The microliths may have served as spurs in these atlatls. (See images of the ancient tools)
"They are parts of a complex composite weapon," Marean said.
Past research suggested microlithic technology appeared briefly between 60,000 and 65,000 years ago.
"Eleven thousand years of continuity is, in reality, an almost unimaginable time span for people to consistently make tools the same way," Marean said. "This is certainly not a flickering pattern." Moreover, heat treatment of stone was seen at Pinnacle Point about 160,000 years ago, suggesting people there mastered this complex technique for nearly 100,000 years.
The researchers suggest these projectile weapons were pivotal to the success of modern humans as they left Africa and encountered Neanderthals, who apparently possessed only hand-thrown spears.
"When Africans left Africa and entered Neanderthal territory, they had projectiles with greater killing reach, and these early moderns probably also had higher levels of pro-social, hyper-cooperative behavior. These two traits were a knockout punch. Combine them, as modern humans did and still do, and no prey or competitor is safe," Marean said. "This probably laid the foundation for the expansion out of Africa of modern humans and the extinction of many prey as well as our sister species such as Neanderthals."