Possums and Cuscuses: Phalangeridae

The Phalangeridae family, or phalangers (fah-LAN-jerz), are made up of five groups of species. Three of these groups are cuscuses and two are possums. Phalangers are small- to medium-sized marsupial mammals. Like all marsupial mammals, the females give birth to tiny, underdeveloped young that finish their development in their mother's pouch.

Possums and cuscuses range in size from 24 to 47 inches (60 to 120 centimeters) long, including the tail, and weigh from 2 to 22 pounds (1 to 10 kilograms). The smallest member of this family is the small Sulawesi cuscus, and the largest is the Sulawesi bear cuscus. Both live in Indonesia.

Members of this family have soft, dense fur that hides small ears. Most species are a solid brown or gray, but the Woodlark cuscus and the black spotted cuscus are spectacularly patterned. Many other species have a dark stripe that runs down the top of their back.

All cuscuses and possums are good climbers. Their feet are adapted to life in the trees. Their hind feet have five toes. The first toe (called the hallux, HAL-lux) has no claw, and is opposed to the other four. This means that this toe, like the thumb on a human hand, can reach across and touch the tip of the other toes (unlike, for example, a dog paw or human foot, where none of the toes can bend to touch each other). The first two toes on the front feet are also opposable. This adaptation makes it easier to grip branches when climbing. Possums and cuscuses also have a prehensile, or flexible grasping, tail that they can wrap around branches to help steady themselves. Usually the tail has no fur on it to improve its grip.