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 Tethytheria McKenna, 1975
             Order Proboscidea Owen, 1859 - elephants
               Suborder Elephantoidea Osborn, 1921 see Suborder Elephantiformes (Tassy, 1988)
                 Family Elephantidae Gray, 1821 - elephants
                   Genus †Mammuthus Brookes, 1828 - mammoths
                     1 †Mammuthus meridionalis (Nesti, 1825) - southern mammoth
                     2 †Mammuthus trogontherii (Pohlig, 1885) - steppe mammoth
                     3 †Mammuthus columbi (Falconer, 1857) - Columbian mammoth
                     4 †Mammuthus imperator (Leidy, 1858) - imperial mammoth
                     5 †Mammuthus primigenius (Blumenbach, 1799) - woolly mammoth