Dating back more than 60,000 years ago, humans in southern Africa were engraving ostrich eggshells with intricate geometric patterns that—the longer we study them—look more organized than we previously realized. A new analysis of the markings found on hundreds of eggshell fragments has revealed our ancestors’ remarkable ability to organize visual space according to abstract principles. The investigation team from the University of Bologna concluded for the first time that these engravings on ostrich eggshells were not random or improvised, but followed recurring and surprisingly organized geometric rules, according to the study published in the journal PLOS One. “These signs reveal a surprisingly structured, geometric way of thinking,” continued Ferrara, who says the eggshells were most likely used as water containers. The most complex compositions — such as hatched bands, grids and diamond-shaped motifs — reveal cognitive operations of rotation, translation, repetition and “embedding”, i.e.