Paleontologists in China have discovered a new species of fossil bird that they say reveals a pivotal point in the evolution of flight, when birds had lost the long bony tail seen in dinosaurs such as Tyrannosaurus and the early bird Archaeopteryx, but before they had developed the fan of feathers on a shortened tail seen in flying birds today.

The 127-million-year-old species, which they have named Jinguofortis perplexus, retains other features of its dinosaur ancestors, such as claws on the fingers of its wings, a jaw with tiny teeth rather than a beak, and a fused shoulder girdle. That last trait is seemingly poorly adapted to flight, hence the name “perplexus.” (Read more about the evolutionary link between