Our recent study has helped to give more context to the extinction of Protemnodon, one of Australia’s prehistoric, megafauna giant kangaroos. At up to 170 kilograms (375 pounds), Protemnodon was almost double in weight compared to the biggest living kangaroo. The study, conducted by scientists at the Wollongong Isotope Geochronology Lab, explores how climate shifts contributed to the demise of this megafauna approximately 300,000 years ago.
Protemnodon was so successful that it ranged throughout Australia as recently as five million years ago. It soon ran into trouble as the rainforest environments started to disappear and the climate became “increasingly dry and unstable.” Natural environmental factors played a huge role in Protemnodon’s extinction. They affected species of a more peculiar variety of megafauna, including giant echidnas, wombat-like marsupials, and enormous carnivorous lizards.
New Techniques Reveal Insights
To reconstruct Protemnodon’s diet, the researchers used cutting-edge methods to study the animal’s foraging behavior. To do this, they calibrated these long-lived chemicals from fossilized teeth with recently unearthed rocks. This find has been instrumental in piecing together the animal’s diet and locomotion.
Anthony Dosseto, the lead researcher of the study, called the findings very significant. He stated, “The debate about the extinction of the Australian megafauna has been going on for decades, but now we can take it to an individual and species-by-species perspective.” With this approach, we can develop a more detailed understanding of just how climate change affected Protemnodon and others like it.
The research brought to attention too, that the last populations of Protemnodon only disappeared as recently as 40,000 years ago in some areas. The researchers noted that while some giant kangaroos managed to endure longer in other parts of Australia and Papua New Guinea, the changing environment ultimately proved detrimental.
Climate Change and Extinction
The research outlines how climate disruption played a major role in Protemnodon’s extinction. But as the climate became more arid, these massive kangaroos held on desperately to the lifestyles they were used to. Regardless, this fierce loyalty ultimately did them in. Researchers stated, “The giant kangaroos’ desire to stay close to home, during a time of major climate upheaval 300,000 years ago, likely contributed to their demise.”
Scott Hocknull, another researcher involved in the project, likened the fossil analysis to a form of surveillance: “We can use the fossils to track individuals, where they moved, what they ate, who they lived with and how they died—it’s like Paleo Big Brother.”
With this great detail, scientists are able to build better and more realistic extinction scenarios for Protemnodon and species like it.
Implications for Understanding Megafauna Extinction
The conclusions drawn from this study are significant to the larger question of how Australia’s megafauna went extinct. Paleontologists now employ more rigorous methods to test single fossils from many different locations. This new method helps them know more about how environmental changes played a role in extinction events.
Dosseto remarked on the significance of their methodology: “With these precise techniques, each site and each individual can now be used to test and build more accurate extinction scenarios.” The study recently appeared in the peer-reviewed journal PLOS One. This is an excitingly important contribution to reconstructing how prehistoric animals lived on in Australia.