From National Geographic’s web page:
A pheasant-size dinosaur found in China is causing a stir among scientists trying to understand the origins of flight.
The newly named species, Serikornis sungei, adds to the ranks of dinosaurs that effectively had four wings, thanks to heavily feathered hindlimbs and forelimbs. But in a twist for paleontologists, the evidence suggests that Serikornis couldn’t fly.
“The feathering of Serikornis shows for the first time a complete absence of barbules—that is, the microstructures that allow feathers to resist air pressure during wing beats,” says study leader Ulysse Lefèvre, a paleontologist at the Royal Belgian Institute of Natural Sciences in Brussels.