Denisova Cave in Siberia Reveals More Information About Rare Prehistoric Human Species

The Denisovans, a strange extinct hominid tribe closely linked to Neanderthals, didn't leave much in fossil evidence. Three additional fossils have been discovered in their former stomping grounds in Siberia, making them the oldest species ever found.

Denisova Cave Fossils

The fossils were discovered in Denisova Cave, a natural refuge in the Altai Mountains of southern Siberia, by Katerina Douka, an evolutionary anthropologist from the University of Vienna, and her colleagues. The researchers looked into the cave's earliest strata, which had yet to yield a single human fossil. Five human fossil fragments were discovered, three of which belonged to Denisovans, one belonged to a Neanderthal, and one which could not be recognized. The longest of these bits is only 1.6 inches (4 cm) in length.

Surprisingly, this small yet valuable collection of fossils was discovered among 3,791 animal bone pieces. Because manual inspection was impossible, the researchers employed a biomolecular approach known as peptide fingerprinting to identify the bones. Collagen was found in the five bones that matched human peptide profiles (peptides are the building blocks of proteins), allowing for their identification (as a reminder, Denisovans and Neanderthals are humans).

"It would have been amazing to find one new human bone, but five? Samantha Brown, a co-author of the study and a junior group leader at the University of Tübingen, stated in a Max Planck Institute release, "This beyond my wildest aspirations."

"We have now rebuilt genomes from some of the earliest and best-preserved human fossils," said Diyendo Massilani, a geneticist from the Max Planck Institute of Evolutionary Anthropology, in a press statement. The researchers discovered enough DNA to rebuild mitochondrial genomes, confirming the bones' Denisovan and Neanderthal origins. Nature Ecology & Evolution released an article outlining this discovery.

Denisovan Bones

The Denisovan bones were discovered in a stratum around 200,000 years old. These are the oldest Denisovan fossils, dating back between 122,000 and 194,000 years. Between 130,000 and 150,000 years ago, the lone Neanderthal bone was discovered. According to the research, the Altai highlands have been an "overlapping zone for both Denisovan and Neanderthal groups for over 150,000 years, observing and probably enabling population [interbreeding] as well as preserving unique hominin populations throughout this long period."

The three new Denisovan fossils join six previously known Denisovan fossils, including a finger bone from which DNA was recovered and a mandible unearthed in a cave on the Tibetan Plateau-the first and only Denisovan fossil discovered outside of Siberia. Denisovans were Neanderthal cousins who interbred with modern humans before dying extinct 50,000 to 30,000 years ago. Denisovan DNA can be found in the genomes of current Southeast Asian and Oceanian peoples.

According to the researchers, the Denisovan stratum contained "a richness of archaeological evidence" in the form of stone tools and animal remains. It's the first time archaeological evidence has been connected to these hominins, opening new possibilities for understanding their behavior.

Denisovan Tools

The style of the stone tools discovered, such as scraping implements for manipulating animal skins, could not be linked to any known lithic tradition. According to the researchers, the Denisovans hunted bison, deer, gazelle, antelope, and woolly rhinoceros in a subsistence pattern that lasted thousands of years, according to the researchers, who lived near the Anui river and occupied the caves during a warm era.

These three Denisovan bones and Denisova Cave, in general, are expected to provide further scientific discoveries in the future. We're slowly but steadily learning more about these exceptional people.