News Finding: For the first time, Professor Solounias and colleagues propose that the reduction in the number of digits is not a matter of simple attrition; instead, they believe that all five digits have merged to form the compacted forelimbs with hooves that we know today.
Paper Finding: Monodactyly also occurred by convergent evolution in the lineage to Pliohippus and Astrohippus, single-toed horses that are now extinct .
News Context: For the first time, Professor Solounias and colleagues propose that the reduction in the number of digits is not a matter of simple attrition; instead, they believe that all five digits have merged to form the compacted forelimbs with hooves that we know today. "While this explanation of the second and fourth digits is viable, it is incomplete and fails to account for the animal's first and fifth digits," the paleontologists said. Fragments of the 'missing' digits can be found in the form of ridges on the backside of the splints."
Paper Context: The first time it occurred was in the Miocene, starting with Dinohippus, leading to the modern horse . Monodactyly also occurred by convergent evolution in the lineage to Pliohippus and Astrohippus, single-toed horses that are now extinct . The reduction to a single complete toe also evolved in the liptotern Thoatherium, an extinct ungulate from the Miocene of South America .