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
             Marmosa grisea Desmarest, 1827 see Thylamys macrura (Olfers, in W.L. Eschwege, 1818)