Moropus

Moropus (meaning 'slow foot') is an extinct genus of perissodactyl ('odd-toed' ungulate) mammal that belonged to the group called chalicotheres. They were endemic to North America during the Miocene from ~20.4—13.6 Mya, existing for approximately 6.8 million years. The closest extant relatives of Moropus are other perissodactyls: horses, rhinos, and tapirs. Like other chalicotheres, they differed from their modern relatives in having large claws, rather than hooves, on the front feet; these claws may have been used for defense or digging for food. Moropus stood about 8 feet (2.4 m) tall at the shoulder. The three highly compressed claw-like hooves on each foot were split down the middle. The name Moropus translates to 'slow (or sloth) foot', implying it was a clumsy mover. However the articulation of the phalangeal (finger) bones, in addition to the likely presence of large foot and toe pads, shows that Moropus probably could raise the claws slightly to enable it to move about quite smoothly. The laterally compressed claws, less robust knuckles, and its large size suggest it didn't knuckle walk like other chalicotheres. Rather, they had a digitigrade stance and lifted its claws by hyperextension of the phalangeal hook. As the hooves curved inward, it probably had a pigeon-toed gait. Another schizotheriine chalicothere, Ancylotherium had a similar gait.