Genus Protohippus is a prehistoric horse species that existed during the Miocene epoch. There are several synonyms for this species, including Pliohippus Texanus, Orohippus Texanus, and Equus Texanus. These synonyms are used interchangeably to refer to Protohippus, as they represent different interpretations of the same fossilized remains. Protohippus is believed to have been the ancestor of modern-day horses, and its fossils have been discovered across various parts of North America. The species was characterized by its slender legs, small hooves, and adaptations that allowed it to thrive in grasslands. Despite its extinction, Protohippus remains an important species in the evolutionary history of horses.