By Claire

A study recently released in the journal Science suggests that it was in fact humans, not climate changes that wiped out Australia’s megafauna.

Australia’s Megafauna (simply meaning ‘large animal’) included a sheep sized echidna, a 2-3m tall kangaroo (the largest kangaroo ever known) and a marsupial lion, similar in size to a leopard.

Australia’s megafauna became extinct about 40 000 years ago, however the reason for the extinction has remained a mystery to scientists. Two possibilities have been put forth to explain their demise: hunting by humans, and climate changes (not to be confused with human induced climate change). Difficulties in pinpointing the exact timing of aboriginal arrival, changes in climate and the extinction of the megafauna has caused problems in determining the order of events, and ultimately, determining the cause of the megafauna’s disappearance.

New research, lead by Susan Rule, from the School of Archaeology and Natural History at the ANU, suggests that humans may be to blame after all. The authors analyse 130 000 years of sediments from Lynch’s Crater in north-east Queensland to produce a record of climate for the region.

“Importantly, the sediments preserve the spore of a fungus that grows in herbivore dung and crucially this shows a long-term decline around 40,000 years ago. In this study, we find the fungus drops away before other environmental changes that could be interpreted as drying took place, implying humans played a significant role in the cause of Australian megafaunal extinction.”

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