper two formations of the Tarutao Group to the middle of Cambrian Stage 10, and lower\u2013middle Tremadocian. Two biozones are erected for Sibumasu: the Eosaukia buravasi Zone, encompassing all Cambrian sections from Ko Tarutao, and the Asaphellus charoenmiti Zone, encompassing the Tremadocian fauna discussed herein. The new genus is Tarutaoia and new species are Tsinania sirindhornae, Pseudokoldinioidia maneekuti, Pagodia? uhleini, Asaphellus charoenmiti, Tarutaoia techawani, Jiia talowaois, Caznaia imsamuti, Anderssonella undulata, Lophosaukia nuchanongi and Corbinia perforata. Other taxa reported for the first time from Tarutao are Mansuyia? sp., Parakoldinioidia callosa Qian, Pseudagnostus sp., Homagnostus sp., Haniwa mucronata Shergold, Haniwa sosanensis? Kobayashi, Lichengia simplex Shergold, Pacootasaukia sp., Wuhuia? sp., Plethopeltella sp., Apatokephalus sp., Akoldinioidia sp. 1 and Koldinioidia sp.", "keyphrases": ["thailand", "trilobita", "cambrian", "ordovician", "sibumasu", "gondwana"]}
{"id": "https://doi.org/10.1002/spp2.1523", "title": "The last Baru (Crocodylia, Mekosuchinae): a new species of \u2018cleaver-headed crocodile\u2019 from central Australia and the turnover of crocodylians during the Late Miocene in Australia", "abstract": "Abstract Baru is a genus that includes several large mekosuchine crocodylians from the Oligo-Miocene of Australia. Here we describe Baru iylwenpeny sp. nov. from a large sample of cranial bones from the Upper Miocene Alcoota Local Fauna of the Northern Territory. Baru iylwenpeny can be diagnosed by several autapomorphies that include, but are not limited to: extreme reduction of the pneumatic foramina associated with the diverticula that invade the bones of the suspensorium; and enlargement of the postcaniniform maxillary teeth resulting in crowding of the postcaniniform alveoli and a reduction in the number of maxillary alveoli to 12. The new species is the geologically youngest known member of the genus. While species of Baru are a ubiquitous component of Oligo-Miocene crocodylian assemblages from northern Australia, they are absent from all known Plio-Pleistocene sites, suggesting the extinction of the genus by the latest Miocene. We suggest that the marked taxonomic turnover of crocodylian assemblages between the Upper Miocene Alcoota Local Fauna and the Lower Pliocene is the result of a short period of severe aridity during the latest Miocene, causing widespread crocodylian extinctions across Australia, followed by the establishment of taxonomically novel crocodylian faunas in the Pliocene. This event mirrors similar contemporary losses of crocodylian diversity in Africa and South America, although these cases are partly driven by local tectonic events. It is likely that late Cenozoic global cooling also played a role in these extinctions.", "keyphrases": ["baru", "crocodile", "mekosuchinae", "miocene", "australia", "extinction"]}
{"id": "https://doi.org/10.1002/spp2.1525", "title": "Evolutionary process of extremely twisted heteromorph ammonites from the Upper Cretaceous of Japan", "abstract": "Abstract The heteromorph ammonite Pravitoceras sigmoidale with extremely twisted retroversal hook and its probable ancestors, Didymoceras awajiense and D. morozumii, occur mainly in the Upper Cretaceous Izumi and Sotoizumi groups in southwest Japan. Their morphological characteristics were investigated in this study. Morphotypes I\u2013II were recognized in D. morozumii. Morphotypes III\u2013V were recognized in D. awajiense. Morphotypes VI\u2013VIII were recognized in P. sigmoidale. Moreover, all morphotypes were recognized in both the dextral and sinistral forms of these three species. Based on the morphological and stratigraphic relationships, it is considered that the evolutionary process of these species is divided into three steps: (1) shift from morphotypes I\u2013II to III; (2) increase in variation from morphotypes III to III\u2013V; and (3) shift from morphotypes III\u2013V to VI\u2013VIII. By comparing these morphotypes based on the \u2018growing tube model\u2019 belonging to the moving frame analysis, it is seen that there are no significant gaps of coiling patterns in the evolutionary processes of this lineage. Meanwhile, morphotypes III\u2013V of D. awajiense have a larger morphological variation than morphotypes I\u2013II of D. morozumii and morphotypes VI\u2013VIII of P. sigmoidale. These results, and the radiometric ages from previous studies, suggest that D. awajiense, with considerable variation between ancestor and descendant species, existed in a short interval. It seems that P. sigmoidale occurred after the continuous but rapid and drastic morphological evolution from D. morozumii via D. awajiense.", "keyphrases": ["ammonite", "cretaceous", "didymoceras", "heteromorph", "nostoceratidae", "pravitoceras"]}
{"id": "https://doi.org/10.1002/spp2.1528", "title": "Newly discovered morphology of the Silurian sea spider Haliestes and its implications", "abstract": "Abstract The three-dimensionally preserved Haliestes dasos from the Silurian (Wenlock) Lagerst\u00e4tte is the most complete fossil sea spider and the oldest unambiguous pycnogonid known from the fossil record. The discovery of two new specimens to add to the holotype reveals new features including proximal annulations of the appendages and segmentation of the trunk end, critical details for comparison with pycnogonids from the Devonian (Emsian) Hunsr\u00fcck Slate and for the interpretation of the evolutionary significance of Palaeozoic genera. There is some evidence of sexual dimorphism. Haliestes dasos was nektobenthic and its morphology indicates an unusual mode of feeding compared with living pycnogonids. The new morphological features of H. dasos are closely similar to those in Palaeoisopus problematicus from the Hunsr\u00fcck Slate and it clearly belongs, together with that species, in stem Pycnogonida and not the crown group.", "keyphrases": ["herefordshire lagerst\u00e4tte", "silurian", "arthropoda", "pycnogonida", "pantopoda", "haliestes"]}
{"id": "https://doi.org/10.1002/spp2.1527", "title": "The Late Miocene mammals from the Humahuaca Basin (northwestern Argentina) provide new evidence on the initial stages of the Great American Biotic Interchange", "abstract": "Abstract We describe new Late Miocene mammalian specimens from the Maimar\u00e1 Formation (Late Miocene to Early Pliocene) exposed at Humahuaca Basin (23\u00b0\u201324\u00b0S), northwestern Argentina (NWA), and analyse their taxonomy and relevance for our understanding of the initial stages of the Great American Biotic Interchange (GABI). The stratigraphical and geochronological control of the studied specimens indicates a time window of c. 6.6\u20135.8 Ma. These data are crucial for establishing the oldest records of the Holarctic immigrants of the GABI. The first record of cricetid rodents from the Maimar\u00e1 Formation is reported. Moreover, with an age of c. 6 Ma it is the first appearance datum (FAD) of these rodents in South America. The age of the procyonid Cyonasua recorded in this unit is estimated between c. 6.6 and c. 6.4 Ma. The record of procyonids and cricetids in the same continuous sedimentary sequence suggests that the time interval between the dispersion of both groups into the continent during GABI was c. 1 myr. Of the autochthonous mammals from the Maimar\u00e1 Formation, the first records of litopterns, chlamyphorid and mylodontine xenarthrans, and caviomorph rodents (including new species Pithanotomys? solisae and Palaeocavia humahuaquense) are described. FADs of immigrant and autochthonous mammals in NWA suggest a major faunal turnover during GABI at the Messinian, probably linked to global climatic changes and the tectonic activity that affected the Humahuaca Basin at that time. Hypsodonty, a dominant feature among Maimaran mammals, may be related to a landscape strongly influenced by the Andean uplift.", "keyphrases": ["late miocene", "humahuaca basin", "great american biotic interchange", "cricetid", "procyonid", "faunal turnover"]}
{"id": "https://doi.org/10.1002/spp2.1529", "title": "Evaluating growth in Macrospondylus bollensis (Crocodylomorpha, Teleosauroidea) in the Toarcian Posidonia Shale, Germany", "abstract": "Abstract The study of how organisms grow is a fundamental aspect of palaeontology. Growth in teleosauroids is poorly understood and little studied, especially in an ontogenetic sense. We investigate growth rates of the most common and abundant teleosauroid, Macrospondylus bollensis, in which a large sample of multiple body sizes is available from the Posidonienschiefer Formation (Posidonia Shale) of southwestern Germany. We perform linear regression analyses on 62 specimens of Macrospondylus (16 juveniles, 7 subadults and 39 adults) using 21 cranial and postcranial measurements. Our results show that juvenile, subadult and adult individuals have near-isometric or isometric growth throughout much of the body. Notably, we find that in Macrospondylus: (1) the femur grows at a faster rate than the skull and hindlimb zeugopodium; (2) the forelimb and hindlimb grow at the same rate; and (3) there is distinct ontogenetic signal in the growth of the orbit and supratemporal fenestra. We also find that limb scaling in Macrospondylus is somewhat comparable to that seen in the extant gavialids Gavialis gangeticus and Tomistoma schlegelii. Last, we examine evolutionary allometry in skull length relative to body size in Crocodylomorpha using femoral length as a proxy, which shows a near-isometric trend. Non-thalattosuchian crocodylomorphs (with the exception of one pholidosaurid and one dryosaurid taxon) are differentiated from thalattosuchians due to their shorter skulls, as previously suggested, but the scaling relationship with femur length remains unchanged.", "keyphrases": ["teleosauroidea", "crocodylomorpha", "evolutionary allometry", "ontogenetic allometry", "macrospondylus bollensis", "posidonia shale formation"]}
{"id": "https://doi.org/10.1002/spp2.1530", "title": "Elucidating the morphology and ecology of Eoandromeda octobrachiata from the Ediacaran of South Australia", "abstract": "Abstract Eoandromeda octobrachiata is a poorly understood Ediacaran organism, with spiral octoradial arms, found in South Australia and South China. The informal Nilpena member of the Rawnsley Quartzite, Flinders Ranges in South Australia preserves more than 200 specimens of Eoandromeda. Here we use the novel application of rotational geometric morphometrics together with palaeoenvironmental information to provide a better insight into their palaeobiology and ecology, and to address conflicting hypotheses regarding mode of life and taxonomic affinity. We find that Eoandromeda probably had a radially symmetrical shape in life, was cone shaped and had a high relief off the microbial mat. Analysis of the symmetric and asymmetric shape components showed that they deform strongly in the direction of palaeocurrent, therefore they are thought to be made of a flexible material. Almost all specimens are compressed flat. Specimens that appear to have not fully collapsed support the idea that Eoandromeda was probably cone shaped and suggest that they possibly collapsed spirally. Our shape analysis, along with observed morphological features, support a benthic rather than pelagic mode of life. Morphological and ecological inconsistencies do not fully support the hypothesis of a Ctenophora taxonomic affinity.", "keyphrases": ["ediacara", "eoandromeda", "south australia", "morphometrics", "benthic"]}
{"id": "https://doi.org/10.1002/spp2.1532", "title": "Katian (Late Ordovician) trilobites of the North Qilian Mountains and their palaeogeographical implications for the Proto-Tethys Archipelagic Ocean", "abstract": "Abstract Trilobites from the middle Koumenzi Formation (Katian, Upper Ordovician) of the North Qilian Mountains, Menyuan, northeastern Qinghai Province are systematically documented for the first time. The fauna consists of five families, seven genera and seven species, one of which is new (Remopleurides zhangi), showing a close relationship to those of the Kazakh terranes (such as the Chu-Ili terrane, Chingiz-Tarbagatai area and the Karatau-Naryn and North-Tien Shan microcontinents), and the North China and Laurentia palaeoplates during the Katian (Late Ordovician). The cluster and non-metric multidimensional scaling analyses of the Middle\u2013Late Ordovician (late Darriwilian\u2013Katian) trilobite faunas with 299 genera or subgenera from 46 horizons of 37 areas, provide valuable information for the palaeogeographical reconstruction of the Proto-Tethys Archipelagic Ocean (PTAO) of this interval. The Qilian terrane and adjacent areas are essential components of the PTAO, some of which include the Qilian terrane, the North Qilian Mountains area, the Altun faulted terrane, the Hexi Corridor area and the East Qinling terrane. Their relative positions in the PTAO are inferred by the palaeobiogeography of trilobite faunas. Furthermore, based on discussions of the spatiotemporal distribution of those faunas, the Pliomerina and/or Sinocybele Province of the Middle\u2013Late Ordovician (late Darriwilian\u2013Katian) age is defined as a trilobite faunal province of the PTAO. Moreover, a distinct faunal subprovince, essentially comprising the South China Palaeoplate and its neighbours (e.g. Tarim, Annamia, Sibuma, East Qinling, Turkestan-Alai and probably Talesh), might be surrounded by the equatorial cold-water tongue.", "keyphrases": ["late ordovician", "trilobite", "north qilian mountains", "proto-tethys archipelagic ocean (ptao)", "palaeogeographical reconstruction", "faunal province"]}
