Mioplosus is an extinct genus of perch found in the Green River Formation of Wyoming, USA. These fish were ferocious, solitary predators armed with several pointy teeth. Many asperation fossils contain Mioplosus with Knightia, Priscacara, and other small fish lodged in their throats. Mioplosus resemble the modern day Yellow Perch and could be the ancestor of modern perches and pikes. Mioplosus lived 50 million years ago during the Eocene epoch. The average length of these fish is 6 inches (15.2 centimeters) with a maximum size of 20 inches (50.8 centimeters). Fossils of these fish are fairly uncommon compared to the more common Knightia and Diplomystus. There is only one documented species of the genus, Mioplosus labracoides.