XL 4.2" Knightia Eocaena Fossil Fish Green River FM Wyoming Eocene Age COA & Stand

Location: Kemmerer, Wyoming

Weight: 10.9 Ounces

Dimensions: 5.2 Inches Long, 3.6 Inches Wide, 0.5 Inches Thick (Plate)

Fish Dimensions: 4.2 Inches Long, 1 Inch Wide

Comes with a Certificate of Authenticity.

Comes with a Free Stand.

The item pictured is the one you will receive.

This is a genuine fossil.

50 million years old, Eocene age

Knightia eocaena is the most common fish discovered in Fossil Lake and may be the most abundant articulated vertebrate fossil in the world. Officially recognized as Wyoming’s State Fossil, Knightia could reach lengths of up to 25 cm (10 inches) and remains one of the most iconic fossils from the Green River Formation.

Around 50 million years ago, during the Eocene Epoch, a vast freshwater lake known as Fossil Lake stretched across what is now southwest Wyoming. At its greatest extent, the lake covered nearly 930 square miles, though only about 500 square miles of sediment remain today. The central 230-square-mile fossil bed is especially rich, preserving exceptionally fossiliferous layers along with ancient deltas, beaches, mineral springs, and nearshore rock formations.

The unique chemistry of Fossil Lake played a vital role in fossil preservation. Its waters prevented decay and scavenging, allowing organisms to settle undisturbed while millimeter-thick layers of limestone slowly accumulated. These finely laminated deposits contain the highest concentration of fossil fish anywhere in the world. Alongside the fish, other aquatic organisms and preserved geologic features make Fossil Lake the most complete Paleogene record of a freshwater lake ecosystem.

 Since the discovery in the 1870s, many perfectly preserved fossil fish have been recovered. Preserved within the fish in the laminated limestone is a complete aquatic ecosystem, comprising cyanobacteria, plants, insects, crustaceans (such as shrimp, crawfish, and ostracods), amphibians (including a primitive salamander and a frog), alligators, turtles, birds, and mammals, including the oldest known pantolestid (an otter-like animal). The subtropical terrestrial ecosystem surrounding the lake is also represented by rare fossils, including a horse, two snakes, lizards, two bat species, birds, an apatemyid (an arboreal insectivore), a miacod (a primitive carnivore), insects, and more than 325 types of leaves, seeds, and flowers.