{"id": "https://doi.org/10.1002/spp2.1531", "title": "Three-dimensional reconstruction, taphonomic and petrological data suggest that the oldest record of bioturbation is a body fossil coquina", "abstract": "Abstract Fossil material assigned to Nenoxites from the late Ediacaran Khatyspyt Formation of Arctic Siberia (550\u2013544 Ma) has been presented as evidence for bioturbation prior to the basal Cambrian boundary. However, that ichnological interpretation has been challenged, and descriptions of similar material from other global localities support a body fossil origin. Here we combine x-ray computed tomography, scanning electron microscopy and petrographic methods to evaluate the body or trace fossil nature of Nenoxites from the Khatyspyt Formation. The fossilized structures consist of densely packed chains of three-dimensionally preserved silicic, bowl-shaped elements surrounded by distinct sedimentary halos, in a dolomitized matrix. Individual bowl-shaped elements can exhibit diffuse mineralogical boundaries and bridging connections between elements, both considered here to result from silicification and dolomitization during diagenesis. This new morphological and petrological evidence, in conjunction with recent studies of the late Ediacaran tubular taxa Ordinilunulatus and Shaanxilithes from China, suggest that the Khatyspyt specimens most probably reflect a coquina deposit of Shaanxilithes-like body fossils. Our data support the possibility of Shaanxilithes-like organisms representing total group eumetazoans.", "keyphrases": ["ediacaran", "sedimentology", "taphonomy", "nenoxites", "bioturbation", "petrology"]}
{"id": "https://doi.org/10.1002/spp2.1535", "title": "Two new species of small-bodied pachycephalosaurine (Dinosauria, Marginocephalia) from the uppermost Cretaceous of North America suggest hidden diversity in well-sampled formations", "abstract": "Abstract Here we report two new small-bodied pachycephalosaurines: one from the Dinosaur Park Formation of Alberta and the other from the Hell Creek Formation of Montana, each represented by an isolated squamosal. These two new specimens are approximately the same size as squamosals of Sphaerotholus buchholtzae, and possess several overlapping morphologies with the genus (such as a strongly posteroventrally projecting and laterally tapering parietosquamosal bar). Therefore, these two new specimens are identified as belonging to the genus Sphaerotholus. However, a suite of characters and combinations differentiate these two new specimens from the other three Sphaerotholus species. Most notably, they possess multiple posterior and lateral node rows on the squamosal, and lack a parietosquamosal node (a single row and a parietosquamosal node define these other species in the genus). Specifically, the Alberta specimen possesses two posterior and two lateral node rows, whereas the Montana specimen has three of each. This analysis provides phylogenetic support for the evolutionary hypothesis that a single-rowed and parietosquamosal node-less taxon underwent a cladogenetic event that gave rise to a single-rowed and parietosquamosal node-bearing lineage and a multi-rowed, parietosquamosal node-less lineage (the two taxa described herein). In turn, these two Sphaerotholus lineages possibly underwent anagenetic change throughout the latest Maastrichtian. Additionally, these new taxa suggest that while large-bodied taxa from well sampled formations are to be found with decreasing frequency, the inverse holds true for small-bodied taxa and that pachycephalosaurines were more diverse than previously recognized, and continued to diversify up until the very end of the Cretaceous.", "keyphrases": ["pachycephalosauria", "sphaerotholus", "anagenesis", "cladogenesis", "dinosaur park formation", "hell creek formation"]}
{"id": "https://doi.org/10.1002/spp2.1533", "title": "The early Paleocene (Danian) climate of Svalbard based on palaeobotanical data", "abstract": "Abstract The early Paleocene (Danian) Barentsburg flora from the Firkanten Formation, Svalbard, provides a valuable insight into the environment and climate of the Arctic early in the warm Palaeogene prior to the Paleocene\u2013Eocene Thermal Maximum (PETM) event. The flora includes c. 50 species of ferns, ginkgos, conifers and angiosperms. Angiosperms predominate and are represented by the families Platanaceae, Cercidiphyllaceae, Trochodendraceae, Hamamelidaceae, Fagaceae, Betulaceae, Nyssaceae and several taxa of uncertain taxonomic position. Palaeoclimate parameters, calculated using a new calibration of the Climate Leaf Analysis Multivariate Program (CLAMP), indicate that Svalbard in the early Paleocene was characterized by a temperate, maritime, humid, seasonal climate with cool mild winters and warm summers. Humidity was highest during winter months. Short-term winter snow cover and light frosts were likely to have been frequent. The CLAMP analysis yields a mean annual temperature of 10.1 \u00b1 1.98\u00b0\u0421, a warmest month mean temperature of 19.2 \u00b1 2.49\u00b0C and a coldest month mean temperature of 1.7 \u00b1 3.24\u00b0\u0421. The growing season lasted c. 6 months. Precipitation during this growth period was 572.4 \u00b1 296.50 mm, while vapour pressure deficit and potential evapotranspiration indicate very high humidity year-round, with summer being only slightly drier than winter. Taken together with data from other early Paleocene circum-Arctic sites, these results point to highly uniform, temperate and extremely humid conditions around the margins of the early Cenozoic Arctic Ocean. This condition represents the warm background condition that dominated in the Arctic prior to the anomalous extreme warmth of the early Eocene.", "keyphrases": ["paleocene", "palaeoclimate", "spitsbergen", "svalbard", "firkanten formation", "climate leaf analysis multivariate program (clamp)"]}
{"id": "https://doi.org/10.1002/spp2.1534", "title": "A taxonomic revision and cranial description of Terrestrisuchus gracilis (Archosauria, Crocodylomorpha) from the Upper Triassic of Pant-y-Ffynnon Quarry (southern Wales)", "abstract": "Abstract Non-crocodyliform crocodylomorphs, formerly referred to the informal group \u2018Sphenosuchia\u2019, are the earliest known crocodylomorph precursors of extant crocodylians. They are therefore crucial for our understanding of early crocodylian evolution and the origin of typical crocodylian characteristics, such as the formation of a secondary palate, complex cranial pneumaticity, and a reinforced braincase. Terrestrisuchus gracilis, known from the Upper Triassic fissure fill deposits of Pant-y-Ffynnon in southern Wales, is represented by almost 200 specimens, comprising articulated, partially associated, and isolated remains. In this contribution we provide a taxonomic revision of Terrestrisuchus gracilis and redescribe its cranial anatomy in detail, based in part on novel micro-computed tomography data. The posterior skull region is extensively pneumatized as indicated, among other features, by large pre- and postcarotid recesses on the parabasisphenoid, and a large pneumatic cavity in the articular of the mandible. In contrast, the quadrate forms only a small, unfused contact with the prootic, suggesting that complex pneumatization of the postorbital region pre-dated the co-ossification of the quadrate and braincase in Crocodylomorpha. Terrestrisuchus gracilis preserves an ossified basihyal, which represents the first occurrence of this bone in non-avemetatarsalian archosaurs. Finally, we show that Terrestrisuchus gracilis was probably cathemeral (i.e. active in a range of light levels), based on a phylogenetic flexible discriminant analysis of the relative dimensions of the sclerotic ring and orbit.", "keyphrases": ["terrestrisuchus", "crocodylomorpha", "triassic", "ct scanning", "cranial osteology", "braincase pneumaticity"]}
{"id": "https://doi.org/10.1002/spp2.1537", "title": "An enigmatic structure in the tail of vetulicolians from the Cambrian Chengjiang biota, South China", "abstract": "Abstract Cambrian vetulicolians have mosaic characteristics of both deuterostomes and protostomes, which has important implications for the origin and early evolution of the Deuterostomia. They are intriguing in their bizarre body plan with a series of pharyngeal gill slits. The anterior section is characterized by five pairs of gill pouches, while the paddle-like posterior part is composed of seven or more segments. Although the overall external morphology and some internal anatomies of vetulicolians, such as pharyngeal cavity, gill system and alimentary canal, have largely been clarified, mysteries remain regarding some other internal structures, and their functional interpretations are highly controversial. In this study we identify an important but hitherto unrecognized feature: a sub-rounded, wrinkled structure located ventrally at the posterior section (or \u2018tail\u2019) of weakly sclerotized members of vetulicolians, including Xidazoon stephanus and Didazoon haoae, from the early Cambrian Chengjiang biota. The enigmatic structure consistently appears at or between the third and fourth segments of the posterior section. We show that the new structure is an internal organ in the body cavity of vetulicolians and infer that it might have functioned for reproduction, excretion or digestion. The finding of this enigmatic structure from X. stephanus and D. haoae enriches our understanding of vetulicolians and might facilitate further exploration of the anatomy and physiology of early deuterostomes.", "keyphrases": ["vetulicolian", "enigmatic structure", "deuterostome", "early cambrian", "chengjiang biota"]}
{"id": "https://doi.org/10.1002/spp2.1536", "title": "A unique Late Cretaceous fossil wood assemblage from Chilean Patagonia provides clues to a high-latitude continental environment", "abstract": "Abstract Fossil plants, including large trunks, stems, some branches, and twigs, were collected from the Maastrichtian (68.9 Ma), upper Dorotea Formation in the Magallanes\u2013Austral Basin, 16 km north of the Cerro Guido\u2013Las Chinas complex in the southern Chilean Magallanes region. These fossil trunks range from 0.2 to 2.2 m in length. Petrographic slides were made in three sections (transverse, radial and tangential) and analysed under a light microscope to study the permineralized fossils. The woods and stems belong to Austroginkgoxylon gen. et sp. nov., Agathoxylon antarcticum, Podocarpoxylon paradoxi sp. nov., Podocarpoxylon mazzonii, Palmoxylon subantarcticae and Notomalvaceoxylon magallanense gen. et sp. nov. The growth rings of gymnosperms and anatomical characters of angiosperms were analysed to obtain palaeoecological data. Interactions between gymnosperm roots growing into the secondary xylem of an angiosperm (nurse logs) are recorded. The data obtained from the fossil woods suggest warm and humid conditions in this southern South American locality during the Late Cretaceous, providing a unique opportunity to study continental environments at high southern latitudes, which are poorly represented on a global scale.", "keyphrases": ["gymnosperm", "angiosperm", "growth ring", "wood anatomy", "cretaceous", "patagonia"]}
{"id": "https://doi.org/10.1002/spp2.1540", "title": "Evidence for the evolutionary history and diversity of fossil sweetgums: leaves and associated capitate reproductive structures of Liquidambar from the Eocene of Hainan Island, South China", "abstract": "Abstract Extant species of Liquidambar L. exhibit a disjunct distribution between western and eastern Asia and eastern North America to Central America, with the highest species diversity being in China. In this study, two new species of Liquidambar are described from the Eocene of Hainan Island, South China: L. hainanensis on basis of the leaf fossils, and L. ovoidea based on compressions of infructescences. The co-occurrences of L. hainanensis leaves, associated infructescences of L. ovoidea and dispersed pantoporate pollen grains have the combination of morphological features peculiar to the genera Liquidambar and former Semiliquidambar and Altingia. This is considered further palaeobotanical justification for the placement of these three genera into a single genus, Liquidambar, proposed earlier based on molecular markers. Our data provide evidence for the occurrence of an ancestral polymorphic group of Liquidambar species (L. maomingensis with associated capitate infructescences, L. bella, L. hainanensis and L. ovoidea) during the Eocene in South China, and corroborate the view that South China could have been a centre of Liquidambar speciation during the Eocene. The morphological similarity of L. hainanensis leaves to those of the extant species L. orientalis from Western Asia and the North American L. styraciflua may support the importance of both the North Atlantic Land Bridge and the Bering Land Bridge for the dispersal of Liquidambar. Analysis of fossil species of Liquidambar from eastern Asia also contributes to further understanding of patterns in the taxonomic diversity and evolutionary history of this genus.", "keyphrases": ["liquidambar", "eocene", "leaf fossil", "infructescence", "pantoporate pollen grain", "hainan island"]}
