Oct 6, 2013

Cave Reveals Ancient Birds' Eye View

The fossil remains of birds found in a cave in the desolate Nullarbor Plain suggest it was a very different place hundreds of thousands of years ago.

The Thylacoleo Caves, 100 kilometers north-west of Eucla in Western Australia, were named after the ancient Pleistocene marsupial "lion"(Thylacoleo carnifex), which was found in the cave.

Most research in the cave has focused on describing the diverse marsupial fauna, including giant kangaroos (procoptodon) and giant wombats (phascolonus).

But avian palaeontologist Elen Shute, a Ph.D. candidate at Flinders University in Adelaide, has turned her attention to describing the diverse range of birds that have been found trapped in the layers of dirt on the cave floor.

She presents her research today at the 14th biennial Conference on Australasian Vertebrate Evolution, Palaeontology & Systematics.

"It's turning out to be a very diverse site in comparison to other Australian Pleistocene cave fossil deposits," said Shute.

Shute, under the supervision of Dr Gavin Prideaux and Dr Trevor Worthy from the University of Adelaide, has identified more than 40 bird species from the cave site.

"It includes pigeons, birds of prey, a lot of parrots and buttonquails. Interestingly there are three types of megapodes, sometimes called mound builders, including a giant malleefowl."

There are also the remains of several duck species suggesting lakes may have formed part of the environment during the Pleistocene -- a stark contrast to the dry plains and saltbushes that make up the Nullarbor today.

Shute said the diverse range of bird species helps paint a clearer picture of past conditions.

"If you're able to determine a large number of species from a cave deposit you can use overlaps in habitat preferences to draw conclusions about the environment," she explained.

According to Shute, the most exciting discoveries, which are yet to be formally described, are birds that appear to resemble coucals and logrunners.

Today, coucals are found in the tropics and subtropics of northern and eastern Australia, while the logrunner tramps around the rainforests of northern Australia and Papua New Guinea -- more than 4000 kilometers away.

"So we're probably looking at the persistence of thick vegetation [in the Nullarbor], at least at certain times, in the recent past," she said.

Read more at Discovery News

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