Aboriginal ancestors first arrived on the continent around 50,000 years ago, but new evidence suggests they left the coastal areas for the arid outback around 10,000 years earlier than previously thought.
Australian archaeologists have discovered new evidence in a rock shelter in the Flinders Ranges that reveals Aboriginal Australians settled in the interior of the continent around 49,000 years ago. The work was carried out in collaboration with the Adnyamathanha Traditional Lands Association, with findings published today in Nature.
Lead researcher Giles Hamm, a PhD candidate from La Trobe University who discovered the cave around 550 kilometres north of Adelaide while on a survey with local Adnyamathanha elder Clifford Coulthard (who spotted the rock shelter) says this shows how fast the traditional owners of the land dispersed through Australia after arrival.
“In terms of inland occupation, it’s significant geographically,” says Hamm. “It shows that people are moving very quickly around the continent and in the interior part of the continent.”
He explains that the research team recovered around 4,300 artefacts from the shelter, including at least three kilograms of bone, plant and animal remains, and ochre pigment used in traditional Aboriginal painting methods.
They also found bones from an extinct giant wombat-like animal called Diprotodon optatum and eggs from a large emu-like creature, which points to early human interaction with the local megafauna. It even raises questions about whether humans actually had a role in their extinction.
Associate Professor Darren Curnoe, director of UNSW’s Palaeontology, Geobiology and Earth Archives Research Centre who was not involved in the study, says the findings highlight the pivotal role of Aboriginal Australian history in understanding the origins of humans.
“This remarkable new finding shows us that pretty much as soon as people arrived here, they successfully settled the many diverse and challenging environments the Australian land mass had to offer,” Curnoe told SBS Science.
“These were smart, highly sophisticated people and they made a really good go of what even today is a difficult place for humans to eke out a living.”
The researchers used archaeological dating techniques, such as radiocarbon dating and optically stimulated luminescence (OSL) dating, to determine the age of the artefacts and bone samples – this allowed them to construct a chronology of human activity in the shelter.
They discovered peaks and troughs in human occupation of the cave, with infrequent activity first occurring around 49,000 years ago before increasing near the 40,000-year mark.
Occupation then dropped off around 35,000 years ago, which the researchers believe coincides with a sudden change in environmental conditions within the Flinders Ranges that lasted around 17,000 years, before activity picked up again.
Professor Sean Ulm, an archaeologist from James Cook University, says the findings challenge our current understanding of how early Aboriginal Australians started occupying arid inland areas.
“The idea is that when people arrived in Australia they would have stuck to the coasts and that idea was sort of reinforced by the arid zone, the arid core of Australia, being seen as a barrier to people occupying it,” he tells SBS Science.
“[But] over the last 12 months there’s been increasing evidence for earlier and earlier occupation of the arid zone and this supports those patterns.”
Ulm says the presence of bone and stone tools also challenges the conventional wisdom of the past few decades that these key technological developments were a relatively recent phenomenon.
“This study shows that that technology may be up to 30,000 years old, so it’s pushing it back at least 15,000 years,” he says.
“What I find exciting about this is it shows that these technologies are not restricted to the last 10 or 20 thousand years, that the knowledge of how to manufacture some of these tools, people probably brought with them when they colonised the continent.”