Fossil sea snail shells reveal that anatomically modern humans carrying stone tools lived 45,900 years ago in the Near East before colonizing Europe. The findings, published in Proceedings of the National Academy of Sciences this week, suggest that advanced stone tools weren’t invented in Europe as previous studies indicated.
Homo sapiens originated in Africa, and according to the Levantine corridor hypothesis, our species spread into Europe via the Near East – which includes the eastern Mediterranean region of southwestern Asia – between 50,000 and 40,000 years ago, during the beginning of the Upper Paleolithic. But recent radiocarbon dates of shell ornaments from Ksâr ‘Akil in Lebanon challenged this hypothesis, suggesting that tool technology arrived in the Near East after its first appearance in Europe. Dating shells from the Levant has been notoriously difficult, however, and now new findings lend renewed support to the Levantine corridor hypothesis.
An international team led by Marjolein Bosch from the Max Planck Institute for Evolutionary Anthropology radiocarbon-dated the shells of marine mollusks called Phorcus turbinatus found in the same archaeological layer as human remains and artifacts at Ksâr ‘Akil. “The importance of Ksâr ‘Akil lies in the fact that we have two modern human fossils, nicknamed ‘Ethelruda’ and ‘Egbert’ by the original excavators, associated with Upper Paleolithic toolkits from the site,” Bosch explains in a news release.
Their approach integrated radiocarbon dates with multiple sources of biochemical data, including an analysis of the proteins preserved in the shell structure. The team knew the snails were eaten because their tops were sliced off (pictured above), which made it easier to get at the flesh. And because the mollusks would have been alive when they were collected for consumption, the researchers reasoned that the shells should be the same age as the human remains – which were too degraded to date directly.
The skeleton Egbert lived around 43,000 years ago, the ages of the shells with the jawbone Ethelruda place the site’s earliest modern human remains at 45,900 years or older. In Europe, the oldest modern human fossils date to between 45,000 and 43,000 years ago – which means that Ethelruda predates all European Homo sapiens.
Modern humans' use of Upper Paleolithic tools in the Near East prior to any Homo sapiens fossils in Europe indicates that the Levant was the corridor for the dispersal of our ancestors out of Africa and into Europe and Asia. “Toolkits similar to those associated with Ethelruda and Egbert are also found in other sites in the Levant as well as in Europe,” Bosch adds. “These similar toolkits and the earlier ages in the Near East suggest population dispersals from the Near East to Europe between 55,000 and 40,000 years ago.”