A New World marsupial belonging to the family Didelphidae. Didelphidae consists of one North American species, the Virginia opossum (Didelphis virginiana), and 65 Central and South American species, including the mouse opossums (Marmosa, Gracilinanus, Marmosops, Micoureus, Thylamys, and Lestodelphys); short-tailed opossums (Monodelphis); gray and black four-eyed opossums (Philander); brown four-eyed opossums (Metachirus); water opossums (Chironectes); woolly opossums (Caluromys); black-shouldered opossums (Caluromysiops); bushy-tailed opossums (Glironia); and thick-tailed opossums (Lutreolina).