Researchers excavating Gorham’s Cave in Gibraltar have found a series of cross-hatched lines, approximately 15 inches from the cave floor. The cave in question has previously yielded Mousterian stone artifacts. These tools are typically associated with Neanderthals.

A geochemical analysis of the engravings shows that they predate overlying sediments. Additional analysis of the lines using stone tools, 3D reconstruction, microscopic and morphometric analysis shows that they were likely man made and not naturally occurring.

“This was not doodling. It required a lot of effort … the pattern was clearly purposefully made, and not a utilitarian activity. There was a will to produce an abstract pattern,” said Francesco d’Errico of the University of Bordeaux to New Scientist.

The study, published in the Proceeedings of the National Academy of Sciences, if confirmed, would add considerably to the idea that Neanderthals were able to create art. While there is additional possible evidence, such as the dot paintings at El Castillo Cave in Spain, many scientists do not believe that Neanderthals had the cognitive capacity for artwork.

Gorham’s Cave and the archeological artifacts discovered there are controversial in their own right. The site has been dated to approximately 40,000 years ago and many researchers believe that Neanderthals had already become extinct by that date. Others believe that the cave is where European Neanderthals made their “last stand” prior to extinction.

“The engravings do appear intentional and it’s hard to easily envisage a purely functional explanation for them. Consequently it’s useful to consider these structured scratches as deriving from abstract or symbolic thought, but linking them directly to Neanderthal populations, or proving Neanderthals made them without any contact with modern humans is harder. The dates presented here are indirect, referring to material from within sediments covering the engravings and not the marks themselves. Given the dates also span a period when we know modern humans have reached Europe, a period where we have unresolved ‘transitional’ archaeological evidence difficult to attribute to either population, I’d be cautious in accepting Neanderthal authorship,” said Dr Matt Pope, a Palaeolithic archaeologist at University College London to BBC News.