Denisovan Jawbone off Taiwan Reveals a Wider World for Ancient Humans

A Jawbone From the Seafloor Changes the Map

A thick human jawbone with five teeth, dredged from the Penghu Channel about 25 kilometers off Taiwan's west coast, has been identified as Denisovan through analysis of ancient proteins. Known as Penghu 1, the fossil provides the first confirmed Denisovan remains outside the cold regions of Siberia and the Tibetan Plateau, extending the physical evidence for these ancient humans into a warm, humid part of Asia.

The identification brings together two kinds of evidence that have long been difficult to connect: rare Denisovan bones and teeth, and traces of Denisovan ancestry carried by people living across Asia and Oceania today. The jawbone places a member of this extinct human lineage much farther south than previously confirmed fossils.

Researchers recovered more than 4,200 amino acid residues, the building blocks of proteins, and identified two protein variants found only in Denisovans, rather than Neanderthals or modern humans. Protein fragments associated with the Y chromosome also indicated that the individual was male.

Penghu 1 still has a wide possible age range. Evidence from animal fossils and ancient sea levels places it either between 10,000 and 70,000 years ago or between 130,000 and 190,000 years ago. Its identity is now much clearer than its age.

The discovery changes the geographic picture of Denisovan life. A group previously known through fossils from cold northern and high mountain environments also occupied subtropical lowlands, showing an ability to live in very different conditions.

From a Fishing Catch to a Museum Collection

Fishermen recovered Penghu 1 from the seafloor in the early 2000s. During periods of lower sea level in the Pleistocene epoch, the area had been dry land, forming a connection between Taiwan and mainland Asia. The fossil therefore comes from a landscape that ancient humans could once have crossed on foot.

The jawbone eventually reached a Taiwanese antique shop, where amateur fossil hunter Kun-Yu Tsai recognized its significance. He bought it and donated it to Taiwan's National Museum of Natural Science, allowing researchers to examine a specimen whose original surroundings had been lost when it was dredged up.

A study published in 2015 described its unusual anatomy. Penghu 1 had a very thick lower jaw and large teeth, setting it apart from modern humans and Neanderthals. Those features made it important, but researchers could not yet identify the ancient human group to which it belonged.

Attempts to extract ancient DNA failed, likely because of the fossil's long exposure to seawater, which speeds the breakdown of DNA. The lack of usable genetic material left scientists with a familiar problem: an unusual fossil whose shape offered clues but whose identity remained uncertain.

The sequence of discoveries stretched across years:

• In the early 2000s, fishermen dredged the jawbone from the Penghu Channel off western Taiwan.
• Kun-Yu Tsai later purchased the fossil from an antique shop and donated it to the National Museum of Natural Science.
• In 2015, researchers published an initial study describing its thick jaw and large teeth.
• By June 19, 2025, analysis of ancient proteins had identified Penghu 1 as a male Denisovan.

Who Were the Denisovans?

Denisovans were an extinct group of archaic humans closely related to Neanderthals and modern Homo sapiens. Scientists first identified them in 2010 using DNA extracted from a finger bone found in Denisova Cave in Siberia.

Genetic studies indicate that Denisovans, Neanderthals and modern humans shared an ancestor who lived in Africa about 600,000 years ago. The Denisovan and Neanderthal lineages separated around 400,000 years ago. Neanderthals spread west into Europe, while Denisovans moved east across Asia.

Physical remains have been exceptionally scarce. Before Penghu 1 was identified, confirmed Denisovan fossils consisted of a handful of bones and teeth from Siberia and the Tibetan Plateau. That small collection limited what scientists could say about their bodies, their environments and the extent of their movements.

Denisovan ancestry survives in many modern populations in Asia and Oceania because Denisovans interbred with early modern humans. This genetic legacy pointed to a much broader history than the fossil locations alone could show. Penghu 1 now supplies direct physical evidence from another part of that wider area.

How Proteins Supplied the Missing Identity

Takumi Tsutaya of Japan's Graduate University for Advanced Studies and an international research team turned to paleoproteomics, the study of ancient proteins preserved in fossils. Proteins can last longer than DNA, making them useful when a fossil has lost the genetic material researchers would normally try to examine.

Proteins are made from chains of amino acids. Differences in those chains can help researchers distinguish between related human groups. For Penghu 1, the team examined proteins extracted from the jawbone and its dental enamel, looking for molecular features associated with Denisovans.

The researchers carefully drilled a small hole in the jawbone to collect bone powder. From the material, they recovered more than 4,200 amino acid residues and identified two protein variants unique to Denisovans among the groups being compared. These molecular signatures provided the evidence needed to assign the fossil to that lineage.

Further examination of dental enamel revealed protein fragments related to the Y chromosome, indicating that the individual was male. All other molecularly confirmed Denisovan fossils identified by sex had also been found to be male, leaving researchers with limited evidence about differences between males and females.

For fossil collections in places where DNA survives poorly, the method creates another route to identification. Penghu 1 had already been studied for its shape; proteins preserved within it supplied information that its appearance and unsuccessful DNA tests had left unresolved.

Why the Jawbone Is Difficult to Date

Penghu 1's journey through the sea and into a collection made its age difficult to determine. Radiocarbon and uranium-series dating attempts were unsuccessful because of the fossil's waterlogged condition and the absence of the sediment in which it had originally rested.

