Diplomystus & Knightia Fossil Fish Association - Wyoming

This is a beautiful Diplomystus and Knightia fish fossil association that was found near Kemmerer, Wyoming. It is from the Green River Formation and approximately 45-50 million years old. There is part of a third fish, likely another Knightia, present on the rock. It shows nicely on the included acrylic display stand.

50 million years ago, in the Eocene, these fish thrived in Fossil Lake, which was fed by the Uinta and Rocky Mountain highlands. The anoxic conditions at the bottom of Fossil Lake slowed bacterial decomposition, prevented scavengers from disturbing corpses and, most interestingly, suffocated creatures that ventured into the oxygen-starved aquatic layer. The result is a miraculous exhibition of Eocene biota: a subtropical aquatic community within sycamore forests, teeming with creatures such as freshwater stingrays, dog-sized horses, menacing alligators, early flying bats, and one of the first primates.

A view of one of the commercial quarries where fossils from the Green River Formation are collected.