Researchers from Griffith University in Queensland, Australia found that the cave paintings discovered in Indonesia date back to at least 40,000 years ago. The findings suggest that it could be the oldest rock art in the world. 

The paintings were discovered in Sulawesi Island, and the estimated age might be older than the oldest known rock painting found in Europe. Study author and dating expert Maxime Aubert from Griffith University believes that this discovery could change the perspective on rock art history, which is considered as a pillar in humanity's evolutionary past.

"It is often assumed that Europe was the center of the earliest explosion in human creativity, especially cave art, about 40 thousand years ago. But our rock art dates from Sulawesi show that at around the same time on the other side of the world people were making pictures of animals as remarkable as those in the Ice Age caves of France and Spain," Aubert said in a university news release.

The images were imprinted inside the limestone caves of southern Sulawesi. They depicted human hands, which were drawn into the rock by either spraying or blowing paint around the hand as it was hard-pressed against the rock. Depictions of ancient pigs called "babirusas" were also found. These paintings were discovered almost 50 years ago, but this is the first attempt to determine their real age.

Researchers measured the amount of uranium and thorium in the stalactite growths, or "cave popcorns," above the art forms.

U-series dating was also used to date samples taken from 14 paintings observed in seven caves. The analysis showed that these paintings were at least 18,000 to 40,000 years old. Since U-series dating can only provide minimum estimates, the art can actually be older than these figures.

The oldest painting dated was a stencil of a human hand, which was estimated to be 40,000 years old, while the depiction of the babirusa could be 35,000 years old.

Further details of the study were published in the Oct.9 issue of Nature.