scientists said Wednesday, and sheds light on how humans first migrated to Australia. The cave art dates back at least 67,800 years, according to research published in the journal Nature by a team of Indonesian and Australian archaeologists. "We have been working in Indonesia for a long time," study co-author Maxime Aubert of Australia's Griffith University told AFP. This time they ventured to caves on the island of Muna in the Sulawesi province on the advice of Indonesian archaeologist Adhi Agus Oktaviana, the study's lead author. There they found "handprints in negative, stencilled, probably using red ochre," Aubert said. The fingers of one of the hands were "retouched to become pointed like claws -- a style of painting only seen in Sulawesi," the Canadian archaeologist added.

To determine the art's age, the team took five-millimetre samples from "cave popcorn", which are small clusters of calcite that form on the walls of limestone caves. Then they zapped the layers of rock with a laser to measure how the uranium decayed over time, compared to a more stable radioactive element called thorium. This "very precise" technique gave the scientists a clear minimum age for the painting, Aubert explained. At 67,800 years old, the Indonesian stencil is more than a thousand years older than other hand stencils found in a Spanish cave which has been attributed to Neanderthals. However the dating of that cave art "has been controversial," the study cautioned. The new discovery is also more than 15,000 years older than previous art found in the Sulawesi region by the same team. The scientists also established that the Muna caves had been used for rock art many times over a long period. Some of the ancient art was even painted over up to 35,000 later, Aubert said. (Bssnews)