Class [Mammalia] Linnaeus, 1758 - mammals Order Marsupialia Jameson, 1818 - marsupials see Cohort Marsupialia Jameson, 1818 Family Didelphidae Gray, 1821 - American opossums Genus Monodelphis Burnett, 1830 - short-tailed opossums Monodelphis maraxina Thomas, 1923 - Marajó short-tailed opossum