do a post on Chalicotherium. then maybe I will remember its name and stop googling "ancient mammal that looked like a weird horse with big arms" every time I think about my favorite prehistoric mammal
Chalicotherium belongs to a group of mammals called the “chalicotheres”, a subgroup of the order Perissodactyla. The members of this group alive today include horses, rhinos, and tapirs, although the chalicotheres were most closely related to horses - a fact that may seem surprising when you see their strange and divergent anatomy.
Chalicotherium was indeed “a weird horse with big arms”. Unlike any other perissodactyls, the chalicotheres developed a semi-bipedal stance, and the digits on their forelimbs developed large claws. These adaptations allowed the chalicotheres to grasp branches and strip them of leaves, which they would then eat - a niche more akin to a gorilla or a giant panda than any modern perissodactyl.
Despite its apparent strangeness, Chalicotherium was a wildly successful animal. Its fossils have been discovered over a 25-million-year span, from the Late Oligocene to the Early Pliocene, in locations ranging from Germany to India to inner Mongolia. During the Oligocene, these areas were quite lush, tropical, and forested; at the beginning of the Pliocene, the Earth’s climate began to grow cooler and drier, and the rainforests began to recede. As they disappeared, so did Chalicotherium.
However, some African species of chalicothere hung on until the Miocene period, 3 million years ago, and almost certainly interacted with some of our early hominid ancestors.
The chalicotheres were closely related to the brontotheres, perhaps a more iconic group of extinct mammals. Despite their close resemblance to rhinoceroses, the brontotheres were more closely related to the chalicotheres than to any living mammal group, and both groups were more closely related to horses than to rhinos.
