Class [Mammalia] Linnaeus, 1758 - mammals Order Marsupialia Jameson, 1818 - marsupials see Cohort Marsupialia Jameson, 1818 Family Didelphidae Gray, 1821 - American opossums Genus Thylamys Gray, 1843 Thylamys velutina (Wagner, 1842) see Thylamys velutinus (Wagner, 1842)