{"id": "https://doi.org/10.1002/spp2.1542", "title": "First Eocene\u2013Miocene anuran fossils from Peruvian Amazonia: insights into neotropical frog evolution and diversity", "abstract": "Abstract Anurans are one of the most diverse vertebrate groups, particularly in Amazonia, where species richness exceeds that of anywhere else. Amazonian frogs belong to three main lineages (Hyloidea, Microhylidae and Pipidae), each of which diversified during the Cenozoic. However, due to the virtual absence of an anuran fossil record in that area, the evolutionary history of modern lineages has so far remained accessible only via molecular data. In recent decades, a series of field campaigns in Peruvian Amazonia led to the discovery of an unparalleled set of anuran bone fragments, scattered across different sites spanning the Eocene\u2013Miocene time interval. Here, we describe these first Palaeogene and early Neogene anurans from Peru with a focus on humeral and ilial morphology, identifying five humeral and five ilial morphotypes. Humeral morphotypes suggest the presence of different lineages of Brachycephaloidea in Peruvian fossil assemblages, whereas ilial morphotypes suggest the presence of Leptodactylidae, although leptodactylid-like ilia also occur in some extant brachycephaloids. Pipids were also identified based on both humeral and ilial fragments. This study fills a major temporal and geographical gap in the evolutionary history of South American anurans, while further uncovering a lack of knowledge in the skeletal morphology of extant anuran families, as well as their inter- and intra-species variability.", "keyphrases": ["anura", "amazonia", "brachycephaloidea", "eocene\u2013miocene", "fossil", "pipidae"]}
{"id": "https://doi.org/10.1002/spp2.1539", "title": "Redefining the Huayquerian Stage (Upper Miocene to Lower Pliocene) of the South American chronostratigraphic scale based on biostratigraphical analyses and geochronological dating", "abstract": "Abstract The Huayquerian Stage of the South American chronostratigraphic scheme (named for the Huayquer\u00edas del Este, Argentina) was originally based on a poorly known mammal association of six taxa from the Huayquer\u00edas Formation. We studied the geology, age and fauna of the Neogene sequence in this area, including the Huayquer\u00edas, Tunuy\u00e1n and Bajada Grande formations. The sequence comprises a monotonous succession of synorogenic epiclastic sediments deposited under arid to semi-arid conditions. Zircon U\u2013Pb dates from 10 tuffaceous levels (7.2\u20131.6 Ma) place deposition of the Huayquer\u00edas Formation during the late Tortonian or Messinian to early Zanclean, the Tunuy\u00e1n Formation during the Zanclean\u2013Piacenzian, and the Bajada Grande Formation during the Piacenzian\u2013Calabrian. We present 43 and 31 new mammal taxon records for the Huayquer\u00edas and Tunuy\u00e1n formations, respectively. Progressive faunal change was observed along the sequence. The first records of the Chaco tortoise Chelonoidis chilensis and the notoungulate Xotodon major, and the latest records of Interatheriidae and Typotheriopsis (notoungulates), Metacaremys calfucalel, Phtoramys hidalguense and Lagostomus pretrichodactyla (rodents), Chasicotatus ameghinoi and Macroeuphractus morenoi (xenarthrans) are reported. The faunal associations of the Huayquer\u00edas and lower Tunuy\u00e1n formations are highly similar to each other, and to other coeval localities in Argentina. The Macroeuphractus morenoi Assemblage Biozone is proposed as the basis for redefining the Huayquerian Stage, due to the co-occurrence of three taxa with wide geographical distribution in southern South America: Macroeuphractus morenoi, Pseudotypotherium subinsigne and Lagostomus pretrichodactyla. The age of this biozone is constrained at c. 8\u20135 Ma in its type area.", "keyphrases": ["assemblage biozone", "huayquerian stage", "late neogene faunal association", "south american chronostratigraphic scale", "zircon u\u2013pb dating"]}
{"id": "doi:10.1098/rsbl.2023.0343", "title": "The first European woolly rhinoceros mitogenomes, retrieved from cave hyena coprolites, suggest long-term phylogeographic differentiation", "abstract": "The woolly rhinoceros (Coelodonta antiquitatis) is an iconic species of the Eurasian Pleistocene megafauna, which was abundant in Eurasia in the Pleistocene until its demise beginning approximately 10 000 years ago. Despite the early recovery of several specimens from well-known European archaeological sites, including its type specimen (Blumenbach 1799), no genomes of European populations were available so far, and all available genomic data originated exclusively from Siberian populations. Using coprolites of cave hyenas (Crocuta crocuta spelea) recovered from Middle Palaeolithic layers of two caves in Germany (Bockstein-Loch and Hohlenstein-Stadel), we isolated and enriched predator and prey DNA to assemble the first European woolly rhinoceros mitogenomes, in addition to cave hyena mitogenomes. Both coprolite samples produced copious sequences assigned to C. crocuta (27% and 59% mitogenome coverage, respectively) and woolly rhinoceros (Coelodonta antiquitatis; 27% and 81% coverage, respectively). The sequences suggested considerable DNA degradation, which may limit the conclusions to be drawn; however, the mitogenomes of European woolly rhinoceros are genetically distinct from the Siberian woolly rhinoceros, and analyses of the more complete mitogenome suggest a split of the populations potentially coinciding with the earliest fossil records of woolly rhinoceros in Europe.", "keyphrases": ["ancient dna", "predator", "prey", "hyaenidae", "rhinocerotidae", "mammal"]}
{"id": "doi:10.1098/rsbl.2023.0312", "title": "<i>Gilsonicaris</i> from the Lower Devonian Hunsr&#xfc;ck slate is a eunicidan annelid and not the oldest crown anostracan crustacean", "abstract": "The Lower Devonian (Lower Emsian, \u2212400 Myr) roof slates of the Hunsr\u00fcck in southeastern Germany have delivered a highly diverse and exceptionally preserved marine fauna that provides a unique snapshot into the anatomy and ecology of a wide range of Palaeozoic animals. Several of the described taxa, however, remain enigmatic in their affinity, at least until new pyritized features hidden under the surface of the slate are revealed using X-ray radiography or micro-computed tomography (\u00b5CT). Here, we redescribe such an enigmatic fossil, the putative anostracan crustacean Gilsonicaris rhenanus Van Straelen, 1943. Using \u00b5CT scanning, we unveil unprecedented details of its anatomy, including a ventral oral opening and four pairs of recalcitrant jaw elements. These jaws are morphologically consistent with the scolecodonts of eunicidan polychaetes, which along with the gross anatomy of the body and head unambiguously identifies G. rhenanus as a polychaete rather than an arthropod. While this discovery firmly discards the Early Devonian record of crown anostracans in the fossil record, it adds a new record of eunicidan soft tissues, which are surprisingly rare considering the abundant microfossil record of scolecodonts.", "keyphrases": ["branchiopoda", "polychaeta", "scolecodonts", "soft-tissue", "x-ray microtomography", "early devonian"]}
{"id": "doi:10.1098/rsbl.2023.0245", "title": "Palaeoecological deductions from osteohistology", "abstract": "Palaeoecological deductions are vital for understanding the evolution and diversification of species within prehistoric environments. This review highlights the multitude of ways in which the microanatomy and microscopic structure of bones enables palaeoecological deductions. The occurrence of growth marks in bones is discussed, and their usefulness in deducing the ontogenetic status and age of individuals is considered, as well as how such marks in bones permit the assessment of the growth dynamics of individuals and species. Here osteohistology is shown to provide insight into the structure of past populations, as well as ecological relationships between individuals. In addition, the response of bones to trauma, disease and moulting is considered. Finally, I explore how osteohistology can give insight into ecomorphological adaptations, such as filter feeding, probe feeding and saltatorial locomotion. Methodological advances in three-dimensional microtomography and synchrotron scanning bodes well for future studies in osteohistology and despite some compromises in terms of tissue identity, circumvents the crucial issue of destructive analyses.", "keyphrases": ["palaeohistology", "bone histology", "microanatomy", "palaeoecology"]}
{"id": "doi:10.1098/rsbl.2023.0078", "title": "A genetic glimpse of the Chinese straight-tusked elephants", "abstract": "Straight-tusked elephants (genus: Palaeoloxodon) including their island dwarf forms are extinct enigmatic members of the Pleistocene megafauna and the most common Pleistocene elephants after the mammoths. Their taxonomic placement has been revised several times. Using palaeogenomic evidence, previous studies suggested that the European P. antiquus has a hybrid origin, but no molecular data have been retrieved from their Asian counterparts, leaving a gap in our knowledge of the global phylogeography and population dynamics of Palaeoloxodon. Here, we captured a high-quality complete mitogenome from a Pleistocene Elephantidae molar (CADG841) from Northern China, which was previously morphologically assigned to the genus Elephas (Asian elephant), and partial mitochondrial sequences (838 bp) of another Palaeoloxodon sp. specimen (CADG1074) from Northeastern China. We found that both Chinese specimens cluster with a 244 000-year-old P. antiquus (specimen name: WE) from Western Europe, suggesting that this clade may represent a population with a large spatial span across Eurasia. Based on the fossil record and the molecular dating of both the divergences of different Palaeoloxodon mitochondrial clades and previously determined hybridization events, we propose that this Eurasian-wide WE clade provides evidence for an earlier migration and/or another hybridization event that happened in the evolutionary history of straight-tusked elephants.", "keyphrases": ["ancient dna", "mitogenome", "palaeoloxodon", "asia", "phylogenetic tree"]}
{"id": "doi:10.1098/rsbl.2023.0124", "title": "Bridging two oceans: small toothed cetaceans (Odontoceti) from the Late Miocene Chagres Formation, eastern Caribbean (Colon, Panama)", "abstract": "Fossil cetaceans are often found in Miocene marine outcrops across the globe. However, because this record is not homogeneous, the dissimilar increase in occurrences, along with the sampling bias has created regions with extensive records and others with great scarcity. Among these, the Caribbean has remained enigmatic due to the lack of well-preserved cetacean fossils. Here, we report new Caribbean fossil cetaceans from the Upper Miocene Chagres Formation exposed along Pi\u00f1a beach, Eastern Panama, including a scaphokogiine kogiid, an Acrophyseter-like physeteroid and the phocoenid Piscolithax. Along with previous records of the iniid Isthminia panamensis and the kogiine Nanokogia isthmia, the Chagres cetacean fauna shows some similarities with other Late Miocene cetacean communities such as the Californias in the North Pacific, although their closest affinities lie with the eastern South Pacific Pisco Formation, Peru. Such findings indicate that though deep and intermediate Caribbean\u2013Pacific water interchange was reduced by the Middle Miocene due to the shallowing of the Central American Seaway, shallow waters marine connection that persisted until the Pliocene might have facilitated the dispersal of coastal species across both sides of the Isthmus.", "keyphrases": ["panama", "miocene", "odontocetes", "pisco formation", "chagres formation"]}
{"id": "doi:10.1098/rsbl.2023.0157", "title": "Cambrian origin but no early burst in functional disparity for Class Bivalvia", "abstract": "Both the Cambrian explosion, more than half a billion years ago, and its Ordovician aftermath some 35 Myr later, are often framed as episodes of widespread ecological opportunity, but not all clades originating during this interval showed prolific rises in morphological or functional disparity. In a direct analysis of functional disparity, instead of the more commonly used proxy of morphological disparity, we find that ecological functions of Class Bivalvia arose concordantly with and even lagged behind taxonomic diversification, rather than the early-burst pattern expected for clades originating in supposedly open ecological landscapes. Unlike several other clades originating in the Cambrian explosion, the bivalves' belated acquisition of key anatomical novelties imposed a macroevolutionary lag, and even when those novelties evolved in the Early Ordovician, functional disparity never surpassed taxonomic diversity. Beyond this early period of animal evolution, the founding and subsequent diversification of new major clades and their functions might be expected to follow the pattern of the early bivalves\u2014one where interactions between highly dynamic environmental and biotic landscapes and evolutionary contingencies need not promote prolific functional innovation.", "keyphrases": ["bivalve", "early burst", "cambrian explosion", "functional disparity", "diversity-disparity", "adaptive radiation"]}
