Xujiayao Fossils Identified as Denisovans
Chinese researchers have identified hominin fossils unearthed at the Xujiayao site in Hebei Province as Denisovans, providing the first morphological identification framework for the extinct human group, according to a research article recently published in the journal Nature. The study resolves a long-standing debate over the taxonomic status of archaic human remains in East Asia during the late Middle Pleistocene.
Denisovans were first identified in 2010 through DNA extracted from a finger bone discovered in Denisova Cave in Siberia. While genetic evidence has established that they interbred with modern humans and inhabited a wide region spanning Siberia, Southeast Asia, and parts of China from roughly 300,000 to 45,000 years ago, scientists previously lacked clear physical criteria to recognize them in the fossil record. To establish these shared traits, researchers needed an archaeological site with molecularly confirmed Denisovan remains, abundant fossils, clear stratigraphic context, and reliable dating. The Xujiayao site, which dates back 199,000 to 138,000 years, provided the necessary material.
Paleoproteomic Analyses Confirm Lineage
A joint research team led by Fu Qiaomei and Xing Song from the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) of the Chinese Academy of Sciences, in collaboration with Nanjing Normal University and Peking University, examined the Xujiayao remains. Researchers drilled small amounts of bone powder from damaged surfaces of the fossils to extract endogenous proteins. Through paleoproteomic analyses, the team confirmed that the Xujiayao hominins belonged to the Denisovan lineage, according to the IVPP.
Excavations conducted at the Xujiayao site between 1976 and 1979 recovered 20 human fossils representing at least 16 individuals at various life stages, including cranial remains, mandibles, and teeth. Using these molecularly confirmed specimens, the team summarized typical Denisovan cranial, mandibular, and dental features. The group retained primitive traits reminiscent of Homo erectus, such as a low, broad cranial vault, thick skull bones, and short mastoid processes, alongside advanced characteristics like simplified premolar chewing surfaces.
Expanded Distribution Across East Asia
By comparing the Xujiayao fossils with previously confirmed Denisovans and other East Asian archaic hominins of unclear taxonomic status, the study suggests that multiple Middle Pleistocene fossil groups across the region also belong to Denisovans. This finding extends the confirmed distribution range of Denisovans to nearly the entire East Asian continent. Fu Qiaomei noted that the research transforms Denisovans from an entity known almost exclusively through molecular traces into a group that can be recognized, compared, and classified through physical morphology.
Frequently Asked Questions
Where was the original Denisovan discovery made?
Scientists first identified Denisovans in 2010 using DNA extracted from a tiny finger bone found in Denisova Cave located in Siberia.
What age are the Xujiayao hominin fossils?
Excavations at the Xujiayao site in Yangyuan County, Hebei Province, have yielded fossils dated between 199,000 and 138,000 years old.
Which institutions led the recent study?
The research was led by scientists from the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences, working alongside researchers from Nanjing Normal University and Peking University.
The research builds on decades of excavation work that established the site as one of the richest late Middle Pleistocene fossil assemblages in East Asia.