Until recently large cutting tools (LCTs) from the Acheulean industry had been found almost exclusively in western Eurasia and Africa. This prompted the creation of a geographic boundary line between the East and West, known as the Movius Line. This line, named for a Harvard archeologist who first described the east-west distinction, divided the two areas, labeling East Asia, which lacked this new technology, as culturally stagnant and western Eurasia and Africa as progressive. Although the validity of the Movius Line has been challenged, the lack LCTs in East Asia, and their presence elsewhere, caused the hypothesis to remain prevalent. Recent work in the Bose Basin in South China has revealed LCTs that are contemporaneous with Acheulean LCTs from western Eurasia and Africa.

These tools have been dated by analyzing the argon content present in tektites (silicate glass) found with the artifacts. The ratio between two forms of the element argon reflects the known rate of radioactive decay, thus providing an accurate date. Using this method, the tools dated to 803,000 +/- 3000 years before the present. This date makes these tools older than the Acheulean tools found in Europe. The tools that are present at the Bose sites are not identical to Acheulean tools, which typically have a known shape and morphology. The Bose tools, though different, show bifacial flaking and evidence of mental templates that were used to create like tools. These artifacts show that toolmakers in the area at that time were equally capable as those who lived to the west of the Movius Line.

The article states that the tools have only been found on the surface in many places and excavated specifically at three sites. Since these discovery sites all occur in one fluvial terrace, they are from the same time period. By contrast, localities on the other side of the Movius Line often exhibit Acheulean LCTs in many layers that span hundreds of thousands of years. According to the article, the presence of tektites and charcoal in the same layer as the Bose artifacts suggests an interesting explanation. Tektites are pieces of earth rock that were once molten due to heating that results from meteorite impact. The Bose tektites are the same as those spread from Australia through Southeast Asia and other parts of China, which resulted from the meteorite event of about 803,000 years ago. The presence of charcoal with the tektites suggests that the meteorite event (and the hot tektites) caused burning of forests throughout the region. The researchers suggest that deforestation exposed large gravel beds of stone cobbles, which had previously been covered by forest soils. Early humans living in the region, or moving into it, were forced to adapt to the widespread forest destruction and made use of the available raw materials, creating tools that paralleled the sophistication seen elsewhere.

The Bose research is a project of the Smithsonian's Human Origins Program, in collaboration with the Chinese Academy of Sciences.