{"id": "doi:10.1098/rsbl.2022.0578", "title": "Anthropogenic predictors of varying Holocene occurrence for Europe's large mammal fauna", "abstract": "Understanding how species respond to different anthropogenic pressures is essential for conservation planning. The archaeological record has great potential to inform extinction risk assessment by providing evidence on past human-caused biodiversity loss, but identifying specific drivers of past declines from environmental archives has proved challenging. We used 17 684 Holocene zooarchaeological records for 15 European large mammal species together with data on past environmental conditions and anthropogenic activities across Europe, to assess the ability of environmental archives to determine the relative importance of different human pressures in shaping faunal distributions through time. Site occupancy probability showed differing significant relationships with environmental covariates for all species, and nine species also showed significant relationships with anthropogenic covariates (human population density, % cropland, % grazing land). Across-species differences in negative relationships with covariates provide ecological insights for understanding extinction dynamics: some mammals (red deer, aurochs, wolf, wildcat, lynx, pine marten and beech marten) were more vulnerable to past human\u2013environmental interactions, and differing single and synergistic anthropogenic factors influenced likelihood of past occurrence across species. Our results provide new evidence for pre-industrial population fragmentation and depletion in European mammals, and demonstrate the usefulness of historical baselines for understanding species' varying long-term sensitivity to multiple threats.", "keyphrases": ["environmental archives", "extinction filter", "extinction risk", "historical baselines", "quaternary extinction", "zooarchaeology"]}
{"id": "doi:10.1098/rsbl.2022.0523", "title": "The earliest pollen-loaded insects from the Lower Permian of Russia", "abstract": "Recent fossil discoveries suggest that the coevolution of insect pollinators and gymnosperms started long before the appearance of flowering plants. One of the keys to understanding the origins of pollination relationships is fossil insects with gymnosperm pollen attached to the body surface. Such fossils are exceedingly rare to find, especially from the Palaeozoic, a time when ambers with insect inclusions were absent. Here, we report compression fossils of Early Permian tillyardembiid insects (Polyneoptera) preserved with pollen on their heads, thoraces, legs and abdomens. This is the earliest finding of pollen-bearing insects, predating the previous oldest record from the Middle Jurassic by ca 120 Ma. Judging by the pollen composition, tillyardembiids visited a narrow range of host plants, including Rufloriaceae (Cordaitales). While it is impossible to say for certain whether tillyardembiids as pollen consumers contributed to pollination, a trophic specialization of this kind could be considered an evolutionary precursor of pollination mutualism.", "keyphrases": ["plant\u2013insect interactions", "pollination", "palaeozoic"]}
{"id": "doi:10.1098/rsbl.2022.0559", "title": "Beetle elytra: evolution, modifications and biological functions", "abstract": "Conversion of forewings into hardened covers, elytra, was a ground-breaking morphological adaptation that has contributed to the extraordinary evolutionary success of beetles. Nevertheless, the knowledge of the functional aspects of these structures is still fragmentary and scattered across a large number of studies. Here, we have synthesized the presently available information on the evolution, development, modifications and biological functions of this crucial evolutionary novelty. The formation of elytra took place in the earliest evolution of Coleoptera, very likely already in the Carboniferous, and was achieved through the gradual process of progressive forewing sclerotization and the formation of inward directed epipleura and a secluded sub-elytral space. In many lineages of modern beetles, the elytra have been distinctly modified. This includes multiple surface modifications, a rigid connection or fusion of the elytra, or partial or complete reduction. Beetle elytra can be involved in a very broad spectrum of functions: mechanical protection of hind wings and body, anti-predator strategies, thermoregulation and water saving, water harvesting, flight, hind wing folding, diving and swimming, self-cleaning and burrow cleaning, phoresy of symbiotic organisms, mating and courtship, and acoustic communication. We postulate that the potential of the elytra to take over multiple tasks has enormously contributed to the unparalleled diversification of beetles.", "keyphrases": ["forewing", "evolution", "development", "coleoptera", "morphology", "biomaterial"]}
{"id": "doi:10.1098/rsbl.2022.0483", "title": "Elbow-joint morphology in the North American &#x2018;cheetah-like&#x2019; cat <i>Miracinonyx trumani</i>", "abstract": "The North American cheetah-like cat Miracinonyx trumani is an extinct species that roamed the Pleistocene prairies 13 000 years ago. Although M. trumani is more closely related to the cougar (Puma concolor) than to the living cheetah (Acinonyx jubatus), it is believed that both A. jubatus and M. trumani possess a highly specialized skeleton for fast-running, including limbs adapted for speed at the expense of restricting the ability of prey grappling. However, forelimb dexterity of M. trumani has not been yet investigated. Here, we quantify the 3D-shape of the humerus distal epiphysis as a proxy for elbow-joint morphology in a sample of living cats to determine whether the extinct M. trumani was specialized to kill open-country prey using predatory behaviour based on fast running across the prairies and steppe terrains of the North American Pleistocene. We show that M. trumani had an elbow morphology intermediate to that of P. concolor and A. jubatus, suggesting that M. trumani had a less specialized pursuit predatory behaviour than A. jubatus. We propose that M. trumani probably deployed a unique predatory behaviour without modern analogues. Our results bring into question the degree of ecomorphological convergence between M. trumani and its Old World vicar A. jubatus.", "keyphrases": ["miracinonyx trumani", "predatory behaviour", "elbow joint", "convergence", "pronghorn"]}
{"id": "doi:10.1098/rsbl.2022.0497", "title": "The unbearable uncertainty of panarthropod relationships", "abstract": "Panarthropoda, the clade comprising the phyla Onychophora, Tardigrada and Euarthropoda, encompasses the largest majority of animal biodiversity. The relationships among the phyla are contested and resolution is key to understanding the evolutionary assembly of panarthropod bodyplans. Molecular phylogenetic analyses generally support monophyly of Onychophora and Euarthropoda to the exclusion of Tardigrada (Lobopodia hypothesis), which is also supported by some analyses of morphological data. However, analyses of morphological data have also been interpreted to support monophyly of Tardigrada and Euarthropoda to the exclusion of Onychophora (Tactopoda hypothesis). Support has also been found for a clade of Onychophora and Tardigrada that excludes Euarthropoda (Protarthropoda hypothesis). Here we show, using a diversity of phylogenetic inference methods, that morphological datasets cannot discriminate statistically between the Lobopodia, Tactopoda and Protarthropoda hypotheses. Since the relationships among the living clades of panarthropod phyla cannot be discriminated based on morphological data, we call into question the accuracy of morphology-based phylogenies of Panarthropoda that include fossil species and the evolutionary hypotheses based upon them.", "keyphrases": ["panarthropoda", "tactopoda", "lobopodia", "protarthropoda", "phylogeny", "topology testing"]}
{"id": "doi:10.1098/rsbl.2022.0404", "title": "Palaeopathological evidence for intraspecific combat in ankylosaurid dinosaurs", "abstract": "Ankylosaurid dinosaurs were heavily armoured herbivores with tails modified into club-like weapons. These tail clubs have widely been considered defensive adaptations wielded against predatory theropod dinosaurs. Here we argue instead that ankylosaurid tail clubs were sexually selected structures used primarily for intraspecific combat. We found pathological osteoderms (armour plates) in the holotype specimen of Zuul crurivastator, which are localized to the flanks in the hip region rather than distributed randomly across the body, consistent with injuries inflicted by lateral tail-swinging and ritualized combat. We failed to find convincing evidence for predation as a key selective pressure in the evolution of the tail club. High variation in tail club size through time, and delayed ontogenetic growth of the tail club further support the sexual selection hypothesis. There is little doubt that the tail club could have been used in defence when needed, but our results suggest that sexual selection drove the evolution of this impressive weapon. This changes the prevailing view of ankylosaurs, suggesting they were behaviorally complex animals that likely engaged in ritualized combat for social dominance as in other ornithischian dinosaurs and mammals.", "keyphrases": ["dinosauria", "ankylosauria", "sexual selection", "animal weaponry"]}
{"id": "doi:10.1098/rsbl.2022.0214", "title": "The origin of modern patterns of continental diversity in Mauritiinae palms: the Neotropical museum and the Afrotropical graveyard", "abstract": "While the latitudinal diversity gradient has received much attention, biodiversity and species richness also vary between continents across similar latitudes. Fossil information can be used to understand the evolutionary mechanisms that generated such variation between continents of similar latitudes. We integrated fossil data into a phylogenetic analysis of the Mauritiinae palms, whose extant diversity is restricted to the Neotropics, but extended across Africa and India during most of the Cenozoic. Mauritiinae diverged from its sister lineage Raphiinae ca 106 Ma. Using ancestral state estimation and a lineage through time analysis, we found that diversity arose globally during the late Cretaceous and Palaeocene across South America, Africa and India. The Palaeocene\u2013Eocene transition (ca 56 Ma) marked the end of global Mauritiinae expansion, and the beginning of their decline in both Africa and India. Mauritiinae disappeared from the Indian subcontinent and Africa at the end of the Eocene and the Miocene, respectively. By contrast, Neotropical diversity steadily increased over the last 80 Myr. Taken together, our results suggest that the Neotropics functioned as a continental-scale refuge for Mauritiinae palms, where lineages survived and diversified while global climatic changes that drastically reduced rainforests led to their demise on other continents.", "keyphrases": ["diversification", "evolution", "longitudinal diversity gradient", "palms", "palynology"]}
{"id": "doi:10.1098/rsbl.2022.0291", "title": "An early nimravid from California and the rise of hypercarnivorous mammals after the middle Eocene climatic optimum", "abstract": "Carnivoraforms (crown carnivorans and their closest relatives) first occupied hypercarnivorous niches near the dawn of the late Eocene, 40\u201337 Ma. This followed the decline or extinction of earlier carnivorous groups, Mesonychia and Oxyaenodonta, leaving carnivoraforms and hyaenodontan meat-eaters as high trophic level consumers. The pattern of this change and the relative contributions of the taxonomic groups has hitherto been unclear. We report a new genus and species of the sabretoothed mammalian carnivore family Nimravidae, Pangurban egiae, from the Eocene Pomerado Conglomerate of southern California, with strongly derived hypercarnivorous features. While geochronologically the oldest named nimravid in North America, Pangurban egiae is recovered as phylogenetically derived, with affinities to Hoplophoneus. This provides unequivocal evidence for rapid radiation and spread of nimravid carnivores across Asia and North America and constrains the timing of early divergences within the family. Pangurban egiae narrows the gap between convergent iterations of sabretoothed mammalian carnivores and demonstrates swift diversification of the hypercarnivorous nimravids during a period of global climatic instability. Furthermore, it highlights the top-to-bottom restructuring North American ecosystems underwent during the Eocene\u2013Oligocene transition, resulting in carnivoraforms taking positions as trophic specialists for the first time, a niche they still occupy today.", "keyphrases": ["sabretooth", "carnassial", "hoplophoneus", "duchesnean", "evolution", "eocene\u2013oligocenebiotic transition"]}
{"id": "doi:10.1098/rsbl.2022.0179", "title": "A possible home for a bizarre Carboniferous animal: is <i>Typhloesus</i> a pelagic gastropod?", "abstract": "By contrast to many previously enigmatic Palaeozoic fossils, the Carboniferous metazoan Typhloesus has defied phylogenetic placement. Here, we document new features, including possible phosphatized muscle tissues and a hitherto unrecognized feeding apparatus with two sets of ca 20 spinose teeth whose closest similarities appear to lie with the molluscan radula. The ribbon-like structure, located well behind the mouth area and deep into the anterior part of the body, is interpreted as being in an inverted proboscis configuration. Gut contents, mostly conodonts, in the midgut area demonstrate that Typhloesus was an active predator. This animal was capable of propelling itself in the water column using its flexible body and a prominent posterior fin. The affinity of Typhloesus as a pelagic mollusc remains problematic but may lie more closely with the gastropods. Heteropod gastropods share with Typhloesus an active predatory lifestyle and have a comparable general body organization, albeit they possess characteristic aragonitic shells and their origins in the Jurassic post-date Typhloesus. Typhloesus may represent an independent radiation of Mid-Palaeozoic pelagic gastropods.", "keyphrases": ["typhloesus", "carboniferous", "molluscs"]}
