World's oldest known rock art predates modern humans' entrance into Europe — and it was found in an Indonesian cave

Scientists have identified the world's oldest known rock art — a hand stencil created at least 67,800 years ago in Indonesia.

This artwork, nestled in a cave in southeast Sulawesi, is also the earliest archaeological evidence of modern humans (Homo sapiens) living on the islands between the Asian and Australian continental shelves, according to a study published Wednesday (Jan. 21) in the journal Nature. The hand stencil is surrounded by younger rock art, including another hand stencil.

This discovery could fill a major gap in scientists' understanding of the journey the ancestors of Indigenous Australians took before reaching the continent at least 60,000 years ago. "It is very likely that the people who made these paintings in Sulawesi were part of the broader population that would later spread through the region and ultimately reach Australia," study first author Adhi Agus Oktaviana, an archaeologist at the National Research and Innovation Agency in Indonesia, said in a statement.

Although the rock art's original meaning is unknown, the hand stencils hint that the artists belonged to a relatively large group with its own cultural identity, study co-author Maxime Aubert, an archaeologist and geochemist at Griffith University in Australia, told Live Science. The hand stencils could have been made to signify group membership, Aubert said. "If you know about that cave and you know about this rock art, you're part of that group, you're part of that culture," he said.

Prehistoric art

Prehistoric rock art — or art on a rock face like a cave wall or a rock shelter — has been discovered all around the world, from 12,000-year-old engravings in Saudi Arabia to 4,000-year-old paintings along the U.S.-Mexico border. The oldest dated rock art previously identified — a roughly 66,700-year-old hand stencil in Spain — was believed to have been made by Neanderthals, as current evidence suggests modern humans didn't reach Europe until 54,000 years ago. But the dating technique used for that discovery is debated.

However, humans have been creating art for even longer than these examples. The oldest known drawing is a 73,000-year-old hashtag on a stone from South Africa, and a 540,000-year-old shell with zigzag carvings from Indonesia may have been crafted by Homo erectus.

Sulawesi also has a longstanding artistic legacy, with a depiction of a human interacting with a warty pig dating to 51,200 years ago. As part of a broader project documenting the prehistoric artwork on Sulawesi, Aubert and his team inspected 11 designs found in eight caves: seven hand stencils, two human figures and two geometric patterns.

All these prehistoric works had lumps of calcium carbonate — called "cave popcorn" — growing over them. Because the cave popcorn must have developed after the artwork was created, dating these growths provides a minimum age for the underlying image. In a handful of instances, maximum ages could also be obtained as the pigment overlaid one of these mineral deposits.

During the project, the researchers dated one hand stencil, measuring 5.5 by 3.9 inches (14 by 10 centimeters), to at least 67,800 years ago, making it 1,100 years more ancient than the rock art linked to Neanderthals in Spain. The image has faded considerably, but the remains of the fingers and palm are still faintly visible. The fingers had been purposefully narrowed — an artistic technique only found in Sulawesi.

About 4.4 inches (11 cm) to the left of this artwork is a hand stencil created using darker pigment that dates to no older than 32,800 years ago. This shows that prehistoric humans used this cave as their canvas over a period of at least 35,000 years.

Although other human species once called Sulawesi home, the researchers believe H. sapiens created these artworks, because the narrowed fingers are technically complex to produce and modern humans are known to have lived in the region at the time.

The stencils may have been created by the individuals spraying pigment over their hands with their mouths. This opens up the possibility for DNA to be extracted from the artwork. "We could have the genetic signature of the people doing this," Aubert said. "That would be amazing."

The identification of the oldest rock art in Sulawesi is an important discovery because it adds another data point on the journey humans took to spread across Island Southeast Asia and Australia. As a critical point on the journey to Australia, this discovery supports the suggestion that modern humans reached Australia by sailing a northern route from present-day Borneo to Sulawesi and then through to western Papua (the western half of the island of New Guinea) or the Indonesian island of Misool, the authors wrote in the study.

"This is a stunning discovery," Chris Clarkson, a professor of archaeology also at Griffith University who was not involved in the new research, told Live Science in an email.

He agreed with the conclusion that ancient modern humans are the most likely artists of the hand stencils because the dates align perfectly with when H. sapiens arrived in the region.

"What amazes me most is that these artworks sit directly on a migration route into Australia," he said. What's more, it shows that the first people to populate Australia had rich cultural lives. "The first people to cross Island Southeast Asia and reach Australia weren't just surviving, they were creating art, crossing oceans, and carrying complex symbolic traditions," Clarkson said.

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