Class Mammalia Linnaeus, 1758 - mammals
   Order Marsupialia Jameson, 1818 - marsupials see Cohort Marsupialia Jameson, 1818
     Family Didelphidae Gray, 1821 - American opossums
       Genus Marmosa Gray, 1821 - murine opossums
         Subgenus Thylamys Gray, 1843 see Genus Thylamys Gray, 1843
           Marmosa elegans group see Genus Thylamys Gray, 1843
             1 Marmosa elegans (Waterhouse, 1839) see Thylamys elegans (Waterhouse, 1839)
             2 Marmosa grisea Desmarest, 1827 see Thylamys macrura (Olfers, in W.L. Eschwege, 1818)
             3 Marmosa tatei Handley, 1957 see Thylamys elegans (Waterhouse, 1839)
             4 Marmosa pusilla Desmarest, 1804 see Thylamys pusilla (Desmarest, 1804)
             5 Marmosa karimii Petter, 1968 see Thylamys pusilla (Desmarest, 1804)
             6 Marmosa formosa Shamel, 1930, nom. illeg. see Gracilinanus agilis (Burmeister, 1854)
             7 Marmosa velutina Wagner, 1842 see Thylamys velutinus (Wagner, 1842)
             8 Marmosa emiliae Thomas, 1909 see Gracilinanus emiliae (Thomas, 1909)
             9 Marmosa agricolai Moojen, 1943 see Gracilinanus emiliae (Thomas, 1909)