Mammaliaformes Rowe 1988
   [crown] Mammalia Linnaeus 1758 [Rowe 1988], nom. cl. inval. see Class Mammalia Linnaeus, 1758
     Theriimorpha Rowe 1993
       [crown] 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
           [crown] Marsupialia Jameson 1818 [O'Leary, Allard, Novacek, Meng & Gatesy 2004] see Cohort Marsupialia Jameson, 1818
             Didelphimorphia Gill 1872 see Order Didelphimorphia Gill, 1872
               †Pucadelphys andinus Marshall & de Muizon, 1988