A report published in the journal Science shows researchers from China's Shandong Tianyu Museum of Nature have found evidence of large feathers in 11 four-winged fossils dating back to more than 100 million years ago. The fossils are being viewed as a "missing link" between large feathered dinosaurs and the birds that we know today.
Scientists aren't sure whether or not the feathers were actually used to fly, since the fossils are two-dimensional. But area analysis shows that the feathers were large enough to be aerodynamic, making them a flight-worthy design.
"These features suggest that the metatarsal feathers were aerodynamic in function, providing lift, creating drag, and/or enhancing maneuverability, and thus played a role in flight," the researchers said in their study, released in the journal "Science."
Some scientists aren't convinced. Paleontologist Kevin Padian of the University of California, Berkeley told "Science" that there's still no hard evidence that the feathers were used for flight, and could have instead been used for decorative or mating purposes.
The Chinese researchers say that more studies are needed before any definitive conclusions, and are planning to continue their work on the museum's fossil collection.