Juvenile Green River Fossil Fish Mioplosus labracoides

Description: This 50 million year old, Eocene-Era fossil fish comes from one of the world's famous Laggerstatten, the Green River Formation in Wyoming. A small portion of the fish fossils from Green River exhibits such fine preservation. The significant extent of soft-tissue preservation that makes the site famous is evident in this specimen.
Mioplosus labracoides is believed to have been a voracious predator among the Green River fish fossils. Failure to find its numbers in mass mortality leads to further conjecture that it was a solitary hunter. A member of the Family Percidae, it has numerous relatives in Northern Hemisphere fresh water as well as fossil relatives in Asia, Europe and New Zealand. It is known as a predatory species as determined from its many pointed teeth, and the fact that several have been found with fish lodged in its throat. It may be related to the modern-day pike of the genus Stezostedion.
Distinguishing features include double dorsal fins and a fan-like tail. Mioplosus is uncommon in the Green River formation, especially the fish of this size and of this exceptional quality of preservation (both bone detail and some soft-tissue preservation are evident). This is a juvenile example. See my other offerings for subadult to adult specimens.