Monster wombat bones discovered in Australia

It's as big as a four-wheel-drive and likes to eat plants, but the diprotodon discovered by palaeontologists this week was long dead - by at least about 55,000 years!

The diprotodon, about the size of a rhinoceros, was found on a remote cattle station in an area rich in the remains of prehistoric megafauna. The discovery of a virtually complete fossil makes it one of Australia’s most significant prehistoric discoveries.

"It was the biggest of them all – the biggest marsupial that ever lived on any continent," one of the researchers, Professor Sue Hand, a palaeontologist at the University of New South Wales, told Australian Geographic.

"It was a bit like a wombat but looked more like a massive, rhino-type beast ... We've found the skull and jaws, as well most of the rest of the skeleton. It's a really good specimen."

The plant-eating diprotodon roamed the country around 2.5 million years ago and became extinct about 55,000 years ago. Scientists believe the species died out because of the arrival of the first indigenous people or climate change, or a combination of the two.

The expedition is a joint project between UNSW, the University of Queensland, Queensland Museum and Xstrata.

Humans tipped megafauna over the edge

THE arrival of humans was probably decisive in the extinction of megafauna living in the South West 40,000 years ago, though climate change and fire may have contributed, according to new research.

Fossils of animals ranging from tiny 30g native mice to giant 500kg marsupials called diprotodontids have been recorded in a cave in the Leeuwin-Naturaliste region.

The cave sediments contain the richest fossil fauna from the western two-thirds of the Australian continent, and provide the best record available of how 90 per cent of the larger mammal species became extinct shortly after the first humans arrived.

Published recently in the Proceedings of the National Academy of Sciences of the United States of America, the findings suggest that one-factor explanations for the extinctions are over-simplistic.

The research team included researchers from the Universities of WA, Wollongong, Melbourne, Flinders and Australian National universities, as well as a scientist working with the Augusta-Margaret River Tourism Association.

They sampled fossils from Tight Entrance Cave and found that within 10 millennia of human arrival, all larger animals except the grey kangaroo and thylacine became extinct. Read more here.