NEW HAVEN, Conn., Nov. 16 (UPI) -- Fossilized moth wings that look blue in death are showing false colors and would have been yellow-green in life, a U.S. study finds.
The brightest hues in nature are produced not by pigments but by tiny structural patterns in, say, feathers or scales, researchers said.
Many animals use this type of color for communication, especially butterflies and moths (Lepidoptera), which display the biggest range of structural colors, they said.
Writing in the journal PLoS Biology, Yale University's Maria McNamara and colleagues described reconstructing those structural colors in fossil moths that are 47 million years old.
Although the original colors of the fossil moths, found in oil shales in Germany, were not preserved, the researchers were able to reconstruct them because the tiny color-producing patterns in the moth scales were intact.
"The level of detail preserved in the scales of the fossil moths is just spectacular", McNamara said.
Today, the front wings of the ancient moths look mostly blue, presumably because the chemistry was altered during the process of fossilization, but the researchers reconstructed the original colors via mathematical analysis of the wings' ultrastructure, revealing that the wings had actually been yellow-green when the moths were alive.
The fossil moths likely used their yellow-green wings to blend in with leaves to hide from predators, the researchers said.