Ancient Climate Shifts Led to Giant Kangaroo Extinction, Fossil Study Reveals.

Cross-sectional analyses of ancient megafauna tooth enamel—specifically have shed new light on the extinction of giant prehistoric kangaroos. Scientists identified strontium transects in the samples by observing a series of large depressions running along the boundary between enamel and dentine. Their findings, published in PLOS One (2025), point to dramatic climate changes as the driving force behind the demise of these colossal creatures.

These now-extinct kangaroos, known as Protemnodon, could weigh up to 170 kilograms (375 pounds)—nearly double the mass of the largest modern kangaroos. Roaming Australia as far back as five million years ago, they thrived in lush rainforest environments.

Using innovative techniques, researchers matched chemical signatures in fossilized teeth with compositions found in ancient rocks. This comparison allowed them to trace the movements and dietary habits of individual kangaroos, offering an unprecedented view into their lives. Queensland Museum scientist Scott Hocknull likened the method to ancient GPS tracking, enabling researchers to map where the animals moved, what they consumed, whom they lived alongside, and even clues about how they met their end. "It's like Paleo Big Brother," he remarked.

The study revealed that these mega-herbivores were largely homebound, relying heavily on the surrounding rainforest for sustenance. However, around 300,000 years ago, the environment began to degrade as the region’s climate turned increasingly dry and unstable. According to the researchers, the kangaroos’ reluctance to venture far during this turbulent period likely contributed to their extinction.

While some species of giant kangaroos managed to survive in other regions of Australia and Papua New Guinea, most populations eventually disappeared, with the last ones vanishing approximately 40,000 years ago.

Anthony Dosseto from the Wollongong Isotope Geochronology Lab highlighted the significance of these new techniques in deepening our understanding of Australia's lost megafauna. He emphasized that, for the first time, scientists can approach the extinction debate from an individual and species-specific perspective. "With these precise techniques, each site and each individual can now be used to test and build more accurate extinction scenarios," Dosseto said.

Once home to giant echidnas, wombat-like marsupials weighing over two tonnes, and massive carnivorous lizards, Australia's prehistoric landscape has long fascinated scientists. This latest research marks a major step forward in uncovering the mysteries behind the continent’s ancient ecological transformations.

Source:https://phys.org/news/2025-04-giant-kangaroos-perished-climate-upheaval.html

This is non-financial/medical advice and made using AI so could be wrong.