4-winged fossil found in Liaoning challenges single origin of dinosaur flight

Scientists have unveiled an exceptionally well-preserved 100-million-year-old fossil of a small, feathered dinosaur in northeastern China that could reshape our understanding of how dinosaurs took to the skies.

The newly discovered species, named Norellraptor barsboldi, is a four-winged predatory dinosaur measuring 57cm (22 inches) long.

Belonging to the microraptorines – small dinosaurs with feathers and wings closely related to birds – the creature offers fresh evidence that flight evolved independently in different dinosaur lineages rather than from a single common origin.

“These results dismiss a shared developmental pattern driving the evolution of the flying dinosaurs and support multiple and independent selective regimes at the origin of the winged taxa in Paraves,” the researchers wrote, referring to the group that includes birds and microraptorines.

The team of scientists from institutions in China, Italy and Slovakia published their findings in the peer-reviewed journal Nature Communications on Tuesday.

For decades, palaeontologists have been looking into whether the aerial abilities of birds and microraptorines shared a single evolutionary origin or arose separately.

While fossils have previously shown that some microraptorines had long feathers on both their forelimbs and hindlimbs, suggesting flight adaptations, it was not clear whether these features marked the origins of flight in Paraves or evolved independently.

In the latest study, the “exquisitely preserved” fossil with a complete skeleton and parts of its plumage was unearthed in the Lower Cretaceous Jiufotang Formation in the northeastern coastal province of Liaoning.

The geological formation, estimated to be between 145 million and 100 million years old, is home to similarly well-preserved fossils from the late phase of the Jehol Biota, a key Early Cretaceous terrestrial ecosystem.

The new Norellraptor barsboldi species was named after American palaeontologist Mark Allen Norell and Mongolian palaeontologist Rinchen Barsbold to honour their work in studying birdlike dinosaurs. They both died in 2025.

Analysis of the dinosaur, which was at least three years old when it died, revealed a collection of features associated with flight.

The scientists compared these results across an evolutionary tree and found that about 30 per cent of anatomical changes in microraptorine evolution also evolved in the bird lineage.

However, the two groups acquired these shared features in a different order.

While birds first fused their wrist bones and elongated their breastbones before shortening their hand digits, microraptorines shortened their manual phalanges – finger bones – much earlier to reduce their grasping ability.

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“The sequences of flight-related novelties reconstructed along the two lineages differ consistently,” the researchers wrote.

This finding challenges the idea that birds and microraptorines inherited a shared flight apparatus or that a common developmental process drove its evolution. Rather, distinct selective pressures are likely to have influenced the development of their flight-adapted traits.

Future research will require sampling more fossils across birdlike dinosaurs to determine how widespread this unique growth pattern was and to further untangle the forces that launched dinosaurs into the air.