Excavations reveal settlements close to rivers and evidence of hunting, reports Zhao Ruixue in Linyi, Shandong province.

It had been raining heavily for more than 10 days in Hekui, a village in Linyi city's Yishui county in Shandong province. The continuous downpour that July in 2020 caused levels at the Bashan Reservoir, about 300 meters to the east of the village, to exceed the safety limit, forcing it to release water.

The cascade eroded the riverbanks, carrying mud and sediment downstream into the Yihe River. However difficult it might have been to imagine at the time, this event changed the fate of the village and the surrounding areas for the best, as the force of the water washed away the soil to reveal significant archaeological remains.

"Someone found animal fossils likely been washed out by the water," says Li Gang, a researcher at the Shandong Institute of Cultural Relics and Archaeology, as he recounted the call he received from the dean. "He said, 'You should go and take a look. There might be artifacts from the Paleolithic period'."

Upon arriving at the village, Li was greeted by a trove of fossils covered in riverbank mud, with one particularly memorable find being a segment of an elephant molar.

However, it was the presence of quartz items in the strata that caught his attention. After examining a few of the pieces, Li, who has dedicated 15 years of his life to Paleolithic archaeology, felt a surge of joy — this vast alluvial plain and sloping hill before him was a rare and well-preserved Paleolithic site.

As he stood there, he tried to picture the scene 100,000 years ago, in what would have been lush grasslands. This was a time when humans wielded stone tools. In the distance, he could almost hear the trumpeting of extinct prehistoric straight-tusked elephants, and the neighing of wild horses.

Sites

Remnants of early human life became more evident as the work progressed. The Bashan archaeological site, which stands on the bank of Yihe River, has been enclosed to prevent it from flooding. After years of hard work, the team led by Li is still excavating Bashan, as well as several other surrounding sites, including the one at Shuiquanyu in Cuijiayu town of the county.

At the Bashan site, the team has dug to a depth of nearly 8 meters, yielding stone tools and animal fossils in 14 layers, each indicating a different culture.

Li says that the oldest layers dating back 100,000 years contain stone tools and fossils of large mammals, including prehistoric straight-tusked elephants and woolly rhinoceroses.

At Shuiquanyu site, discovered in 2022, the stone tools found suggested it could be an Upper Paleolithic era site. Radiocarbon dating confirmed that the tools are approximately 24,000 years old.

Archaeologists have identified over 80 Paleolithic sites in the Yihe River Basin, which form a group centered on Bashan. They are known collectively as the Bashan site complex, or the Bashan site group.

Li says the stratigraphic sequence and the types of artifacts unearthed in the group are consistent, and illustrate the history and material culture of the peoples that lived on the upper reaches of Yihe River between 100,000 and 10,000 years ago.

To date, more than 40,000 artifacts have been found around the Bashan site group, among them stone items like smashed cores, disc-shaped cores, and flakes. The array of tools includes spheroids, scrapers, choppers, points, stone drills and hammerstones.

Most of the stone artifacts are made out of quartz, sourced from the abundant veins in the nearby Bashan Hill.

The team also found the mandibles, and a femur fragment, of straight-tusked elephants (Palaeoloxodon antiquus), alongside a wealth of fossils, including those of aurochs, red deer, woolly rhinoceroses, elk, sheep, wild boars, as well as small-sized cervids (hoofed animals from the deer family) and small mammals.

"The fossils of straight-tusked elephants and a plethora of stone tools were located in multiple layers, which is rare not only in northern China, but in the entire country," Li says, adding that this has provided important archaeological evidence for the study of early human settlements and livelihoods during the Pleistocene, which lasted from about 2.6 million to 12,000 years ago.

"These ancient inhabitants strategically positioned their settlements close to rivers and sources for stone tools, demonstrating their skill at choosing places to live," Li says.

Fan Chengtai, an official at the archaeology office of the Shandong Provincial Department of Culture and Tourism confirmed the significance of the discoveries at Bashan. "Excavation findings indicate that human development in the region around Yishui continued uninterrupted, illustrating a flourishing scenario in which indigenous inhabitants coexisted with wildlife," Fan says.

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.

Meaning

Prior to discovering Bashan, archaeologists from the Shandong Institute of Cultural Relics and Archaeology had already discovered a great number of sites from the late Paleolithic and the Paleolithic-to-Neolithic transitional periods in the Yihe River Basin.

"However, the vast majority of stone artifacts were surface finds, posing challenges to dating due to the absence of original strata," Li says. "The discovery of the Bashan site significantly improved the situation."

The excavation of the Bashan site group is focused on multidisciplinary cooperation. The team works on collecting chronological and environmental samples, reinforcing animal bones, conducting indoor CT scanning, and making protection plans for fragile remains. There are also team members analyzing paleogeomorphology (ancient topographic features) and ancient DNA samples. This allows inter-site variability and connections between the Bashan group sites to be discussed based on different kinds of data.

For its key academic value and cultural significance, the Bashan site group was listed as one of China's top 10 new archaeological discoveries last year, and its discovery marked a turning point in improving Paleolithic archaeology in Shandong.

Exploration of the province's Paleolithic sites began in 1965 when animal fossils were unearthed at the Qianrendong cave in Yiyuan county, Zibo city. A joint effort between the Shandong Provincial Museum and the Institute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences then discovered stone artifacts made of vein quartz.

The following year, a fossilized human tooth was found in Xintai city. This discovery marked the beginning of a series of findings on the Jiaodong Peninsula in eastern Shandong, where stone tools and vertebrate fossils were found.

Throughout the 1980s, a nationwide survey of artifacts propelled archaeological work in southern Shandong and on the eastern coast of the province. Notable discoveries during this period included the unearthing of the Yiyuan Man skull and seven teeth in 1981, which demonstrated traits akin to Peking Man and Anhui province's Yuanmou Man, a stage in the development of Homo erectus.

In 1982, 700-odd pieces of microlith (small fragments of stone, often flints) were discovered at the Fenghuangling site in Linyi, the first find of microlithic remains discovered in Shandong.

Entering the new millennium, efforts in Shandong have focused on three river basins where over 50 Paleolithic sites have been discovered.

Compared to other provinces in northern China, Shandong boasts a significant number of late Paleolithic sites.

"Despite the numerous discoveries of Paleolithic sites, the lack of primary strata has hindered comprehensive research in Shandong," Li says. "The Bashan site group discovery has filled in critical gaps in Paleolithic archaeology in the province, paving the way for continued in-depth Paleolithic archaeological work in the region."

Contact the writer at zhaoruixue@chinadaily.com.cn