Early humans successfully engineered symmetrical spheroids

The researchers developed 3-D analysis methods involving spherical harmonics and surface curvature, which helped analyze a collection of 150 limestone spheroids. 

The spheroids were excavated from the 'Ubeidiya archaeological site, dating back to approximately 1.4 million years ago, a statement by the scientists said. 

Professor Leore Grosman emphasized: “Ubeidiya is presently recognized as the earliest known Acheulean occurrence outside of Africa, making it a crucial location for investigating the evolution of early hominin technology.”

Accidental spherical stones

The team reconstructed the spheroid reduction sequence after analyzing scar facets and geometry using the tools at hand. They uncovered a unique pattern in the spheroids from Ubediya, noticing that the craftsmanship was deployed using a premeditated reduction strategy. 

The product was an accidental result, scientists ruled. The spheroids became spherical, not smoother, during the manufacturing process.

“This transformation towards an ideal sphere required exceptional knapping skills and a clear preconceived goal,” researchers stated. 

In light of the discovery, the study challenges the preexisting notions about the early hominins' capabilities to develop new technology. 

This study proves that people in taxonomic tribes, too, were keen to evolve. For instance, the tool –  Acheulean bifaces from the prehistoric French society is traditionally believed to represent the earliest evidence of hominins.

It was concluded that tools were produced intentionally, with symmetrical shapes on stone. Scientists stated: “The intentional production of sphere-like objects at Ubeidiya similarly suggests that these early hominins had a desire for and achieved intentional geometry and symmetry in stone.” 

Spheroids can be traced back to African sites older than the ones analyzed. Additionally, archaeologists believe similar intentional behavior can be proven on those stones. 

The study highlighted evidence that points towards early hominins successfully engineering symmetrical stones. This has paved the way for new studies, including understanding prehistoric humans' cognitive abilities and technological achievements. 

The study was published earlier today (September 6) in the journal – Royal Society Open Science.

Study Abstract:

Spheroids are one of the least understood lithic items yet are one of the most enduring, spanning from the Oldowan to the Middle Palaeolithic. Why and how they were made remains highly debated. We seek to address whether spheroids represent unintentional by-products of percussive tasks or if they were intentionally knapped tools with specific manufacturing goals. We apply novel three-dimensional analysis methods, including spherical harmonics and surface curvature, to 150 limestone spheroids from ‘Ubeidiya (ca 1.4 Ma), presently the earliest Acheulean occurrence outside of Africa, to bring a new perspective to these enigmatic artefacts. We reconstruct the spheroid reduction sequence based on trends in their scar facets and geometry, finding that the spheroid makers at ‘Ubeidiya followed a premeditated reduction strategy. During their manufacture, the spheroids do not become smoother, but they become markedly more spherical. They approach an ideal sphere, a feat that likely required skilful knapping and a preconceived goal. Acheulean bifaces are currently thought to represent the earliest evidence of hominins imposing a premeditated, symmetrical shape on stone. The intentional production of sphere-like objects at ‘Ubeidiya similarly shows evidence of Acheulean hominins desiring and achieving intentional geometry and symmetry in stone.