Elasmosaurus was a large marine reptile that lived during the Late Cretaceous (about 80 million years ago) in a shallow sea that once covered what is now central North America. It belonged to a group of reptiles called plesiosaurs which are characterized by the possession of a very long neck, small head, turtle-shaped body with flippers rather than legs, and a short tail.Scientific Name: Elasmosaurus, which means ‘thin plate lizard’. This odd name refers to the thin, plate-like bones in the hip skeleton of this animal.Characteristics: At nearly