Researchers identify giant Denisovan remains beneath Taiwan Strait

An analysis of ancient bones from the Penghu Channel in the Taiwan Strait suggests that Denisovans living there about 45,000 years ago may have stood up to 190 centimetres tall, ERR reported. The findings have not yet been independently verified.

Tibia and femur fragments recovered from the seabed indicate that the extinct human species was exceptionally large compared with its contemporaries. Researchers estimate that Denisovans may have weighed more than 90 kilograms. The long, massive leg bones also show anatomical features associated with heavy physical strain and a highly mobile lifestyle.

During ice ages, sea levels were about 100 metres lower, and the present seabed formed a land bridge connecting Taiwan with mainland Asia. Floodplains and open grasslands covered the region, which was inhabited by large herbivores including buffalo, deer and the now-extinct straight-tusked elephant Palaeoloxodon namadicus. This ecosystem would have provided abundant food for ancient humans.

Until now, researchers identifying human species in the region had largely been limited to studying the external shape of bones. DNA breaks down quickly in warm, humid climates, often leaving geneticists without usable material at lower latitudes.

Researchers from Taiwan and Japan extracted 45,000-year-old collagen from a Penghu tibia and used paleoproteomics, or protein analysis, to search for a specific amino acid sequence. A protein sequence unique to Denisovans provided strong evidence that the bones belonged to the rare human species.

The team also analysed carbon and nitrogen isotopes preserved in the remains. The high nitrogen content indicates that the Denisovans in Taiwan occupied a high position in the food chain. According to the study authors, the ratio of amino acids and isotopes corresponds to a trophic level of 2.9, which they say is characteristic of a predator feeding exclusively on terrestrial animals.

A separate analysis found no evidence that the Denisovans caught fish or ate seafood. The researchers said this diet, heavily reliant on animal protein, resembles that of the predatory Neanderthals who lived in Europe.

The findings also challenge Bergmann’s rule, according to which mammals living in colder climates tend to become larger to reduce heat loss, while those in warmer climates become smaller. The researchers suggest that the Denisovans’ large bodies may have helped them hunt prey successfully in open landscapes. They also said their large brains may have been partly a biomechanical consequence of their greater body size.

The team additionally identified a distinctive anatomical feature called a pilaster on the femur, an area of thickening that is usually associated with an active lifestyle.