A digital reconstruction of a million-year-old skull from China suggests that humans may have diverged from their ancient ancestors 400,000 years earlier than previously believed — and that this pivotal evolutionary event may have happened in Asia rather than Africa, according to a new study published Friday.

The research centers on a crushed fossil skull known as Yunxian 2, discovered in Hubei province in 1990 and long thought to belong to Homo erectus, an early human ancestor. But advanced reconstruction techniques have revealed a surprising mix of features that more closely resemble later-evolving species, including Homo longi — the recently identified "Dragon Man" — and even Homo sapiens.

“This changes a lot of thinking,” said Chris Stringer, a prominent anthropologist at London’s Natural History Museum and co-author of the study. “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 findings, published in the journal Science, could help resolve what scientists have long referred to as the “Muddle in the Middle” — the unclear and complicated fossil record of human evolution between 1 million and 300,000 years ago.

To reconstruct Yunxian 2, scientists used high-resolution CT scanning, structured light imaging, and digital modeling techniques, drawing comparisons with more than 100 other fossils. The reconstructed skull showed a distinctive blend of features: a projecting lower face similar to Homo erectus, but a larger brain capacity and other traits more typical of Homo longi and modern humans.

“This fossil may help us untangle the confusing web of early human evolution in this critical time period,” said Stringer.

If confirmed, the study could challenge the long-standing theory that early human species evolved and spread out from Africa in a linear fashion. Michael Petraglia, director of the Australian Research Centre for Human Evolution at Griffith University, called the study “provocative” and said it adds weight to growing evidence that East Asia played a more central role in human evolution.

“There’s a big change potentially happening here, where East Asia is now playing a very key role in hominin evolution,” he said.

Still, several experts cautioned that the findings would likely face scrutiny. Archaeologist Andy Herries of La Trobe University expressed skepticism, pointing out that fossil shapes alone may not fully reflect evolutionary relationships, especially in the absence of genetic data.

“They’ve got this interpretation that I just don’t really think is taking into account the genetic histories of these things that we do know,” Herries said.

Despite differing opinions, researchers agree that the findings highlight how much of human prehistory remains uncertain. The discovery of Homo longi — identified as a new species as recently as 2021 — and the reanalysis of Yunxian 2 are both reminders that the human evolutionary tree is far from settled.

“Fossils like Yunxian 2 show just how much we still have to learn about our origins,” said Stringer.