[DIGEST: Ars Technica, The Sydney Morning Herald, news.com.au]  

A quick bathroom break led to a stunning discovery in Australia’s Flinders Ranges. An archaeologist and an Adnyamathanha aboriginal elder were surveying gorges in the area at the time. One man went off to find some privacy and instead found evidence overturning all previous hypotheses of when humans colonized Australia and how they interacted with animals.

The two men noticed a rock shelter with a blackened roof about 20 meters above a nearby creek bed. “We knew that was obviously an indication of people firing insider the shelter,” said Giles Hamm, the archaeologist and a doctoral student at La Trobe University.

“We only thought it might have been five or six thousand years old because there’s no way that a meter-deep deposit would go back so far,” Hamm continued. But the group continued excavating and soon came across emu shells and other long-extinct species. That was “the first inkling we knew it was old,” said Hamm. “Then it just kept getting older.”

Credit: Source.

Using carbon dating on chunks of hearth charcoal and eggshells, the scientists discovered that the shelter was first used by humans about 50,000 years ago. The findings were published in Nature last week.

While researchers had previously believed that humans first came to Australia about 50,000 years ago, the timing of the settling of the arid interior of Australia had been put at closer to 40,000 years ago. This research “shows that people are moving very quickly around the continent and in the interior part of the continent. If people are coming in at 50,000 [years ago], it means that people are moving in a whole range

of directions perhaps,” said Hamm.

It is still unclear how the first settlers to Australia moved within the continent. “It is likely they traveled along the great river systems,” speculated Hamm. “But we clearly need to find out more.”

The shelter was packed with tools and decorative pigments—4,300 in all were found when excavating 3.3 cubic meters of soil. Some of these objects represented the earliest-known use of bone tools and pigments in Australia.

In addition, scientists found bones. About 70 percent of those bones came from a diprotodon, a rhinoceros-sized marsupial.

Credit: Source.

The diprotodon bones were significant because scientists had previously believed that humans had not interacted with ancient animals. “There is no way a diprotodon could scale to that shelter. It must have been brought there,” said Gavin Prideaux, a megafauna expert from Flinders University. “Humans evidently lived alongside these animals and hunted them, so the idea that there wasn’t any interaction between people and these animals is put to bed now,”

Clifford Coulthard, the aboriginal man whose bathroom break led to the discovery, said the long history unearthed in the cave did not come as a surprise. “A lot of the old people said that our people were here a long time,” he said. It appears they were correct.