{"id": "doi:10.1098/rsbl.2022.0222", "title": "The emblematic South African therocephalian <i>Euchambersia</i> in China: a new link in the dispersal of late Permian vertebrates across Pangea", "abstract": "Therapsids were widely distributed in Pangea in the late Permian. South Africa in Gondwana and Russia in Laurasia are the principal areas recording tetrapods (including therapsids) of this age. More recent field explorations have increased the importance of Chinese late Permian fossil assemblages. This is clearly reflected in the discovery of several new therocephalians from the Naobaogou Formation in Nei Mongol. Here, we report a therocephalian from that unit identified as a new species of the emblematic South African taxon Euchambersia. The new species, Euchambersia liuyudongi, is represented by a well-preserved skull and mandible showing a well-developed maxillary fossa and the absence of postcanine teeth. This is the third akidnognathid therocephalian recovered from the Naobaougou Formation, but oddly, the two basal Chinese akidnognathids previously known were recovered from a younger unit of the formation than the derived E. liuyudongi. This is the first time that the same therocephalian genus has been recorded in northern and southern continents, making the record of the Naobaougou Formation key to understanding the evolution of late Permian continental fauna in general, and of akidnognathid therocephalians in particular.", "keyphrases": ["therocephalia", "lopingian", "naobaougou formation", "china", "south africa"]}
{"id": "doi:10.1098/rsbl.2022.0118", "title": "Giant gar from directly above the Cretaceous\u2013Palaeogene boundary suggests healthy freshwater ecosystems existed within thousands of years of the asteroid impact", "abstract": "The Cretaceous\u2013Palaeogene (K\u2013Pg) mass extinction was responsible for the destruction of global ecosystems and loss of approximately three-quarters of species diversity 66 million years ago. Large-bodied land vertebrates suffered high extinction rates, whereas small-bodied vertebrates living in freshwater ecosystems were buffered from the worst effects. Here, we report a new species of large-bodied (1.4\u20131.5 m) gar based on a complete skeleton from the Williston Basin of North America. The new species was recovered 18 cm above the K\u2013Pg boundary, making it one of the oldest articulated vertebrate fossils from the Cenozoic. The presence of this freshwater macropredator approximately 1.5\u20132.5 thousand years after the asteroid impact suggests the rapid recovery and reassembly of North American freshwater food webs and ecosystems after the mass extinction.", "keyphrases": ["gar", "k\u2013pg", "lilliput effect", "lepisosteidae", "fish"]}
{"id": "doi:10.1098/rsbl.2022.0013", "title": "Genetic evidence for post-glacial expansion from a southern refugium in the eastern moa (<i>Emeus crassus</i>)", "abstract": "Cycles of glacial expansion and contraction throughout the Pleistocene drove increases and decreases, respectively, in the geographical range and population size of many animal species. Genetic data have revealed that during glacial maxima the distribution of many Eurasian animals was restricted to small refugial areas, from which species expanded to reoccupy parts of their former range as the climate warmed. It has been suggested that the extinct eastern moa (Emeus crassus)\u2014a large, flightless bird from New Zealand\u2014behaved analogously during glacial maxima, possibly surviving only in a restricted area of lowland habitat in the southern South Island of New Zealand during the Last Glacial Maximum (LGM). However, previous studies have lacked the power and geographical sampling to explicitly test this hypothesis using genetic data. Here we analyse 46 ancient mitochondrial genomes from Late Pleistocene and Holocene bones of the eastern moa from across their post-LGM distribution. Our results are consistent with a post-LGM increase in the population size and genetic diversity of eastern moa. We also demonstrate that genetic diversity was higher in eastern moa from the southern extent of their range, supporting the hypothesis that they expanded from a single glacial refugium following the LGM.", "keyphrases": ["ancient dna", "megafauna", "new zealand", "phylogeography", "quaternary"]}
{"id": "doi:10.1098/rsbl.2022.0092", "title": "Evolution of amniote dentine apposition rates", "abstract": "In amniotes, daily rates of dentine formation in non-ever-growing teeth range from less than 1 to over 25 \u03bcm per day. The latter value has been suggested to represent the upper limit of odontoblast activity in non-ever-growing teeth, a hypothesis supported by the lack of scaling between dentine apposition rates and body mass in Dinosauria. To determine the correlates and potential controls of dentine apposition rate, we assembled a dataset of apposition rates, metabolic rates and body masses for ca 80 amniote taxa of diverse ecologies and diets. We used phylogenetic regression to test for scaling relationships and reconstruct ancestral states of daily dentine apposition across Amniota. We find no relationship between body mass and daily dentine apposition rate (DDAR) for non-ever-growing teeth in Amniota as a whole or within major clades. Metabolic rate, the number of tooth generations, diet and habitat also do not predict or correspond with DDARs. Similar DDARs are found in large terrestrial mammals, dinosaurs and marine reptiles, whereas primates, cetaceans and some smaller marine reptiles independently evolved exceptionally slow rates. Life-history factors may explain the evolution of dentine apposition rates, which evolved rapidly at the origin of major clades.", "keyphrases": ["dentine", "amniota", "odontoblast"]}
{"id": "doi:10.1098/rsbl.2022.0094", "title": "Dietary isotopes of Madagascar's extinct megafauna reveal Holocene browsing and grazing guilds", "abstract": "Megafauna play a disproportionate role in developing and maintaining their biomes, by regulating plant dispersal, community structure and nutrient cycling. Understanding the ecological roles of extinct megafaunal communities, for example through dietary reconstruction using isotope analysis, is necessary to determine pre-human states and set evidence-based restoration goals. We use \u03b413C and \u03b415N isotopic analyses to reconstruct Holocene feeding guilds in Madagascar's extinct megaherbivores, which included elephant birds, hippopotami and giant tortoises that occurred across multiple habitats and elevations. We compare isotopic data from seven taxa and two elephant bird eggshell morphotypes against contemporary regional floral baselines to infer dietary subsistence strategies. Most taxa show high consumption of C3 and/or CAM plants, providing evidence of widespread browsing ecology. However, Aepyornis hildebrandti, an elephant bird restricted to the central highlands region, has isotope values with much higher \u03b413C values than other taxa. This species is interpreted as having obtained up to 48% of its diet from C4 grasses. These findings provide new evidence for distinct browsing and grazing guilds in Madagascar's Holocene megaherbivore fauna, with implications for past regional distribution of ecosystems dominated by endemic C4 grasses.", "keyphrases": ["elephant bird", "hippopotamus", "isotope ecology", "megafauna", "quaternary extinction"]}
{"id": "doi:10.1098/rsbl.2022.0047", "title": "Body-axis organization in tetrapods: a model-system to disentangle the developmental origins of convergent evolution in deep time", "abstract": "Convergent evolution is a central concept in evolutionary theory but the underlying mechanism has been largely debated since On the Origin of Species. Previous hypotheses predict that developmental constraints make some morphologies more likely to arise than others and natural selection discards those of the lowest fitness. However, the quantification of the role and strength of natural selection and developmental constraint in shaping convergent phenotypes on macroevolutionary timescales is challenging because the information regarding performance and development is not directly available. Accordingly, current knowledge of how embryonic development and natural selection drive phenotypic evolution in vertebrates has been extended from studies performed at short temporal scales. We propose here the organization of the tetrapod body-axis as a model system to investigate the developmental origins of convergent evolution over hundreds of millions of years. The quantification of the primary developmental mechanisms driving body-axis organization (i.e. somitogenesis, homeotic effects and differential growth) can be inferred from vertebral counts, and recent techniques of three-dimensional computational biomechanics have the necessary potential to reveal organismal performance even in fossil forms. The combination of both approaches offers a novel and robust methodological framework to test competing hypotheses on the functional and developmental drivers of phenotypic evolution and evolutionary convergence.", "keyphrases": ["macroevolution", "development", "phenotypic evolution", "tetrapod axis"]}
{"id": "doi:10.1098/rsbl.2021.0603", "title": "The impact of molecular data on the phylogenetic position of the putative oldest crown crocodilian and the age of the clade", "abstract": "The use of molecular data for living groups is vital for interpreting fossils, especially when morphology-only analyses retrieve problematic phylogenies for living forms. These topological discrepancies impact on the inferred phylogenetic position of many fossil taxa. In Crocodylia, morphology-based phylogenetic inferences differ fundamentally in placing Gavialis basal to all other living forms, whereas molecular data consistently unite it with crocodylids. The Cenomanian Portugalosuchus azenhae was recently described as the oldest crown crocodilian, with affinities to Gavialis, based on morphology-only analyses, thus representing a potentially important new molecular clock calibration. Here, we performed analyses incorporating DNA data into these morphological datasets, using scaffold and supermatrix (total evidence) approaches, in order to evaluate the position of basal crocodylians, including Portugalosuchus. Our analyses incorporating DNA data robustly recovered Portugalosuchus outside Crocodylia (as well as thoracosaurs, planocraniids and Borealosuchus spp.), questioning the status of Portugalosuchus as crown crocodilian and any future use as a node calibration in molecular clock studies. Finally, we discuss the impact of ambiguous fossil calibration and how, with the increasing size of phylogenomic datasets, the molecular scaffold might be an efficient (though imperfect) approximation of more rigorous but demanding supermatrix analyses.", "keyphrases": ["crocodylia", "molecular data", "divergence-age", "calibration", "portugalosuchus"]}
{"id": "doi:10.1098/rsbl.2021.0403", "title": "Ostracods had colonized estuaries by the late Silurian", "abstract": "The fossil record of terrestrialization documents notable shifts in the environmental and physiological tolerances of many animal and plant groups. However, for certain significant components of modern freshwater and terrestrial environments, the transition out of marine settings remains largely unconstrained. Ostracod crustaceans occupy an exceptional range of modern aquatic environments and are invaluable palaeoenvironmental indicators in the fossil record. However, pre-Carboniferous records of supposed non-marine and marginal marine ostracods are sparse, and the timing of their marine to non-marine transition has proven elusive. Here, we reassess the early environmental history of ostracods in light of new assemblages from the late Silurian of Vietnam. Two, low diversity but distinct ostracod assemblages are associated with estuarine deposits. This occurrence is consistent with previous incidental reports of ostracods occupying marginal and brackish settings through the late Silurian and Devonian. Therefore, ostracods were pioneering the occupation of marginal marine and estuarine settings 60 Myr before the Carboniferous and they were a component of the early phase of transition from marine to non-marine environments.", "keyphrases": ["silurian", "ostracods", "pioneer", "colonizers", "estuary"]}
{"id": "doi:10.1098/rsbl.2021.0383", "title": "Growth variability, dimensional scaling, and the interpretation of osteohistological growth data", "abstract": "Osteohistological data are commonly used to study the life history of extant and extinct tetrapods. While recent advances have permitted detailed reconstructions of growth patterns, physiology and other features using these data, they are most commonly used in assessments of ontogenetic stage and relative growth in extinct animals. These methods have seen widespread adoption in recent years, rapidly becoming a common component of the taxonomic description of new fossil taxa, but are often applied without close consideration of the sources of variation present or the dimensional scaling relationships that exist among different osteohistological measurements. Here, we use a combination of theoretical models and empirical data from a range of extant and extinct tetrapods to review sources of variability in common osteohistological measurements, their dimensional scaling relationships and the resulting interpretations that can be made from those data. In particular, we provide recommendations on the usage and interpretation of growth mark spacing/zonal thickness data, when these are likely to be unreliable, and under what conditions they can provide useful inferences for studies of growth and life history.", "keyphrases": ["osteohistology", "ontogeny", "growth", "dinosaur", "mammal", "bird"]}
