Clifford Coulthard has always known that his people have thousands of years of history in the arid Australian interior. Or as the Adnyamathanha elder told the Sydney Morning Herald, “Our old people know we’ve been here a long time.”

But he wasn’t looking for proof of that when he got out of his car near the Flinders mountain range several years ago. He just needed a secluded spot to relieve himself.

“Nature called, and Cliff walked up this creek bed into this gorge and found this amazing spring surrounded by rock art,” archaeologist Giles Hamm told the Australian Broadcasting Corp. “A man getting out of the car to go to the toilet led to the discovery of one of the most important sites in Australian prehistory.”

Coulthard and Hamm are co-authors of a new study in the journal Nature analyzing 49,000-year-old artifacts they uncovered in a rock shelter at the site. They represent the oldest known evidence of human settlement in that part of Australia. The discovery pushes back the timing of human arrival in the hot, dry interior by 10,000 years, demonstrating the rapid pace at which prehistoric people were able to explore and take advantage of a continent they had reached only a few millennia earlier.

Hamm, a doctoral student at La Trobe University in Melbourne, Australia, has spent several years scouring the remote Flinders mountains about 300 miles north of Adelaide, looking for evidence that early humans lived there. Some scientists thought the people of 50,000 years ago couldn’t have reached the region because they didn’t yet have the technology to survive in its stark environment.

But the rock shelter, dubbed Warratyi, would have been an appealing spot for the first early people to arrive in the area. Situated on a high ridge, it offers protection from the wind, heat and cold and a commanding view of the gorge below.

It also harbors a trove of evidence that those early settlers were capable of eking out an existence in what appeared to be a barren and unforgiving landscape. The archaeologists uncovered 4,300 stone artifacts, more than six pounds of animal bone, emu egg shells, traces of pigments and piles of plant material.

“There is a Eurocentric view that material culture in Australia is quite simplistic and backward, but this helps rewrite that story,” paleoanthropologist Michael Westaway of Griffith University told the Australian Broadcasting Corp. Westaway was not a part of this study, but the findings support his own genetic research that argues that modern Aboriginal Australians are the descendants of people who colonized the continent more than 40,000 years ago.

One slim, sharpened bone tool from the site, called a uni point, is estimated to be between 38,000 and 40,000 years old. Another bit of bone, dated to about 46,000 years ago, comes from a Diprotodon — a giant marsupial that weighed as much as an elephant and looked like a guinea pig that got its nose broken in a boxing match. The scientists also uncovered the burned eggshell of a giant bird. These and several other species of megafauna died out around the time that humans arrived on the continent, and scientists have debated whether Homo sapiens would even have interacted with the now extinct species.

The Nature study suggests that humans not only coexisted with the megafauna but also may have eaten them.

“One good thing about this study … is there’s no doubt there are megafauna remains in the form of Diprotodon and a giant bird in that rock shelter in a well-dated, well-stratified context sometime between 45,000 and 50,000 years ago,” co-author Gavin Prideaux told the Australian Broadcasting Corp. Because there is a steep incline up to the rock shelter that the Diprotodon couldn’t have climbed, “the only way those bones and shells got there is because people brought them there.”

“In terms of megafauna, that’s the really significant finding,” he added.

The bones and stone tools also revealed other aspects of these early settlers’ lives. Some tools bore tiny feather barbules (microscopic hairs that help give shape to a feather) — a suggestion that the people used the feathers for decorative or ceremonial purposes. The ocher and white gypsum pigments — also the earliest in Australia — were probably painted on the body for ceremonies, as well.

The researchers determined the age of the organic material from the site through radiocarbon dating, a technique that measures the radioactive decay of carbon by comparing isotope ratios. They also dated quartz crystals from the floor of the rock shelter and found that its lowest layers were from about 44,000 years ago.

Some scientists have reservations about Hamm’s conclusions. The dates in the Nature paper are so out of step with other archaeological findings that they require a lot more study, Peter Hiscock, professor of Australian archaeology at the University of Sydney, told the Guardian.

“Either they stem from an analytical problem, or else they reveal a revolutionary shift in the chronology for ancient Australia,” he said.

If the latter case is true, the discovery at Warratyi cave could shift scientists’ understanding of how Australia’s earliest inhabitants made their way across the continent. Hamm told the Guardian he thinks that people quickly migrated south after arriving about 50,000 to 60,000 years ago but got “trapped” in the Flinders mountains as the climate changed and the region became more arid. That situation could have given rise to new tools and cultural practices.

“The old idea is that people might have come from the east, from the Levant, out of Africa, and these modern humans may have come with a package of innovative technologies,” he said. “But the development of these fine stone tools, the bone technology, we think that happened as a local innovation, due to a local cultural evolution.”

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