A 40,000-year-old Chinese stone tool culture unlike any other

We know the oldest human cultures only from their most durable parts: mostly stone tools, sometimes bone. Show an experienced Pleistocene archaeologist a chert blade, and they can probably tell you which hominin species made it, how long ago, and where. But the 40,000-year-old stones and bones archaeologist Fa-Gang Wang and his colleagues recently unearthed at a 40,000-year-old Chinese site called Xiamabei look like nothing archaeologists have seen before.

Unique stone tool technology

The people who lived at Xiamabei, in northern China's Niwehan Basin, used a toolkit that consisted mostly of tiny bladelets (small, sharp pieces of stone), often hafted onto bone handles. Based on microscopic traces of wear and tear on the tools, people at Xiamabei seemed to have used the same generic bladelets for everything from scraping hides and cutting meat to boring wood and whittling softer plant matter.

Nearly every one of the 382 stone tools unearthed at Xiamabei is less than four centimeters long; making and using these smaller blades would have allowed early humans to do more work with less material. Handles helped make the tools easier to grip and more versatile; Wang and his colleagues found one bladelet with part of a bone haft still attached to the stone. On several of the 17 other bladelets the researchers examined closely for microscopic signs of wear, they found tiny scratches left by bone handles, along with imprints from the plant fibers used to bind the bladelets in place.

The result, as Wang and his colleagues put it, is a "complex technical system" completely different from what any other group of people—whether Homo sapiens, Neanderthal, or Denisovan—used at the time.

A Pleistocene workshop

Along with their bone-handled bladelets, people at Xiamabei made and used prodigious quantities of ocher—enough to stain the ground red for the next 40 millennia.

Wang and his colleagues found two chunks of ocher, along with an ocher-smeared limestone slab and a battered cobblestone hammer, lying at the center of a patch of red-stained dirt. Closer inspection with X-ray fluorescence and a scanning electron microscope showed that the dirt was full of iron oxide and microscopic fragments of hematite.

"The quantity of ocher powder produced was large enough for the leftover material to permanently impregnate the sediment of the area on which tasks took place," wrote Wang et al.

Ocher makes a good pigment for painting walls, objects, or skin; it's also useful for tanning animal hides or mixing adhesives to help haft stone tools. Wang and his colleagues say the people at Xiamabei almost certainly used ocher for making resin glue and tanning hides. The archaeologists believe this because, at the site, they found bits of ocher on four stone tools that were still stuck to the part of the tool that would once have sat inside a haft, or handle. Ocher also still clung to the working edges of two other tools that showed traces of wear from scraping hides.

The tableau at Xiamabei—ocher nodules and worker's tools lying amid ground stained by previous work—is the continent's oldest evidence of people doing the work of processing ocher. An engraved and painted bone from another site, 105,000 to 125,000 years old, has bits of ocher residue still clinging to its crevices. This older site suggests that Neanderthals and Denisovans in the region had been working with ocher long before our species arrived and long before anyone set up shop at Xiamabei. But we've had no indication of the processing associated with that older site.