Description

This article is from the soc.culture.australian FAQ, by Stephen Wales with numerous contributions by others.

9.5.2 Marsupials

Marsupials are another group of mammals distinguished by their method of
reproduction. Their young are born at very early stage and crawl to
their mothers nipple where remain attached as they grow. Often these
nipples a protected by a fold of skin forming a pouch. This is
well-developed in the kangaroos where the young remain in this pouch for
up to 9 months and for some time after that occasionally return to the
pouch. In some marsupials pouches are temporary and lost after
breeding, other marsupials have no pouches at all. The pouches of
wombats and Koalas face the rear.

A few species of possum occur in North America and a larger number in
South America otherwise marsupials are restricted to Australia and a few
islands north of Australia. They are known from fossils in Europe,
Africa and Asia.

Globally most mammals fall into a third group called the placental
mammals (or eutherians). Apart from marine mammals, the only placental
mammals native to Australia are bats and rodents. Even so they make up
almost half our mammal species.

One group of rodents seems to have made a long sea journey from Asia at
least 5 million years ago and has adapted considerably to Australia
conditions. Other rodents have arrived from Asia more recently. A
recently discovered bat fossil, apparently the oldest known anywhere,
indicates bats were present in Australia much longer than previously
thought and may have been present in Australia before it became isolated.

Marsupials are sometimes described as more primitive than placental
mammals. This is the result of Eurocentric bias causing differences to
be perceived inferiorities. Neither reproductive method is consistently
superior to the other.

Many thought that Australia's marsupial diversity results from isolation
protecting them from placental mammal competition. A recent discovery
of a placental tooth disproves this, showing terrestrial placental
mammals reached Australia before it became isolated but did not persist.

Lone Pine Koala Sanctuary in Fig Tree Pocket in Brisbane has Kangaroos
in an enclosure that will willing eat out of the palm of your hand.
You may also find some at Alma Park Zoo in Narangba, north of Brisbane
(to quote the TV commercials - Take the Bruce Highway north and follow
the signs.)

See the separate section below for Koala information.

Continue to:

• prev: 9.5.1 The Monotremes
• Index
• next: 9.5.3 Tasmanian devils and Tasmanian Tigers [KB]