This is a ferocious looking, 11.3" example of one of the more uncommon fossil fish found in the Green River Formation. It is a Phareodus testis from Warfield's Quarry near Kemmerer. This is a good sized specimen, that is well prepared and makes for a very impressive display. There is a repaired crack running through the rock and the back of the head of the specimen. The rock has been backed with wood for stability and to make it easy to hand on a wall.
If you look closely you can see how Phareodus has a mouthful of sharp pointy teeth making is a voracious lake predator. In fact the name Phareodus actually means "to have tooth" Spines from other fish such as Mioplosus and Priscacara have frequently been found preserved in it's stomach.