Mammalia Linnaeus 1758 [Rowe 1988], nom. cl. inval. see Class Mammalia Linnaeus, 1758
   Metatheria Huxley 1880 [O'Leary, Allard, Novacek, Meng & Gatesy 2004] see Infraclass Metatheria Huxley, 1880
     Marsupialiformes Vullo, Gheerbrant, de Muizon & Néraudeau, 2009
       Notometatheria Kirsch, Lapointe & Springer 1997
         Family †Derorhynchidae Marshall, 1987
           1 Genus †Derorhynchus Paula Couto, 1952
           2 Genus †Rumiodon Goin & Candela, 2004