the first fossil butterfly to be found in North America... The single known specimen of P. persephone is a compression fossil, discovered by the "homesteader turned naturalist" Charlotte Hill, in shale deposits of Late Eocene age of the Florissant Formation near Florissant, Colorado.It staggers the mind to think how fine the silt must have been to preserve detail to the degree of individual scales on the wings. The closest modern famiily related to it would probably be the Admirals.
The butterfly has a wing length of 24.5 mm (1.0 in), and the specimen is complete, although the trailing edge of one hind wing was originally covered... The wing venation is exquisitely preserved, and even the patterns of color on the wings are clearly visible. Individual wing scales can be discerned in parts of the forewing.
Image credit: LepTree.