© Jakob Vinther/Yale University
Scientists discovered that nanostructures found in this 40-million-year-old fossil were responsible for producing iridescent colors in the living feather.
Nanostructures preserved in feather fossils more than 40 million years old show evidence that those feathers were once vivid and iridescent in color, paleontologists say.
Iridescence is the quality of changing color depending on the angle of observation - it's what makes you see a rainbow in an oil slick.
Many insects, such as butterflies, display iridescent colors on their wings, as do many modern birds on their feathers.
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.
Scientists found smooth layers of these melanin structures, called melanosomes, when they examined feather fossils from the Messel Shale in Germany with an electron microscope.