Hypohippus
Hypohippus, "horse" ) is an extinct genus of three-toed horse, which lived 17–11 million years ago. It was the largest anchitherine equid about the size of a modern domestic horse, at and long. It was a long-necked, high-shouldered browser with sub-hypsodont, lophodont dentition, that fed on the tough vegetation of forest understory and shrubs. Its deep preorbital fossae and retraction of the nasal notch hint at the presence of a long, muscular and prehensile upper lip that would aid during selective browsing. Overall its ecology would have been more comparable to modern okapi than to grazing horses.
Fossils of it have been found in Nebraska, Colorado, and Montana.