Deep inside a Siberian cave that Neanderthals occupied tens of thousands of years ago, a single molar sat embedded in sediment for roughly 59,000 years. When researchers finally examined it under high-resolution imaging, they found something unexpected: a deep cavity surrounded by tiny, deliberate-looking grooves that radiate outward like the spokes of a wheel. Those marks, according to a peer-reviewed study published in May 2026 in PLOS ONE, are consistent with a pointed stone tool being used to drill out decayed tissue. If the interpretation holds, it represents the oldest known example of invasive dentistry by roughly 50,000 years.
What the tooth reveals
The specimen, cataloged as Chagyrskaya 64, was recovered from Chagyrskaya Cave in the Altai Mountains of southern Siberia, a site that has yielded dozens of Neanderthal remains and stone tools. An international team led by researchers at the University of Kansas examined the molar using micro-CT scanning and scanning electron microscopy, revealing a centrally located lesion that extends into or near the pulp cavity, the innermost chamber where nerves and blood vessels reside.
Surrounding that lesion, the team identified microscopic radial and V-shaped grooves. The groove patterns, they argue, are inconsistent with natural wear, accidental chipping, animal gnawing, or sediment abrasion. Instead, the marks match what you would expect from repeated contact with a sharp, pointed instrument.
To test that hypothesis, the researchers drilled three modern teeth using replica Neanderthal stone points. The experiment produced groove patterns that closely matched those on the ancient molar, both in shape and in microscopic texture. The team concluded that Neanderthals could identify a dental infection and physically remove damaged tissue, a capability previously attributed only to anatomically modern humans living tens of thousands of years later.
How this compares to other prehistoric dentistry
Before this study, the oldest widely accepted evidence of deliberate tooth drilling came from Mehrgarh, a Neolithic site in present-day Pakistan. A 2006 paper in Nature documented drilled molars there with clear signs that the procedures were performed on living people. Those specimens date to roughly 7,500 to 9,000 years ago.
Separately, a 2012 study in PLOS ONE identified beeswax used as a dental filling on a Neolithic human canine tooth from Slovenia, dated to approximately 6,500 years ago and validated through radiocarbon dating, synchrotron micro-CT, and infrared spectroscopy.
Both of those cases involved anatomically modern humans. The Chagyrskaya 64 finding is significant precisely because it attributes a similar capability to Neanderthals at a dramatically earlier date. If confirmed, it would suggest that the ability to diagnose and mechanically treat an internal bodily problem did not originate with our own species.
Where the evidence is still thin
A single tooth from one cave cannot establish whether dental drilling was a widespread Neanderthal practice or a one-off improvisation by an individual in severe pain. The experimental replication, while compelling, involved only three modern teeth, a small sample that captures limited variability. No independent lab has yet attempted to reproduce the results, though that is standard for a newly published finding rather than a red flag.
Several practical questions remain open. Drilling into or near the pulp cavity without anesthesia would have been agonizing and could have introduced new infection. Whether Neanderthals used any herbal antiseptic or pain management alongside the mechanical procedure is unknown. No residue analysis on the tooth or surrounding artifacts has been published, and the cave sediments have not yielded direct evidence of medicinal plants linked to the specimen.
The full experimental protocol is described only in summary form in the published paper and associated press materials. Detailed raw data on drilling pressure, duration, angle, and tool replacement have not been released in a separate dataset, which limits outside researchers’ ability to assess how closely the lab conditions matched plausible Neanderthal behavior. The molar also is not part of an intact jaw, so the individual’s broader dental health remains unclear.
What it would mean for our understanding of Neanderthals
The finding fits into a growing body of evidence that Neanderthals were more socially and cognitively sophisticated than older stereotypes suggested. Previous research has documented healed fractures and signs of long-term survival with debilitating injuries among Neanderthal remains, indicating that group members cared for sick or injured individuals over extended periods. Treating a dental infection would add a new dimension: it implies the ability to diagnose a specific problem, select an appropriate tool, and perform a precise physical intervention on another person’s body.
The Chagyrskaya study also reflects a broader shift in paleoanthropology toward re-examining known fossils with advanced imaging and experimental archaeology. Microscopic wear patterns that would have been invisible during a conventional visual inspection can now reveal traces of complex behavior preserved on small or damaged remains.
What independent replication and residue analysis could settle
For now, the claim rests on one specimen and one replication experiment. The evidence is internally consistent and suggestive, but the scientific community will likely need additional examples of drilled Neanderthal teeth, ideally from different sites and time periods, before treating invasive Neanderthal dentistry as established fact rather than a compelling hypothesis.
Future research could include targeted surveys of existing Neanderthal dental collections for similar lesions, expanded experimental work with stone tools under varied conditions, and chemical analyses of residues on both teeth and artifacts. Even if the drilling hypothesis is eventually revised, the work underscores how much a single damaged molar can reveal when examined with the right tools: not just anatomy, but behavior, skill, and perhaps even care in deep time.
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*This article was researched with the help of AI, with human editors creating the final content.
