Class [Mammalia] Linnaeus, 1758 - mammals
   Order Perissodactyla Owen, 1848 - odd-toed ungulates
     Family Equidae Gray, 1821 - horses, zebras, and asses
       Genus Equus Linnaeus, 1758 - horses, zebras, and asses
         1 Equus africanus (Fitzinger, 1857) - African ass see Equus asinus africanus Heuglin & Fitzinger, 1866
         2 Equus asinus Linnaeus, 1758 - ass
         3 Equus burchellii (Gray, 1824) - Burchell's zebra
         4 Equus ferus Boddaert, 1785 - wild horse see Equus caballus Linnaeus, 1758
         5 Equus caballus Linnaeus, 1758 - horse
         6 Equus grevyi Oustalet, 1882 - Grévy's zebra
         7 Equus hemionus Pallas, 1775 - onager
         8 ‡Equus quagga Boddaert, 1785 - quagga
         9 Equus zebra Linnaeus, 1758 - mountain zebra