Equus (genus) - Classification

Classification

Family Equidae (in addition to Equus, the family includes approximately 35 other genera, all extinct)

• Genus Equus
  • Subgenus Equus
    • Equus ferus Wild horse
      • Equus ferus caballus Domestic horse
      • †Equus ferus ferus Tarpan (historically extinct)
      • Equus ferus przewalskii Przewalski's Horse or Mongolian Wild Horse or takhi
      • †Equus algericus (Pleistocene of Algeria)
      • † North American caballid horses (Pleistocene; most likely synonymous with E. ferus):
        • †Equus lambei Yukon Wild Ass (or Yukon Wild Horse)
        • †Equus niobrarensis
      • Subgenus †Amerhippus Hoffstetter, 1950 (jr synonym subgenus Tomolabis Cope, 1892) (this subgenus and the species therin are possibly synonymous with E. ferus)
        • †Equus andium
        • †Equus neogeus
        • †Equus fraternus Leidy, 1860 (North America)
        • †Equus santaeelenae
        • †Equus scotti Gidley
        • †Equus niobrarensis Hay
        • †Equus conversidens Owen, 1863 ("Mexican Horse") (North America)
    • †New World stilt-legged horse (all following species within the group may be synonyms or regional races of a single species)
      • †Equus francisci Hay, 1915
      • †Equus semiplicatus Cope, 1893 (North America)
  • Subgenus Asinus
    • Equus africanus African Wild Ass
      • Equus africanus africanus Nubian Wild Ass
      • Equus africanus asinus Domestic Donkey, Ass or Burro
      • †Equus africanus atlanticus Atlas Wild Ass
      • Equus africanus somalicus Somali Wild Ass
    • Equus hemionus Onager or Asiatic Ass
      • Equus hemionus hemionus Mongolian Wild Ass, Dziggetai or Gobi Kulan
      • †Equus hemionus hemippus Syrian Wild Ass
      • Equus hemionus khur Indian Wild Ass or Khur
      • Equus hemionus kulan Turkmenian Kulan
      • Equus hemionus onager Persian Onager
    • Equus kiang Kiang
      • Equus kiang chu Northern Kiang
      • Equus kiang kiang Western Kiang
      • Equus kiang holdereri Eastern Kiang
      • Equus kiang polyodon Southern Kiang
    • †Equus hydruntinus European Ass (late Paleolithic of southern Europe)
    • †Equus altidens (middle Pleistocene of Tadjikistan)
    • †Equus tabeti (early middle Pleistocene of Algeria, known only from teeth and limb bones)
    • †Equus melkiensis (late Paleolithic of Algeria, based on teeth and limb bones)
    • †Equus graziosii (late Pleistocene of Italy)
  • Subgenus Dolichohippus
    • Equus grevyi Grevy's Zebra
    • †Equus koobiforensis Eisenmann, 1983 (East Africa, ~2 million years (late Pliocene), similar but more derived than E.simplicidens and E.sanmeniensis
      • †Equus oldowayensis Hopwood, 1937 (East Africa, late Pleiocene, early Pleistocene, likely conspecific with E.koobiforensis
  • Subgenus Hippotigris
    • Equus quagga Plains Zebra
      • Equus quagga boehmi Grant's Zebra
      • Equus quagga borensis Maneless Zebra
      • Equus quagga chapmani Chapman's Zebra
      • Equus quagga crawshayi Crawshay's Zebra
      • Equus quagga burchellii Burchell's Zebra
      • †Equus quagga quagga Gmelin, 1788 Quagga (South Africa, extinction in early 20th century)
      • Equus quagga selousi Selous' Zebra
    • Equus zebra L.,1758 Mountain Zebra
      • Equus zebra hartmannae Hartmann's Mountain Zebra
      • Equus zebra zebra Cape Mountain Zebra
    • †Equus mauritanicus Pomel, 1897 (Pleistocene transitional form between E. (Dolichohippus) and E. (Hippotigris), possibly via E.koobiforensis)
  • Subgenus †Parastylidequus
    • †Equus parastylidens Mooser’s Horse
  • incertae sedis
    • †Equus simplicidens Hagerman Horse (North American Pleiocene - earliest known species of genus Equus) (perhaps closest to Dolichohippus)
    • †Equus cumminsii Cope, 1893 (North America; based on a single, 3 million year old tooth)
    • †Equus livenzovensis Baihusheva, 1978 (southern Russia and western Europe, Pleiocene - highly similar to E. simplicidens
    • †Equus sanmeniensis Teilhard&Piveteau, 1930 (south China, late? Pliocene; similar but more derived than E.livenzovensis
    • †Equus teilhardi Eisenmann, 1975 (south China, late(?) Pliocene; similar to E.sanmeniensis but smaller, likely synonym)
    • †Equus numidicus Pomel, 1897
    • †Equus plicidens Owen, 1844 (late Pliocene, only teeth known)
    • †Equus stenonis group
      • †Equus stenonis Cocchi, 1867 (Europe to China, late Pleiocene)
        • †Equus stenonis guthi (late Pliocene, France)
        • †Equus stenonis senezensis (late Pliocene)
        • †Equus stenonis pamirensis (=Hippotigris pamirensis) (late Pliocene, central Asia)
        • †Equus stenonis petraloniensis Tsoukala (Greece - Petralona cave)
        • †Equus stenonis vireti (late Pliocene)
      • †Equus sivalensis (late Pleiocene (?), India; similar to E.stenonis in skull shape)
      • †Equus stehlini (early Pleistocene, ~1 million years ago; similar but smaller than E. stenonis
      • †Equus bressanus (early Pleistocene, ~1 million years ago; similar but much larger than E. stenonis
      • †Equus sussenbornensis Wüst, 1901 (early middle Pleistocene of Europe)
      • †Equus verae Sher, 1971 (middle Pleistocene of north eastern Asia)
      • †Equus namadicus (middle paleolithic sites in India)
    • †subgenus Allozebra & Hesperohippus (N. American lineage of middle to late Pleistocene)
      • †Equus idahoensis
      • †Equus (A.) occidentalis
      • †Equus (A.) excelsus
      • †Equus (H.) pacificus
    • †Equus complicatus
    • †Equus fraternus
    • Equus major Boule (nomen dubium)
    • †Equus giganteus group
      • †Equus giganteus
      • †Equus pectinatus
      • †Equus crinidens

• Przewalski's Horse, the only remaining type of "wild" horse that has never been domesticated

• A domesticated horse

• An onager, one type of wild ass

• A pair of kiangs

• Quagga (now extinct)

• Plains zebra

• Grévy's zebra

• Equus conversidens (extinct)