During the Eocene, 40-50 million years ago, vast shoals of freshwater fish inhabited a large shallow inland sea across the American West. The herring-like fish of the genus Knightia were far and away the most abundant freshwater fish during this era, and because of this they are one of the most frequently found vertebrate fossils on earth. Originating from the famed Green River Formation in Wyoming, fossils of Knightia eocaena and their close relatives are popular among both amateur and seasoned collectors due to their delicate preservation of detail, often including scale and other soft tissue traces against a high contrast laminated limestone slab. Each of our fish fossil specimens has been expertly prepared and is 100% authentic and unrestored or repaired.