Feather-Tailed Possums: Acrobatidae

The family Acrobatidae is made up of two species: the pygmy glider and the feather-tailed possum. Although they are very different in many ways, these two species have similarities that make them part of the same family.

The pygmy glider is the smaller of the two species. Their heads and bodies are usually between 2.5 and 3 inches (6.5 to 8 centimeters). They have tails that are also between 2.5 and 3 inches (6.5 to 8 centimeters) in length. The pygmy glider weighs less than 0.5 ounces (14 grams). Feather-tailed possums are larger, with a head and body length that ranges from 4 to 5 inches (10 to 13 centimeters). Their tail is longer than their body, with a length of between 5 and 6 inches (12 to 15 centimeters). They weigh between 1 and 2 ounces (30 to 60 grams).

Pygmy gliders and feather-tailed possums both have tails that are long and have long straight hairs sticking off both sides of their tail. These hairs make the tail look like a feather, which is how they got their name. Both species have large eyes and round ears. They both also have gray fur. The feather-tailed possum has black and white stripes on its face. The pygmy glider does not have these stripes and has a white belly.

Both species of this family have sharp claws that help them grip trees. They also have six pads on their feet to help them grip. The pygmy glider has a thin membrane, or piece of skin, that goes from its front legs to its back legs. This membrane allows it to glide. The feather-tailed possum does not glide and does not have this membrane.

Both species are marsupial mammals. This makes them different from most familiar mammals such as cats, dogs, and horses. These familiar mammals are all eutherian (yoo-THEER-ee-an) mammals, which means they have a well-developed placenta. A placenta is an organ that grows in the mother's uterus, womb, and lets the mother and developing baby share food and oxygen. Marsupial mammals do not have this type of placenta. Because of this, they give birth to young that are not physically developed enough to be able to survive on their own. Instead, the young are carried around either in a pouch or attached to the mother's teats, or nipples, on her underside until they have developed more fully and can survive on their own.