An international team of palaeontologists, which includes the University of Bristol, has discovered that the flying reptiles, pterosaurs, actually had four kinds of feathers, and these are shared with dinosaurs — pushing back the origin of feathers by some 70 million years.
Professor Mike Benton from the University of Bristol’s School of Earth Sciences, said: “We ran some evolutionary analyses and they showed clearly that the pterosaur pycnofibres are feathers, just like those seen in modern birds and across various dinosaur groups.
“Despite careful searching, we couldn’t find any anatomical evidence that the four pycnofibre types are in any way different from the feathers of birds and dinosaurs. Therefore, because they are the same, they must share an evolutionary origin, and that was about 250 million years ago, long before the origin of birds.”
Birds have two types of advanced feathers used in flight and for body smoothing, the contour feathers with a hollow quill and barbs down both sides.
These are found only in birds and the theropod dinosaurs close to bird origins. But the other feather types of modern birds include monofilaments and down feathers, and these are seen much more widely across dinosaurs and pterosaurs.
The armoured dinosaurs and the giant sauropods probably did not have feathers, but they were likely suppressed, meaning they were prevented from growing, at least in the adults, just as hair is suppressed in whales, elephants, and hippos. Pigs are a classic example, where the piglets are covered with hair like little puppies, and then, as they grow, the hair growth is suppressed.
Professor Benton added: “This discovery has amazing implications for our understanding of the origin of feathers, but also for a major time of revolution of life on land.
“When feathers arose, about 250 million years ago, life was recovering from the devasting end-Permian mass extinction. Paper. (paywall) – Zixiao Yang, Baoyu Jiang, Maria E. McNamara, Stuart L. Kearns, Michael Pittman, Thomas G. Kaye, Patrick J. Orr, Xing Xu, Michael J. Benton. Pterosaur integumentary structures with complex feather-like branching. Nature Ecology & Evolution, 2018; 3 (1): 24 DOI: 10.1038/s41559-018-0728-7 More.
It certainly is “amazing,” as Professor Benton says, that a complex array of features appeared 250 million years ago, rather abruptly, just as life was recovering from the Permian extinction. Would anyone have predicted that? Talk about “fossil rabbits in the Cambrian.”
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See also: The Founding Feathers?
Dinosaur found with preserved tail feathers, skin