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
       [Order] †Alphadontia Archer, 1984
         Family †Alphadontidae Marshall, Case & Woodburne, 1990
           1.1 Genus †Aenigmadelphys Cifelli & Johanson, 1994
           1.2 Genus †Protalphadon Cifelli, 1990
           2.1 Genus †Eoalphadon Eaton, 2009
           2.2.1 Genus †Nortedelphys Case, Goin & Woodburne, 2004
           2.2.2 Genus †Alphadon Simpson, 1927
           2.2.3 Genus †Albertatherium Fox, 1971