See the zigzag lines on the shell above? A human ancestor, Homo erectus, etched those markings half a million years ago.

Nick Barton, an archaeologist at the University of Oxford who was not involved in the discovery, told Nature this shell “has the potential to overturn the way we look at early Homo.”

How did researchers date the engravings on the shell? Analysis of sand grains embedded in the shell give us the 500,000 years old date.

It was a stroke of luck that the engravings were even discovered. The shell was collected back in the 1890s at a site called Trinil in eastern Java (an island of Indonesia). It was reexamined in the 1930s and then packed into a box in a museum in Leiden, the Netherlands.

We can thank Josephine Joordens for the discovery. A biologist at Leiden University, Josephine was working on a project about how H. erectus used the marine environment at Trinil. While looking through the shells, Josephine spotted a few with small holes created by a sharp object.

java shell

The zigzag pattern wasn’t discovered until a colleague photographed the shells and noticed it.

“People never found this engraving because it’s hardly visible,” Joordens told Nature. “It’s only when you have light from a certain angle that it stands out.”

“We’ve looked at all possibilities, but in the end we are really certain that this must have been made by an agent who did a very deliberate action with a very sharp implement,” Joordens said.

Is it art? Joordens hesitated to call it that, but did say “it is an ancient drawing.” Why the human ancestor decided to etch on this shell will never be known, though.

The discovery does shake up preconceptions about human ancestors. It appears abstract concepts go a lot further back than we previously believed.

Image credit: Wim Lustenhouwer/VU University Amsterdam, Henk Caspers/Naturalis


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