In western France, seven dinosaur-era feathers have been found perfectly preserved in amber. The team of researchers is uncertain whether the feathers belonged to a bird or a dinosaur, since the 100 year-old plumage has similar features to fibers from both.
Either way, the amber-encased feathers show for the first time the transition from downy filaments toward an aerodynamic, planar shape that enabled flight. Perrichot and colleagues described their research last month in the journal Proceedings of the Royal Society B.
Studies suggest that primitive feathers first evolved in flightless dinosaurs with the function of generating internal heat. It was not until much later on when feathers evolved for use in flight.