Hyracotherium

This small dog-sized animal represents the oldest known horse. It had a primitive short face, with eye sockets in the middle and a short diastema (the space between the front teeth and the cheek teeth).

Although it has low-crowned teeth, we see the beginnings of the characteristic horse-like ridges on the molars.

Hyracotherium is better known as "eohippus" - which means "the dawn horse." The name also refers to the fact that it lived during the Eocene.