Helicoprion is a long-lived genus of extinct, eugeneodontid holocephalid fish. Almost all fossil specimens are of spirally arranged clusters of the individuals' teeth, called "tooth whorls." This fossilized jaw shows the spiral dentures.
Edmontosaurus is a genus of hadrosaurid (duck-billed) dinosaur. It contains two known species: Edmontosaurus regalis and Edmontosaurus annectens. Fossils of E. regalis have been found in rocks of western North America.
Green River Fossilized dragonfly: Many species of insects are found in the Green River Formation including dragonflies. The wetland margins of Fossil Lake provided ideal breeding and foraging opportunities.