Authentic Green River Formation Fish Fossil – Kemmerer Wyoming Limestone Matrix

Step back approximately 50 million years with this authentic Knightia eocaena Fish Fossil from the world-famous Green River Formation near Kemmerer, Wyoming. Dating to the Eocene Epoch, this beautifully preserved fossil offers a remarkable glimpse into an ancient freshwater ecosystem that once flourished in what is now the western United States.

During the Eocene, the Green River region was covered by vast subtropical freshwater lakes surrounded by lush vegetation and rich wildlife. Knightia was one of the most common fish species inhabiting these calm ancient waters, swimming in large schools and feeding on small aquatic organisms and plant material. Closely related to modern herring and sardines, Knightia played an important role within this prehistoric lake ecosystem.

When this fish died, it sank to the quiet lakebed where it was rapidly buried beneath ultra-fine sediment. Low oxygen conditions at the bottom of the lake prevented scavengers and decay, allowing delicate skeletal structures to remain beautifully intact. Over millions of years, these sediments compressed and hardened into the fine-grained limestone that made the Green River Formation internationally famous for its extraordinary fossil preservation.

Today, the Green River Formation is regarded as one of the most important fossil localities in the world, providing scientists and collectors with an exceptionally detailed record of prehistoric freshwater life. Fossils from this region help researchers understand ancient climates, lake environments, and the evolution of early fish species while preserving a stunning snapshot of life from the Eocene Epoch.

This authentic Knightia fish fossil is more than a collector’s specimen — it is a genuine piece of prehistoric natural history preserved for millions of years within ancient stone

The Details You Need

✓ SPECIMEN: Fossil Fish
✓ SPECIES: Knightia eocaena
✓ AGE: Eocene Epoch (Approx. 50 Million Years Old)
✓ FORMATION: Green River Formation
✓ LOCATION: Near Kemmerer, Wyoming, USA
✓ SPECIMEN SIZE: 193mm x 131mm x 7.5mm Approximately
✓ FISH SIZE: 130mm x 53mm Approximately
✓ WEIGHT: 423 grams
✓ PRESERVATION: Natural fossil preserved in fine-grained limestone
✓ AUTHENTICITY: Genuine prehistoric freshwater fish fossil
✓ DISPLAY: Ideal for fossil collections, educational displays, and natural history décor

Bring the ancient lakes of the Eocene into your collection and own a beautifully preserved survivor from a world that existed millions of years before humanity.