Researchers from the University of Bologna have found that engravings on 60,000-year-old ostrich eggshell fragments from southern Africa were not random doodles but followed deliberate, repeated geometric rules. The team, led by PhD student Valentina Decembrini and professor Silvia Ferrara, conducted a quantitative analysis of 112 fragments from the Diepkloof and Klipdrift sites in South Africa and the Apollo 11 site in Namibia.
Over 80% of the engraved configurations showed consistent spatial patterns, including angles close to 90 degrees and parallel lines. Simpler designs featured repeated right angles and parallel bands, while more complex pieces revealed hatched grids and diamond motifs built through rotation and systematic repetition, indicating the makers held a full mental image of the design before carving it.
The findings, published in PLOS One, push back the timeline for abstract visual planning tens of thousands of years before the emergence of written language, suggesting early Homo sapiens in the Howiesons Poort tradition already possessed sophisticated geometric and spatial reasoning.