( es and its impacts on modern species. ...)Small species back-up giant marsupial climate change extinction claim

Megafauna roamed the globe in the Pleistocene epoch, between 1.8 million and 10,000 years ago.

In the northern hemisphere species such as the woolly mammoth and sabretooth tiger dominated the landscape, while in Australia - which evolved for 40 million years in isolation - giant marsupials ruled.

Current theories suggest that between 50,000 and 20,000 years ago, increasing aridity in Australia led to cooler and drier conditions that decreased wooded habitats and expanded deserts and grasslands, but researchers are still not clear what impact it had on fauna.

The Darling Downs contain some of the most extensive and significant Pleistocene megafauna deposits in Australia but because it's been excavated since the 1840s it was assumed that the palaeoenvironment record was well established.

Closer examination revealed a bias in sample collection in favour of larger animals and there had been few attempts to document ecological and sediment data.

"Our samples show that species dependent on habitats such as woodlands and vine thickets dominate the lowest section of the trench, which dates to around 45,000 years ago," says Mr Price.

"Other younger sections have a mixture of both large and small species that are habitat generalists or are species found in open areas, suggesting the landscape was evolving towards open grassland.

"By the latest Pleistocene species dependent on wetter conditions disappear from the fossil record while animals such as long-nosed bandicoots that aren't habitat specific remain."

Analysis of sediment and ecological data shows that it became increasingly arid during the late Pleistocene, which led to the disappearance of woodland and scrubland and expansion of grassland.

To verify their results carbon dating was performed on samples. And further work, due to be published later in the year, on other sites in the region confirm the str
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Source:Research Australia