Resembling a tic-tac-toe board, newly discovered cave engravings may be the most convincing piece of Neanderthal art to date.

According to BBC News, the etchings were found on a rock in the back of Gorham's Cave in the British Territory of Gibraltar. An international, multi-institutional team of researchers published a study on the carvings in the journal Proceedings of the National Academy of Sciences.

The discovery puts more distance between Neanderthals' perceived nature and the one they actually had. More and more evidence has suggested the ancient human species buried their dead, put thought into their garb and had a diverse diet.

The Neanderthals were likely to have lived alongside modern humans, meaning their societies could have directly interacted. The cave also had ancient Neanderthal tools, leading the study authors to believe what was on the walls also belonged to the ancient humans.

"[Dolomite] is a very hard rock, so it requires a lot of effort to produce the lines," Francesco d'Errico, director of research at the French Centre National de la Recherche Scientifique (CNRS) in Bordeaux, told BBC News. "If you did it in a single session, you would most probably injure your hand, unless you cover your tool with a piece of skin.

"It does not necessarily mean that it is symbolic - in the sense that it represents something else - but it was done on purpose."

The overlap of when Neanderthals and modern humans apparently coexisted could also mean much more. Since there were thousands of years where both species were on the Earth, the art could belong to modern humans.

"Any discovery that helps improve the public image of Neanderthals is welcome," Clive Gamble, an archaeologist at the University of Southampton, told the Associated Press. "We know they spoke, lived in large social groups, looked after the sick, buried their dead and were highly successful in the ice age environments of northern latitudes. As a result rock engraving should be entirely within their grasp.

"What is critical, however, is the dating... While I want Neanderthals to be painting, carving and engraving, I'm reserving judgment."