Knightia Fish Fossils Death Assemblage from Fossil Lake Gosiute

Description: I was privileged to pick up this wonderful mass fish mortality plate from an associate recently. The plate was legally quarried from a private ranch. The adjoining known collecting areas on government-managed land have been closed to the public for many years. This plate has five mostly complete specimens along with many that are partial or partially exposed. Further careful preparation would reveal more detail on several of the fish. The plate itself is solid and heavy, weighing in at 6 pounds 10 ounces. It would make an intriguing collection centerpiece, or, add a decorative flourish to any room. This is the last plate I have to offer in 2014.

The fossil fish from Lake Goisute have a different type preservation compared to the more commonly found “split fish” or “18 inch layer” fish from Fossil Lake. The Lake Gosiute shales are often dolostones, limestones, or oil shales. Though the fish in both lakes comprise the same species, the ones from Lake Goisute have a different look and presence. They exhibit very good bony detail and a somewhat ghostly appearance. Their distinctive look makes them instantly recognizable to the knowledgeable collector's eye. The fossil fish from Lake Gosiute are also difficult to acquire since the prohibition of collecting in these beds a few decades ago.

This particular fish is Knightia alta, a close relative of Knightia eocaena. Knightia was a schooling fish, which is sometimes found in mass mortality layers, confined to a single plane, indicative of a single event. Theories as to the reasons include stratified water turnovers as well as poisoning due to blooms of blue-green algae.