Traci Watson

Special for USA TODAY

Sometime during the last Ice Age, an unknown human placed his or her outstretched hand on the wall of an Indonesian cave and carefully sprayed a reddish mineral powder atop it. The result was a perfect hand stencil that scientists have now identified as the oldest rock art in the world.

The hand stencil dates to at least 39,900 years ago, and nearby animal figures are of nearly the same age — a finding with major implications for understanding how and where humans developed elaborate art. Until now, researchers had credited humans in Europe with the invention of cave painting 5,000 to 40,000 years ago. Now it's clear that people living in southeastern Asia knew their way around a paint pot at the same time.

The new art "changes our view of when and where humans became completely modern," says Maxime Aubert, an archaeologist and geochemist at Australia's Griffith University and a co-author of a study in this week's Nature reporting the new dates. The old view "led people to believe that our species became aware of ourselves, became modern, in Europe. Now we can show that's not true."

Antique paintings sprawl across 100 caves and rock shelters in Sulawesi, a large island in the Indonesian archipelago. Along with stenciling their hands, the artists drew pig-like animals called babirusas and a type of Asian buffalo. All were dismissed as relatively recent creations when they were discovered in the 1950s.

But when Aubert processed samples of minerals from atop a few paintings, he got a shock.

"I looked at the numbers and said, 'Whoa, that's pretty old!'" he recalls.

The oldest Sulawesi hand stencil dates to at least 39,900 years old, making it the oldest in the world. One Sulawesi babirusa is least 35,400 years old, putting it in the running for the oldest depicted object. France's Chauvet cave is adorned with animals dated to roughly 35,000 years ago, but the dating technique used at Chauvet yields a maximum age, not a minimum. It's "highly possible" that some of the Sulawesi animals were made more than 35,000 years ago, Aubert says, which would make them the world's most ancient figurative art.

Whether artists on Sulawesi were first or second to paint animals, the new discoveries will have a profound impact on our understanding of human cultural development, other experts say.

The newly dated art is "exceptionally significant," says archaeological scientist Alistair Pike of Britain's University of Southampton, who was not involved with the new study. The existence of two collections of rock art of about the same vintage, but separated vastly in space, implies that humans developed cave painting sometime after leaving Africa, where Homo sapiens evolved.

That cave art should be found in both Spain and Sulawesi "suggests to me that moving out of Africa required some quite complex development in human social behavior," Pike says. Rituals associated with cave art may have helped glue people together.

Perhaps humans invented cave art wherever they found caves, says Paleolithic archaeologist Paul Pettitt of Britain's Durham University. Or perhaps they were already painting on bits of leather or bark when they left Africa and simply transferred their artistic talents to rock walls in far-flung locales. In either case, it's clear that Europeans have no sole claim to rock painting.

"We've grown up over the last century and a half believing … that everything important in the world has happened in Europe," Pettitt says. "The appearance of very early rock art somewhere other than Europe shows "we have to cast our net far wider in seeking to understand why art developed."