40,000 years ago, humans had a system of signs that was a precursor to written language.

The first modern humans Europe central, about 40,000 years ago, carved sequences of signs, a level of complexity and information density comparable to the first protocuneiform writing of ancient Mesopotamia.

Those humans carved into cave walls, tools and figurines of ivory, bone or horn sequences of signs, often repeated lines of notches, dots and crosses, the meaning of which is unknown but which they may have used to convey information and record their thoughts.

Researchers led by Saarland University (Germany) analyzed more than 3,000 geometric signs in 260 objects associated with the Aurignacian culture, from between 43,000 and 34,000 years ago, and published the results in PNAS.

The objective was not to discover their specific meaning, but to analyze the frequency trends and the tangible and measurable aspects of the signs, to analyze what they have in common with later systems and how they differ.