New Feathered Dinosaur Challenges Bird Evolution Theory

Paleontologists at the University of Southampton, U.K., have discovered the fossilized remains of a bird-like dinosaur, which offers new clues on bird evolution.

A widely accepted theory about birds is that they evolved from a group of dinosaurs called theropods around 120-130 million years ago, during the Early Cretaceous period. But the discovery of a "bird-dinosaur" Eosinopteryx in north-eastern China has cast doubt on the old theory.

Eosinopteryx belonged to the older Middle-Late Jurassic period and lived more than 145 million years ago. The dinosaur was 11.8 inches tall and was feathered. Despite having feathers, Eosinopteryx was flightless because it had a small wingspan and a bone structure that would have restricted its ability to flap its wings.

Eosinopteryx also had toes to help it walk on the ground. It had fewer feathers on its tail and lower legs, which would have made it easier to run.

"This discovery sheds further doubt on the theory that the famous fossil Archaeopteryx -- or "first bird" as it is sometimes referred to -- was pivotal in the evolution of modern birds," co-author of the study Gareth Dyke, senior lecturer in vertebrate palaeontology at the University of Southampton, said in a statement.

"Our findings suggest that the origin of flight was much more complex than previously thought."

The details of the study, "Reduced plumage and flight ability of a new Jurassic paravian theropod from China", appear in the journal Nature Communications.