Class [Mammalia] Linnaeus, 1758 - mammals Order Marsupialia Jameson, 1818 - marsupials see Cohort Marsupialia Jameson, 1818 Family Didelphidae Gray, 1821 - American opossums Genus Didelphis Linnaeus, 1758 - large American opossums Didelphis marsupialis Linnaeus, 1758 - common opossum