Reviews
MIOPLOSUS FOSSIL FISH FOR SALE
More About Mioplosus
Mioplosus is a genus of perciform fish (related to perches and basses) that lived from the early to mid Eocene. These perches were built for speed, as exhibited by their slender bodies and parallel drag-cutting fins that allowed for the efficient pursuit of lunch. They were the prehistoric lake fish equivalent of F/A-18 Hornet jet fighters. These fish were thought to be solitary, aggressive piscivorous predators in maturity, despite an early lifestyle of nearshore schooling behavior observed in many other small fish species. This habit is evident in mass mortality plates of fry and larval Mioplosus individuals found in shoreline deposits.
These fish have gone through a slew of familial designations within the order Perciformes, the largest order of vertebrates, eventually landing in the Percidae family, though some still vehemently vouch for assignment to Latidae. In large families, phylogenetic connections can get a little muddy, but at this point, pike-perches from the genus Sander are believed to be the closest living relative of Mioplosus. There are four recognized species of Mioplosus, the most abundant being Mioplosus labracoides.
A beautiful fossil Mioplosus from Warfield Quarry showing its sleek body shape.
Mioplosus is one of the more easily recognizable species coming out of the Green River Formation. It has a rather long, slender body with two distinct dorsal fins. Perhaps their most identifiable characteristics are their deeply forked, fanned tail fins and their parallel opposing rear dorsal and anal fins. These fish have a sleeker, predatory look than Knightia and Diplomystus, though these three may be confused in their superficial appearance. Luckily, they look nothing like the other major perch species in their habitat, Cockerellites and Priscacara, who are often confused for one another. Where Mioplosus looks like an offensive weapon, Priscacara has the appearance of a stalwart defensive unit lined with spines.
Where And When Did Mioplosus Live?
Mioplosus went strong from the beginning of the Eocene till its extinction in the middle of that same era, a span of roughly 15 million years. These fish were abundant in the Green River Formation of Wyoming and were believed to be quite successful among the many other fish species, including other well known GRF perches Priscacara and Cockerellites. Additional Mioplosus fossils have been recovered in European and Asian deposits, and occasionally in the fossil beds of New Zealand.
Though their modern relatives inhabit both freshwater and brackish environments, Mioplosus appears to have lived only in freshwater environments; a lifestyle not uncommon for perches and pikes, both extant and extinct.
What Did Mioplosus Eat, And What Ate Them?
They were believed to be primarily solitary predators that inhabited the deeper water of the ancient fossil lakes. Their mouthful of extremely sharp teeth and sleek, powerful body plan gave them quite the advantage over the smaller fish that they voraciously devoured. Most larger Mioplosus specimens are collected from the mid-lake beds of the Green River formation and are often discovered either near their prospective prey or with a fish in their stomachs. Sometimes the smaller fish is on its way down, sticking out of a Mioplosus's mouth in an aspiration. They were also quite cannibalistic in all stages of life: young individuals have been found with smaller Mioplosus in their stomachs.
Even though Mioplosus had a reputation as a tireless predator, they weren’t immune to the other, bigger predators with hankerings for perch. Softshell Trionyx turtles, semi-aquatic mammals, birds, crocodilians, and larger fish all made a meal of Mioplosus and many of the other lake fish. In the Green River Formation, something was always eating-–or being eaten by–-something else.
Featured Photos
