Large 6 Inch Knightia Eocaena

This is a large Knightia eocaena from the famous Green River Formation, not to be confused with the more common and smaller Knightia alta. The 50 million year old fish is wonderfully detailed and the coffee colored preservation contrasts very well with the large rectangular slab of shale it is displayed on.

It comes from the coveted 18 inch layer of the Green River Formation which produces darker and more detailed fish than the majority on the market. The rock from this layer is much harder and more durable. This layer is typically collected at night using low angle light to see the bump in the rock that the back bone create. They then cut these fish out and take them to a lab where the fish which maybe up to an inch under the surface of the rock are meticulously extracted under microscope with hand tools.

Like essentially ALL fish from the 18 inch layer, there is some minor restoration to repair small bits of scale that flaked off during prep and on some fin tips (which typically don't preserve well)

The 12x8 matrix can be cut down to a smaller size at the buyers request.

Knightia is an extinct genus of schooling, ray-finned, spindle-shaped, bony fish that shares a family with herrings and sardines. They lived in the freshwater (lacustrine) environments of North America and were eaten by just about everything that was bigger. They ate insects and smaller fish, and used gill rakers to feast on plankton. Knightia eocena is the largest of the three species of Knightia, with a typical length of about 15 centimeters. It is the state fossil of Wyoming.

These fish had rows of dorsal and ventral scutes running from the back of the head to the medial fins. They had heavy scales, and small conical teeth. They are popular finds in the Wyoming lagerstätte, and were a primary food source to the large and hungry vertebrates of that once hunted the Green River Formation.

The Green River Formation is an Eocene-aged geologic formation that records the sedimentation in a group of intermountain lakes in three basins along the present-day Green River in Colorado, Wyoming, and Utah. The Eocene spanned approximately 55.8 to 33.8 million years ago. This formation has distinct stratigraphy that displays alternating light and dark layers representing seasonal erosion and deposition.

Freshwater basins, charged by the Uinta Mountains on the Wyoming-Utah border, contained an enormous representation of taxa. The beginning of the Eocene was marked by warm upper latitudes, a greenhouse atmosphere rich in methane and carbon dioxide, and local climates stabilized by large lakes populated by such creatures as crocodiles. Fossil Lake in Wyoming, of which the Green River Formation includes, is known for its well-preserved warm, lacustrine ecology.

The end of the Eocene was dramatically different, with the onset of icehouse climate characteristics, a change in atmospheric chemistry, and possible bolide impacts. The Green River fossils date about 48 million years, but cover several million years, including the transition between the moist early Eocene climate and the slightly drier mid-Eocene.
SOLD
DETAILS
SPECIES
Knightia eocaena
LOCATION
Kemmerer, Wyoming
FORMATION
Green River Formation
SIZE
6" on 12x8 plate
CATEGORY
ITEM
#272
GUARANTEE
We guarantee the authenticity of all of our
specimens. Read more about our
Authenticity Guarantee.