Moth fossils show their colours

摘要

Fossils of 47-million-year-old moths reveal that the insects once had a yellow-green sheen that both warned predators of their toxicity when they were exposed and provided camouflage when they were resting among leaves. Some moths and other creatures, such as birds, derive colour not from degradable pigments, but from tiny structural patterns in feathers or scales that scatter light to produce different hues. These structures can be preserved in fossils. Maria McNamara at Yale University in New Haven, Connecticut, and her colleagues analysed fossils of moths from Germany and reconstructed the insects' original colour using electron microscopy and mathematical calculations.