A Mysterious Third Human Species Lived Alongside Neanderthals in This Cave

It's a “fascinating part of human history."

Scientists digging in the mountains of southern Siberia have revealed key insights into the lives of Denisovans, a mysterious branch of the ancient human family tree. While these relatives are extinct, their legacy lives on in the modern humans who carry fragments of their DNA and in the tiny artifacts and bones they left behind. Compared to the well-known Neanderthals, there’s a lot we don’t know about the Denisovans — but a pair of papers published Wednesday hint at their place in our shared history.

Both Neanderthals and Denisovans belong to the genus Homo, though it’s still not entirely clear whether the Denisovans are a separate species or a subspecies of modern humans — after all, we only have six fossil fragments to go on. Nevertheless, we’re one step closer to finding out. Both studies, published in Nature, describe new discoveries in the Denisova Cave of the Altai Mountains, where excavations have continued for the past 40 years. Those efforts have revealed ancient human remains carrying the DNA of both the Denisovans and Neanderthals who made the high-ceilinged cave their home — sometimes, even having children together.

For a long time, nobody knew exactly how long this cave was occupied and the nature of the interactions of the hominins living there. But now, the studies collectively reveal that humans occupied the cave from approximately 200,000 years ago to 50,000 years ago.

The authors of one study focused on Denisovan fossils and artifacts to determine “aspects of their cultural and subsistence adaptions.” Katerina Douka, Ph.D., the co-author of that study and a researcher at Max Planck Institute for the Science of Human History, tells Inverse that confirming that they lived in this cave is a “fascinating part of human history.” However, she adds, we still don’t know so much about the Denisovans — not their geographic range, their location of origin, or even what they looked like.

Denisova cave
View of the entrance to the Denisova Cave. 

When they lived in the cave, and with whom, is another mystery about the Denisovans that was investigated, sediment layer by sediment layer, in the second study. Published by scientists from the University of Wollongong and the Russian Academy of Sciences, the analysis is the most comprehensive dating project ever done on the Denisova Cave deposits. The team dated 103 layers of sediment layers and 50 items within them, mostly bits of bone, charcoal, and tools. The oldest Denisovan DNA comes from a layer between 185,000 and 217,000 years old, and the oldest Neanderthal DNA sample is from a layer that’s about 172,000 to 205,000 years old. In the more recent layers of the cave, between 55,200 to 84,100 years old, only Denisovan remains were found.

And it’s in these more recent years where more advanced objects begin to emerge — pieces of tooth pendants and bone points, which “may be assumed” as “associated with the Denisovan population,” write Douka and her team. Those artifacts are the oldest of their kind found in northern Eurasia and representative of something previously unexplored: Denisovan culture.

At this point, says Douka, we cannot definitively say that Denisovans created those items, though the evidence is pointing that way. More sites with Denisovan remains and material culture are needed to answer deeper questions about their culture and symbols.

Denisova, artifacts
Personal ornaments and bone points found in the Denisova Cave.

April Nowell, Ph.D. is a University of Victoria professor and Paleolithic archeologist who specializes in the origins of art and symbol use and wasn’t a part of these recent papers. Evaluating the pendants and bones, she tells Inverse that, assuming these artifacts were made by the Denisovans, she’s “not particularly surprised.” Human culture, very broadly, is thought to have emerged 3.3 million years ago, with the first stone tools. Other ancient humans used the natural clay ochre to paint at least 100,000 years ago, the same time period where archeologists have found the oldest beads.

So, it makes sense that a human subspecies would create cultural artifacts around this time.

What’s novel in the new studies, Nowell says, is that “we know virtually nothing about who Denisovans were, so every study like this one helps to enrich our understanding of their place in the human story.”

“Given that we have items of personal adornment associated with Neanderthals and modern humans all around the same date as the ones thought to be associated with the Denisovans,” she adds, “I would find it more surprising if they were not making similar objects.”

Denisova remains
Human remains found in the Denisova Cave.

These particular items, Nowell explains, especially the tooth pendant, likely speak to “issues of personal identity and group belonging.” The teeth were purposefully chosen, modified, and worn — standing as jewelry that communicates something about both the wearer and likely influenced how the wearer felt about themselves.

Jewelry, she says, can be powerful and laden with meaning — just think about putting on a wedding ring or holding your grandfather’s pocket watch. We can’t tell what these pendants meant to the Denisovans who created and wore them, but their very existence allows archeologists to begin to piece together an idea of the culture from which they were wrought.