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 †Meridiungulata McKenna, 1975 - South American ungulates see Grandorder Meridiungulata McKenna, 1975
                             Order †Notoungulata Roth, 1903
                               Suborder †Toxodontia Owen, 1853
                                 Family †Isotemnidae Ameghino, 1897
                                   01 Genus †Isotemnus Ameghino, 1897
                                   02 Genus †Hedralophus Ameghino, 1901, nom. dub.
                                   03 Genus †Thomashuxleya Ameghino, 1901
                                   04 Genus †Pampatemnus Vucetich & Bond, 1982
                                   05 Genus †Coelostylodon Simpson, 1970
                                   06 Genus †Pleurostylodon Ameghino, 1897
                                   07 Genus †Anisotemnus Ameghino, 1902
                                   08 Genus †Periphragnis Roth, 1899
                                   09 Genus †Rhyphodon Roth, 1899
                                   10 Genus †Distylophorus Ameghino, 1902
                                   11 Genus †Lophocoelus Ameghino, 1904
                                   12 Genus †Pleurocoelodon Ameghino, 1895