While humans can be blamed for some past extinctions, it seems that we're actually innocent when it comes to Australian giants. A new study concludes that climate change, not humans, was the reason behind the extinction of gigantic animals, or megafauna, in Sahul.
"The interpretation that humans drove the extinction rests on assumptions that increasingly have been shown to be incorrect. Humans may have played some role in the loss of those species that were still surviving when people arrived about 45,000 to 50,000 years ago -- but this also needs to be demonstrated," said lead author of the study, University of New South Wales associate professor Stephen Wroe.
Sahul, which includes Australia, Tasmania, and New Guinea, was once home to a diverse population of megafauna, most of which were wiped out by a 450,000-year period of climate deterioration. Many past theories place the blame on the arrival of the Aborigines, however, of the 90 species of megafauna that inhabited Sahul, only 8 to 14 species were present at the time humans set foot on the continent. The rest had already died out.
The megafauna present on Sahul varied from massive marsupials, to mammoth reptiles.
"These leviathans included the largest marsupial that ever lived -- the rhinoceros-sized Diprotodon - and short-faced kangaroos so big we can't even be sure they could hop. Preying on them were goannas the size of large saltwater crocodiles with toxic saliva and bizarre but deadly marsupial lions with flick-blades on their thumbs and bolt cutters for teeth," Wroe explained.
The Aborigines have been blamed for the extinction due to their native practice of burning the landscape. Environmental data, however, showed that the increased rate of burning was more closely linked to the climate, which was became increasingly arid before the Aborigines landed.
You can read the full published study in the Proceedings of the National Academy of Sciences.
- Contribute to this Story:
- Send us a tip
- Send us a photo or video
- Suggest a correction
