The wild horse (Equus ferus) is a species of the genus Equus, which includes as subspecies the modern domesticated horse (Equus ferus caballus) as well as the undomesticated tarpan (Equus ferus ferus), now extinct, and the endangered Przewalski's horse (Equus ferus przewalskii). Przewalski's horse was saved from the brink of extinction and reintroduced successfully to the wild. The tarpan became extinct in the 19th century, though it was a possible ancestor of the domestic horse, and roamed the steppes of Eurasia at the time of domestication. However, other subspecies of Equus ferus may have existed and could have been the stock from which domesticated horses are descended. Since the extinction of the tarpan, attempts have been made to reconstruct its phenotype, resulting in horse breeds s