{"id": "doi:10.1098/rsbl.2020.0666", "title": "Causal analysis of the temperature impact on deep-sea biodiversity", "abstract": "The deep sea comprises more than 90% of the ocean; therefore, understanding the controlling factors of biodiversity in the deep sea is of great importance for predicting future changes in the functioning of the ocean system. Consensus has recently been increasing on two plausible factors that have often been discussed as the drivers of deep\u2010sea species richness in the contexts of the species\u2010energy and physiological tolerance hypotheses: (i) seafloor particulate organic carbon (POC) derived from primary production in the euphotic zone and (ii) temperature. Nonetheless, factors that drive deep-sea biodiversity are still actively debated potentially owing to a mirage of correlations (sign and magnitude are generally time dependent), which are often found in nonlinear, complex ecological systems, making the characterization of causalities difficult. Here, we tested the causal influences of POC flux and temperature on species richness using long-term palaeoecological datasets derived from sediment core samples and convergent cross mapping, a numerical method for characterizing causal relationships in complex systems. The results showed that temperature, but not POC flux, influenced species richness over 103\u2013104-year time scales. The temperature\u2013richness relationship in the deep sea suggests that human-induced future climate change may, under some conditions, affect deep-sea ecosystems through deep-water circulation changes rather than surface productivity changes.", "keyphrases": ["climate", "deep-sea", "biodiversity"]}
{"id": "doi:10.1098/rspb.2023.2177", "title": "Giant baleen whales emerged from a cold southern cradle", "abstract": "Baleen whales (mysticetes) include the largest animals on the Earth. How they achieved such gigantic sizes remains debated, with previous research focusing primarily on when mysticetes became large, rather than where. Here, we describe an edentulous baleen whale fossil (21.12\u201316.39 mega annum (Ma)) from South Australia. With an estimated body length of 9 m, it is the largest mysticete from the Early Miocene. Analysing body size through time shows that ancient baleen whales from the Southern Hemisphere were larger than their northern counterparts. This pattern seemingly persists for much of the Cenozoic, even though southern specimens contribute only 19% to the global mysticete fossil record. Our findings contrast with previous ideas of a single abrupt shift towards larger size during the Plio-Pleistocene, which we here interpret as a glacially driven Northern Hemisphere phenomenon. Our results highlight the importance of incorporating Southern Hemisphere fossils into macroevolutionary patterns, especially in light of the high productivity of Southern Ocean environments.", "keyphrases": ["mysticeti", "chaeomysticeti", "southernhemisphere", "body size", "gigantism"]}
{"id": "doi:10.1098/rspb.2023.2212", "title": "Convergent evolution of ventral adaptations for enrolment in trilobites and extant euarthropods", "abstract": "The ability to enrol for protection is an effective defensive strategy that has convergently evolved multiple times in disparate animal groups ranging from euarthropods to mammals. Enrolment is a staple habit of trilobites, and their biomineralized dorsal exoskeleton offered a versatile substrate for the evolution of interlocking devices. However, it is unknown whether trilobites also featured ventral adaptations for enrolment. Here, we report ventral exoskeletal adaptations that facilitate enrolment in exceptionally preserved trilobites from the Middle Ordovician Walcott\u2013Rust Quarry in New York State, USA. Walcott\u2013Rust trilobites reveal the intricate three-dimensional organization of the non-biomineralized ventral anatomy preserved as calcite casts, including the spatial relationship between the articulated sternites (i.e. ventral exoskeletal plates) and the wedge-shaped protopodites. Enrolment in trilobites is achieved by ventrally dipping the anterior margin of the sternites during trunk flexure, facilitated by the presence of flexible membranes, and with the close coupling of the wedge-shaped protopodites. Comparisons with the ventral morphology of extant glomerid millipedes and terrestrial isopods reveal similar mechanisms used for enrolment. The wedge-shaped protopodites of trilobites closely resemble the gnathobasic coxa/protopodite of extant horseshoe crabs. We propose that the trilobites' wedge-shaped protopodite simultaneously facilitated tight enrolment and gnathobasic feeding with the trunk appendages.", "keyphrases": ["walcott\u2013rust", "exceptional preservation", "glomerida", "trilobita", "limulus", "isopoda"]}
{"id": "doi:10.1098/rspb.2023.1095", "title": "Millennial processes of population decline, range contraction and near extinction of the European bison", "abstract": "European bison (Bison bonasus) were widespread throughout Europe during the late Pleistocene. However, the contributions of environmental change and humans to their near extinction have never been resolved. Using process-explicit models, fossils and ancient DNA, we disentangle the combinations of threatening processes that drove population declines and regional extinctions of European bison through space and across time. We show that the population size of European bison declined abruptly at the termination of the Pleistocene in response to rapid environmental change, hunting by humans and their interaction. Human activities prevented populations of European bison from rebounding in the Holocene, despite improved environmental conditions. Hunting caused range loss in the north and east of its distribution, while land use change was responsible for losses in the west and south. Advances in hunting technologies from 1500 CE were needed to simulate low abundances observed in 1870 CE. While our findings show that humans were an important driver of the extinction of the European bison in the wild, vast areas of its range vanished during the Pleistocene\u2013Holocene transition because of post-glacial environmental change. These areas of its former range have been climatically unsuitable for millennia and should not be considered in reintroduction efforts.", "keyphrases": ["extinction dynamics", "rewilding", "process-basedmodel", "megafauna", "range dynamics", "conservation biogeography"]}
{"id": "doi:10.1098/rspb.2023.0525", "title": "Uncovering the Holocene roots of contemporary disease-scapes: bringing archaeology into One Health", "abstract": "The accelerating pace of emerging zoonotic diseases in the twenty-first century has motivated cross-disciplinary collaboration on One Health approaches, combining microbiology, veterinary and environmental sciences, and epidemiology for outbreak prevention and mitigation. Such outbreaks are often caused by spillovers attributed to human activities that encroach on wildlife habitats and ecosystems, such as land use change, industrialized food production, urbanization and animal trade. While the origin of anthropogenic effects on animal ecology and biogeography can be traced to the Late Pleistocene, the archaeological record\u2014a long-term archive of human\u2013animal\u2013environmental interactions\u2014has largely been untapped in these One Health approaches, thus limiting our understanding of these dynamics over time. In this review, we examine how humans, as niche constructors, have facilitated new host species and \u2018disease-scapes\u2019 from the Late Pleistocene to the Anthropocene, by viewing zooarchaeological, bioarchaeological and palaeoecological data with a One Health perspective. We also highlight how new biomolecular tools and advances in the \u2018-omics\u2019 can be holistically coupled with archaeological and palaeoecological reconstructions in the service of studying zoonotic disease emergence and re-emergence.", "keyphrases": ["niche construction theory", "zoonotic diseases", "disease ecology"]}
{"id": "doi:10.1098/rspb.2023.2232", "title": "Contrasting terrestrial and marine ecospace dynamics after the end-Triassic mass extinction event", "abstract": "Mass extinctions have fundamentally altered the structure of the biosphere throughout Earth's history. The ecological severity of mass extinctions is well studied in marine ecosystems by categorizing marine taxa into functional groups based on \u2018ecospace\u2019 approaches, but the ecological response of terrestrial ecosystems to mass extinctions is less well understood due to the lack of a comparable methodology. Here, we present a new terrestrial ecospace framework that categorizes fauna into functional groups as defined by tiering, motility and feeding traits. We applied the new terrestrial and traditional marine ecospace analyses to data from the Paleobiology Database across the end-Triassic mass extinction\u2014a time of catastrophic global warming\u2014to compare changes between the marine and terrestrial biospheres. We found that terrestrial functional groups experienced higher extinction severity, that taxonomic and functional richness are more tightly coupled in the terrestrial, and that the terrestrial realm continued to experience high ecological dissimilarity in the wake of the extinction. Although signals of extinction severity and ecological turnover are sensitive to the quality of the terrestrial fossil record, our findings suggest greater ecological pressure from the end-Triassic mass extinction on terrestrial ecosystems than marine ecosystems, contributing to more prolonged terrestrial ecological flux.", "keyphrases": ["palaeoecology", "functional ecology", "ecospace", "triassic\u2013jurassic", "mass extinction"]}
{"id": "doi:10.1098/rspb.2023.1400", "title": "Evolutionary ecomorphology for the twenty-first century: examples from mammalian carnivores", "abstract": "Carnivores (cats, dogs and kin) are a diverse group of mammals that inhabit a remarkable range of ecological niches. While the relationship between ecology and morphology has long been of interest in carnivorans, the application of quantitative techniques has resulted in a recent explosion of work in the field. Therefore, they provide a case study of how quantitative techniques, such as geometric morphometrics (GMM), have impacted our ability to tease apart complex ecological signals from skeletal anatomy, and the implications for our understanding of the relationships between form, function and ecological specialization. This review provides a synthesis of current research on carnivoran ecomorphology, with the goal of illustrating the complex interaction between ecology and morphology in the skeleton. We explore the ecomorphological diversity across major carnivoran lineages and anatomical systems. We examine cranial elements (skull, sensory systems) and postcranial elements (limbs, vertebral column) to reveal mosaic patterns of adaptation related to feeding and hunting strategies, locomotion and habitat preference. We highlight the crucial role that new approaches have played in advancing our understanding of carnivoran ecomorphology, while addressing challenges that remain in the field, such as ecological classifications, form\u2013function relationships and multi-element analysis, offering new avenues for future research.", "keyphrases": ["carnivora", "ecomorphology", "geometric morphometrics"]}
{"id": "doi:10.1098/rspb.2023.1932", "title": "From teeth to pad: tooth loss and development of keratinous structures in sirenians", "abstract": "Sirenians are a well-known example of morphological adaptation to a shallow-water grazing diet characterized by a modified feeding apparatus and orofacial morphology. Such adaptations were accompanied by an anterior tooth reduction associated with the development of keratinized pads, the evolution of which remains elusive. Among sirenians, the recently extinct Steller's sea cow represents a special case for being completely toothless. Here, we used \u03bc-CT scans of sirenian crania to understand how motor-sensor systems associated with tooth innervation responded to innovations such as keratinized pads and continuous dental replacement. In addition, we surveyed nine genes associated with dental reduction for signatures of loss of function. Our results reveal how patterns of innervation changed with modifications of the dental formula, especially continuous replacement in manatees. Both our morphological and genomic data show that dental development was not completely lost in the edentulous Steller's sea cows. By tracing the phylogenetic history of tooth innervation, we illustrate the role of development in promoting the innervation of keratinized pads, similar to the secondary use of dental canals for innervating neomorphic keratinized structures in other tetrapod groups.", "keyphrases": ["sirenians", "tooth loss", "keratinous pad", "steller\u2019ssea cow", "dental pseudogenes"]}
{"id": "doi:10.1098/rspb.2023.2284", "title": "A Morrison stem gekkotan reveals gecko evolution and Jurassic biogeography", "abstract": "Geckos are a speciose and globally distributed clade of Squamata (lizards, including snakes and amphisbaenians) that are characterized by a host of modifications for nocturnal, scansorial and insectivorous ecologies. They are among the oldest divergences in the lizard crown, so understanding the origin of geckoes (Gekkota) is essential to understanding the origin of Squamata, the most species-rich extant tetrapod clade. However, the poor fossil record of gekkotans has obscured the sequence and timing of the assembly of their distinctive morphology. Here, we describe the first North American stem gekkotan based on a three-dimensionally preserved skull from the Morrison Formation of western North America. Despite its Late Jurassic age, the new species already possesses several key characteristics of the gekkotan skull along with retained ancestral features. We show that this new stem gekkotan, and several previously named species of uncertain phylogenetic relationships, comprise a widespread clade of early crown lizards, substantiating faunal homogeneity in Laurasia during the Late Jurassic that extended across disparate ecological, body-size and physiological classes.", "keyphrases": ["squamata", "gekkota", "phylogenetics", "macroevolution", "biogeography"]}
