Sixty years ago, on the Indonesian island of Sulawesi, a group of archaeologists discovered a series of paintings spread across 100 limestone caves. The images—rendered, by the time of their discovery, in sepias of varying saturations—featured stencil-like outlines of human hands and stick-legged animals in motion; they were in appearance, at least, quite similar to the cave paintings that had already been discovered, and made famous, in Spain and France.

The paintings were proto-graffiti. They were early versions of that car window in Titanic. They were humans, making their mark.

They were also, obviously, old. But they were not, it was thought, oooooold-old. They couldn't have been created, their finders figured, much more than 10,000 years ago. Had they been any older, everyone assumed, they would have faded away in the humid tropical air.

But you know what they say about assumptions. According to a paper published today in the journal Nature, those paintings, etched into those caves, are much older than those first scientists had thought. Tens of thousands of years older, in fact. So old that they are now thought to be the oldest known specimens of art in the world. If art is one of the things that make us human … then it seems we've been human for even longer than we've realized.

That it took us so long to make that realization, though, is a reminder of some other things that make us human: technological limitation, resource limitation, cultural myopia. It's long been assumed that the oldest human paintings were created in Europe, in the caves of France and Spain. That's an assumption that has political implications as well as scientific ones. "The truth of it was, no one had really tried to date it," the Smithsonian's Matt Tocheri told NPR of the Sulawesi find.

That wasn't because we lacked the tools to do the dating. While the Sulawesi paint itself can't be accurately dated, what we've long been able to do is to estimate the age of the rocky bumpscalcium carbonate, more commonly and more delightfully known as "cave popcorn"—that now cover it. Uranium-thorium dating takes advantage of the decay rate of uranium as it turns into thorium to estimate, to a high degree of accuracy, the age of the rock in question. It allows scientists to determine an age—a minimum age—for the paintings that cover the cave walls.

Using that method, the Griffith University professor Maxime Aubert and his team were able to determine that the Sulawesi paintings are, at minimum, 39,900 years old. Which makes their minimum age at least 2,000 years older than the minimum age of the oldest European cave art. (While the paintings are strikingly similar in content—human hands, animals teetering on stick-like appendages—they are also strikingly different in style. The Indonesian images "look ‘line-y,’ almost like brush strokes," Alistair Pike, the archaeologist who identified what was preciously considered the world’s oldest cave art, in Europe, told Nature. Early European images, on the other hand, "look dabbed, almost like finger paint.")

All of which make the Sulawesi dating not just a scientific discovery, and not just a cultural revelation, but also something of a political point. "It allows us to move away from the view that Europe was special," Aubert told Nature. "There was some idea that early Europeans were more aware of themselves and their surroundings." The discovery of proto-art in Indonesia—the flecked and frozen outlines of the hands of unknown humans—negates that idea, scientifically. "Now," Aubert says, "we can say that’s not true.”