Paleontologists have discovered peptide markers for three extinct Australian megafauna. This breakthrough facilitates research on creatures such as hippo-sized wombats, colossal kangaroos, and marsupials with enormous claws, aiding our understanding of the series of enigmatic extinctions that took place 50,000 years ago and the potential role of humans in these events.
“The geographical distribution and extinction timeline of Australia’s megafauna, along with their interaction with early modern humans, are subjects of intense debate,” commented Professor Katerina Dorca from the University of Vienna.
“The limited fossil finds at various paleontological sites across Australia complicate the testing of hypotheses regarding the extinction of these animals,” added Dr. Kali Peters, Ph.D., of the University of Algarbe.
“Using ZooMS (Zoo departments by mass spectrometry) can aid in increasing the number of identified megafauna fossils, provided that collagen peptide markers for these species are accessible.”
Through the analysis of peptides in collagen samples, researchers can differentiate between various animal species, occasionally even distinguishing among different variants.
Collagen proves to be more resilient than DNA, making this method effective in tropical conditions where DNA may not endure.
However, most reference markers originate from Eurasian species that are not found elsewhere.
This study aims to develop new reference markers tailored for Australian contexts, enhancing the understanding gleaned from the fragmented fossil records of Australia.
“Proteins tend to endure better over extensive time periods and in harsh environments compared to DNA,” noted Dr. Peters.
“Thus, in studying megafauna extinction, proteins might still be preserved even in the absence of DNA.”
The research focused on three species crucial for comprehending megafauna extinction: Zygomaturus trilobus, Palorchestes Azael, and Protemnodon Mamkurra.
Zygomaturus trilobus and Palorchestes Azael belong to a lineage of animals that vanished entirely during the late Quaternary period, while Protemnodon Mamkurra survived long enough to likely coexist with humans arriving in Tasmania.
Scientists previously dated fossilized bones from one species back over 43,000 years.
“Zygomaturus trilobus was among the largest marsupials that ever lived, appearing much like a hippo-sized wombat,” said Professor Douka.
“Protemnodon Mamkurra was a massive, sluggish kangaroo that might have occasionally walked on all fours.”
“Palorchestes Azael was a uniquely shaped marsupial with a distinctive nose and long tongue, powerful forelimbs, and a skull equipped with large claws.”
“If ancient continents connected early modern humans to what we now know as Australia, New Guinea, and Tasmania 55,000 years ago, they would have encountered astonishing creatures.”
The researchers eliminated contaminants and compared peptide markers using reference markers.
The collagen in all three samples was well-preserved, enabling the identification of appropriate peptide markers for each species.
With these markers, paleontologists successfully differentiated Protemnodon from five living genera and one extinct genus of kangaroo.
They could also differentiate Zygomaturus and Palorchestes as these two species couldn’t be distinguished from other large extinct marsupials.
This is common in ZooMS, given that collagen changes accumulate slowly over millions of years of evolution.
Unless further studies enhance specificity, these markers are most effective at identifying bones at the genus level rather than the species level.
Nevertheless, Zoom’s ability to distinguish genera from temperate regions presents opportunities to try and identify bones from tropical regions, where closely related species may feature similar or identical peptide markers, since DNA preservation is rare in these environments.
“The introduction of newly developed collagen peptide markers allows us to identify a multitude of megafauna remains in Australia’s paleontological collections,” stated Dr. Peters.
“Yet, many more species still require characterization through collagen peptide markers.”
“For instance, Diprotodon, the largest marsupial genus ever known, and Thylacoleo, the largest marsupial predator.”
The team’s findings will be published in the journal Frontiers in Mammal Science.
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Kari Peters et al. 2025. Collagen peptide markers from three Australian megafauna species. Front. Mammal. Sci. 4; doi:10.3389/fmamm.2025.1564287
Source: www.sci.news
