🦖 This four-winged dinosaur followed its own evolutionary path toward flight

A small feathered dinosaur shows that wings may have emerged through several evolutionary pathways.

Its name is Norellraptor barsboldi. Its nearly complete skeleton was discovered in western Liaoning, China, in Early Cretaceous rocks. The fossil measures only 57 cm in length, with traces of plumage still visible around several parts of the body.

Norellraptor belonged to the microraptorines, small predatory dinosaurs closely related to birds. Some had long feathers not only on their forelimbs, but also on their hind legs. This arrangement earned them the nickname “four-winged” dinosaurs, even though their exact flying abilities remain debated.

The new fossil is particularly complete. Studying its bones indicates that it was at least three years old when it died. Its hands, limbs and skeleton display several traits associated with movement through the air, which are also found in different forms among the earliest birds.

This resemblance raises a question: did birds and microraptorines inherit their ability to fly from the same ancestor? Another possibility is that the two groups independently acquired comparable adaptations, each over the course of its own evolution.

To distinguish between these scenarios, the researchers did not compare only the traits that were present. They also reconstructed the order in which they appeared. In microraptorines, the fingers first became shorter, probably reducing their role in grasping. Other transformations of the wrist, breastbone and limbs came later.

In the ancestors of birds, these changes did not appear in the same order. Comparable structures were therefore assembled along two different trajectories. About 30% of the traits specific to the microraptorines studied are also found in the bird lineage, but they are thought to have been acquired independently.

The flight of dinosaurs therefore does not seem to have followed a single recipe. Several closely related groups may have experimented with different combinations of feathers, elongated limbs and transformed bones. Some lineages disappeared, while the bird lineage survived the mass extinction 66 million years ago.

The name Norellraptor honors the American paleontologist Mark Norell, who died in 2025. The species name, barsboldi, honors the Mongolian paleontologist Rinchen Barsbold, who also died that year. Both made major contributions to revealing the links between feathered dinosaurs and birds.