Order Perissodactyla Author Wilson, Don E. Author Reeder, DeeAnn text 2005 The Johns Hopkins University Press Baltimore Mammal Species of the World: a Taxonomic and Geographic Reference (3 rd Edition), Volume 1 629 636 book chapter 0-8018-8221-4 10.5281/zenodo.7316519 Equus Linnaeus 1758 Equus Linnaeus 1758 , Syst. Nat., 10th ed., Vol. 1: 73 . Type Species: Equus caballus Linnaeus 1758 Synonyms: Asinohippus Trumler 1961 ; Asinus Brisson 1762 ; Asinus Gray 1824 ; Caballus Rafinesque 1815 ; Dolichohippus Heller 1912 ; Grevya Hilzheimer 1912 ; Hemionus F. Cuvier 1823 ; Hemionus Stehlin and Graziosi 1935 ; Hemippus Dietrich 1959 ; Hippotigris C. H. Smith 1841 ; Ludolphozecora Griffin 1913 ; Megacephalon Hilzheimer 1912 ; Megacephalonella Strand 1943 ; Microhippus Matschie 1924 ; Onager Brisson 1762 ; Pseudoquagga Hoffstetter 1951 ; Quagga Shortridge 1934 ; Quaggoides Willoughby 1974 ; Zebra J. A. Allen 1909 . Species and subspecies: 8 species with 24 subspecies: Species Equus asinus Linnaeus 1758 Subspecies Equus asinus subsp. asinus Linnaeus 1758 Subspecies Equus asinus subsp. africanus Heuglin and Fitzinger 1866 Subspecies Equus asinus subsp. somalicus P. L. Sclater 1885 Species Equus burchellii Gray 1824 Subspecies Equus burchellii subsp. burchellii Gray 1824 Subspecies Equus burchellii subsp. antiquorum C. H. Smith 1841 Subspecies Equus burchellii subsp. boehmi Matschie 1892 Subspecies Equus burchellii subsp. crawshaii De Winton 1896 Subspecies Equus burchellii subsp. kaokensis Zukowsky 1924 Subspecies Equus burchellii subsp. zambeziensis Trouessart 1898 Species Equus caballus Linnaeus 1758 Subspecies Equus caballus subsp. caballus Linnaeus 1758 Subspecies Equus caballus subsp. ferus Boddaert 1785 Subspecies Equus caballus subsp. przewalskii Poliakov 1881 Species Equus grevyi Oustalet 1882 Species Equus hemionus Pallas 1775 Subspecies Equus hemionus subsp. hemionus Pallas 1775 Subspecies Equus hemionus subsp. blanfordi Pocock 1947 Subspecies Equus hemionus subsp. hemippus I. Geoffroy Saint-Hilaire 1855 Subspecies Equus hemionus subsp. khur Lesson 1827 Subspecies Equus hemionus subsp. kulan Groves and Mazák 1967 Subspecies Equus hemionus subsp. luteus Matschie 1911 Subspecies Equus hemionus subsp. onager Boddaert 1785 Species Equus kiang Moorcroft 1841 Subspecies Equus kiang subsp. kiang Moorcroft 1841 Subspecies Equus kiang subsp. holdereri Matschie 1911 Subspecies Equus kiang subsp. polyodon Hodgson 1847 Species Equus quagga Boddaert 1785 Species Equus zebra Linnaeus 1758 Subspecies Equus zebra subsp. zebra Linnaeus 1758 Subspecies Equus zebra subsp. hartmannae Matschie 1898 Discussion: Species-groups with potential subgeneric names, based on Groves and Willoughby (1981) , are as follows: E. asinus or Asinus group; E. caballus or nominate Equus group (synonym: Caballus ); E. grevyi or Dolichohippus group (synonyms: Grevya , Ludolphozecora , Megacephalon , and Megacephalonella ); E. hemionus or Hemionus group (synonyms: Asinohippus , Hemippus , Microhippus and Onager ), including also E. kiang ; E. quagga or Quagga group (synonyms: Pseudoquagga , Quaggoides , and Zebra ), including also E. burchellii ; and E. zebra or Hippotigris group. Earliest generic name for the E. quagga group ( Zebra J. A. Allen, 1909 ) is preoccupied and next available name († Kraterohippus van Hoepen, 1930 ) would have priority over Quagga Shortridge, 1934 if these nominal genera were treated as valid taxa.