Chalicotherioidea

Chalicotherioidea is an extinct group of clawed perissodactyls that lived from the early Eocene to the Pleistocene subepochs. It began and thrived largely in Eurasia, based on the fossil record, although specimens have been found in both Africa and North America. They were likely browsers that fed mainly on leaves, twigs, and other nonresistant vegetation. Many of the contained genera had derived specializations of the forelimb and manus that allowed the claws to be used as hooks for browsing and to be kept off of the ground while walking. Chalicotheres lived primarily in forested areas. Size sexual dimorphism and morphological structures such as the domed skulls of Tylocephalonyx suggest agonistic behaviour in some sort of social setting. They are related to the extinct brontotheres, as well as modern day horses, rhinoceroses, and tapirs.