September 15, 2011
Study Sheds Light On ‘Story of Feather Evolution’
Researchers at the University of Alberta have discovered Cretaceous-era feathers trapped in tree resin in western Canada--fossils which may tell "the most complete story of feather evolution ever seen," according to BBC News reports.A total of 11 fragments were discovered by paleontology graduate student Ryan McKellar, according to the British news agency, which reportedly show the progression from "hair-like 'filaments' to doubly-branched feathers of modern birds."
McKellar's discovery is detailed in the journal Science.
According to a University of Alberta press release, the roughly 80 million year old feathers were discovered at the Royal Tyrrell Museum in southern Alberta, and originated from amber deposits near Grassy Lake in the southwestern quadrant of the province.
"No dinosaur or avian fossils were found in direct association with the amber feather specimens, but McKellar says comparison between the amber and fossilized feathers found in rock strongly suggest that some of the Grassy Lake specimens are from dinosaurs," the press release said. "The non-avian dinosaur evidence points to small theropods as the source of the feathers."
Among the feathers recovered were some similar in nature to the Grebe, which have special feathers that can take on water and allow it to swim underwater. Furthermore, the university notes that McKellar's findings illustrate that there were "numerous evolutionary stages of feathers" present during that era, and that they had numerous functions for both dinosaurs and birds alike.
"We're finding two ends of the evolutionary development that had been proposed for feathers trapped in the same amber deposit," McKellar told the BBC.
"We've got feathers that look to be little filamentous hair-like feathers, we've got the same filaments bound together in clumps, and then we've got a series that are for all intents and purposes identical to modern feathers," he added. "We're catching some that look to be dinosaur feathers and another set that are pretty much dead ringers for modern birds."
AP Science Writer Randolph P. Schmid also notes that a separate study, written by Roy A. Wogelius of the University of Manchester and published by Science over the summer, noted that trace metals had been discovered in feather fossils. Wogelius' study demonstrated that the color of feathers could have included black, brown, and reddish-brown, Schmid claims.
Image 2: Recently analyzed chunks of Canadian amber include filaments presumed to be protofeathers (left, top) like those seen in some Chinese fossils of dinosaurs and fragments of feathers (right, bottom) similar to those sported by modern-day birds. Credit: Science/AAAS
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