Class Mammalia Linnaeus, 1758 - mammals
Subclass Theria Parker & Haswell, 1897
Order Perissodactyla Owen, 1848 - odd-toed ungulates
Family Equidae Gray, 1821 [monotypic] - horses, zebras, and asses
Genus Equus Linnaeus, 1758 - horses, zebras, and asses
Equus caballus group Linnaeus, 1758 [monotypic]
Equus caballus Linnaeus, 1758 - horse
Equus caballus ferus Boddaert, 1785 - tarpan