Scientists Find a Trove of Denisovan Fossils and Tools in Southwest China, Giving an Unprecedented Glimpse Into Our Extinct Cousins' Lives

In 2010, researchers who had extracted DNA from an ancient finger bone revealed that it belonged to a previously unknown human relative. The fossil, recovered from Denisova Cave in Siberia, came from a member of a group nicknamed Denisovans, now formally called Homo longi. But these cousins of ours, who lived in Asia between 400,000 and 30,000 years ago, have remained mysterious in the years since.

Relatively few of their fossils have been found, and never a near-complete skeleton. On the other hand, scientists have uncovered thousands of remains that belonged to our Neanderthal relatives. A recent discovery is changing that.

Researchers found a trove of Denisovan fossils, along with their stone and bone tools and remains of animals they used, in a cave in southwestern China. The findings suggest the enigmatic hominins used the site for tens of thousands of years and shed light on Denisovans’ physical characteristics and lives, according to two studies published September 9 in the journal Nature. The researchers sifted through more than 60,000 bone fragments recovered from Bianfu Cave in China’s Yunnan Province.

They sorted the pieces according to shape to figure out which ones probably belonged to hominins, then they used a protein-analysis technique to pinpoint which pieces came from Denisovans. The work yielded two skull fragments, four teeth and part of a forearm bone from at least four Denisovan individuals that lived between 134,000 and 167,000 years ago. Homo sapiens, Neanderthals and Denisovans all share a common ancestor.

The modern human lineage parted ways with the lineage that would produce Neanderthals and Denisovans around 600,000 years ago. The three cousins existed concurrently and sometimes mated with one another before the Neanderthals and Denisovans went extinct. While the fossils’ ancient amino acids that make up proteins were preserved, their DNA—which is more delicate—was not.

The old and relatively warm cave didn’t allow for it, Qiaomei Fu, a paleogeneticist at the Chinese Academy of Science’s Institute of Vertebrate Paleontology and Paleoanthropology who co-authored both studies, tells Scientific American’s Tom Metcalfe. Even without genetic information, the findings are significant. The forearm fragment—the first of this bone ever found belonging a Denisovan—shares some similarities with arm bones of Neanderthals, but its overall shape corresponds more closely to those of modern humans.