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 microtarsus (Wagner, 1842) - Brazilian gracile opossum [Gracilinanus microtarsus microtarsus]ᵀ (Wagner, 1842)