Structural coloration in the wing scales of Jurassic moths

[Halichoeres]

Structural coloration based on wing scale morphology is how butterflies are able to make crazy colors like blues and purples that are almost impossible to achieve with pigments, and helps explain the showy, sexually selected appearance of many species (especially but not only males). Here's the most ancient known example of these scales in this lineage, from Jurassic and Cretaceous exemplars. They would probably have resembled extant micropterigid moths.

Open access: http://advances.sciencemag.org/content/4/4/e1700988.full