{"id": "doi:10.1098/rspb.2023.1810", "title": "Quantifying the complexity of plant reproductive structures reveals a history of morphological and functional integration", "abstract": "Vascular plant reproductive structures have undoubtedly become more complex through time, evolving highly differentiated parts that interact in specialized ways. But quantifying these patterns at broad scales is challenging because lineages produce disparate reproductive structures that are often difficult to compare and homologize. We develop a novel approach for analysing interactions within reproductive structures using networks, treating component parts as nodes and a suite of physical and functional interactions among parts as edges. We apply this approach to the plant fossil record, showing that interactions have generally increased through time and that the concentration of these interactions has shifted towards differentiated surrounding organs, resulting in more compact, functionally integrated structures. These processes are widespread across plant lineages, but their extent and timing vary with reproductive biology; in particular, seed-producing structures show them more strongly than spore or pollen-producing structures. Our results demonstrate that major reproductive innovations like the origin of seeds and angiospermy were associated with increased integration through greater interactions among parts. But they also reveal that for certain groups, particularly Mesozoic gymnosperms, millions of years elapsed between the origin of reproductive innovations and increased interactions among parts within their reproductive structures.", "keyphrases": ["macroevolution", "networks", "gymnosperms", "angiosperms"]}
{"id": "doi:10.1098/rspb.2023.1129", "title": "Large-scale application of palaeoproteomics (Zooarchaeology by Mass Spectrometry; ZooMS) in two Palaeolithic faunal assemblages from China", "abstract": "The application of Zooarchaeology by Mass Spectrometry (ZooMS) on Pleistocene sites in Europe and northern Asia has resulted in the discovery of important new hominin fossils and has expanded the range of identified fauna. However, no systematic, large-scale application of ZooMS on Palaeolithic sites in East Asia has been attempted thus far. Here, we analyse 866 morphologically non-diagnostic bones from Jinsitai Cave in northeast China and Yumidong Cave in South China, from archaeological horizons dating to 150\u201310 ka BP. Bones from both sites revealed a high degree of collagen preservation and potentially time-related deamidation patterns, despite being located in very distinct environmental settings. At Jinsitai, we identified 31 camel bones, five of which were radiocarbon dated to 37\u201320 ka BP. All dated specimens correspond to colder periods of Marine Isotope Stages 3 and 2. We regard the presence of camels at Jinsitai as evidence of wild camels being a megafauna taxon targeted, most likely by early modern humans, during their expansion across northeast Asia. This large-scale application of ZooMS in China highlights the potential of the method for furthering our knowledge of the palaeoanthropological and zooarchaeological records of East Asia.", "keyphrases": ["zooms", "palaeoproteomics", "deamidation", "radiocarbon dating", "palaeolithic", "camels"]}
{"id": "doi:10.1098/rspb.2023.1882", "title": "Colonial green algae in the Cambrian plankton", "abstract": "The fossil record indicates a major turnover in marine phytoplankton across the Ediacaran\u2013Cambrian transition, coincident with the rise of animal-rich ecosystems. However, the diversity, affinities and ecologies of Cambrian phytoplankton are poorly understood, leaving unclear the role of animal interactions and the drivers of diversification. New exceptionally preserved acritarchs (problematic organic-walled microfossils) from the late early Cambrian (around 510 Ma) reveal colonial organization characterized by rings and plates of interconnected, geometrically arranged cells. The assemblage exhibits a wide but gradational variation in cell size, ornamentation and intercell connection, interpreted as representing one or more species with determinate (coenobial) colony formation via cell division, aggregation and growth by cell expansion. An equivalent strategy is known only among green algae, specifically chlorophycean chlorophytes. The fossils differ in detail from modern freshwater examples and apparently represent an earlier convergent radiation in marine settings. Known trade-offs between sinking risk and predator avoidance in colonial phytoplankton point to adaptations triggered by intensifying grazing pressure during a Cambrian metazoan invasion of the water column. The new fossils reveal that not all small acritarchs are unicellular resting cysts, and support an early Palaeozoic prominence of green algal phytoplankton as predicted by molecular biomarkers.", "keyphrases": ["colonial", "algae", "cambrian", "plankton", "phytoplankton", "cambrian explosion"]}
{"id": "doi:10.1098/rspb.2023.1803", "title": "Musculature of an Early Cambrian cycloneuralian animal", "abstract": "Cycloneuralians are ecdysozoans with a fossil record extending to the Early Cambrian Fortunian Age and represented mostly by cuticular integuments. However, internal anatomies of Fortunian cycloneuralians are virtually unknown, hampering our understanding of their functional morphology and phylogenetic relationships. Here we report the exceptional preservation of cycloneuralian introvert musculature in Fortunian rocks of South China. The musculature consists of an introvert body-wall muscular grid of four circular and 36 radially arranged longitudinal muscle bundles, as well as an introvert circular muscle associated with 19 roughly radially arranged, short retractors. Collectively, these features support at least a scalidophoran affinity, and the absence of muscles associated with a mouth cone and scalids further indicates a priapulan affinity. As in modern scalidophorans, the fossil musculature, and particularly the introvert circular muscle retractors, may have controlled introvert inversion and facilitated locomotion and feeding. This work supports the evolution of scalidophoran-like or priapulan-like introvert musculature in cycloneuralians at the beginning of the Cambrian Period.", "keyphrases": ["introvert musculature", "priapulida", "scalidophora", "cycloneuralia", "cambrian fortunian", "south china"]}
{"id": "doi:10.1098/rspb.2023.1333", "title": "The origins of colour patterns in fossil insects revealed by maturation experiments", "abstract": "Many fossil insects show monochromatic colour patterns that may provide valuable insights into ancient insect behaviour and ecology. Whether these patterns reflect original pigmentary coloration is, however, unknown, and their formation mechanism has not been investigated. Here, we performed thermal maturation experiments on extant beetles with melanin-based colour patterns. Scanning electron microscopy reveals that melanin-rich cuticle is more resistant to degradation than melanin-poor cuticle: with progressive maturation, melanin-poor cuticle regions experience preferential thinning and loss, yet melanin-rich cuticle remains. Comparative analysis of fossil insects with monotonal colour patterns confirms that the variations in tone correspond to variations in preserved cuticle thickness. These preserved colour patterns can thus be plausibly explained as melanin-based patterning. Recognition of melanin-based colour patterns in fossil insects opens new avenues for interpreting the evolution of insect coloration and behaviour through deep time.", "keyphrases": ["fossil insect", "colour pattern", "melanin", "taphonomy", "insect cuticle", "maturation experiments"]}
{"id": "doi:10.1098/rspb.2023.1262", "title": "Infectious diseases may have arrested the southward advance of microblades in Upper Palaeolithic East Asia", "abstract": "An unsolved archaeological puzzle of the East Asian Upper Palaeolithic is why the southward expansion of an innovative lithic technology represented by microblades stalled at the Qinling\u2013Huaihe Line. It has been suggested that the southward migration of foragers with microblades stopped there, which is consistent with ancient DNA studies showing that populations to the north and south of this line had differentiated genetically by 19 000 years ago. Many infectious pathogens are believed to have been associated with hominins since the Palaeolithic, and zoonotic pathogens in particular are prevalent at lower latitudes, which may have produced a disease barrier. We propose a mathematical model to argue that mortality due to infectious diseases may have arrested the wave-of-advance of the technologically advantaged foragers from the north.", "keyphrases": ["microblades", "ancient dna", "diffusion equation", "infectious disease", "qinling\u2013huaihe line"]}
{"id": "doi:10.1098/rspb.2023.0522", "title": "Fossilization can mislead analyses of phenotypic disparity", "abstract": "Analyses of morphological disparity can incorporate living and fossil taxa to facilitate the exploration of how phenotypic variation changes through time. However, taphonomic processes introduce non-random patterns of data loss in fossil data and their impact on perceptions of disparity is unclear. To address this, we characterize how measures of disparity change when simulated and empirical data are degraded through random and structured data loss. We demonstrate that both types of data loss can distort the disparity of clades, and that the magnitude and direction of these changes varies between the most commonly employed distance metrics and disparity indices. The inclusion of extant taxa and exceptionally preserved fossils mitigates these distortions and clarifies the full extent of the data lost, most of which would otherwise go uncharacterized. This facilitates the use of ancestral state estimation and evolutionary simulations to further control for the effects of data loss. Where the addition of such reference taxa is not possible, we urge caution in the extrapolation of general patterns in disparity from datasets that characterize subsets of phenotype, which may represent no more than the traits that they sample.", "keyphrases": ["disparity", "morphology", "simulation", "fossilization", "decay", "biostratinomy"]}
{"id": "doi:10.1098/rspb.2022.2490", "title": "A macroscopic free-swimming medusa from the middle Cambrian Burgess Shale", "abstract": "Cnidarians are regarded as one of the earliest-diverging animal phyla. One of the hallmarks of the cnidarian body plan is the evolution of a free-swimming medusa in some medusozoan classes, but the origin of this innovation remains poorly constrained by the fossil record and molecular data. Previously described macrofossils, putatively representing medusa stages of crown-group medusozoans from the Cambrian of Utah and South China, are here reinterpreted as ctenophore-grade organisms. Other putative Ediacaran to Cambrian medusozoan fossils consist mainly of microfossils and tubular forms. Here we describe Burgessomedusa phasmiformis gen. et sp. nov., the oldest unequivocal macroscopic free-swimming medusa in the fossil record. Our study is based on 182 exceptionally preserved body fossils from the middle Cambrian Burgess Shale (Raymond Quarry, British Columbia, Canada). Burgessomedusa possesses a cuboidal umbrella up to 20 cm high and over 90 short, finger-like tentacles. Phylogenetic analysis supports a medusozoan affinity, most likely as a stem group to Cubozoa or Acraspeda (a group including Staurozoa, Cubozoa and Scyphozoa). Burgessomedusa demonstrates an ancient origin for the free-swimming medusa life stage and supports a growing number of studies showing an early evolutionary diversification of Medusozoa, including of the crown group, during the late Precambrian\u2013Cambrian transition.", "keyphrases": ["cambrian explosion", "cnidarian", "medusae"]}
{"id": "doi:10.1098/rspb.2023.1102", "title": "Allometric wing growth links parental care to pterosaur giantism", "abstract": "Pterosaurs evolved a broad range of body sizes, from small-bodied early forms with wingspans of mostly 1\u20132 m to the last-surviving giants with sizes of small airplanes. Since all pterosaurs began life as small hatchlings, giant forms must have attained large adult sizes through new growth strategies, which remain largely unknown. Here we assess wing ontogeny and performance in the giant Pteranodon and the smaller-bodied anurognathids Rhamphorhynchus, Pterodactylus and Sinopterus. We show that most smaller-bodied pterosaurs shared negative allometry or isometry in the proximal elements of the fore- and hindlimbs, which were critical elements for powering both flight and terrestrial locomotion, whereas these show positive allometry in Pteranodon. Such divergent growth allometry typically signals different strategies in the precocial\u2013altricial spectrum, suggesting more altricial development in Pteranodon. Using a biophysical model of powered and gliding flight, we test and reject the hypothesis that an aerodynamically superior wing planform could have enabled Pteranodon to attain its larger body size. We therefore propose that a shift from a plesiomorphic precocial state towards a derived state of enhanced parental care may have relaxed the constraints of small body sizes and allowed the evolution of derived flight anatomies critical for the flying giants.", "keyphrases": ["giantism", "growth", "allometry", "flight", "pterosauria", "wing shape"]}
