Baishiya Karst Cave in Xiahe county, Northwest China's Gansu province, was recently recognized by Archeology magazine in the US as one of the top 10 archeological discoveries in 2019.

Some 40 years ago, a Buddhist monk uncovered a mandible (lower jaw) in the cave, which is more than 10,000 feet above sea level on the Tibetan Plateau.

Archeologists have verified that the mandible can be dated back 160,000 years, and analysis of proteins from its teeth indicates that it belonged to a member of the hominin species known as Denisovans.

"This mandible reveals that Denisovans were geographically distributed much more widely and at a higher altitude than we previously thought," said archaeologist Zhang Dongju of Lanzhou University.

The mysterious ancient humans were previously known only through fragmentary remains found solely in southern Siberia's Denisova Cave, which is merely 2,300 feet above sea level and almost 1,750 miles northwest of Baishiya Karst Cave.

Earlier studies of Denisovan genetic material had detected a mutation that enabled them to survive in low-oxygen environments characteristic of extremely high-altitude locations, such as the Tibetan Plateau.

This same mutation has been identified in present-day Tibetans, and the discovery that Denisovans once inhabited the region may explain how they obtained this life-preserving adaptation.