[organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Kingdom Animalia Linnaeus, 1758 - animals
     Branch Eumetazoa Butschli, 1910 see [unranked] Eumetazoa Bütschli, 1910
       Division Bilateria Hatschek, 1888 see Subkingdom Bilateria Hatschek, 1888
         Subdivision Deuterostomia Grobben, 1908 see Infrakingdom Deuterostomia Grobben, 1908
           Phylum Chordata Bateson, 1885 - chordates
             Subphylum Vertebrata Cuvier, 1812 - vertebrates
               Superclass Tetrapoda Goodrich, 1930 - tetrapods see Clade Tetrapoda Hatschek & Cori 1896 [Gauthier, Kluge & Rowe 1988]
                 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 asinus Linnaeus, 1758 - ass
                             Equus burchelli (Gray, 1824) see Equus burchellii (Gray, 1824)
                             Equus caballus Linnaeus, 1758 - horse