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
         Marsupialia Jameson 1818 [O'Leary, Allard, Novacek, Meng & Gatesy 2004] see Cohort Marsupialia Jameson, 1818
           Australidelphia Szalay 1982 see Magnorder Australidelphia Szalay, 1982
             [Order] Microbiotheria Ameghino, 1889
               1 Genus †Woodburnodon Goin, Zimicz, Reguero, Santillana, Marenssi & Moly, 2007
               2.1 Genus †Microbiotherium Ameghino, 1887
               2.2 Genus Dromiciops Thomas, 1894 - monito del monte