{"id": "doi:10.1098/rspb.2023.0316", "title": "Evidence of artefacts made of giant sloth bones in central Brazil around the last glacial maximum", "abstract": "The peopling of the Americas and human interaction with the Pleistocene megafauna in South America remain hotly debated. The Santa Elina rock shelter in Central Brazil shows evidence of successive human settlements from around the last glacial maximum (LGM) to the Early Holocene. Two Pleistocene archaeological layers include rich lithic industry associated with remains of the extinct giant ground sloth Glossotherium phoenesis. The remains include thousands of osteoderms (i.e. dermal bones), three of which were human-modified. In this study, we perform a traceological analysis of these artefacts by optical microscopy, non-destructive scanning electron microscopy, UV/visible photoluminescence and synchrotron-based microtomography. We also describe the spatial association between the giant sloth bone remains and stone tools and provide a Bayesian age model that confirms the timing of this association in two time horizons of the Pleistocene in Santa Elina. The conclusion from our traceological study is that the three giant sloth osteoderms were intentionally modified into artefacts before fossilization of the bones. This provides additional evidence for the contemporaneity of humans and megafauna, and for the human manufacturing of personal artefacts on bone remains of ground sloths, around the LGM in Central Brazil.", "keyphrases": ["zooarchaeology", "traceology", "south america", "pleistocene", "bone surface modification", "palaeometry"]}
{"id": "doi:10.1098/rspb.2023.0638", "title": "Raptorial appendages of the Cambrian apex predator <i>Anomalocaris canadensis</i> are built for soft prey and speed", "abstract": "The stem-group euarthropod Anomalocaris canadensis is one of the largest Cambrian animals and is often considered the quintessential apex predator of its time. This radiodont is commonly interpreted as a demersal hunter, responsible for inflicting injuries seen in benthic trilobites. However, controversy surrounds the ability of A. canadensis to use its spinose frontal appendages to masticate or even manipulate biomineralized prey. Here, we apply a new integrative computational approach, combining three-dimensional digital modelling, kinematics, finite-element analysis (FEA) and computational fluid dynamics (CFD) to rigorously analyse an A. canadensis feeding appendage and test its morphofunctional limits. These models corroborate a raptorial function, but expose inconsistencies with a capacity for durophagy. In particular, FEA results show that certain parts of the appendage would have experienced high degrees of plastic deformation, especially at the endites, the points of impact with prey. The CFD results demonstrate that outstretched appendages produced low drag and hence represented the optimal orientation for speed, permitting acceleration bursts to capture prey. These data, when combined with evidence regarding the functional morphology of its oral cone, eyes, body flaps and tail fan, suggest that A. canadensis was an agile nektonic predator that fed on soft-bodied animals swimming in a well-lit water column above the benthos. The lifestyle of A. canadensis and that of other radiodonts, including plausible durophages, suggests that niche partitioning across this clade influenced the dynamics of Cambrian food webs, impacting on a diverse array of organisms at different sizes, tiers and trophic levels.", "keyphrases": ["cambrian", "anomalocaris", "predation", "kinematics", "biomechanics", "computational fluid dynamics"]}
{"id": "doi:10.1098/rspb.2023.0704", "title": "A giant armoured skink from Australia expands lizard morphospace and the scope of the Pleistocene extinctions", "abstract": "There are more species of lizards and snakes (squamates) alive today than any other order of land vertebrates, yet their fossil record has been poorly documented compared with other groups. Here, we describe a gigantic Pleistocene skink from Australia based on extensive material that includes much of the skull and postcranial skeleton, and spans ontogenetic stages from neonate to adult. Tiliqua frangens substantially expands the known ecomorphological diversity of squamates. At approximately 2.4 kg, it was more than double the mass of any living skink, with an exceptionally broad, deep skull, squat limbs and heavy, ornamented body armour. It probably filled the armoured herbivore niche that land tortoises (testudinids), absent from Australia, occupy on other continents. Tiliqua frangens and other giant Plio-Pleistocene skinks suggest that small-bodied groups that dominate vertebrate biodiversity might have lost their largest and often most morphologically extreme representatives in the Late Pleistocene, expanding the scope of these extinctions.", "keyphrases": ["pleistocene", "megafauna", "australia", "tiliqua", "reptile", "extinction"]}
{"id": "doi:10.1098/rspb.2023.0871", "title": "Developmental and functional controls on enrolment in an ancient, extinct arthropod", "abstract": "Three-dimensional models reveal how the mechanics of exoskeletal enrolment changed during the development of a model organism for insights into ancient arthropod development, the 429-million-year-old trilobite Aulacopleura koninckii. Changes in the number, size and allocation of segments within the trunk, coupled with the need to maintain effective exoskeletal shielding of soft tissue during enrolment, necessitated a transition in enrolment style about the onset of mature growth. During an earlier growth phase, enrolment was sphaeroidal, with the venter of the trunk fitting exactly against that of the head. In later growth, if lateral exoskeletal encapsulation was to be maintained trunk length proportions did not permit such exact fitting, requiring an alternative, non-sphaeoridal enrolment style. Our study favours the adoption of a posture in later growth in which the posterior trunk extended beyond the front of the head. This change in enrolment accommodated a pattern of notable variation in the number of mature trunk segments, well known to characterize the development of this species. It suggests how an animal whose early segmental development was remarkably precisely controlled was able to realize the marked variation in mature segment number that was related, apparently, to life in a physically challenging, reduced oxygen setting.", "keyphrases": ["biomechanics", "kinematics", "ontogeny", "tagmosis", "trilobites", "silurian"]}
{"id": "doi:10.1098/rspb.2023.0873", "title": "A new dolphin with tusk-like teeth from the late Oligocene of New Zealand indicates evolution of novel feeding strategies", "abstract": "All extant toothed whales (Cetacea, Odontoceti) are aquatic mammals with homodont dentitions. Fossil evidence from the late Oligocene suggests a greater diversity of tooth forms among odontocetes, including heterodont species with a variety of tooth shapes and orientations. A new fossil dolphin from the late Oligocene of New Zealand, Nihohae matakoi gen. et sp. nov., consisting of a near complete skull, earbones, dentition and some postcranial material, represents this diverse dentition. Several preserved teeth are horizontally procumbent, including all incisors and canines. These tusk-like teeth suggest adaptive advantages for horizontally procumbent teeth in basal dolphins. Phylogenetic analysis places Nihohae among the poorly constrained basal waipatiid group, many with similarly procumbent teeth. Features of N. matakoi such as its dorsoventrally flattened and long rostrum, long mandibular symphysis, unfused cervical vertebrae, lack of attritional or occlusal wear on the teeth and thin enamel cover suggest the rostrum and horizontally procumbent teeth were used to injure and stun prey though swift lateral head movements, a feeding mode that did not persist in extant odontocetes.", "keyphrases": ["phylogeny", "dolphin", "evolution", "functional morphology", "palaeoecology", "evolution"]}
{"id": "doi:10.1098/rspb.2023.0333", "title": "Multivariate mapping of ontogeny, taphonomy and phylogeny to reconstruct problematic fossil taxa", "abstract": "Exceptionally preserved fossils of soft-bodied organisms provide unique evidence of evolutionary history, but they are often contentious; different approaches frequently produce radically different reconstructions of taxa and their affinities. Conflict arises due to difficulties in disentangling the three non-independent factors that underlie all morphological variation within and between fossils: ontogeny, taphonomy and phylogeny. Comparative data from extant organisms can be extremely powerful in this context, but is often difficult to apply given the multi-dimensionality of anatomical variation. Here, we present a multivariate ordination method using discrete morphological character data from modern taxa at different ontogenetic and taphonomic stages (semaphoront and \u2018semataphonts\u2019). Analysing multiple axes of morphological variation simultaneously allows us to visualize character combinations that are likely to exist in fossil specimens at intersecting stages of growth and decay, and thus constrain interpretation of fossils. Application to early vertebrates finds variation in fossil specimens to be accounted for by all three axes: primarily decay in Mayomyzon, ontogeny in Priscomyzon and phylogeny in \u2018euphaneropoids\u2019 and Palaeospondylus. Our demonstration of empirical multi-factorial variation underscores the power of multivariate approaches to fossil interpretation, especially non-biomineralized taxa. As such, this conceptual approach provides a new method for resolving enigmatic taxa throughout the fossil record.", "keyphrases": ["ontogeny", "taphonomy", "early vertebrates", "soft-tissue", "fossil", "non-metric multidimensional scaling"]}
{"id": "doi:10.1098/rspb.2023.0220", "title": "Colonial coral resilience by decreasing size: reaction to increased detrital influx during onset of the late Palaeozoic Ice Age", "abstract": "Modern coral reefs and associated biodiversity are severely threatened by increasing terrestrial runoff. Similar scenarios could be suspected for geological times, but reef coral resilience is still an enigma. In late Visean-Serpukhovian (Mississippian foraminiferal zones/MFZ 14-16) times, a major glaciation phase of the late Palaeozoic Ice Age (LPIA) associated with enhanced terrestrial weathering and runoff coincides with a biodiversity crisis and coral reef decline. In this study, the impact of enhanced terrestrial runoff is tested on size variations of colonial corals Aulina rotiformis and Lithostrotion decipiens along a gradient of contemporaneous (Serpukhovian) open marine carbonate to near-shore siliciclastic facies in South China. Along this gradient, their sizes decrease from carbonate, through intermediate carbonate-siliciclastic, to siliciclastic facies. This is consistent with increasing abundance of terrestrial materials of high silicon, aluminium and phosphorus values. On a larger million-year-long interval (MFZ14-16) and for several palaeocontinents, size data of Lithostrotion decipiens and Siphonodendron pauciradiale show a distinct decline in late Visean, when enhanced terrestrial weathering occurred commonly with palaeosols developed during regression. This suggests that terrestrial sediment and nutrient input may have mainly controlled phenotypic plasticity in Mississippian reef corals, with a decrease in size as a component of resilience across the LPIA onset.", "keyphrases": ["terrestrial runoff", "reef coral", "phenotypic plasticity", "facies", "biodiversity crisis", "mississippian"]}
{"id": "doi:10.1098/rspb.2023.0106", "title": "A 2200-year record of Andean Condor diet and nest site usage reflects natural and anthropogenic stressors", "abstract": "Understanding how animals respond to large-scale environmental changes is difficult to achieve because monitoring data are rarely available for more than the past few decades, if at all. Here, we demonstrate how a variety of palaeoecological proxies (e.g. isotopes, geochemistry and DNA) from an Andean Condor (Vultur gryphus) guano deposit from Argentina can be used to explore breeding site fidelity and the impacts of environmental changes on avian behaviour. We found that condors used the nesting site since at least approximately 2200 years ago, with an approximately 1000-year nesting frequency slowdown from ca 1650 to 650 years before the present (yr BP). We provide evidence that the nesting slowdown coincided with a period of increased volcanic activity in the nearby Southern Volcanic Zone, which resulted in decreased availability of carrion and deterred scavenging birds. After returning to the nest site ca 650 yr BP, condor diet shifted from the carrion of native species and beached marine animals to the carrion of livestock (e.g. sheep and cattle) and exotic herbivores (e.g. red deer and European hare) introduced by European settlers. Currently, Andean Condors have elevated lead concentrations in their guano compared to the past, which is associated with human persecution linked to the shift in diet.", "keyphrases": ["palaeoecology", "volcano", "condor", "diet", "birds", "nest"]}