Andrewsarchus preying on Embolotherium. Illustration of the mammal Andrewsarchus preying on the mammal Embolotherium, with a predatory Sarkastodon mammal in the background. The latter existed around 35 million years ago, during the Late Eocene. The fossils of all three species have been found in Mongolia, dating from the Eocene. Embolotherium was an example of a brontothere, and looked like a rhinoceros but was more closely related to horses. Andrewsarchus was a carnivorous ungulate. Sarkastodon was a hypercarnivore, and may have occupied an ecological niche similar to today's hyenas.