In a stunning discovery, a team of archaeologists in Australia has found extensive remains of a sophisticated human community living 50,000 years ago. The remains were found in a rock shelter in the continent's arid southern interior. Packed with a range of tools, decorative pigments, and animal bones, the shelter is a wide, roomy space located in the Flinders Ranges, which are the ancestral lands of the Adnyamathanha. The find overturns previous hypotheses of how humans colonized Australia, and it also proves that they interacted with now-extinct megafauna that ranged across the continent.

Dubbed the Warratyi site, the rock shelter sits above a landscape criss-crossed with deep gorges that would have flowed with water when Paleolithic humans lived here. From extensive excavations conducted last year, the archaeologists estimate that people occupied Warratyi on and off for 40,000 years, finally abandoning the site just 10,000 years ago.

By analyzing layers of earth in the shelter, the scientists were able to construct a timeline of settlement in the space. They used carbon dating on nuggets of hearth charcoal and eggshells to discover that the shelter was first occupied about 50,000 years ago. They also used a dating technique called optically simulated luminescence (OSL) on buried grains of quartz. This technique determines when those quartz grains last saw sunlight and heat. Both techniques returned similar dates, adding to the researchers' confidence in their findings.

This makes Warratyi the oldest evidence of human occupation in the arid Australian interior, long believed too hostile for ancient people who had few tools. But these findings make it clear that the ancestors of Australia's indigenous people were, in fact, seasoned explorers who could survive in difficult conditions.



Giles Hamm

Giles Hamm

Giles Hamm

FWS

Peter Murray





The earliest signs of habitation, older than 38,000 years, showed a human culture that was sophisticated for its time. The people of Warratyi had a wide range of tools, ranging from tiny handheld blades to bone awls. They had two colors of pigment, white and red, for use in art, body decoration, and possibly adhesive. They were accomplished hunters and gatherers, using many kinds of blades to butcher animals and cut plant stalks. Thousands of discarded bones and eggshell shards were buried at Warratyi, representing 17 different species.

Two of those species, D. optatum (a massive creature the size of a rhino) and G. newtoni (an enormous flightless bird) are extinct megafauna. Neither would have naturally found its way into the cave, so their bones and eggshells must have been brought there by humans. This proves that humans hunted, ate, and interacted with Australia's megafauna for a considerable time, over a considerable range, before the beasts died out. These findings also provide solid evidence for what archaeologists have long suspected, which is that humans in Australia had an impact on the lives (and extinctions) of megafauna across the continent.

What's truly incredible about Warratyi is the story it tells about how humans first populated Australia. We're still certain that the early human explorers island-hopped from southern Asia to Australia in reed boats. But archaeologists have long believed that these people settled the continent's coastal regions for thousands of years before broaching the deadly interior.

Now the coastal hypothesis has been disproven. The discovery of the Warratyi rock shelter, write the scientists in Nature, "suggests that, following their arrival in Australia, people dispersed more rapidly across the continent than previously thought. The location of Warratyi could imply a more direct north–south route for pioneering human settlers rather than an exclusive coastal route."

The scientists add that people lived in the shelter sporadically, never settling down there for a long period of time. "Human occupation was repeated but ephemeral in nature, indicating that Aboriginal people may have used Warratyi both as a refuge at a time when the surrounding lowlands and open plains were too arid to exploit and as a temporary campsite when environmental conditions became more stable regionally."

The authors conclude:

Archaeological sites with evidence of modern human colonization, unique cultural innovation, and interaction with now-extinct megafauna are rare in southern Asia and Australia. Sites preserving 50,000-year-old records of human occupation are rarer still. In addition to these landmark discoveries, Warratyi rock shelter reveals evidence for the development of modern human behavior in Australia and Asia. Important technological innovations and early symbolic behavior reveal that a dynamic, adaptive Aboriginal culture existed in arid Australia within only a few millennia of settlement on the continent.

Ancient people adapted to Australia's harshest environment shortly after arriving on its shores. Warratyi was a resting point for groups who traveled widely, created art, and manufactured tools for everything from cutting to sewing. The Aborginals who settled the Adnyamathanha lands were basically high-tech explorers of the Paleolithic world.

Nature, 2016. DOI: 10.1038/nature20125 (About DOIs).

Listing image by Giles Hamm