for National Geographic News
Just like modern-day starlings, some ancient birds had glossy black feathers with a metallic, glimmering sheen, scientists report in a new study.
The discovery is based on 40-million-year-old fossils of an unidentified bird species that were stored at the Senckenburg Museum in Frankfurt, Germany for up to 30 years. The fossils represent the first evidence of ancient iridescence in feathers.
Iridescence is caused by an interaction of light with the material that the light hits. The color changes depending on the angle of observation, like the rainbow sheen on an oil slick.
The research moves scientists a step closer to determining the true colors of extinct creatures, said study co-author Richard Prum, an ornithologist at Yale University in New Haven, Connecticut. (Read more about the search for prehistoric color at National Geographic magazine's Blog Central.)
Most of what scientists know about the hues of extinct species are best guesses, based on factors such as the color of related living species, Prum said.
"We are eagerly hoping to be able to work on some of the Chinese dinosaur feathers to try to reconstruct the colors of the feathered dinosaurs," said Prum, who received funding for his work from the National Geographic Society. (The National Geographic Society owns National Geographic News.)
The new research builds on Prum's previous discovery of pigment-containing, organic structures called melanosomes in a hundred-million-year old black-and-white-striped feather from Brazil.
(Related: "Dino-Era Feathers Found Encased in Amber.")
Previously scientists had thought that the microscopic color capsules were bacteria that had consumed the feather during fossilization, Prum said.
The melanosome discovery "led us to start looking at feathers that were extraordinarily well preserved, and that led us to the [newly studied] fossils," he said.
Found in shale oil deposits taken from the Messel Pit near Darmstadt, Germany, the fossilized feathers contain melanosomes arranged in a tightly packed, smooth pattern—similar to the feathers of modern-day starlings and grackles.
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