Humans linked to extinction of megafauna in Tasmania
New radiocarbon dating tests on the skeletal remains of megafauna show that humans and megafauna coexisted in Tasmania before the large marsupials became extinct more than 40,000 years ago.
Previous research showed that the extinction of megafauna happened thousands of years before humans arrived on the island, crossing Bass Strait when sea levels were very low about 43,000 years ago.
However, radiocarbon dating conducted at ANSTO shows that the ages of megafauna skeletons overlap with the ages of human archaeological sites in Tasmania, indicating that humans may have hunted the large animals to extinction.
Researchers analysed skeletal samples of four species of extinct megafauna, including Protemnodon anak, a long-faced, long-necked kangaroo (Image right, courtesy of http://io9.com/protemnodon-anak/)
The research team were able to accurately date the fossils by taking samples of the protein part of the bone, rather than the mineral fraction.
“A lot of the results that have been recorded in previous research tended to be unreliable,” says Dr Vladimir Levchenko, an ANSTO scientist, who was involved in the research.
“Bones consist of both mineral and protein fractions, and previous measurements have used minerals to date fossil remains. Unless you know the bone samples have been well-preserved, the minerals found in bones used to carbon date a fossil tend to interact with the environment,” Levchenko explains.
While the results show that humans lived in Tasmania at the same time as megafauna, scientists still don’t have direct proof that humans hunted these large marsupials.
“Humans may have had a hand in the disappearance of the megafauna, but we haven’t found evidence of any interactions between humans and megafauna to make our findings conclusive,” says Levchenko.
References
Gillespie et al. (2012). “Man and megafauna in Tasmania: Closing the gap”. Quaternary Science Reviews. 37:38-47.
http://www.sciencedirect.com/science/article/pii/S027737911200025X
