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 †Mammutidae Hay, 1922
                   Genus †Mammut Blumenbach, 1799 - mastodons
                     1 †Mammut americanum (Kerr, 1792) - American mastodon