Paleontologists recently uncovered fossilized remains of two bird species dating back to the Jurassic period in Zhenghe County, located in Fujian province, southeast China. These 149-million-year-old specimens highlight the early emergence of advanced avian characteristics and, alongside another specimen from the same site, suggest that birds originated earlier than previously thought and experienced a significant diversification during the Jurassic era.

Baminornis zhenghensis. Image credit: Chuang Zhao.

“Birds represent the most varied group of land vertebrates,” stated Professor Min Wang from the Institute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences and his team.

“Some macroevolutionary analyses indicate that their initial diversification may trace back to the Jurassic period.”

“Despite this, the earliest evolutionary timeline of birds has been largely obscured due to a sparse fossil record, with Archaeopteryx being the only widely acknowledged Jurassic bird.”

“Although Archaeopteryx possessed feathered wings, its resemblance to non-avialan dinosaurs was pronounced, particularly with its notably elongated, reptilian tail, contrasting sharply with the shorter tails found in modern and Cretaceous birds.”

“Recent investigations have raised doubts about the classification of Archaeopteryx as an avialan, suggesting it could be a deinonychosaurian dinosaur, closely related to birds.”

This introduces the question of the existence of unambiguous records of Jurassic avians.

In their latest research, Professor Wang and co-authors identified and analyzed fossils of two primitive bird species, part of the notable Zhenghe biota.

One of these species, named Baminornis zhenghensis, holds the title of the earliest known short-tailed bird.

“Baminornis zhenghensis features a compact tail concluding with a pygostyle, a bone structure also found in contemporary birds,” explained the paleontologists.

“Previously, the earliest evidence of short-tailed birds was from the Early Cretaceous period.”

“Baminornis zhenghensis stands as the only Jurassic example and the oldest known short-tailed bird, extending the timeline for this advanced avian trait by nearly 20 million years.”

The research team indicates that Baminornis zhenghensis is among the earliest known birds.

“If we reconsider the phylogenetic uncertainties surrounding Archaeopteryx, we firmly believe that Baminornis zhenghensis is the true representative of Jurassic birds,” remarked Dr. Zhonghe Zhou, also from the Institute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences.

The second bird, which has not yet been named, is represented by a single fossilized furcula, or wishbone.

“Our findings support the classification of this furcula as belonging to Ornithuromorpha, a diverse category of Cretaceous birds,” the researchers commented.

The team’s comprehensive study has been published in the journal Nature.

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R. Chen et al. 2025. Earliest short-tailed bird from the Late Jurassic of China. Nature 638, 441-448; doi: 10.1038/s41586-024-08410-z