Butterflies from the Middle Eocene: The Earliest Occurrence of Fossil Papilionoidea (Lepidoptera)
Three fossil butterflies recently collected from the Green River Shale of Colorado extend the known range of Rhopalocera eight to ten million years back, to 48 Ma. Praepapilio Colorado n. g., n. sp., and P. gracilis n. sp. are primitive Papilionidae related to the modern Baronia brevicornis Salvin, but they require a new subfamily, Praepapilioninae. Riodinella nympha n. g., n. sp. is a primitive member of the Lycaenidae, related to modern Ancyluris, Riodina, and Rhetus, in the tribe Riodinidi.