Produced by National Geographic in the IMAX 3D format, Sea Monsters: A Prehistoric Adventure blends educational information about major paleontological discoveries of the 20th and 21st centuries, and impressive CG recreations of life in the Earth s vast oceans during the late Cretaceous period. The story begins with a re-enactment of the discovery of a Dolichorhynchops fossil in the once submerged plains of Kansas in the 1920s. From there, the movie traces the life of this flippered, dolphin-sized plesiosaur, nicknamed Dolly, as she migrates from the spawning grounds of her birth, through deeper waters teeming with life that is often massive and predatory, and back to shallow water to birth offspring herself. Along the way, the feature cuts back to live-action reproductions of other paleontological discoveries that serve as introductions to sea creatures such as the long and toothy Styxosaurus, snail-like Ammonites, prehistoric sharks called Cretoxyrhina, and the 50-foot long Tylosaurus. Voice-over narration by Liev Schrieber (X-Men Origins: Wolverine) provides necessary context for the creatures we meet.