A Tylosaurus, a 40-foot super predator, blasts through the surface of the water, having narrowly missed its prey.

Travel back 82 million years to witness the life-or-death struggles taking place in the depths of the vast inland sea that once covered what is now Kansas in the thrilling IMAX film Sea Monsters 3D: A Prehistoric Adventure.

The film, directed by Sean MacLeod Phillips and produced by National Geographic, brings these prehistoric monsters to toothy life on screen with the aid of realistic computer-generated animation and the 3-D process which brings some of the monsters as close as your nose.

Although most of us are familiar with such legendary dinosaurs as the giant Tyrannosaurus Rex, the three-horned triceratops and the flying pterodactyls, the ancient oceans of the world and their very real sea monsters have remained largely untapped. Sea Monsters 3D gives them their due. It not only presents these denizens of the deep in all their frightening glory, but cleverly creates a personal story that gives them personalities.

Narrator Liev Schreiber follows the adventures of a family of Dolichorhynchops, which he soon affectionately calls “Dollies.” These air-breathing sea creatures look a bit like plump geese as they glide beneath the surface, always on the lookout for small fish to eat while also keeping a wary eye peeled for such terrors as primeval sharks, the bulldog-like fish called Xiphactinus and the 40-foot-long monstrous Tylosaurus, the T-Rex of the Cretaceous ocean. We follow the Dollies — a mother and her twins: a male and a female — as they try to survive in the dangerous sea that once divided North America in two.

Along the way they encounter not only toothy terrors, but also more benign creatures, such as the 35-foot-long Styxosaurus, whose long neck accounted for half its length; the Hesperornis, a flightless bird that prowls the oceans like today’s penguins; and the ammonites, which encased their squid-like tentacles inside a large shell.

Sea Monsters 3D jumps between the prehistoric sea and modern-day Kansas, where a team of paleontologists is unearthing the fossilized bones of a Dolly that has been uncovered by a rainstorm. We learn that they are not the first paleontologists who have been digging up the rolling plains of Kansas, as we are taken back to the early 1900s and the expeditions of Charles F. Sternberg and his sons who unearthed a treasure trove of fossils that included many previously unknown prehistoric sea creatures. One of them, a giant Tylosaurus had the fossil of a recently devoured six-foot-long fish in its stomach. Sea Monsters 3D takes us back 82 million years to bring to life a fascinating theory of how the giant monster died before being able to digest his dinner.

The hunt for fossils continues as we’re taken to more recent finds in Australia, Texas, North Dakota and Israel. But it’s the sea monsters that people have come to see. And there are a lot of very scary ones in the film, which pauses on a lighter note from time to time, such as the story of the cute Dollies and the beauty of a school of ammonites that glow red underwater like brilliant flames. It is a lost world that has been brought to life again.

mjanuson@projo.com