Large as life: a 3D IMAX film provides a close encounter with prehistoric denizens of the deep.(CGI/Stereoscopy)

Gorgosaurus. Pteranodon. Tylosaur. Styxosaurus. Dolichorynchops. These monikers are as large as the creatures they belong to. And these are but a few of the massive beasts that ruled the land and seas more than 82 million years ago. During the late Cretaceous period, size did matter. But then again, nearly all the creatures at the time were super sized. So, it should come as no surprise that when National Geographic decided to bring more than 30 species of these creatures to life for the documentary Sea Monsters: A Prehistoric Adventure, it did so in a big way, via 3D IMAX.

[ILLUSTRATION OMITTED]

The large-format stereoscopic film takes viewers on a journey deep in time, when the middle of North America was submerged beneath a sea inhabited by these otherworldly creatures. Directed by Sean McLeod Phillips and produced by Jini Durr, Lisa Truitt, and Jack Geist, the story follows a curious dolichorynchops and its family as they traverse the most dangerous waters to ever exist.

These 10- to 25-foot-long beasts cruised through the shallow Cretaceous oceans with long paddle-flippers that propelled them through the water. Their long snouts and 30 to 40 thin, sharp teeth enabled them to grab their dinner--fish, squid, and small animals--and swallow their catch whole. No matter how frightening the dolichorynchops may appear today, back in its time period, this dinosaur lived at the bottom of the prehistoric food chain.

The dolichorynchops truly was part of a lost world. Until 2005, only one species, D. osborni, belonged to the genus dolichorynchops. But a happenstance discovery in Saskatchewan, Canada, led to the addition of D. herschelensis to this family of polycotylid plesiosaur. And it is this chance discovery that helps set the film's story in motion.

How do you bring to life a creature that has been extinct for millions of years and whose life scientists can only piece together based on fossil information? For National Geographic, the only choice was with "nearly larger than life" (these were giants, after all) photorealistic stereoscopic 3D containing live-action elements and stunning CGI. Assisting National Geographic on this quest was CineVision Visual Effects and DamnFX, both of which provided a substantial portion of the CGI, with assists from FloqFX and Sassoon Film Design.

Under the supervision of Robin Aristorenas, the small London facility CineVision handled a number of compelling sequences totaling 75 shots, most of which occur underwater as well as some on land. The aboveground shots featured a 30-foot-tall gorgosaurus (a relative of tyrannosaurus) and a family of pteranodons, featherless flying dinosaurs with a 25-foot wingspan. But, as the title of the film suggests, the majority of the action takes place in the water, where CineVision produced most of its shots, ranging from deep-water environments for a big tylosaur fight sequence to clearer, warmer, shallow-water sequences featuring the dolichorynchops, styxosaurus, and a variety of prehistoric fish.