FINE GAR FISH FOSSIL GREEN RIVER FORMATION, USA, LOWER EOCENE PERIOD, 50 MILLION YEARS B.P. a large and fine fossil plaque featuring Lepisosteus simplex, Priscacara liops and Knightia eocaena specimens (74cm x 125.5cm) Footnote: Note: An exceptionally well-preserved specimen of Lepisosteus simplex. Large and impressive, Lepisosteus simplex (commonly known as a gar) is among the rarest types of fossil fish uncovered at the Green River Formation. A prehistoric hunter, gar fossils are occasionally found with remains of smaller species of the Green River within them. They appear to have preferred the thick reed beds of the shallows rather than deep water. Unusually they also possessed the ability to breathe both air and water, to this day modern gar species surface to take gulps of air. Dating to as early as the Cretaceous, the comparative lack of change in this species has led to it sometimes being referred to as a living fossil.