Colours of Wildlife: Moropus, the Foolish-Foot
Created | Updated Sep 4, 2016
Moropus, the Foolish-Foot
Willem is a wildlife artist based in South Africa. He says "My aim is simply to express the beauty and wonder that is in Nature, and to heighten people's appreciation of plants, animals and the wilderness. Not everything I paint is African! Though I've never been there, I'm also fascinated by Asia and I've done paintings of Asian rhinos and birds as well. I may in future do some of European, Australian and American species too. I'm fascinated by wild things from all over the world! I mainly paint in watercolours. . . but actually many media including 'digital' paintings with the computer!"
Time for another Golden Oldie! This strange beast is a Moropus elatus, a critter that lived in the Miocene Period, about 20 million years ago, in North America. It is a kind of animal that doesn't exist any more – a Chalicothere. Chalicotheres were relatives of horses, rhinos and tapirs, belonging with them in the order Perissodactyla, sometimes called the uneven-hoofed animals – though not all members have an uneven number of hooves per foot. And indeed, not all of its members had hooves – Moropus being a case in point! Instead of having hooves, it had large claws on its feet. This strange situation gave Moropus its scientific name, which means 'slow foot' or 'foolish-foot'. It certainly does not appear to have been a fast runner. In addition to the claws on its feet, it also was unusual in having its front limbs much longer than the rear ones, giving it a sloping back.
What were the Chalicotheres, and How did they Live?
This ancient group included several known species, living in America, Europe, Asia and Africa. They were an early offshoot of the horse/rhino/tapir group, the first members being known from the Eocene period, around 50 million years ago. Chalicotheres did not have high-crowned teeth like horses and rhinos, and therefore probably did not graze, instead likely browsing from trees and bushes. But what of the claws? These appear to have been retractile or semi-retractile like those of cats. But they were likely not for catching prey – chalicothere dentition certainly was not for eating meat. Instead, they might have used their claws for digging up roots and tubers. But this also doesn't seem to be a good fit.
The unusual limb proportions might offer a clue. The forelimbs were especially long in species such as Chalicotherium itself (of which the genera Anisodon and Macrotherium might be synonyms). This species indeed seems to have walked on the knuckles of its front feet, like a gorilla! The hind limbs were short and sturdy. With such a build, the species might have used its long, clawed forelimbs to reach up high while standing on its hind legs, pulling branches closer so as to browse them. This mode of feeding is similar to the present-day species, the Gerenuk antelope, which unfortunately hasn't (yet!) grown claws and extra-long forelimbs to make the task easier.
It's not clear though whether Moropus used the same style of feeding, being built rather differently from Chalicotherium. The size of a large horse, standing over 2 m at the shoulder, it would have had much difficulty rearing up on its hind legs – but it might indeed have done that. It might also have used its claws to defend itself against predators. We just don't really know! This weird species took its secrets along with it into extinction.
Animals similar to Moropus, called Ancylotherium, lived in Africa. A very unusual chalicothere was the genus Tylocephalonyx, which had a big, bony bump on its forehead, suggesting that they engaged in head-butting contests. Most chalicotheres died out in or before the Pliocene, the second-most recent period, lasting from 5 to 1 million years ago. At least some of them hanged on, however, into the Pleistocene, the most recent period, in Africa. Geologically speaking, we only just missed them. Unlike many others, their demise probably was not caused by humans. Indeed, we don't really know why they went extinct. It might have been due to competition with more 'modern' browsers like antelopes – but without knowing more about their lives, we can't say for sure.
