living organisms see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Superkingdom Eukaryotae see Domain Eukaryota Chatton, 1925
     Kingdom Animalia Linnaeus, 1758 - animals
       Subkingdom Eumetazoa Butschli, 1910 see [unranked] Eumetazoa Bütschli, 1910
         Phylum Chordata Bateson, 1885 - chordates
           Subphylum Vertebrata Cuvier, 1812 - vertebrates
             Class Mammalia Linnaeus, 1758 - mammals
               Subclass Theria Parker & Haswell, 1897
                 Infraclass Eutheria Gill, 1872
                   Order Perissodactyla Owen, 1848 - odd-toed ungulates
                     Family Equidae Gray, 1821 - horses, zebras, and asses
                       Genus Equus Linnaeus, 1758 - horses, zebras, and asses
                         Equus caballus Linnaeus, 1758 - horse
                           Equus caballus prezewalskii see Equus caballus przewalskii Poliakov, 1881