Multiple Fossil March Fly (Plecia) - Green River Formation

This is a multiple fossil "March Fly", Plecia pealei from the Eocene aged Green River Formation in Wyoming. The largest fly is .45" long and shows quite a bit of detail under magnification.

Beware: I've seen many of these flies for sale of fossil shows that are more or less just painted onto the rock and don't have any visible detail to their bodies.