Engravings believed to have been made by Neanderthals more than 39,000 years ago is pictured in Gorham’s Cave, Gibraltar, in this handout photo courtesy of Stewart Finlayson of the Gibraltar Museum.

Joaquín Rodríguez-Vidal and his colleagues have found a 40,000 year old pattern scratched in into the floor of a cave in Gibraltar.

Is it a doodle, a message or a work of art?

We’ve found Neanderthal art before, such as red ochre handprints on cave walls. But this new discovery is some sort of a tic-tac-toe pattern, to which the New Scientist cheekily dubbed them a “hashtag”). The team found the carving in near to many Neanderthal tools, about 300 or so. The researchers ruled out the possibility that the engravings were accidental or from cutting meat or animal skins. Instead, they were made by repeatedly and intentionally using a sharp stone tool to etch the rock…