Uintatherium was a large browsing animal and an herbivore that lived during the Eocene period. With a length of about 13 feet and a height of 5.6 feet, it was similar to today's rhinoceros, both in size and in shape. Its legs were robust to sustain the weight of the animal and were equipped with hooves. The male had three pairs of horns, probably used in mating combat and rituals. The skull was concave, limiting brain-size, and the elongated canine teeth were larger in males than in females.