Researchers have uncovered the oldest fossils belonging to the enigmatic Denisovans, an ancient hominin lineage that is thought to be closely related to modern humans. Dated to 200,000 years ago, the bone fragments were found in a layer of sediment that also contained butchered animal remains and stone tools, providing a glimpse into the lifestyles of our long-extinct ancestors.
While little is known about this mysterious ancient hominin, the recent discovery of Denisovan DNA in the genomes of indigenous people in Southeast Asia and Oceania implies that the species was once widespread in this region and that interbreeding with modern humans was not uncommon. Until now, however, only six Denisovan fossils had ever been found, five of which were excavated from the Denisova Cave in Siberia while the other was discovered in the Baishiya Karst Cave in China.
In a new study in the journal Nature Ecology & Evolution, researchers describe how they sifted through 3,791 bone fragments in the Denisova Cave, three of which were identified as Denisovan remains based on their mitochondrial DNA. A further specimen was determined to have belonged to a Neanderthal individual, whose genome provided evidence of interbreeding between these two extinct species between 200,000 and 250,000 years ago.
Prior to this discovery, the oldest known Denisovan remains were dated to between 122,000 and 194,000 years old. However, the specimens described by the researchers were found in a layer of sediment that was dated to 200,000 years ago, making these the oldest Denisovan bones ever unearthed.
The same layer also contained the hacked remains of a number of different animal species, allowing the study authors to start piecing together the Denisovan diet. Deer, horse, bison, gazelle, and woolly rhinoceros all appear to have been on the menu, implying that our ancient ancestors were no strangers to hunting.
Significantly, the presence of stone utensils in the same sediment layer provides the first direct evidence that Denisovans manufactured and used tools. Based on the shape of these artifacts and the fact that they were coated in fatty residues, the study authors conclude that they were probably used for “animal skin processing activities, such as scraping, cutting and/or sawing.”
According to the researchers, tools of this type are completely absent from the North and Central Asian archaeological records for this period in history. Interestingly, though, similar artifacts dated to between 250,000 and 400,000 years ago have been found at a site in Israel.
Finally, the study authors report the presence of a number of other carnivorous inhabitants within the cave, such as wolves and wild dogs. Based on this finding, they surmise that Denisovans and other ancient humans “may have been actively competing with these predators over resources and perhaps the cave itself.”
Cave life, it seems, was no stroll in the park.