Pliohippus is an extinct genus of Equidae, the "horse family". Pliohippus arose in the middle Miocene, around 15 million years ago. It was similar in appearance to Equus, but had two long extra toes on both sides of the hoof, externally barely visible as callused stubs. The long and slim limbs of Pliohippus reveal a quick-footed steppe animal. Fossils of Pliohippus have been found at many late Miocene localities in Colorado, the Great Plains (Nebraska and the Dakotas) and also Canada. Pliohippus has been found beside Neohipparion. \n* Specimen at American Museum of Natural History \n*