Select options This product has multiple variants. The options may be chosen on the product page Unknown Feather $19.00 – $400.00 Feathers are epidermal growths that form the distinctive outer covering, or plumage, on birds. They are considered the most complex integumentary structures found in vertebrates[1][2] and a premier example of a complex evolutionary novelty.[3]They are among the characteristics that distinguish the extant birds from other living groups.[4]