Equus occidentalis
Equus occidentalis is an extinct species of wild horse that once inhabited North America, specifically the Southwestern United States, during the Pleistocene epoch. It was first described from three teeth with insufficient diagnostic characters, one even being suggested to be a separate taxon related to the American Zebra, leading some researchers to consider it a nomen dubium, though this taxonomic debate is yet to be fully resolved.
E. occidentalis was about the same size as the modern Arabian horse, measuring up to in shoulder height. It was morphologically and proportionally similar to the modern day zebra.