Ancient skull pushes back Homo sapiens origins by 400,000 years, study says

A fossil skull found in Hubei province, China, dating to about one million years ago, is prompting researchers to redraw the early human family tree. In a new analysis, scientists reclassify Yunxian 2 as not a Homo erectus but an early member of the Homo longi lineage, also linked to Denisovans, a distant group known from Siberia and Tibet.

Using CT scanning, light imaging and virtual reconstruction, a multinational team reconstructed what the undistorted skull would have looked like and integrated elements from Yunxian 1, another site skull found in 1989. The researchers then compared the reconstruction with 104 other fossil specimens and high-quality replicas. The analysis found that Yunxian 2 displays some primitive traits—such as a large, squat braincase and a strong brow ridge—that resemble Homo erectus. Yet it also shows derived features in the face and rear of the braincase, and a larger brain capacity, that align more closely with later groups such as Homo longi and Homo sapiens.

Crucially, the researchers say Yunxian 2 is not Homo erectus; they stop short of declaring it a Homo longi, noting that further evidence is needed before a final classification. The team says Yunxian 3, a skull found at the same site in 2022, will act as an important test of the reconstruction and help refine the picture. The work was led by researchers from Fudan University in Shanghai and the Chinese Academy of Sciences in Beijing, alongside Professor Chris Stringer of the Natural History Museum in London.

The analysis suggests that Yunxian 2 is part of a longi-related lineage linked to the Denisovans, a group whose existence became clear through fossils in Siberia and later studies across Asia. Homo longi, already known from other Chinese finds, is thought to have evolved in Asia and to have lived at least 146,000 years ago. The longi lineage is strongly connected with Denisovan DNA, and the new study adds that the lineage dates back more than one million years, implying an earlier and more complex split among early human groups than previously recognized. "Our research reveals that Yunxian 2 is not Homo erectus, but an early member of the longi clade and linked to the Denisovans," Stringer said. "This changes a lot of thinking because it suggests that by one million years ago, our ancestors had already split into distinct groups, pointing to a much earlier and more complex human evolutionary split than previously believed."

The researchers, however, caution against definitively naming Yunxian 2 as Homo longi at this stage. They describe Yunxian 2 as part of a longi-related lineage and plan to test the reconstruction further with additional data and more fossils, including Yunxian 3. "We will now be extending our analyses to include further sources of data and other fossils, which will be critical for refining this picture," Stringer added.

Homo longi, or 'Dragon Man,' is a species identified from the Harbin cranium found in Heilongjiang province in 1933. The new analysis comes as part of a broader view of human evolution that the researchers describe as radically different. They note that in the last 800,000 years, most large-brained humans can be traced to five major branches—Asian erectus, heidelbergensis, longi, sapiens, and neanderthalensis—and that these groups were already diverging more than a million years ago.

Overall, the study reinforces a Africa-origin model for Homo sapiens with a complex pattern of early dispersals and interbreeding as modern humans migrated out of Africa about 60,000 to 70,000 years ago. In Europe and Asia, modern humans encountered Neanderthals and, in Asia, Denisovans, with genetic traces of Denisovans found in some contemporary populations, including Aboriginal Australians. The Denisovans are understood to have contributed to the genetic makeup of several populations across Asia, reflecting deep and widespread interactions among ancient human lineages.

The team published its findings in the journal Science, noting that the picture of human evolution in the last million years is far more intricate than previously believed. As researchers continue to analyze Yunxian skulls and other fossils, the understanding of how ancient populations related to one another—and how they migrated across continents—will likely continue to evolve.