Phylum [Vertebrata] Lamarck, 1801 see Infraphylum Vertebrata Lamarck, 1801
   Class Mammalia Linnaeus, 1758 - mammals
     Subclass Theria Parker & Haswell, 1897
       Infraclass Eutheria Gill, 1872
         Cohort Epitheria McKenna, 1975
           Superorder Ungulata Linnaeus, 1766
             Order Perissodactyla Owen, 1848 - odd-toed ungulates
               Suborder Ceratomorpha Wood, 1937
                 Family †Hyrachyidae (Osborn, 1892) H.E. Wood, 2nd, 1927 see Subfamily Hyrachyinae Osborn, 1892
                   1 Genus †Hyrachyus Leidy, 1871