Ancient Weapons

A stone artifact from Grotta del Cavallo showing an impact fracture

Katsuhiro Sano

Mechanical weapons, such as bows and arrows or spear-launching atlatls, allowed early hunters to take down bigger and faster game from a safe distance. The creation of such weapons marks an important milestone in the evolutionary development of the genus Homo. New archaeological findings suggest that these mechanical weapons were used in Europe 20,000 years earlier than previously thought.

An international team of researchers, led by archaeologist Katsuhiro Sano, of Tohoku University in Sendai, Japan, analyzed 146 stone pieces found in Grotta del Cavallo, a cave in southern Italy first excavated in the 1960s. The small stone pieces, which averaged only one inch long, dated from 40,000 to 45,000 years ago, during the Later Stone Age. Digital microscopy showed that they were intentionally sharpened and contained many long fractures consistent with high-velocity impacts, suggesting they were used as arrowheads or spearheads.

A closer examination of the pieces revealed an adhesive residue, identified by spectromicroscopy as a mixture of tree gum, beeswax, and ochre. Such an adhesive would have been necessary for mechanically delivered projectiles, to ensure that the stone tips remained attached to their shafts upon high-speed impact. The size of the pieces also suggested that they were part of arrows or atlatl-thrown spears, as handheld spears had larger stone heads. Finally, mechanical weapons also would have had feathers, or fletching, to ensure a straight flight. While direct evidence in the form of shafts and feathers would have long since decomposed, the researchers did find avian bones in Grotta del Cavallo with cut marks indicating the removal of feathers, potentially for use in tandem with the sharpened stone tips.

Researchers debate whether mechanical weapons were unique to Homo sapiens or also used by H. neanderthalensis. The Grotta del Cavallo pieces, however, are thought to have belonged to H. sapiens, based on teeth found in the same rock layer. Future studies may confirm the extent to which the development of advanced weapons and hunting techniques contributed to the ultimate decline of H. neanderthalensis and to the spread of H. sapiens. (Nature Ecology & Evolution)