Clade Mammaliaformes Rowe 1988 [Rowe 1988]
   [crown] Class Mammalia Linnaeus, 1758 - mammals
     Subclass Theriiformes (Rowe, 1988) M.C. McKenna & S.K. Bell, 1997 see Division Theriiformes
       Infraclass Holotheria (Wible et al., 1995) M.C. McKenna & S.K. Bell, 1997 see [unranked] Holotheria
         Superlegion Trechnotheria McKenna, 1975 see [unranked] Trechnotheria McKenna, 1975
           Legion Cladotheria McKenna, 1975 see [unranked] Cladotheria McKenna, 1975
             Sublegion Zatheria McKenna, 1975 see [unranked] Zatheria McKenna, 1975
               Infralegion Tribosphenida McKenna, 1975 see Sublegion Boreosphenida
                 Supercohort Theria (Parker & Haswell, 1897) M.C. McKenna & S.K. Bell, 1997 - therians see [unranked] Theria
                   Cohort Placentalia (Owen, 1837) M.C. McKenna & S.K. Bell, 1997 - placentals
                     Magnorder Epitheria (McKenna, 1975) M.C. McKenna & S.K. Bell, 1997 see Cohort Placentalia (Owen, 1837) M.C. McKenna & S.K. Bell, 1997
                       Superorder Preptotheria (McKenna, 1975) McKenna, 1993
                         Grandorder Anagalida (Szalay & McKenna, 1971) McKenna, 1975 see Order Anagalida Szalay & McKenna, 1971
                           Mirorder Simplicidentata Weber, 1904
                             Order Rodentia Bowdich, 1821 - rodents
                               Suborder Myomorpha Brandt, 1855
                                 Infraorder Geomorpha (Thaler, 1966) M.C. McKenna & S.K. Bell, 1997
                                   Superfamily Geomyoidea (Bonaparte, 1845) Weber, 1904
                                     Family Geomyidae (Bonaparte, 1845) Gill, 1872 - pocket gophers
                                       Subfamily Heteromyinae (Gray, 1868) Alston, 1876 - pocket mice, kangaroo rats, and kangaroo mice
                                         Tribe Perognathini (Coues, 1875) M.C. McKenna & S.K. Bell, 1997 - pocket mice
                                           Genus †Oregonomys J.E. Martin, 1984