Class Mammalia Linnaeus, 1758 - mammals
   Order Didelphimorphia Gill, 1872
     Family Didelphidae Gray, 1821 - American opossums
       Subfamily Didelphinae Gray, 1821
         Genus Thylamys Gray, 1843
           1 Thylamys elegans (Waterhouse, 1839) - elegant fat-tailed mouse opossum
           2 Thylamys macrura (Olfers, in W.L. Eschwege, 1818) see Thylamys macrurus (Olfers, 1818)
           3 Thylamys pallidior (Thomas, 1902) - white-bellied fat-tailed mouse opossum
           4 Thylamys pusilla (Desmarest, 1804) see Thylamys pusillus (Desmarest, 1804)
           5 Thylamys velutinus (Wagner, 1842) - dwarf fat-tailed mouse opossum