Class Mammalia Linnaeus, 1758 - mammals Subclass Theria Parker & Haswell, 1897 Order Didelphimorphia Gill, 1872 Family Didelphidae Gray, 1821 - American opossums Subfamily Didelphinae Gray, 1821 Genus Marmosops Matschie, 1916 Marmosops impavidus (Tschudi, 1845) - Tschudi's slender opossum