Feathers are one of the most distinctive and diverse features of birds. They provide insulation, flight, camouflage, and display. But how did feathers evolve and what is their connection to dinosaurs?
- Feathers are modified scales: Feathers are made of the same protein, keratin, as reptile scales and mammal hair. They are derived from the skin cells of the epidermis, just like scales. The earliest feathers were simple filaments that covered the body of some dinosaurs.
- Feathers evolved for different functions: Feathers did not evolve for flight at first. They may have served as insulation, protection, or signaling. Some dinosaurs had feathers on their limbs, tails, or crests, but could not fly. Later, feathers became more complex and asymmetrical, allowing some dinosaurs to glide or flap.
- Birds are living dinosaurs: Birds are the descendants of a group of theropod dinosaurs called maniraptorans, which includes Velociraptor and Tyrannosaurus. They are the only surviving branch of the dinosaur family tree. Birds share many features with their dinosaur ancestors, such as hollow bones, air sacs, and a wishbone.
- Birds diversified after the mass extinction: About 66 million years ago, a massive asteroid impact wiped out most of the dinosaurs and many other species. Only a few groups of birds survived the catastrophe. They took advantage of the new ecological opportunities and evolved into many different forms and habitats.
