Science|What Can Four-Winged Dinosaurs Teach Us About Birds?

More than 120 million years ago, a small creature soared across the Cretaceous skies above China. Was it a bird or a pterosaur or … a four-winged raptor?

Researchers recently examined a remarkably well-preserved skeleton of such a dinosaur — it sported sharp claws, a mouthful of teeth and twice the number of wings expected for an avian relative.

The newly identified species, about the size of a crow, sheds light on how other groups of flying dinosaurs achieved liftoff alongside the ancestors of living birds.

Scientists have long debated the evolutionary runway that took dinosaurs into the skies. In 2020, researchers constructed a tree of early birds and closely related dinosaurs, and concluded that flight evolved at least three times, indicating that aerial behavior was most likely more widespread in dinosaurs than previously thought.

“Today’s birds are the only survivors of this once bountiful Mesozoic aviary of airborne dinosaurs,” said Stephen Brusatte, a paleontologist at the University of Edinburgh who was not involved in the new research, published in the journal Nature Communications. He added that over the past decade, researchers have uncovered fossil evidence that dinosaurs were most likely capable of all kinds of flying styles.

These ancient aviators included the microraptorines, a group of small, carnivorous dinosaurs that sported long feathers along each of their limbs. Paleontologists have unearthed hundreds of microraptorine fossils from China, many of which are very well-preserved and offer detailed looks at these dinosaurs’ skeletons and feathers.