The new species is part of the group -- known informally as raptors -- that would precede birds, the only dinosaurs remaining on Earth today.
Many smaller species in the group have been found with long forelimbs and feathered wings, indicating that they might have flown. But bigger species in the group tend to have shorter forelimbs not well-suited for flight, and paleontologists had never found feathers on one of those big-boned raptors -- until now.
Zhenyuanlong suni probably didn't fly, according to researchers' analysis of its fossilized remains. Its arm structure couldn't have supported its five-foot-long body with the kind of muscle-powered flight that birds use today. But that doesn't make the fossilized remnants of intricate feathers less exciting: It indicates that other members of the raptor family could have had feathers, too -- even the ones not suited for flight.
"This new dinosaur is one of the closest cousins of Velociraptor, but it looks just like a bird," study co-author Steve Brusatte of the University of Edinburgh's School of GeoSciences said in a statement. "It's a dinosaur with huge wings made up of quill pen feathers, just like an eagle or a vulture. The movies have it wrong -- this is what Velociraptor would have looked like too."
The debate over how many dinosaurs were feathered is still ongoing. We know that birds must have had a common dinosaur ancestor with feathers, and scientists have found some fossils that take us pretty close to where feathers might have first evolved -- but they still aren't sure exactly when feathers first emerged in dinosaurs, or for what purpose. If they first evolved for warmth or decoration and later were adapted to allow bird ancestors to fly, it's possible that most dinosaurs had feathers, albeit simple, quill-like ones.
Zhenyuanlong suni didn't have wings well suited for flight -- but it did have the feathers one would need to get off the ground. Because of this, they suspect that suni came after a flying ancestor, losing the capability for muscle-powered flight but retaining the related plumage, perhaps to use its wings for mating displays.