19.5x21x.75" deep, superb 21.5 lb. specimen contains the fossilized remains of a large 19.5" long Diplomystus fish in the act of eating another fish, a small Knightia. Diplomystus is an extinct genus of freshwater fish distantly related to modern-day herrings, alewives, and sardines. This Diplomystus specimen came from the Lower Eocene (55 million years old) deposits of the Green River Formation in Wyoming. Diplomystus specimens are commonly found in close association w/the extinct herring Knightia as it was a food source, though capturing the moment of feeding is extremely rare. During the Eocene, large inland seas covered much of what is now the Western United States. The most well-preserved Eocene fish fossils come from this region. The example we are offering is nicely preserved, w/nearly all of the vertebrae present and the small tail of the Knightia still clearly visible, clenched in the larger fish's jaws.