Fish Fossils

Fish fossils can preserve remarkable details, including bones, fins and the outline of the body. Some of the best-known examples come from the Green River Formation in the western United States, where ancient freshwater lakes supported a rich variety of life.

At Fossil Lake in Wyoming, lake sediments accumulated around 52 million years ago. Fine sediment and microbial mats on the lake bed helped preserve many fish with their skeletons still connected. These remains became enclosed in layers of limestone, recording details of an ancient freshwater ecosystem.

When choosing a fish fossil, look at the visibility of the skeleton, the completeness of the outline and the contrast between the fossil and its surrounding stone. Each specimen offers a different view of life from the distant past.