Class Mammalia Linnaeus, 1758 - mammals
   Order Didelphimorphia Gill, 1872
     Family Didelphidae Gray, 1821 - American opossums
       Subfamily Didelphinae Gray, 1821
         Genus Marmosops Matschie, 1916
           1 Marmosops cracens (Handley & Gordon, 1979) - narrow-headed slender opossum
           2 Marmosops dorothea (Thomas, 1911) - Dorothys' slender opossum
           3 Marmosops fuscatus (Thomas, 1896) - dusky slender opossum
           4 Marmosops handleyi (Pine, 1981) - Handley's slender opossum
           5 Marmosops impavidus (Tschudi, 1845) - Tschudi's slender opossum
           6 Marmosops incanus (Lund, 1840) - gray slender opossum
           7 Marmosops invictus (Goldman, 1912) - Panama slender opossum
           8 Marmosops noctivagus (Tschudi, 1844) - white-bellied slender opossum
           9 Marmosops parvidens (Tate, 1931) - delicate slender opossum