Hyohippus evolved out of Miohippus and was a specialised, pony-sized browser. Its feet ended in tree toes, which was an adaptation to soft forest floor. It had a long neck and comparatively short legs. It lived around 17 to 11 mya in what is Nebraska, Colorado, and Montana today. Together with Megahippus and Achniterium, it belonged to the group of Anchiteria, which thrived over millions of years but eventually became extinct.