Feather Evolution - Photo Gallery - National Geographic Magazine

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The Long, Curious, Extravagant Evolution of Feathers

If feathers did not evolve first for flight, what was their purpose?

/2011/02/feathers/img/01-blue-fronted-amazon-parrot-714.jpg /2011/02/feathers/img/feathers-60-01.jpg Photograph by Robert Clark /2011/02/feathers/img/02-bird-fossil-714.jpg /2011/02/feathers/img/feathers-60-02.jpg Photograph by Robert Clark First Came Fuzz Birds evolved from dinosaurs, but the origin of their feathers may trace back even deeper in time, to the common ancestor of dinosaurs and pterosaurs, like the fossil at left. These flying reptiles were covered with thin filaments that may have looked something like the down on this pheasant chick. Jeholopterus ningchengensis 168-152 million years ago, China At Institute of Vertebrate Paleontology and Paleoanthropology, Beijing]]> /2011/02/feathers/img/03-single-plume-fossil-714.jpg /2011/02/feathers/img/feathers-60-03.jpg Photograph by Robert Clark Archaeopteryx, discovered in a German quarry in 1861, triggered a still unresolved debate over the origin of one of nature's most elegant inventions: the feather. Archaeopteryx lithographica 150 to 148 million years ago, Germany At Museum of Natural History, Humboldt University, Berlin]]> /2011/02/feathers/img/04-beipiaosaurus-inexpectus-714.jpg /2011/02/feathers/img/feathers-60-04.jpg Photograph by Robert Clark Shaggy Dino Simple, quill-like filaments on the head (upper right on fossil), back, and tail of Beipiaosaurus inexpectus surprised paleontologist Xu Xing when he first saw this fossil in 1997. More elaborate dinosaur feathers had already been found, but "these structures were novel," says Xu, of Beijing's Institute of Vertebrate Paleontology and Paleoanthropology. Smaller dinosaurs may have used feathers for insulation, but seven-foot-long Beipiaosaurus would have needed to shed, not keep, heat. So, says Xu, "they probably had a display function, like the mane of a horse or a lion." Beipiaosaurus inexpectus 125 million years ago, China At Shandong Tianyu Museum of Nature]]> /2011/02/feathers/img/05-smuggled-specimen-714.jpg /2011/02/feathers/img/feathers-60-05.jpg Photograph by Robert Clark Fringe Character Until 2001 feathered dinosaurs were known only on the saurischian branch of the dinosaur tree, which includes birds. That year a fossil from the other branch, the ornithischians, surfaced on the international market, with long, curved filaments on its tail. Without more information on Psittacosaurus, scientists were reluctant to believe dinosaurs so distantly related to birds bore featherlike structures. The 2009 announcement of similar filaments on another ornithischian, Tianyulong, changed many minds. But did the trait evolve independently in the two branches, or in their common ancestor? Psittacosaurus Sp. 125 to 121 million years ago, China; smuggled specimen of unknown provenance Currently in custody of Senckenberg Research Institute, Germany, pending repatriation to China]]> /2011/02/feathers/img/06-jurassic-peacock-714.jpg /2011/02/feathers/img/feathers-60-06.jpg Photograph by Robert Clark Jurassic Peacock Sporting a quartet of long, ribbonlike feathers with barbs arranged in vanes, pigeon-size Epidexipteryx may provide the earliest evidence of a dinosaur flaunting its feathers for display. Such extravagant plumage would have been virtually useless for insulation or flying, but it might have attracted mates or allowed individuals of the species to recognize one another. Epidexipteryx hui 168 to 152 million years ago, China At Shandong Tianyu Museum of Nature]]> /2011/02/feathers/img/07-peacock-panorama-714.jpg /2011/02/feathers/img/feathers-60-07.jpg Photograph by Robert Clark /2011/02/feathers/img/08-king-bird-paradise-714.jpg /2011/02/feathers/img/feathers-60-08.jpg Photograph by Robert Clark King bird of paradise
