Green River Formation : Insects

Though not as famous as the fish and other vertebrates, the insects from the Green River Formation are just as spectacular. The preservation of some fossils is good enough to allow not only identification to family and subfamily, but will sometimes show color patterns, wing venation, and sex-related characters.

The fossil insects in the UCMP collection have not been fully identified, but we present some of them anyway to illustrate the fine preservation. The identification given is the family name.

Orthoptera (crickets & grasshoppers)

Gryllidae - a cricket

Though the head of this specimen was crushed, the wing venation is well preserved. The ovipositor (egg-laying tube) shows this is an adult female.

Diptera (flies)

Dolichopodidae - a long-legged fly.

Nearly every part of this specimen is well-preserved, including the external genitalia. We know this fly is a male.

Rhagionidae - a snipe-fly.

An adult snipe-fly. There is also a smaller, unidentified insect near its abdomen.

Hemiptera (true bugs)

Reduviidae - an assassin bug.

The identification of this bug is uncertain.


Cixiidae - plant-hoppers.

Plant-hoppers are herbivorous insects. On these specimens, the color patterns are preserved, though the pigments themselves are not.

Hymenoptera (bees, ants, & wasps)

Ichneumonidae - ichneumon wasp.

This group of wasps is easily recognized by the long tapering abdomen.

Coleoptera (beetles)

Carabidae - a ground beetle.

Beetles are the most diverse insects today.

Curculionidae - weevils.

Weevils are herbivorous insects with long snouts.