New Delhi, Jan. 22 -- Handprints on cave walls in a largely unexplored area of Indonesia may be the oldest rock art studied so far, dating back to at least 67,800 years ago.

The tan-colored prints analyzed by Indonesian and Australian researchers on the island of Sulawesi were made by blowing pigment over hands placed against the cave walls, leaving an outline. Some of the fingertips were also tweaked to look more pointed.

This prehistoric art form suggests the Indonesian island was home to a flourishing artistic culture. To figure out how old the paintings were, researchers dated mineral crusts that had formed on top of the art.

Upon seeing the new study, independent paleoanthropologist Genevieve von Petzinger said she "let out a litt...