Dinohippus was a prehistoric horse that lived around 12 to 5 million years ago during the late Miocene to early Pliocene epochs. It is known for its three toes on each foot, which were adaptations for running on soft ground. This animal was about the size of a modern horse and had a similar body shape, but its teeth were more suited for grazing on tough grasses. Fossils of Dinohippus have been found primarily in North America, providing valuable insights into the evolution of horses. It is considered a key ancestor of the modern Equus genus, which includes today's horses, zebras, and donkeys.