Also found in: Dictionary, Thesaurus, Medical, Wikipedia.
the most ancient representative of the fossil horse, from the Lower Eocene. It was the size of a fox and had short legs. The front legs had four toes and the rear had three. The snout was short with the eye sockets located in the front part of the skull, not shifted back as in the later horses. The molars were low, tuberculate, and simple in shape. The hyracotheriùm lived in forests and ate small plants, primarily grass and shoots. Its remains have been found in Western Europe and North America.