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 microtarsus group see Genus Gracilinanus Gardner & Creighton, 1989
             1 Marmosa microtarsus (Wagner, 1842) see Gracilinanus microtarsus (Wagner, 1842)
             2 Marmosa agilis (Burmeister, 1854) see Gracilinanus agilis (Burmeister, 1854)
             3 Marmosa marica Thomas, 1898 see Gracilinanus marica (Thomas, 1898)
             4 Marmosa unduaviensis Tate, 1931 see Gracilinanus agilis (Burmeister, 1854)
             5 Marmosa aceramarcae Tate, 1931 see Gracilinanus aceramarcae (Tate, 1931)
             6 Marmosa dryas Thomas, 1898 see Gracilinanus dryas (Thomas, 1898)