Taiwan Jawbone Fossil Identified as Denisovan, Expanding Known Range

A fossil jawbone, recovered in 2008 off the coast of Taiwan, has been identified as belonging to a Denisovan male. The discovery, detailed in a *Science* journal publication, extends the known geographical range of this extinct hominin group beyond Siberia and Tibet to the warmer, more humid regions of East Asia. The fossil was initially caught by a fisherman approximately 25 km off the western coast of Taiwan, in an area that was part of the mainland during the Pleistocene epoch when sea levels were lower. The fisherman sold the jawbone to an antique dealer, from whom it was later acquired by a citizen who donated it to the National Museum of Natural Sciences in Taiwan. Led by physical anthropologist Takumi Tsutaya from the Sokendai University of Advanced Studies in Japan, and researchers from the University of Copenhagen, a paleoproteomic analysis was conducted on the fossil. This analysis of proteins from the jawbone and dental enamel identified over 4,200 amino acid residues, including two variants specific to Denisovans. The dating of the fossil places it between 10,000 and 190,000 years old. The team also observed a jaw structure similar to that of the confirmed Tibetan Denisovan specimen, characterized by a thick, low body with large molars and robust root structures. The researchers suggest that these traits were characteristic of the Denisovan lineage, possibly specific to males. This discovery supports the idea that two hominin groups, Denisovans and Neanderthals, coexisted in Eurasia during the Middle and Late Pleistocene. Neanderthals had small teeth with high jaws, in contrast to the Denisovan jaw structure. The Denisovans remained largely unknown until 2010, when a finger bone fragment was discovered in the Denisova Cave in Siberia. Genetic material extracted from fossils and soil within the cave, dating back 200,000 years, confirmed the existence of this hominin. Prior to this Taiwanese jawbone, direct evidence of Denisovans outside of Siberia was limited to the Tibetan Plateau, where a jawbone and rib dating back 160,000 years were found. A tooth found in a cave in Laos has also been attributed to a Denisovan child, although molecular confirmation is pending. The Taiwan discovery highlights the Denisovans' adaptability to diverse climates and terrains.