Bone remains found in a Tibetan cave 3,280 metres above sea level indicate an ancient group of humans survived here for many millennia, according to a new study published in the journal Nature.  The Denisovans are an extinct species of ancient human that lived at the same time and in the same places as Neanderthals and Homo sapiens. Only a handful of Denisovan remains have ever been discovered by archaeologists. Little is known about the group, including when they became extinct, but evidence exists to suggest they interbred with both Neanderthals and Homo sapiens. 

The scientists identified one rib bone as belonging to a new Denisovan individual. The layer where the rib was found was dated to between 48,000 and 32,000 years ago, implying that this Denisovan individual lived at a time when modern humans were dispersing across the Eurasian continent. The results indicate that Denisovans lived through two cold periods, but also during a warmer interglacial period between the Middle and Late Pleistocene eras. 

The research team studied more than 2,500 bones from the Baishiya Karst Cave on the high-altitude Tibetan Plateau, one of the only two places where Denisovans are known to have lived. Their new analysis has identified a new Denisovan fossil and shed light on the species’ ability to survive in fluctuating climatic conditions — including the ice age — on the Tibetan plateau from around 200,000 to 40,000 years ago. 

Bone remains from Baishya Karst Cave were broken into numerous fragments preventing identification. The team used a novel scientific method that exploits differences in bone collagen between animals to determine which species the bone remains came from.  The research team determined that most of the bones were from blue sheep, known as the bharal, as well as wild yaks, equids, the extinct woolly rhino, and the spotted hyena. The researchers also identified bone fragments from small mammals, such as marmots, and birds. The team was able to identify that Denisovans hunted, butchered and ate a range of animal species.

Detailed analysis of the fragmented bone surfaces shows the Denisovans removed meat and bone marrow from the bones, but also indicate the humans used them as raw material to produce tools.