China Cave Finds Offer New Clues to What Denisovans Looked Like

New analysis of ancient bones and tools from Bianfu Cave in China's Yunnan province has revealed fresh clues about how Denisovans, one of modern humans' closest ancient relatives, looked and lived more than 130,000 years ago. The findings, described in two studies published September 9 in the journal Nature, could also help researchers identify other ancient hominin remains as belonging to Denisovans.

Until now, solid evidence of Denisovan life was confined to two sites: Siberia's Denisova Cave, where the species was first identified in 2008, and China's Baishiya Karst Cave in the northeastern Tibetan Plateau. Bianfu Cave, on the Tibetan Plateau in Yunnan, is now among the richest known Denisovan sites, containing many Denisovan bones along with simple stone and bone tools the hominins made and traces of the animals they hunted, according to archaeologist Hao Li of China's Institute of Tibetan Plateau Research, a co-author of one of the studies.

The bones were unearthed in 2019 but only recently identified as Denisovan, using a distinctive amino acid found in tooth enamel rather than ancient DNA analysis, which was not possible because the cave's age and warmth made conditions unsuitable for DNA preservation, according to geneticist Qiaomei Fu of China's Institute of Vertebrate Paleontology and Paleoanthropology, who led the research team. The newly described remains include four teeth, part of an arm bone and two skull fragments, alongside roughly 60,000 animal bone fragments indicating the Denisovans mainly hunted deer and wild bovids, including water buffalo and gaur.

One skull fragment dates to between 167,000 and 161,000 years old, while the other skull fragment, the arm bone and the teeth date to between 142,000 and 134,000 years old. Analysis of the arm bone suggests Denisovan bones were shaped more like those of modern humans than the more robust bones of Neanderthals, implying Denisovans may have looked more like modern humans than Neanderthals did, even though genetic studies show Denisovans and Neanderthals were closely related.

Evidence of ancient interbreeding between modern humans and Neanderthals appears in the genomes of all modern humans outside Africa, while evidence of Denisovan interbreeding is found mainly in some modern populations in Southeast Asia and Oceania, with only traces in human genomes elsewhere in Asia and none in genomes from Africa or Europe. University of Toronto paleoanthropologist Bence Viola, who was not involved in the research, said the new findings add significant detail about Denisovans, particularly their teeth, which can now be compared with those of unidentified hominin remains from other sites.