Eocene lake deposits famous for fish, plants, insects, birds, reptiles, and exceptionally fine lamination.
RegionWyoming, Utah, and Colorado, USA
Best recordFormation + source
Risk controlLegality + disclosure
Commonly associated fossils
- Knightia and Diplomystus fish
- leaves and insects
- rare birds and reptiles
- stromatolites
Collector cautions
- painted or transferred fish are a known risk
- ask for quarry and layer information
- large or rare vertebrates deserve heightened scientific scrutiny
Provenance questions
- What is the most precise locality that can be responsibly shared?
- What formation, member, quarry, or horizon is claimed?
- Who collected it, when, and on what type of land?
- Was export documentation required, and does paperwork accompany the specimen?
- What preparation, stabilization, repair, or assembly occurred after collection?
Why locality affects identification
Fossil groups have geographic and stratigraphic ranges. Matrix, preservation style, associated fauna, and preparation traditions can support or contradict a locality claim. A famous locality name should never substitute for documentation.
Build a comparison set
Use listings to compare morphology, matrix, preparation, locality claims, dimensions, repairs, and seller disclosure. Similar appearance alone does not establish identity or legality.
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