In a groundbreaking study, researchers have determined that Denisovans, an enigmatic ancient human species, not only survived but thrived on the high-altitude Tibetan plateau for more than 100,000 years. The study sheds light on the behaviors and adaptability of these little-known ancestors of modern humans.

The research team examined thousands of animal bone fragments discovered at Baishiya Karst Cave, located at an elevation of 3,280 meters near Xiahe in China's Gansu province. This site is among the few places where Denisovans were known to have inhabited. The analysis revealed that Denisovans were skilled hunters, proficient in the butchering and processing of various large and small animals, including woolly rhinos, blue sheep, wild yaks, marmots, and birds.

Furthermore, the team discovered a rib bone fragment in a sediment layer dating back between 48,000 and 32,000 years, making it the most recent Denisovan fossil found to date. This finding suggests that Denisovans existed more recently than previously thought, possibly coexisting with modern humans as they dispersed across the Eurasian continent.

The study highlights the resilience of the Denisovans who inhabited Baishiya Karst Cave, enduring extreme environmental conditions during both warmer and colder periods. Their adaptive behavior allowed them to maximize the diverse animal resources available in the surrounding grassland landscape.

Dongju Zhang, an archaeologist and professor at Lanzhou University and co-lead author of the study, expressed the importance of understanding how the Denisovans lived in such a challenging environment. Zhang emphasized that the Denisovans utilized the available animals, displaying their flexibility and resourcefulness.

The discovery of the rib bone fragment in the sediment layer provides an intriguing context, suggesting the presence of modern humans in the wider region during that time. Coauthor Frido Welker, from the University of Copenhagen, hopes that further research in the area will shed light on whether the two groups had interactions.

Denisovans were initially identified more than a decade ago through DNA sequences extracted from a finger bone fragment. Since then, only a handful of fossils have been found worldwide, with most located in Denisova Cave in Siberia. Genetic analysis revealed interbreeding between Denisovans, Neanderthals, and modern humans. Evidence of Denisovan DNA in present-day populations suggests their widespread presence across Asia.

The new study utilized the Zooarchaeology by Mass Spectrometry (ZooMS) technique to examine more than 2,500 animal bone fragments from Baishiya cave. This innovative approach revealed the diverse range of animal species, including herbivores, carnivores like hyenas, and animals still common in the Himalayas today, such as blue sheep.

The presence of cut marks on many bones indicates that the Denisovans processed animals for hides, meat, and bone marrow. Some bones were also used as tools, unveiling their resourcefulness.

The findings suggest that the area surrounding Baishiya Karst Cave was dominated by a grass landscape with intermittent forested areas, similar to the present-day. However, Zhang noted that most of the animals currently living in the region are domesticated yaks and goats.

The discovery of the rib bone fragment has prompted the researchers to attempt DNA recovery from the specimen, potentially providing detailed genetic information about its owner and the wider Denisovan population of the area.

Archaeological scientist Samantha Brown, who has worked on remains from Denisova Cave but was not involved in the study, highlighted the significance of each discovery concerning the Denisovans. Brown pointed out that the presence of modern humans in the region at the time opens up discussions about the possibility of interactions between the two groups as modern humans migrated into Asia and the Pacific.

Excavations continue at Baishiya Karst Cave, and researchers are also exploring another paleolithic site in the region that may have been occupied by Denisovans or their successors.

The Tibetan plateau, often referred to as "the roof of the world," holds significant importance in unraveling the mysteries surrounding the Denisovans, including their appearance, disappearance, and their place in the human family tree. The study's findings shed new light on the intriguing history of these ancient humans and their remarkable survival on the Tibetan plateau for thousands of years.