New research upends theory that Indigenous Australians hunted large animals to extinction

Some extinct mammals from Australia's Mammoth Cave included (from left) a giant long-nosed echidna, a short-faced kangaroo, a wombat-like marsupial and a Tasmanian thylacine. (Peter Schouten via CNN Newsource)

Recent analysis of two fossils from Australia, estimated to be about 50,000 years old, suggests that Australia’s First Peoples valued big animals for their fossils as well as for their meat, collecting bones and transporting them over great distances.

For decades, scientists viewed cut marks on the fossils as signs that Indigenous Australians hunted large prey — possibly to the point of extinction. When humans first arrived in Australia around 65,000 years ago, the continent was home to enormous animals that are now long gone, such as giant long-nosed echidnas, short-faced kangaroos that stood nearly 10 feet (3 metres) tall, and wombat-like tusked marsupials as big as rhinos. But by about 46,000 years ago, all these large animals had disappeared.

In the 1960s, scientists detected a human-made cut mark on a fossilized kangaroo tibia found between 1909 and 1915 at Mammoth Cave in southwestern Australia. At the time that the cut was identified, researchers proposed that the mark proved that First Peoples butchered ancient megafauna.

However, researchers recently scanned the internal structure of the bone and presented a new interpretation: The cut on the bone was made after the animal was long dead — perhaps after its remains had fossilized. This finding would rule out butchering, suggesting instead that the kangaroo’s preserved bone was the prize, scientists reported Wednesday in the journal Royal Society Open Science.

A second fossil that the authors examined in the study — a premolar from the extinct giant wombat Zygomaturus trilobus — provided another clue about First Peoples’ fossil collection. This marsupial species is common in fossil deposits in southern Australia but is unknown in the north. However, an Indigenous man in northern Australia kept the tooth as a charm, mounted in resin and attached to a string made of human hair. (He gifted the charm to an anthropologist in the late 1960s, but it was unknown how long the Indigenous man had the charm or where it originated.)

For the tooth to end up in the northern part of the country, “it seemed probable to us that it had been collected as a fossil in the southwest of Western Australia and then traded up the coast to the Kimberley region,” said Dr. Michael Archer, lead author of the new study and a professor and researcher at the University of New South Wales in Sydney.

No evidence of ‘over-killing’

Together, the tooth and tibia tell a tale of First Peoples as fossil collectors, Archer told CNN in an email. They also call into question the long-standing hypothesis that First Peoples hunted Australia’s megafauna to extinction, as that assumption was gleaned from marks on fossil bones that collectors could have made rather than hunters.

The findings demonstrate the lack of hard evidence to support the hypothesis that Australia’s First Peoples “were potentially ‘over-killing’ these animals soon after human arrival on the continent,” he said. “In fact, the evidence suggests that humans and these megafaunal animals coexisted for at least (15,000) years, probably until climate change led to the progressive extinction of those animals.”

First Peoples were already known to use bones and shells as adornment or cultural objects, said archaeologist Dr. Judith Field, a University of New South Wales honourary associate professor who was not involved in the new research. Some examples are shell beads dating to more than 10,000 years ago, from Barrow Island off the coast of Western Australia, and a necklace of Tasmanian devil teeth that is about 7,000 years old, found near Lake Nitchie, Field told CNN in an email.

“These findings correlate with what we know about human behaviour,” Field added. “People collect things and move them around the landscape.”

What’s more, “there is only one site on the Australian continent that unequivocally places megafauna and humans into the same place at the same time: Cuddie Springs,” Field said. While people overlapped with some megafauna species, climate variability probably also contributed to the extinction of Australia’s largest animals, rather than human hunting alone, she added. The new study “adds another interesting facet to our wealth of knowledge of the complexities of human behaviour.”

Inside the bone

In 1980, Archer co-authored a paper describing the cut mark as a sign that humans butchered the animal. But in 2013, with the availability of more sophisticated tools for fossil analysis, Archer wondered if further examination of that bone might uncover clues that had been overlooked previously.

Archer said he asked study co-author Dr. Blake Dickson, then a student at the University of New South Wales, to perform a micro-CT scan of the fossil, “just to find out what the internal structure associated with this cut on the bone might reveal.” Micro-CT scans enable scientists to peer inside fossils without damaging them.

“That’s when we were shocked to find that the evidence clearly indicated the cut had occurred on the bone only after the bone had already become a fossil,” Archer said.

In the tibia, multiple longitudinal cracks indicated that it had dried out before becoming part of the fossil deposit, and the area where the cut was made included a crosswise fracture that happened after the desiccation cracks formed.

“Clearly it was not in any way an indication that the animal had been killed and/or butchered by people,” Archer said. “The cut was part of an effort to collect the fossilized bone as a curiosity by First Nations People — they were fossil collectors, just like us!”

The authors don’t suggest that First Peoples did not hunt large animals. But the notion that they hunted megafauna until no more remained likely originated from Western biases, established by centuries of mass extinction patterns that followed colonization in Australia, Archer said. These extinctions were driven mostly by European agriculture and the introduction of non-native species that outcompeted Australian animals.

“Because of these modern European-caused extinction events, some scientists have naively presumed that all peoples in the past similarly created the same kind of mayhem when they first entered new lands,” Archer said.

“What we’re suggesting is that, at least in Australia, the First Peoples may well have quickly become an integral part of this continent’s ecosystems, valuing and sustainably utilizing this continent’s native biota rather than the alien species involved in unsustainable agricultural practices that we now inflict on this continent.”