Feather - Origins

Feathers are one of the epidermal growths that form the distinctive outer covering, or plumage, on birds. They are the outstanding characteristic that distinguishes the Class Aves from all other living groups. Other Theropoda also had feathers (see Feathered dinosaurs). Feather - Characteristics. Feathers are among the most complex structural organs found in vertebrates: integumentary appendages, formed by controlled proliferation of cells in the epidermis, or outer skin layer, that produce keratin proteins ...

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• Feather - Characteristics
• Feather - Origins
• Feather - Feathered dinosaurs
• Feather - Human uses

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Feathers are among the most complex structural organs found in vertebrates: integumentary appendages, formed by controlled proliferation of cells in the epidermis, or outer skin layer, that produce keratin proteins. The β-keratins in feathers, beaks and claws — and the claws, scales and shells of reptiles — are composed of protein strands hydrogen-bonded into β-pleated sheats, which are then further twisted and crosslinked by disulfide bridges into structures even tougher than the α-ke ...

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Feather, Feather - Characteristics, Feather - Origins, Feather - Feathered dinosaurs, Feather - Human uses

Read more here: » Feather: Encyclopedia II - Feather - Characteristics

Main article: Feathered dinosaurs Although birds use feathers primarily for flight, several dinosaurs have been discovered with feathers on their limbs that would not have functioned for flight. One theory is that feathers originally developed on dinosaurs as a means of insulation; those small dinosaurs that then grew longer feathers may have found them helpful in gliding, which would have begun the evolutionary process that resulted in some proto-birds like Archaeopteryx and Microraptor zhaoianus. Other dinosaurs ...

See also:

Feather, Feather - Characteristics, Feather - Origins, Feather - Feathered dinosaurs, Feather - Human uses

Read more here: » Feather: Encyclopedia II - Feather - Feathered dinosaurs