Mammalia Linnaeus 1758 [Rowe 1988], nom. cl. inval. see Clade Mammalia Linnaeus 1758 [Rowe 2020]
   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
         1.1.1 Genus †Pauladadelphys Carneiro, Oliveira & Goin, 2018, orth. inval. see Genus Pauladelphys Goin, Case, Woodburne, Vizcaino & Reguero, 1999
         1.1.2.1 Genus †Didelphopsis Paula Couto, 1952
         1.1.2.2 Genus †Itaboraidelphys Marshall & de Muizon, 1984
         1.2.1 Genus †Swaindelphys Johanson, 1996
         1.2.2 Genus †Coona Simpson, 1938
         1.2.3.1 Family †Herpetotheriidae Trouessart, 1879 [monotypic]
         1.2.3.2.1 Family †"Sternbergiidae" Szalay, 1994 [paraphyletic]
         1.2.3.2.2.1 Genus †Peratherium Aymard, 1850
         1.2.3.2.2.2 Family †Derorhynchidae Marshall, 1987
         2 Marsupialia Jameson 1818 [O'Leary, Allard, Novacek, Meng & Gatesy 2004] see Cohort Marsupialia Jameson, 1818