Named By: Druckenmiller - 2002.
Classification: Chordata, Reptilia, Sauropterygia, Plesiosauria, Plesiosauroidea, Polycotylidae.
Species: E. muddi (type).
Size: Estimated around 3.5 meters long.
Known locations: USA - Montana - Thermopolis Shale.
Time period: Albian of the Cretaceous.
Fossil representation: Remains of a single individual including the skull, vertebrae and most of a front leg.
Edgarosaurus seems to have been one of the first polycoylid plesiosaurs to swim in the late Cretaceous Western Interior Seaway, a shallow sea that submerged much of central North American during the Cretaceous. Like its relatives, Edgarosaurus had a typical plesiosaur body but a short neck an elongated jaws, features reminiscent of the pliosaurs. As such Edgarosaurus probably relied upon to speed and manoeuvrability to actively chase down fish where the long jaws would compensate for the lack of a long neck.