Jurassic bird fossils discovered in China rewrite evolutionary timeline

Paleontologists have unearthed the fossilized remains of two Jurassic bird species in Zhenghe County, Fujian province, southeast China.

These 149-million-year-old fossils provide crucial insights into the early evolution of birds, revealing the presence of advanced avian features much earlier than previously thought. The findings suggest that birds may have originated and diversified in the Jurassic period, pushing back key evolutionary milestones, Caliber.Az reports via foreign media.

The discovery, made by a team led by Professor Min Wang from the Institute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences, challenges long-standing assumptions about early bird evolution.

“Birds are the most diverse group of terrestrial vertebrates,” Professor Wang and his colleagues stated. “Certain macroevolutionary studies suggest that their earliest diversification dates back to the Jurassic period.”

For decades, Archaeopteryx—a feathered dinosaur-like creature with a long, reptilian tail—was considered the only widely accepted Jurassic bird. However, recent studies have questioned its classification, with some researchers arguing that it belongs to a different branch of the dinosaur family tree rather than being a direct ancestor of modern birds.

“Recent studies have questioned the avialan status of Archaeopteryx, classifying it as a deinonychosaurian dinosaur, the sister group to birds,” the researchers explained. “This raises the question of whether any unambiguous records of Jurassic birds exist.”

Among the newly discovered fossils, one species, Baminornis zhenghensis, stands out as the earliest known bird with a short tail. This trait, a defining feature of modern birds, was previously thought to have emerged in the Early Cretaceous—nearly 20 million years later than the age of this fossil.

“Baminornis zhenghensis has a short tail ending in a compound bone called the pygostyle, a feature also observed in living birds,” the team noted. “Baminornis zhenghensis is the sole Jurassic and the oldest short-tailed bird yet discovered, pushing back the appearance of this derived bird feature by nearly 20 million years.”

Another fossil, an isolated furcula (wishbone), is believed to belong to Ornithuromorpha, a diverse group of Cretaceous birds. Though the species remains unnamed, its presence further supports the idea of an earlier radiation of birds.

“If we take a step back, and reconsider the phylogenetic uncertainty of Archaeopteryx, we do not doubt that Baminornis zhenghensis is the true Jurassic bird,” said Dr. Zhonghe Zhou, a co-author of the study.

These groundbreaking discoveries provide fresh evidence that birds evolved earlier than traditionally believed, reshaping the understanding of avian evolution.

By Vugar Khalilov