News Finding: We find these ridges, located on the posterior of each splint, to be the partially formed remains of the first and fifth digits, which were once connected to the cartilages of the hoof."
Paper Finding: In none of the described embryonic specimens does the horse limb commence as a flattened paddle that characterizes early limb development in humans and other species ; the horse limb at early stages already resembles the adult form.
News Context: "However, these partially formed digits also appear to contain their own elevated surfaces which hold additional evolutionary clues. We find these ridges, located on the posterior of each splint, to be the partially formed remains of the first and fifth digits, which were once connected to the cartilages of the hoof." However, the scientist noticed that the bottom surface of Hipparion's fossilized forelimb appeared to be divided in five sections, as though small toes had bonded together.
Paper Context: Skeletal precursors are evident for digits II, III and IV, and are apparently absent for digits I and V; areas of apoptosis have been visualized surrounding digits II and IV [22] . In none of the described embryonic specimens does the horse limb commence as a flattened paddle that characterizes early limb development in humans and other species ; the horse limb at early stages already resembles the adult form. In the adult, our proposed position of these digits remains ventral to digit III both proximally at the wrist and distally towards the distal phalanx, retaining their embryonic relations.