Eocene Green River Formation Ichneumonid Wasp Fossil

The Green River Formation deposits of Wyoming, Colorado, and Utah are best known for their immaculately-preserved fish, but other examples are known as well, as this specimen attests. This fine piece displays an example of a member of the Ichneumonidae or Ichneumonid Wasps. In the Ichneumonid wasps, the extension seen here is the ovipositor of the female, who uses it to place eggs in the beetle grubs which they parasitize.