By Britt Melinauskas
People Editor
New body fragments found in the Bianfu Cave in southwestern China revealed recent details about extinct hominins. The uncovered fossils include four teeth, part of an arm bone, and two skull fragments of a hominin species called Denisovas; with this discovery, the total of known fossils from the Denisovas increases to more than 20. Since hominins are close relatives to humans, this discovery could help researchers better understand how ancient humans lived and survived. The archaeologists also found tools made of stone, bones, fossilized pollen, and animal remains. These newly discovered fossilized instruments reveal how Denisovas lived in their region’s conifer forests 167,000 to 134,000 years ago.
According to research professor Hao Li at the Chinese Academy of Sciences’ Institute of Tibetan Plateau Research in Beijing, “We first identified some isolated teeth and then from the huge amount of animal fossils, we identified the bones—but the fragments were very hard to find at the beginning.” Previously, Denisovan findings were discovered on random occasions and remained isolated from regular breakthroughs. The group gained the name Denisovans after ancient DNA was extracted from a tiny finger bone found in Denisova Cave in Siberia in 2010.
Evidence suggests that Bianfu Cave was solely inhabited by Denisovans for an extended period of time. Researchers found the fossils in their original context alongside the aforementioned tools and other remains that allow archaeologists to date them more accurately. Scientists theorize that Denisovans lived throughout Asia, and people today in Southeast Asia and Oceania carry the most Denisovan DNA. These findings indicate that the Denisovans interbred with modern humans in these areas tens of thousands of years ago. However, most Denisovan fossils have been found in North Asia.
The team dug three trenches at the cave site to a depth of 22 feet, but only one trench contained human fossils, in two layers of sediment that dated back 167,000 to 134,000 years. “DNA is more vulnerable to degradation than proteins, and it is hard for it to be preserved in these fossils as they were more than 100,000 years old. The relatively warmer climate in Yunnan also hampered DNA preservation,” said Qiaomei Fu, a professor at the Institute of Vertebrate Paleontology and Paleoanthropology, and a part of the Chinese Academy of Sciences in Beijing. Fu was also part of the team that first identified Denisovans in 2010. To conclude the findings, Li added, “We are very lucky because this is the first site in South China to have the direct association between Denisovan fossils and rich cultural remains. This is very rare.”
(Sources: CNN, Science Daily, Smithsonian)