(from Greek chalix
, gravel + therion
, beast) were a group of perissodactyl mammals
that evolved in the mid Eocene
around 40 million years ago from small, forest animals similar to the early horses
. Many chalicotheres, including such animals as Moropus
, reached the size of a horse
. By the late Oligocene
, they had divided into two groups: one that grazed in open areas and another that was more adapted to woodlands. They died out around 3.5 million years ago, and are related to the extinct brontotheres
, as well as modern day horses
, and tapirs
Unlike modern perissodactyls, chalicotheres had long forelimbs and short hind limbs. Consequently, Chalicotheres probably moved with most of their weight on their short, strong hind legs. Their front legs had long, curved claws which meant they probably walked on their knuckles. Fossil
remains have shown thick, developed front knuckles, much like those on gorillas
today. It was once thought that the claws were used to dig up roots and tubers, however, the wear on the claws and teeth do not suggest that they dug or ate dirt-rich foods such as tubers. The chalicotheres probably used their claws to strip vegetation from trees and to forage for food.
Chalicotheres did not have front teeth in their upper jaw, and their back teeth show little wear, suggesting that they probably were selective browsers.
have hypothesised that (the supposedly carnivorous) cryptid
, the Nandi Bear
could be a chalicothere.