Feather development occurs in the epidermal layer of the skin in birds. It is a complicated process involving many steps. Once the feathers are fully developed, there are six different types of feathers: contour, flight, down, filoplumes, semiplumes, and bristle feathers. Feathers were not originally meant for flight. The exact reason why feathers evolved is still unknown. Birds are thought to be descendants of dinosaurs and new technology using melanosomes found in dinosaur fossils has shown that certain dinosaurs that could not fly had feathers.