About the Green River Fish |
| Knightia (knightia sp.) - The Knightia is an ancestor of the modern herring. It is the most common of the fish species found in the sedimentary layers (some up to 2,000 feet deep) of the Green River Formation that were deposited in the Green River Lake System of western Wyoming, eastern Utah and northwestern Colorado. |
| Priscacara (Prisacara liops)- This fish is thought to have been a schooling fish found only in fresh water. The maximum length is about 6 inches. |
| Dyplomystus - Related to the Knightia, but may be somewhat larger. Fossil remains of this fish are rarely found in large groups, indicating that they may not have had the schooling behavior of the Knightia. The unique mouth structure of the dyplomystus appears to have been designed to feed on small animals and plants near the surface. |
| Phareodus - This unique fish had spike-like fins below it's body that helped it to forage for food along the lake bottom. It was probably a combination of a predator and a scavenger. Fossilized remains of all of the other Green River Formation fish have been found in its stomach. |
| Mioplosus - This fish grows to a larger size (12 to 16 inches) than the other Green River species and has a mouth full of small teeth. This feature, combined with the fact that fewer fossilized remains of this specie are found in the area, indicates that the Mioplosus may have lived on a diet that included Knightia and Dyplomystus. |
| An important note: The dark, shiny areas on the specimens below are actual petrified skin or bone rather than the imprint left as the fish decayed and was replaced by mineralization. |
