Hyposaurus was a genus of crocodile that lived in the sea.
This fearsome marine crocodile was first described in 1849 by the noted paleontologist Richard Owen. His type specimen is from our New Jersey greensands. Its long tail, snout and body, with smooth, lightweight armor lead him to conclude that unlike most modern crocodiles, Hyposaurus spent its life in the ocean, hunting sea creatures. It probably preyed on the fish, rays, smaller sharks, turtles and ammonites that are also found in the quarry.