Grooves etched 35,000 years ago into a piece of flint provide strong evidence that Neanderthals practiced representational, symbolic art, researchers suggest.

In a paper published in the journal PLOS ONE, a team led by Anna Majkic of the University of Bordeaux, France, suggest that a series of intersecting lines engraved on a flint flake excavated from an archaeological site called Kiik-Koba in Crimea constitute deliberate and skilled design.

Incised stones have been found at 27 Neanderthal sites across Europe and the Middle East, but understanding how and why the marks were made has proved challenging. {%recommended 6666%}

Some marks, undoubtedly, arose unintentionally, as by-products of butchery or cutting. Others, however, might have been produced deliberately – but the question of why remains unanswered.

Using the Kiik-Koba artefact as a focus, Majkic and her colleagues present a series of guidelines intended to narrow the range of possible interpretations.

The edges of the flake, they say, clearly show that it was napped from a larger piece before being engraved, excluding the possibility that the marks were originally made in a different context.

Indeed, the flake itself is too small to have any practical use as a cutting or scraping tool, suggesting that its sole purpose was to carry the grooves.

The researchers dismiss possibilities that the marks were merely the end results of attempts to create a powder, or even simply a purposeless doodle. The intersecting, angled markings, they say, were very deliberately started and ended. They were made using two pointed tools – which, combined with the small surface area available, mark them as precision work.

The analysis also discounts the possibility that the marks represent a method of recording a count – the grooves seem to have been deliberately overlapped in several cases, making them useless as a number mark.

Majkic and colleagues also suggest that it is a mistake to simply look at the grooves in isolation – the Neanderthals, they speculate, deliberately contrasted them with the whitish background of the flake, with the aim to “recall an information to the flake user or eventually communicate one when the tool was passed to somebody else”.

The Kiik-Koba flake, they conclude, should be added “to the growing evidence” that Neanderthal culture “included practices that could be consistent with symbolic interpretations”.