Mammalia Linnaeus 1758 [Rowe 2020]
Theria Parker & Haswell 1897 [McKenna 1975]
see Subclass Theria Parker & Haswell, 1897
Metatheria Huxley 1880 [O'Leary, Allard, Novacek, Meng & Gatesy 2004]
see Infraclass Metatheria Huxley, 1880
Marsupialiformes Vullo, Gheerbrant, de Muizon & Néraudeau, 2009
†Ameridelphia Szalay 1982
Sudameridelphia Szalay 1994
Notometatheria Kirsch, Lapointe & Springer 1997
Marsupialia Jameson 1818 [O'Leary, Allard, Novacek, Meng & Gatesy 2004]
see Cohort Marsupialia Jameson, 1818
Paucituberculata Ameghino, 1894
Genus Caenolestes Thomas, 1895 - common "shrew" opossums