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 Gracilinanus Gardner & Creighton, 1989 Gracilinanus dryas (Thomas, 1898) - wood sprite gracile opossum