Big dig is on to save giants of past

Skeletons of the largest marsupials that lived are being unearthed near an iron ore mine in Western Australia’s north.

Paleontologists are excavating the rare diprotodon fossils to preserve them.

Skeletons of the largest marsupials that lived are being unearthed near an iron ore mine in Western Australia’s north.

Western Australian Museum has begun moving the rare and nearly complete megafauna skeletons because they are in the Fortescue River floodplain and at risk of heavy abrasion from water. Excavation is critical if they are to be preserved, the museum says.

The skeletons are partly visible, including sections of skulls, jaws and teeth, and embedded in hard rock. The fossils are diprotodons, extinct marsupials related to koalas and wombats.

Adult diprotodons are believed to have weighed 2800kg. They grew to almost 4m in length and were 1.8m at shoulder height.

They are close to Citic Pacific’s Sino Iron mining operation at Cape Preston, 100km southwest of the Pilbara’s most populated town of Karratha. The area has been known to megafauna experts since 1991 when a worker from the state’s agricultural protection board was there monitoring a noxious weed called mesquite and saw an almost complete skeleton in a creek bed.

A skeleton at the WA Museum.

The museum sent paleontologists to investigate. With volunteers from Karratha, they dug up the specimen using picks and a jackhammer. It is now at WA Museum Boola Bardip in Perth.

Since then, more specimens have been collected close by. One was largely rock, with a diprotodon foot thought to be enclosed.

Experts consider the site unique because several diprotodon skeletons, and only diprotodons, are just a few metres from each other. It is unusual for several specimens of a single species to be present at one site. The newly excavated skeletons will form part of the museum’s collection and are likely to be studied by international megafauna experts.

Diprotodons lived in the Pleistocene era that began about 2.5 million years ago. They are thought to have become extinct about 13,000 years ago, according to WA Museum curator of mammalogy Kenny Travouillon.

Dr Travouillon said Operation Megafauna had identified at least 10 skeletons but there could be more. “First all the bones that we can see, we dig around them, and as we see more bones we expose them, and so we can have an idea how we can dig them out,” he said.

“For big animals we use a plaster jacket which will make the bones very hard and protect them and get them out without breaking them.”