For more than a century and a half, the origins of birds have been dominated by a single, iconic fossil from Germany: Archaeopteryx. Long regarded as the first bird and a textbook example of evolution in action, it stood alone as the only known avian species from the Jurassic period. Now, a discovery in China has upended that narrative, revealing that birds were already experimenting with different body plans far earlier than scientists once believed.
Researchers have identified a new genus of Jurassic bird, Baminornis, from fossils uncovered in southeast China and described in February 2025. The find, reported by scientists writing in Nature, marks only the second confirmed bird genus from the Jurassic period, roughly 150 million years ago. Its anatomy differs strikingly from Archaeopteryx, suggesting that early birds were not a single, tentative experiment but a diverse and evolving group.
During the Jurassic, Europe and much of Asia lay closer to the equator, with large areas submerged beneath shallow seas. Archaeopteryx lived on small islands in what is now southern Germany, inhabiting lagoons whose calm waters preserved its delicate bones and feathers. These fossils, first discovered in the 1860s, showed a creature with wings and feathers but also teeth, a long bony tail, and clawed fingers, blurring the line between dinosaur and bird.
Despite its fame, Archaeopteryx has always posed problems for scientists. It possessed flight feathers, yet lacked key features associated with strong, sustained flight, such as a robust breastbone for anchoring powerful muscles. Many palaeontologists have concluded that it was a weak flier at best, more akin to a chicken than a soaring bird. For decades, debates raged over whether it could truly fly and whether it even deserved to be called a bird.
The emergence of Baminornis complicates that picture. Unearthed from the Zhenghe Fauna in Fujian province, the small bird weighed roughly 140 to 300 grams and lived at the same time as Archaeopteryx. Crucially, it possessed a pygostyle — a short, fused tail bone seen in modern birds and many later Cretaceous species, but absent in Archaeopteryx, which retained a long dinosaur-like tail.
That anatomical leap has profound implications. A fused tail is linked to improved flight control and aerodynamics, meaning Baminornis may have flown differently, and possibly more efficiently, than its famous contemporary. Its presence so early in the fossil record suggests that some birds had already evolved advanced flight-related features by the end of the Jurassic.
“This tells us birds were already experimenting with different flying styles,” said Stephen Brusatte, a palaeontologist at the University of Edinburgh. The stark differences between Baminornis and Archaeopteryx imply that birds had begun diversifying earlier than previously assumed, raising the possibility that even older, as-yet-undiscovered bird species existed in the middle or early Jurassic.
The discovery was made by a team led by Min Wang of the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing. The Zhenghe site, dated to around 148 to 150 million years ago, appears to represent an ancient wetland, an environment well suited to preserving small, fragile animals such as birds. The same site has already yielded other bird-like dinosaurs, offering rare insight into a critical but poorly documented chapter of evolution.
Not all researchers are ready to rewrite the textbooks. Jingmai O’Connor of the Field Museum in Chicago urged caution, noting that early interpretations of fossils can change with further study. With only two confirmed Jurassic bird genera, the evidence remains thin, and broad conclusions about the timing and spread of early birds are still tentative.
Even so, the implications are far-reaching. By the early Cretaceous, birds had spread across the globe and diversified into numerous lineages, many of which later went extinct alongside non-avian dinosaurs. The presence of two very different birds in the Jurassic suggests that this explosive diversification did not come out of nowhere but was rooted in a deeper evolutionary history that remains largely hidden.
For now, Baminornis stands as a reminder of how incomplete the fossil record is — and how a single discovery can challenge ideas that have endured since Darwin’s time. As more fossils emerge, scientists hope to answer lingering questions about when birds first took to the skies, how often powered flight evolved, and how quickly these early avians conquered the ancient world.
