The largest of the common fishes from the Green River Formation  is Phareodus. There are two known species, P. encaustus and P. testis. They average fifteen inches, with a maximum of thirty inches. With the dorsal and anal fins located at the very back of the body, these fish cannot be confused with any other Green River species. They have large very sharp teeth and have been found with the remains of Mioplosus and Priscacara inside.