High on a cliff in Lushan county of Pingdingshan city, Central China's Henan province, a small cave is rewriting the story of the region's earliest modern humans.

The Xianrendong site, or "Immortal's Cave", located about 800 kilometers south of Beijing, was first discovered in 2020. Excavations have continued since, and in 2025, it was recognized as one of Henan's top 10 archaeological discoveries.

"It has yielded the oldest known early modern human fossils in Henan province, significantly contributing to our understanding of human evolution in the Central China Plains," said Zhao Qingbo, project leader from the Henan Provincial Institute of Cultural Relics and Archaeology, on April 9.

Researchers have uncovered nearly 400 fragments of human skulls and teeth in the cave's main chamber. Despite their fragmented condition, the quantity of these fossils is unusual for a site of this age, according to Zhao.

Scientists have determined that one skull fragment is approximately 32,000 years old, while two others date back to 12,000 and 13,000 years ago.

Evidence of the earliest human activity in the cave dates back to around 70,000 years ago, with the oldest sediment layers being about 120,000 years old, Zhao said.

Earlier hominin discoveries in Henan, including the Xuchang Man and upright-walking Nanzhao and Luanchuan hominins, are not direct ancestors of extant humans, Zhao noted.

In contrast, the fossils from the Xianrendong site belong to early modern humans, the same lineage as people alive today. The excavation has provided rare and important clues and tangible materials for the study of ancient human archaeology on a global scale.

"This discovery fills a gap in our understanding of early modern human evolution in Henan from 100,000 to 12,000 years ago," Zhao said.

Alongside human remains, archaeologists found 51 stone tools, including scrapers, cores, flakes and chunks. These were made using a traditional northern Chinese lithic technique, in which hammer-stones were used to strike flakes from a core.

"The tools show the same cultural features seen in earlier periods in the region," Zhao said. "This points to continuity in technological development."

Around 70,000 years ago, during the last Ice Age, people in Central China relied on caves for shelter, said Zhang Shuimu, a senior official of Pingdingshan Municipal Bureau of Cultural Heritage.

"Xianrendong sits on a cliff, offering natural protection from wind and rain. At that time, natural caves were the best available shelter," Zhang said.

The cave was not always habitable. In its early stages, it was too damp. Animals only began occupying it during drier periods about 100,000 years ago, he added.

Excavations have also yielded numerous animal fossils, all belonging to typical northern late Pleistocene species, with no extinct animals identified. The animal remains will help researchers reconstruct how early humans sourced food, what they hunted and how they survived in a changing environment, Zhang said.

"Seventy thousand years ago, ancient humans in the Central China Plains region lacked the ability to construct artificial dwellings. Instead, they deliberately chose natural caves like Xianrendong for shelter from the elements and protection against wild animals," Zhao said.

This contrasts with Europe during the same period, where simple structures made from mammoth ivory had already appeared. No comparable remains have been found in China.

The Xianrendong discoveries offer important evidence for understanding how early humans in the Central Plains lived and adapted, Zhao said.

Only about half of Xianrendong I (XRD-I), just 24 square meters, has been excavated. The rest is being left untouched for future researchers with better technology, Zhao said.

In paleoanthropology, spectacular finds often grab headlines, but most real progress comes slowly, layer by layer. Xianrendong is that kind of site, according to Zhang.

"The fossils from Xianrendong present a remarkable opportunity to extract ancient DNA, which could provide invaluable genetic insights," he noted.

The team is shifting to multidisciplinary research, including morphology, ancient proteins, pollen analysis, and environmental reconstruction. Focus is also turning to the site's larger cave, known as Xianrendong II (XRD-II), where animal fossils dating to around 40,000 years ago have already been found.

This discovery offers concrete evidence of the habitation and survival strategies employed by ancient humans in the Central Plains during that era, he added.

"We will also focus on researching the site's formation process, conducting palynological analysis, and reconstructing the ancient environment," Zhao said.

The team will also continue studying skull morphology and pursuing ancient DNA research.