Disk tail-feather tip, wobbles during display Courtesy Peter Mullen, Ph.D.]]> /2011/02/feathers/img/09-gray-peacock-pheasant-714.jpg /2011/02/feathers/img/feathers-60-09.jpg Photograph by Robert Clark Gray peacock pheasant Tail covert, fan display Institute of Zoology and Zoological Museum, University of Hamburg]]> /2011/02/feathers/img/10-ostrich-chick-714.jpg /2011/02/feathers/img/feathers-60-10.jpg Photograph by Robert Clark Ostrich (chick) Body feathers, first and second stage, insulation Institute of Zoology and Zoological Museum, University of Hamburg]]> /2011/02/feathers/img/11-red-bird-paradise-714.jpg /2011/02/feathers/img/feathers-60-11.jpg Photograph by Robert Clark Red bird of paradise Flank plumes, display Institute of Zoology and Zoological Museum, University of Hamburg]]> /2011/02/feathers/img/12-spotted-eagle-owl-714.jpg /2011/02/feathers/img/feathers-60-12.jpg Photograph by Robert Clark Spotted eagle-owl Wing feather with serrated edge, muffles sound Courtesy Peter Mullen, Ph.D.]]> /2011/02/feathers/img/13-scarlet-macaw-714.jpg /2011/02/feathers/img/feathers-60-13.jpg Photograph by Robert Clark Scarlet macaw Wing covert feather, flight Institute of Zoology and Zoological Museum, University of Hamburg]]> /2011/02/feathers/img/14-golden-headed-quetzal-714.jpg /2011/02/feathers/img/feathers-60-14.jpg Photograph by Robert Clark Golden-headed quetzal Tail covert, display Institute of Zoology and Zoological Museum, University of Hamburg]]> /2011/02/feathers/img/15-golden-pheasant-714.jpg /2011/02/feathers/img/feathers-60-15.jpg Photograph by Robert Clark Golden pheasant Head crest, display Courtesy Peter Mullen, Ph.D.]]> /2011/02/feathers/img/16-northern-flicker-714.jpg /2011/02/feathers/img/feathers-60-16.jpg Photograph by Robert Clark Northern flicker Tail feather, assists in climbing Institute of Zoology and Zoological Museum, University of Hamburg]]> /2011/02/feathers/img/17-red-crested-turaco-714.jpg /2011/02/feathers/img/feathers-60-17.jpg Photograph by Robert Clark Red-crested turaco Wing feather with copper-containing pigment, flight and display Courtesy Peter Mullen, Ph.D.]]> /2011/02/feathers/img/18-anchiornis-microscopic-714.jpg /2011/02/feathers/img/feathers-60-18.jpg Photograph by Robert Clark /2011/02/feathers/img/19-anchiornis-fossil-714.jpg /2011/02/feathers/img/feathers-60-19.jpg Photograph by Robert Clark Anchiornis.]]> /2011/02/feathers/img/20-drab-pheasant-714.jpg /2011/02/feathers/img/feathers-60-20.jpg Photograph by Robert Clark The Eyes Have it The male great argus of Southeast Asia is a fairly drab pheasant—until he dances before a female with his enormous wing feathers fanned open, revealing the spectacular inner surface shown on this four-inch section. Hundreds of jewel-like ocelli, or eyespots, keep hens enchanted. At Institute of Zoology and Zoological Museum, University of Hamburg]]> /2011/02/feathers/img/21-chukar-partridge-714.jpg /2011/02/feathers/img/feathers-60-21.jpg Photograph by Robert Clark Outta Here Furiously flapping, a chukar partridge speeds up a ramp at the University of Montana flight lab. Studies show that even before a young bird is able to fly, its flapping wings act like a car spoiler, pushing its body down to gain traction when running from predators up steep inclines—a clue perhaps to how flight first evolved.]]> /2011/02/feathers/img/23-confuciusornis-wings-714.jpg /2011/02/feathers/img/feathers-60-23.jpg Photograph by Robert Clark Poised for Flight The wings of a Confuciusornis (above) and a modern cock of the rock (next photo) convey the evolutionary distance traveled since the origin of flight. Confuciusornis and other early birds retained primitive claws on their wings that may have been used for climbing or predation; narrow feathers and weak flight muscles suggest it was not a powerful flier. Confuciusornis sanctus 125 to 120 million years ago, China At Shandong Tianyu Museum of Nature]]> /2011/02/feathers/img/22-modern-cock-feathers-714.jpg /2011/02/feathers/img/feathers-60-22.jpg Photograph by Robert Clark Poised for Flight In contrast, the male cock of the rock's wing is designed for agility and tricked up for display. A tiny feathered "thumb," the alula, improves flight control. The protruding shaft on the first wing feather makes a loud, rustling sound—adding acoustics to the visual display. At Peabody Museum of Natural History, Yale University]]>