MENU - DIDELPHIMORPHIA
The Didelphimorphia order is composed of 4 recent families, 15 genera and 66 species. They are distributed throughout a large portion of North America from southeastern Canada, eastern United States, through Mexico to about 47° south in Argentina, South America. Some species are also found on some of the islands of the Lesser Antilles. The fossil history indicates a once greater geologic distribution as specimens have been found from the Eocene to early Miocene in Europe and in the Oligocene in North Africa. In their current range, their fossil history extends from early Cretaeous to early Miocene and Pleistocen to Recent in North America, and late Cretaceous to Recent in South America.
The Didelphimorphians are small to medium in size and in many species the tail doubles the overall body length. The smallest species are in the Gracilinanus genus and have a head and body length of approximately 70-135 mm and a tail length of 100-155 mm. The largest genus is Didelphia with head and body length of 325-500 mm and tail length of 255-535 mm.
The members of the Didelphimorphia order tend to be nocturnal in their activity levels. Depending on species they are arboreal, terrestrial and in one case, semi-aquatic. Their diets are for the most part omnivorous, however some are more insectivorous or carnivorous.
As marsupials, the Didelphimorphians complete their development within a pouch, but the appearance and pouch-like qualities vary among the species. In Didelphis, Chironectes, Philander and Lutreolina the pouch is well defined. The other genera either do not have a defined pouch or it consists of two longitudinal folds of skin. Typical of all marsupials, the gestation period is shorter than the period of development within the pouch. At birth, the young crawl using well-developed front legs and sharp claws into the pouch and attach to one of the five to seven mammae to suckle almost continuously. Young Didelphimorphians do not have the ability to thermoregulate and are dependant upon the mother's body heat for warmth. After leaving the pouch, some species remain with the female for a short while, clinging to her back when traveling.