Archaeologists working at several sites in southern Africa have uncovered engraved ostrich eggshell fragments that may represent the oldest use of geometry by humans. Dating back more than 60,000 years, the markings suggest that Homo sapiens were organizing space using abstract rules tens of thousands of years before writing or formal mathematics emerged.
The fragments offer rare material evidence that early humans were not only making marks, but applying structure, planning, and shared visual principles to everyday objects.
Engraved shells reveal early symbolic behavior
The ostrich eggshells were deliberately engraved, researchers say. The markings are fine, repeated, and consistent across fragments, ruling out accidental damage or casual scratching.
Ostrich eggshells were widely used in prehistoric Africa, often as portable water containers. Scientists believe the engravings may have helped signal ownership, social identity, or group affiliation. Their presence at multiple sites suggests that early communities shared visual traditions and communicated ideas across regions.
Study finds consistent geometric rules
A new investigation led by researchers from the University of Bologna provides the strongest evidence yet that these markings followed clear geometric rules. The study was published in the journal PLOS One.
An analysis of markings on hundreds of ostrich eggshell fragments dating back more than 60,000 years, found in South Africa and Namibia, shows that early humans could organize visual space using abstract principles. pic.twitter.com/5RSsSJ7sB0
— Tom Marvolo Riddle (@tom_riddle2025) February 26, 2026
Researchers found that the engravings were not improvised. Instead, they were built around recurring visual principles, including parallel lines, right angles, and repeated patterns. These features point to intentional design rather than decoration made on impulse.
“These signs reveal a surprisingly structured, geometric way of thinking,” said Silvia Ferrara, who coordinated the study.
Researchers apply new analytical methods
The research team analyzed 112 engraved fragments from three archaeological sites: Diepkloof Rock Shelter and Klipdrift Shelter in South Africa, and Apollo 11 Cave.
Using geometric and statistical techniques never before applied to these artifacts, the researchers reconstructed the angles, trajectories, and spatial relationships of the engravings. This allowed them to study how the designs were planned and executed across curved shell surfaces.
Most patterns show strong spatial order
The results showed a high level of consistency. More than 80 percent of the analyzed designs displayed clear spatial organization. Many included repeated angles close to 90 degrees and sets of parallel lines.
Some fragments featured complex compositions such as hatched bands, grid-like structures, and diamond-shaped motifs. According to the researchers, producing these designs required advanced mental operations, including rotation, translation, repetition, and what the study describes as “embedding,” or organizing multiple levels of signs within a single surface.
“These engravings are organized and consistent, and show mastery of geometric relationships,” Ferrara said. “There is real visuo-spatial planning.”
Findings point to early abstract thinking
Beyond the meaning of the markings themselves, researchers say the study’s main importance lies in what it reveals about early human cognition. The ability to organize visual space according to shared rules is widely seen as a key indicator of abstract thought.
“Our analysis shows that Homo sapiens 60,000 years ago already possessed a remarkable ability to organize visual space according to abstract principles,” said Valentina Decembrini, the study’s first author.
Decembrini said transforming simple lines into complex systems through rule-based planning is a deeply human trait. Researchers argue that this ability formed the foundation for later symbolic systems, including art and writing.
Geometry predates writing by tens of millennia
The findings add to growing evidence that the roots of human culture and cognition extend far deeper into the past than previously assumed. Long before agriculture, cities, or written language, early humans were already planning designs, organizing space, and applying geometric logic.
Researchers say the engraved ostrich eggshells may represent the oldest known expression of geometry—marking a crucial moment in the evolution of human thought.
