27 August 2009

Iridescent feathers - 40 million years ago

Known for their wide variety of vibrant plumage, birds have evolved various chemical and physical mechanisms to produce these beautiful colors over millions of years. A team of paleontologists and ornithologists led by Yale University has now discovered evidence of vivid iridescent colors in feather fossils more than 40 million years old.

Iridescence is the quality of changing color depending on the angle of observation, such as the rainbow of colors seen in an oil slick. The simplest iridescent feather colors are produced by light scattering off the feather's surface and a smooth surface of melanin pigment granules within the feather protein. Examining feather fossils from the Messel Shale in Germany with an electron microscope, scientists have documented this smooth layer of melanin structures, called melanosomes...

"Of course, the 'Holy Grail' in this program is reconstructing the colors of the feathered dinosaurs," said Yale graduate student and lead author Jakob Vinther. "We are working hard to determine if this will be possible."
More at the link, and prior work on this matter at this link. The photo is certainly of a modern feather or is digitally-altered for purposes of illustration. I'm impressed by the fineness of the clay/sediment in which the fossil feathers were preserved if it was able to preserve structures at the subcellular level.

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