April 11 (UPI) -- Scientists have successfully determined the color of an ancient butterfly wing. It's the first time scientists have identified the color of a 200-million-year-old insect.
The coloration of a butterfly's wing is determined by wavelength-selective scattering patterns, which cause some wavelengths to be absorbed and others to be reflected. Unlike pigments, which can survive for millions of years, structural colors are more difficult to identify among ancient fossils.
An international team of researchers used a combination of advanced imaging techniques to reveal the ultrastructures, the architecture of cells visible with magnification, on the surface of the fossil butterfly wing. Scientists used optical modeling to interpret the structural patterns and characterize the wing's optical properties.
The findings, published Wednesday in the journal Science Advances, mark the earliest evidence of structural colors among insect fossils.
The ultrastructures identified by the new research revealed a color pattern nearly identical to those found on several extant species from the Micropterigidae superfamily -- the most primitive extant lineage of Lepidoptera, the insect order that includes butterflies and moths.
According to the new study, the butterfly fossil confirms the use of fused wing scales and layer scale patterns to produce structural color patterns is an early hallmark of the Micropterigidae lineage.
The wings of the ancient butterfly would have displayed a range of metallic hues, similar to many of its Micropterigidae relatives.
"These findings have broader implications," Wang Bo, a professor at the Nanjing Institute of Geology and Palaeontology, said in a news release.
The early evidence of structural coloration among Lepidoptera species suggests diversification of color patters among moths and butterflies likely began earlier than previously thought. Scientists may need to reconsider the models of the evolution of structural colors in lepidopterans.