Long ago in the age of dinosaurs, a volcano in eastern China erupted and buried a host of strange creatures in ash, creating exquisite fossils that preserved a big surprise–many dinosaurs were covered in feathers. In The Four-Winged Dinosaur, NOVA investigates the most bizarre of these feathered dinosaurs, which has rekindled a fierce, decades-long debate over the origin of bird flight.
https://www.youtube.com/watch?v=yL0UIzU0EEc
