Nov. 19 (UPI) -- New analysis of what archaeologists call the "Swiss Army knife of prehistoric tools," originally recovered from a dig site in China, suggests stone tool technology developed independently in East Asia -- and much earlier than previously thought.
The stone tools, sometimes called Levallois cores, were used by early humans between 80,000 to 170,000 years ago. Previously, researchers dated the arrival of stone tool technology in East Asia to between 30,000 to 40,000 years ago.
Researchers described their work this week in the journal Nature.
"It used to be thought that Levallois cores came to China relatively recently with modern humans," Ben Marwick, an associate professor of anthropology at the University of Washington, said in a news release. "Our work reveals the complexity and adaptability of people there that is equivalent to elsewhere in the world. It shows the diversity of the human experience."
Levallois cores are named for Levallois-Perret, the Paris suburb where they were first unearthed in the 19th century. They're known as the Swiss Army knife of prehistoric tools because of their versatility. The faceted stone core could be used to spear, slice, scrape or dig. The cores were more durable, efficient and sophisticated than the oval-shaped stones used by earlier groups.
The cores were originally recovered in the 1960s and 70s from Guanyindong Cave in China's Guizhou Province, but the stone technology was only recently examined carefully by archaeologists.
Over the last several decades, the cave has yielded a variety of archaeological evidence dated to between 50,000 and 240,000 years ago, but a detailed analysis of the sediment surrounding the Levallois cores showed the tools were used between 80,000 and 170,000 years ago.
"Dating for this site was challenging because it had been excavated 40 years ago, and the sediment profile was exposed to air and without protection," said Bo Li, an associate professor of archaeology at the University of Wollongong in Australia. "So trees, plants, animals, insects could disturb the stratigraphy, which may affect the dating results if conventional methods were used for dating."
Researchers used a newly developed single-grain dating technique to date individual mineral grains from the area where the tools were excavated.
"Luckily we found residual sediment left over by the previous excavations, so that allowed us to take samples for dating," Li said.
Archaeologists tallied a total of 45 tools and related flakes recovered from the dig site. The oldest artifacts were dated to 130,000 to 180,000 years old.
In Africa and Europe, Levallois cores, classified as Mode III technology, show up in the archaeological record between 200,000 and 300,000 years ago. Previously, researchers thought Mode III technology came to Asia from the West.
Most of the human remains recovered from Asia belong to a group of human ancestors known as the Denisovans. The record of Homo sapiens in Asia is sparse compared to Europe and Africa, leading some researchers to suggest Asia was mostly occupied by more primitive groups until the region was populated by groups migrating from Europe.
Because Guanyindong Cave has yet to turn up the remains of migrating humans, researchers believe the artifacts are proof of homegrown technology.
"Our work shows that ancient people there were just as capable of innovation as anywhere else," Marwick said. "Technological innovations in East Asia can be homegrown, and don't always walk in from the West."