What is a marsupial?
A marsupial is a mammal whose young are born very small and underdeveloped, then grow in a pouch on their mother's belly. Kangaroos, koalas, wombats and opossums are marsupials.
After a short pregnancy, a newborn marsupial crawls into its mother's pouch, where it attaches to a teat and drinks milk while it continues to develop. A red kangaroo is pregnant for only about 33 days, and its newborn is about the size of a jelly bean. The young stay in the pouch for months.
There are more than 330 species of marsupials. About two-thirds live in Australia and nearby islands, including kangaroos, wallabies, koalas, wombats, Tasmanian devils and possums. The rest live in the Americas, mostly opossums in Central and South America.
Why so many in Australia?
Australia separated from other continents tens of millions of years ago. With few placental mammals there, marsupials spread and evolved into many forms, filling roles that other animals play elsewhere. The Tasmanian tiger, a wolf-like marsupial, went extinct in the 1930s.
Did You Know?
The Virginia opossum is the only marsupial native to the United States and Canada.