Researchers instead used indirect clues, including animal fossils found with the jawbone and models of ancient sea levels. Those clues produced two possible periods: 10,000 to 70,000 years ago, or 130,000 to 190,000 years ago.

The younger range would make Penghu 1 a possible candidate for the youngest known Denisovan fossil. At its youngest possible age, it could place a Denisovan near the very end of the lineage's survival. The broad dating window leaves the timing unresolved, with further discoveries and improved dating techniques needed to narrow it.

The age question also affects how the fossil fits into the wider history of ancient humans in Asia. Researchers have identified who the jaw belonged to, but placing that individual more precisely in time is necessary to understand when Denisovans occupied this particular landscape.

From Cold Mountains to Subtropical Lowlands

Siberia, the Tibetan Plateau and the lowlands near Taiwan represent very different environments. The earlier confirmed fossils placed Denisovans in cold regions, including high elevations. Penghu 1 extends that record into a warm, humid setting.

The Taiwan Strait was not always the stretch of water visible today. When sea levels were lower, exposed land connected Taiwan with mainland Asia. The jawbone therefore adds evidence of Denisovan life on a former land bridge that is now submerged.

Fabrice Demeter, a paleoanthropologist at the University of Copenhagen, described the significance of finding Denisovans across such varied settings:

It shows that Denisovans were able to adapt to various environments—an ability that we only thought Homo sapiens capable of.

The expanded range helps explain how Denisovans could have encountered other human groups across Asia. Their ability to occupy different environments would have created opportunities for contact with both Neanderthals and Homo sapiens, including the interbreeding reflected in modern genomes.

What the Jaw Reveals About Appearance

Penghu 1 adds to the limited evidence for what Denisovans looked like. Its robust jaw and large molars fit a picture of a human group with substantial jaws and teeth, contrasting with the smaller teeth and more slender lower jaws of Neanderthals.

The fossil lacks a prominent chin, a familiar feature of modern humans. Its teeth are exceptionally large, even when compared with those of Neanderthals. Together, those traits suggest a lower face different from our own, although the small number of fossils limits any reconstruction.

Ryan McRae, a paleoanthropologist at the Smithsonian National Museum of Natural History, explained what the Penghu and Tibetan jaws suggest, and why the individual's sex matters:

Neither mandible has a chin, like modern humans do, so the front of their jawline would probably look flatter than ours. The authors wisely point out that the Penghu mandible is male, which means that it may exhibit the larger, more robust end of variation for this species. In other words, female Denisovans could look the same, or quite different, we just don't know yet.

Both the Penghu 1 jaw and the Tibetan Denisovan jaw also lack wisdom teeth, a trait more commonly associated with modern humans. Large teeth and thick jaws therefore occur alongside a feature familiar in our own species. This mixture of older and more recently evolved traits adds detail to the Denisovan branch of the human family, within the genus Homo.

A Fossil Link to Ancestry in Living People

Modern populations in East and Southeast Asia and Oceania carry traces of Denisovan DNA. Those inherited sequences show that Denisovans and early modern humans had children together, leaving a genetic legacy that survived after Denisovans disappeared as a distinct group.

People on Luzon in the Philippines, south of Taiwan, have some of the highest levels of Denisovan ancestry. That distribution has suggested that Denisovans may have reached island Southeast Asia or crossed into it. Penghu 1 adds a physical location to a history previously traced largely through genes.

Frido Welker, a molecular anthropologist and a coauthor of the study, described both the limits of knowledge about Denisovan disappearance and the ancestry that remains:

We have so little archaeological and fossil information about Denisovans that we can only speculate as to why they disappeared. A lasting legacy, though, is that some human populations in East and Southeast Asia carry some Denisovan ancestry in their genomes today.

The Taiwan discovery connects a wider geographic range with that surviving ancestry. Denisovans occupied diverse environments and interacted with migrating Homo sapiens across a broad area, making them part of the history of human settlement in Asia and the Pacific.

Museum Collections May Hold More Answers

Penghu 1's identification gives researchers a reason to revisit fossils whose origins remain uncertain, especially specimens from regions where heat, humidity or water have damaged ancient DNA. Proteins can preserve clues that other methods cannot recover.

Taiwan's National Museum of Natural Science holds material from a region where thousands of fossils have been recovered from the seabed in the Taiwan Strait. Further study could add evidence about Denisovan distribution, physical diversity and adaptation.

Chun-Hsiang Chang, a paleontologist at the museum, expressed optimism about what remains to be identified:

Maybe inside my collection there's some treasure we don't know about.

Penghu 1 shows the value of examining existing collections with new molecular techniques. A fossil recovered by fishermen, recognized by an amateur collector and studied for years has now become evidence of Denisovan life far beyond the places where the group was first confirmed.

Key Points

• Penghu 1, a jawbone with five teeth found about 25 kilometers off western Taiwan, has been identified as Denisovan.
• Researchers recovered more than 4,200 amino acid residues and found two Denisovan protein variants after DNA extraction failed.
• Dental enamel proteins indicated that the individual was male.
• The fossil extends confirmed Denisovan remains beyond Siberia and the Tibetan Plateau into subtropical lowlands.
• Its possible age ranges are 10,000 to 70,000 years and 130,000 to 190,000 years.
• The thick jaw, large teeth and lack of a prominent chin add to the limited evidence for Denisovan appearance.
• The discovery connects a wider fossil range with Denisovan ancestry in people across Asia and Oceania.
• Ancient protein analysis could help identify more Denisovan remains in museum collections.