Identifying prehistoric Australian megafauna from fossils may have gotten easier thanks to collagen peptide markers. These peptides can help researchers distinguish different animal genera and perhaps even species.
This new information, published in Frontiers in Mammal Science, could not only help researchers identify animals such as a wombat that was the size of a hippo, a large-clawed marsupial, and a giant kangaroo, but it could also help provide clues as to why and how these animals went extinct.
Studying Ancient Animal Remains
Megafauna, such as woolly mammoths, moas, and giant sloths, went extinct some 50,000 to 10,000 years ago, leaving behind few fossilized remains. Pulling DNA to identify these animals from those remains isn’t always viable, especially if the ecosystem the animal lived in was hot and swampy. However, researchers have now found a way to isolate collagen peptides from these remains, and possibly identify some of Australia’s megafauna.
“The low number of fossils that have been found at paleontological sites across the country means that it is difficult to test hypotheses about why these animals became extinct,” said study first author Carli Peters of the University of Algarve, in a press release. “Zooarchaeology by mass spectrometry (ZooMS) could increase the number of identified megafauna fossils, but only if collagen peptide markers for these species are available.”
Collagen preserves better than DNA, making it ideal for identifying animals that once lived in Australia’s warm climate.
“Proteins generally preserve better over longer timescales and in harsh environments than DNA does,” said Peters in a press release. “This means that in the context of megafauna extinctions, proteins may still be preserved where DNA is not.”
Read More: The Woolly Mammoth's Evolutionary History Over a Million Years Was a Complex Web
Identifying Megafauna with Collagen
Before this study, there had only been peptide reference markers for Eurasian megafauna species. This new study helps provide markers for Australian species.
Using mass spectrometry, the research team analyzed collagen peptides (short chains of amino acids) from Zygomaturus trilobus (wombat), Palorchestes azael (marsupial), and Protemnodon mamkurra (kangaroo). These species are key, according to the study, to understanding the extinction of megafauna.
Z. trilobus and P. azael likely went extinct during the Late Quaternary, but P. mamkurra may have survived long enough to walk among humans that had arrived in Tasmania.
“Zygomaturus trilobus was one of the largest marsupials that ever existed — it would have looked like a wombat the size of a hippo,” said lead study author Professor Katerina Douka of the University of Vienna, in a press release.
“Protemnodon mamkurra was a giant, slow-moving kangaroo, potentially walking on all fours at times. Palorchestes azael was an unusual-looking marsupial that possessed a skull with highly retracted nasals and a long protrusible tongue, strong forelimbs, and enormous claws. If the early modern humans who entered Sahul — the palaeocontinent that connected present-day Australia, New Guinea, and Tasmania 55,000 years ago — came across them, they would have certainly got a big surprise,” Douka added in the release.
The More Megafauna, the Merrier
From the samples collected from the species fossils, the research team identified and compared the peptide markers with the reference markers. According to the study, the samples were well-preserved, allowing the team to identify peptide markers for all three species.
With these collagen peptides, the team identified P. mamkurra from five living and one extinct genera of kangaroos, and Z. trilobus and P. azael from other living and extinct marsupials, but had trouble differentiating the two from each other.
According to the research team, however, this wasn't unusual with ZooMS, as collagen takes longer to change with evolution. Because of this, the team believes that this method is best used for identifying bones at a genus level instead of a species level.
The new find now makes it possible to use this method to test the collagen of other fossils from warm and temperate regions where DNA may not have been preserved as well.
“By using the newly developed collagen peptide markers, we can begin identifying a larger number of megafauna remains in Australian paleontological assemblages,” said Peters in a press release. “However, there are a lot more species for which collagen peptide markers still need to be characterized. Two examples would be Diprotodon, the largest marsupial genus to have ever existed, and Thylacoleo, the largest marsupial predator.”
Read More: Did Humans Hunt the Biggest Animals to Extinction?
Article Sources
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
Frontiers in Mammal Science. Collagen peptide markers for three extinct Australian megafauna species
Cambridge University Press. The late-Quaternary megafauna extinctions: Patterns, causes, ecological consequences and implications for ecosystem management in the Anthropocene
A graduate of UW-Whitewater, Monica Cull wrote for several organizations, including one that focused on bees and the natural world, before coming to Discover Magazine. Her current work also appears on her travel blog and Common State Magazine. Her love of science came from watching PBS shows as a kid with her mom and spending too much time binging Doctor Who.
