The Priscacara liops comes from the Eocene era of 50 million years ago. The genus can be extracted from the Green River formation in Wyoming quarries. The Green River formation covers 25,000 square miles of southwestern Wyoming, west of Colorado and eastern Utah. This specie exhibits a fine preservation due to the cold period in the Eocene era and the depth of the lakes. The Priscacara liops is the smaller of the two species in the Priscacaridae family. Priscacara means primitive head. The liops went extinct towards the end of the Miocene era.
The Knightia eocaena also comes from the Eocene era of 50 million years ago. The preserved fossil can be extracted from the Green River formation in Wyoming quarries. In 1987, the State of Wyoming declared the Knightia eocaena as their state fossil. This prehistoric herring could reach a maximum size of 9.84 inches or 25cm. However, the Knightia typically reached about half that length. The knightia is the most common of its species. The freshwater fish had an appetite for plankton and algae.
The Diplomystus dentatus is related to the Ellimmichthyidae family. This preserved fish comes from the lower Eocene era. The dentatus is found in the Green River formation. However, this species can also be discovered in the Cretaceous strata in South America. Take notice to the upturned mouth. This feature of the fish is an indication the dentatus was a surface feeder. The dentatus can size up to 20.5 inches.
The Phareodus encaustus is related to the Osteoglossidae family. The Phareodus encaustus comes from the Eocene era of 50 million years ago. The long pectoral fin and large pointed teeth characterizes the encaustus. This feature suggests the encaustus engaged in carnivorous behavior. It has been known to discover scales in the stomach of the encaustus.