Tasmanian Tiger

While European mammals belong to the ‘placental’ group – meaning that the offspring is carried in the mother’s uterus, being nourished by the placenta, until a fairly late stage of development – Australasian mammals are mostly marsupials.

Marsupials opt for a completely different reproductive strategy, where a jellybean-like foetus is born at a relatively early stage, then makes its way from the mother’s birth canal to a pouch situated on her abdomen. Here, it will attach to a nipple in the pouch, and feed on milk as it continues to develop.

There are 335 marsupial species currently in existence today, with some 70 per cent of those species native to Australasia. As they have inhabited the region for a long time, they have evolved many different body types to occupy various niches. There are the familiar kangaroos, koalas and Tasmanian devils, but also less well-known bandicoots, quolls and numbats (look them up, they’re SUPER cute).

When humans first arrived in Australasia some 50,000 to 65,000 years ago, there would have been even more intriguing fauna, including giant, carnivorous kangaroos (we wouldn’t fancy meeting one of those) and hippo-sized wombats. These became extinct over the course of a few thousand years, either due to climate change, human impact, or a combination of the two.

But one marsupial species was only wiped out within the last century, and it’s currently capturing the attention of scientists who want to de-extinct it. It is, of course, the thylacine.

The thylacine, also known as the Tasmanian tiger, is not a tiger. Nor is it a dog, a fox, or a wolf. It is an extinct carnivorous marsupial. They first made an appearance in the fossil record some four million years ago. The adults had a body length of 100 to 130cm, with a long, stiff tail measuring 50 to 65cm. While earlier studies suggested thylacines weighed up to 30kg, newer research says that they weighed around 16.7kg on average. They had a short, brownish-yellow coat with a distinctive pattern of stripes along the rump.

Their mouths were able to open unusually wide, to an angle of more than 80°. While they were often blamed for killing farmers’ sheep, research suggests their weak jaws couldn’t manage anything larger than a possum.

The shy animals were nocturnal and crepuscular, spending daylight hours hidden away.

Uniquely among Australian marsupials, both male and female thylacines had a pouch. Females could hold a litter of up to four babies in her rear-facing pouch. In the males, the pouch was used to keep the genitalia protected.

Science Focus