sedimentary

Fossilized Knightia Fish

Knightia eocaena (set in fossiliferous Micritic Limestone)

AI-generated identification · may be incorrect

Hardness: 3-4 (matrix); Color: Tan/Brown fossil on creamy white/buff matrix; Luster: Dull/Earthy; Structure: Fine-grained laminate; Specific Gravity: Approx. 2.5-2.7

Hardness: 3-4 (matrix)
Color: Tan/Brown fossil on creamy white/buff matrix
Luster: Dull/Earthy

Identified March 11, 2026More sedimentary →

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Physical properties

Hardness: 3-4 (matrix); Color: Tan/Brown fossil on creamy white/buff matrix; Luster: Dull/Earthy; Structure: Fine-grained laminate; Specific Gravity: Approx. 2.5-2.7

Formation & geological history

Formed during the Eocene Epoch (approx. 50 million years ago) in the Green River Formation. Preserved in a low-oxygen, high-calcium lake environment (Lagerstätte) specifically within the Fossil Lake unit.

Uses & applications

Primarily used as educational specimens, interior decor, and for scientific study in paleontology. Highly valued as an introductory piece for fossil collectors.

Geological facts

Knightia is the state fossil of Wyoming. It is an extinct genus of clupeid (herring-like) fish that traveled in massive schools, which often led to large-scale 'mass mortality layers' that are now commercially quarried.

Field identification & locations

Identify by finding thin, flat layers of shale or limestone that split easily to reveal dark, carbonized skeletons. Most commonly found in Kemmerer, Wyoming. Collectors look for complete skeletons with clear fins and skulls.