Mammaliaformes Rowe 1988
   [crown] Class Mammalia Linnaeus, 1758 - mammals
     Subclass Theriiformes Rowe, 1988 see Division Theriiformes Rowe, 1988
       Infraclass Holotheria Wible, Rougier, Novacek, McKenna & Dashzeveg, 1995 see Clade Holotheria Wible, Rougier, Novacek, McKenna & Dashzeveg 1995
         Superlegion Trechnotheria McKenna, 1975 see Clade Trechnotheria McKenna 1975
           Legion Cladotheria McKenna, 1975 see Clade Cladotheria McKenna 1975
             Sublegion Zatheria McKenna, 1975 see Clade Zatheria McKenna 1975
               Infralegion Tribosphenida McKenna, 1975 see Subclass Boreosphenida Luo, Cifelli & Kielan-Jaworowska, 2001
                 [crown] Supercohort Theria Parker & Haswell, 1897 - therians see Subclass Theria Parker & Haswell, 1897
                   Cohort Placentalia Owen, 1837 - placentals
                     Magnorder Epitheria McKenna, 1975 see Cohort Placentalia Owen, 1837
                       Superorder Preptotheria McKenna, 1975
                         Grandorder Ungulata Linnaeus, 1766
                           Mirorder Altungulata Prothero & Schoch, 1989
                             Order Perissodactyla Owen, 1848 - odd-toed ungulates
                               Suborder Hippomorpha Wood, 1937
                                 Family Equidae Gray, 1821 - horses, zebras, and asses
                                   01 Genus †Hyracotherium Owen, 1840
                                   02 Genus †Orohippus Marsh, 1872
                                   03 Genus †Epihippus Marsh, 1878
                                   04 Genus †Haplohippus McGrew, 1953
                                   05 Genus †Mesohippus Marsh, 1875
                                   06 Genus †Miohippus Marsh, 1874
                                   07 Genus †Archaeohippus Gidley, 1906
                                   08 Genus †Anchitherium von Meyer, 1844
                                   09 Genus †Kalobatippus Osborn, 1915
                                   10 Genus †Hypohippus Leidy, 1858
                                   11 Genus †Sinohippus Zhai, 1962
                                   12 Genus †Megahippus McGrew, 1938
                                   13 Genus †Parahippus Leidy, 1858
                                   14 Genus †Merychippus Leidy, 1857
                                   15 Genus †Acritohippus Kelly, 1995
                                   16 Genus †Pseudhipparion Ameghino, 1904
                                   17 Genus †Nannippus Matthew, 1926
                                   18 Genus †Neohipparion Gidley, 1903
                                   19 Genus †Hipparion de Christol, 1832
                                   20 Genus †Proboscidipparion Sefve, 1927
                                   21 Genus †Stylohipparion van Hoepen, 1932
                                   22 Genus †Cormohipparion Skinner & MacFadden, 1977
                                   23 Genus †Protohippus Leidy, 1858
                                   24 Genus †Parapliohippus Kelly, 1995
                                   25 Genus †Heteropliohippus Kelly, 1995
                                   26 Genus †Pliohippus Marsh, 1874
                                   27 Genus †Calippus Matthew & Stirton, 1930
                                   28 Genus †Astrohippus Stirton, 1940
                                   29 Genus ‡Hippidion Owen, 1869
                                   30 Genus †Onohippidium Moreno, 1891
                                   31 Genus †Dinohippus Quinn, 1955
                                   32 Genus Equus Linnaeus, 1758 - horses, zebras, and asses