By Mark Brown, Wired UK
Confuciusornis sanctus, a prehistoric beaked bird which co-existed with dinosaurs some 120 million years ago, had a dark body, neck and tail, and impressive patterns along its feathers.
We know that, in remarkable detail, because a team of paleontologists from California and Manchester have used innovative x-ray techniques to get an close look at the shades and patterns of the ancient bird’s plumage.
The team used equipment at the Department of Energy’s SLAC National Accelerator Laboratory to map the chemical traces of eumelanin — a colouring agent responsible for brown eyes and dark hair in many species — in well preserved fossils of two ancient birds.
Those were Confuciusornis sanctus and the 100 million year old Gansus yumenensis, which is considered the oldest modern bird.
To find this pigment the team looked for residue of trace metals like copper, nickel, zinc and iron, because the atoms of those elements are often incorporated into eumelanin.
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http://www.wired.com/wiredscience/2011/07/fossil-feather-colors/