River Fossil Fish Mioplosus labracoides
mm = 1 inch): Fish fossil is 175 mm in length on a 235 mm by 125 mm matrix
Site: Green River Formation, Fossil Lake, Kemmerer, Wyoming
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.
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
to the modern-day pike of the genus Stezostedion.
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).