Quartz tools found at Shuiquanyu site in Cuijiayu town of Yishui. CHINA DAILY

Discoveries

Li recalls a particular day during the excavation of the Bashan site. "As the team members were clearing the lower cultural layers, they shouted out to me. When I went over, we discovered a section of an incisor of a straight-tusked elephant, along with a portion of an elephant molar," he says, adding that at about half a meter long, the incisor was weighty, and the thicker end had a diameter of 15 centimeters and a smooth, polished appearance.

"Microscope observations revealed scratches on the cross-section, suggesting it was likely a tool used by humans."

Test results indicated that the shovel-shaped tool was 99,000 years old and was made from the incisor of an adult straight-tusked elephant that could have weighed up to 15 metric tons.

The team also found eight straight-tusked elephant mandibles, two of which belonged to adult elephants, and the other six to juveniles.

Li says the shovel-shaped tool, stone tools and animal fossils suggest human activity such as tool making and animal processing. "If it wasn't humans hunting and butchering animals, it would be hard to explain why six of the eight straight-tusked elephants' mandibles belonged to juveniles, which were weaker and easier to capture, while hardly any other parts were found," he says.

The team also discovered charcoal fragments and the residue of multiuse fires at the Bashan site, as well as grains of carbon at the Shuiquanyu site.

These findings led the team to conclude that humans did not become extinct in East Asia during the last glacial period 20,000 years ago. "Between 20,000 to 30,000 years ago, during the last harsh glacial period, ancient humans in the region used fire-making techniques to stay warm, and adapt to deteriorating environmental conditions," Li says.

The Bashan Paleolithic site group is characterized by its thicker strata and extended temporal framework of ancient human activities. It has yielded a wealth of stone artifacts and animal fossils, shedding light on ancient human behavior linked to fire making and animal butchering.

"All these findings indicate the continuous behavioral evolution of ancient humans in the region," Li adds.