Fish Fossils

FIsh Fossils

• The Green River Formation records the sedimentation of a group of intermountain lakes in what is now present-day Wyoming, Colorado and Utah. The largest of these lakes was known as Fossil Lake.
• The fossil fish are preserved in very fine sediments that were deposited continuously for 6 million years. Each year two distinct layers were deposited, one during the growing season and the other during the dry season. The average thickness of these fine layers is about .2mm
• The fossil record indicates that this represented a sub-tropical to temporate region during the Eocene.
• There are about 25 known species of fish from the Green River Formation but many are extremely rare. Knightia, Diplomystus and Priscacara are the most common species. Phareodus and Mioplosus are uncommon and after that everything gets pretty rare.

**If ordering online, a random fossil will be packaged and shipped, not all fossils may be available at time of order. Picking a fossil is best done in person, at the shop in Idaho Falls.**