Filmmaker Breathes Life Into 'Sea Monsters'

National Geographic's Lisa Truitt is a veteran producer of Imax films, and her latest project, "Sea Monsters 3D: A Prehistoric Adventure," opening Friday at the National Museum of Natural History, was her biggest challenge yet: re-creating the underwater world of Cretaceous Period marine reptiles. (See review on Page 38.)

"Sea Monsters" follows a young fictional Dolichorhynchops (called a "dolly" for short) who journeys from her shallow-water birthplace to a dangerous ocean teeming with huge sharks, giant fish and fierce predator the Tylosaurus.

The idea for the movie came from a December 2005 story in National Geographic magazine that explored the creatures of the Cretaceous seas. Truitt and her fellow filmmakers scoured fossil records, looking for evidence of "interactions that had happened between species," she says. One fossil became the starting point of the "Sea Monsters" tale: "The Tylosaurus's fossil with the Dolichorhynchops in its belly gave us a point around which we could build the story."

That discovery, as well as another fossil of a shark's tooth embedded in a dolly's rear flipper, propelled the dolphin-size reptile into the movie's spotlight. "Though we can't anthropomorphize it and make it lovable," Truitt says of the Dolichorhynchops, "we wanted an animal that an audience could relate to and see as the heroine of the story." Its appearance -- a cross between a dolphin and a duck, with pointy flippers and a long beak -- helped, too. "It's as cute as marine reptiles get," Truitt says.

Shot and created entirely in 3-D, the 40-minute film contains a lot of computer-generated footage, and Truitt says five animation houses in four countries worked on the film. But the filmmakers also needed to do old-fashioned camera work.

First came a shoot in the Bahamas. To get realistic-looking water for the ocean scenes, Truitt and her team needed footage of open water. Because modern-day sea life wouldn't have existed in the Cretaceous Period, they could only use shots of fish-free ocean. "It was the strangest thing to film scenes of empty water for National Geographic," Pruitt says. "To be saying, 'Make sure there are no fish in the shot!' was very ironic."

Land scenes, depicting fossil excavation sites around the world, were shot in Kansas. Using photos of those actual sites, they "found places in Kansas that looked very, very similar. . . . It would have been really cost-prohibitive to have gone to Israel and Australia and all the various places that appear in the film," she explains. "It's funny because you get out there [to Kansas] and it's all just flat farmland. But in the middle of these farms you find these gorgeous natural features" -- such as limestone cliffs and red-clay flats -- "that we ended up filming."

Kansas is also a treasure trove of marine fossils, because during the Cretaceous Period, the Western Interior Seaway stretched from the Arctic to the Gulf of Mexico, with much of present-day Canada, Mexico and the western and southern United States underwater. Truitt says: "We'd be out there filming and find bones. One time we found a fish fossil right there in the rock."

There was another reason she kept her eyes trained on the ground. Where giant reptiles once swam, now swarm dangerous reptiles of a different sort. "One of the locals said to us, 'Oh, you're filming in late spring? The ground moves out there,' " Truitt recalls. "We weren't quite sure what he meant, but then we found out: There are rattlesnakes and copperheads all over out there."