Swimming With Sea Rex

The new IMAX 3-D film Sea Rex starts off with a groaner. Standing in front of a shark tank, a young woman named Julie gazes wistfully into the blue water and imagines a plesiosaur paddling through the open sea. "I just know marine dinosaurs still exist!" she says. At this point anyone with even a modest background in vertebrate paleontology would probably facepalm and start mumbling "they weren't dinosaurs, and they have been extinct for millions of years," but just then one of the giants of paleontology steps out of the shadows to tell Julie just that. Stripped of his French accent, but not his early 19th-century garb, the ghost of Georges Cuvier introduces himself to Julie and takes her on a prehistoric sight-seeing tour to set her straight on the science of marine reptiles.

Focused on marine reptiles that were contemporaries of non-avian dinosaurs, Sea Rex follows two different threads: the discovery of the first mosasaur and the succession of ichthyosaurs, plesiosaurs and mosasaurs in the fossil record. The first thread is set up in a historical reenactment showing the delivery of one of the first mosasaur skulls ever found to Paris in 1794. Originally found in a Dutch mine around 1770, the fossil was obtained by the French army, according to paleontological lore, in exchange for 600 bottles of wine. The story is a bit oversimplified, but it goes on to show how the eventual realization that the skull belonged to an ancient marine reptile supported the fact that extinction was real (something which Cuvier had first shown using fossil elephants before turning his attention to the mosasaur in 1808).

The bulk of the film, however, consists of Cuvier showing Julie the highlights of the fossil record. Apparently the ghost of the French naturalist kept up with modern science since his death, as he begins his tour of Deep Time by reviewing the timing of a few major events in evolutionary history to place the film's marine reptiles in context. Once this is done, the documentary takes on a Walking With Dinosaurs theme, following Nothosaurus, Mixosaurus, Shonisaurus, Elasmosaurus, Liopleurodon, Mosasaurus and other marine reptiles as they swim, bite and otherwise mug for the camera.

The strangest part of this middle portion of the film was the appearance of several well-known marine reptile experts. The first to be introduced was University of California at Davis paleontologist Ryosuke Motani, but the man on the screen was not the same person who I had seen at the annual Society of Vertebrate Paleontology meeting a few weeks before. As the credits would later confirm, Motani and several of his colleagues did not actually appear in the film, but were played by actors impersonating real scientists. This was very odd—why not simply invite the real scientists to explain their work, or make up a fictional scientist rather than use the names and affiliations of actual scientists?

I was also disappointed that the evolution of marine reptiles was almost entirely left out of the film. Admittedly the origins of ichthyosaurs, plesiosaurs and mosasaurs have not been entirely worked out, but we do know enough that the filmmakers could have outlined how each lineage changed over time. Perhaps fitting for a film starring the ghost of Cuvier, the animals are simply presented as successive rulers of the sea, just as 19th century naturalists talked about series of successive worlds without drawing direct connections among them. If audiences are already being taken on a tour of Deep Time, it is a shame to waste an opportunity to talk about what fossils can tell us about how life has evolved.

While I have grown tired of the Walking With Dinosaurs type of storytelling, the film deserves credit for taking the time to place marine reptiles within the more expansive context of geological time. The historical aspect of the film, while not entirely accurate, also drove home the point that the study of the fossil record opened up entire vanished worlds of strange creatures the likes of which had never been seen before, and modern paleontologists are still carrying on in the tradition of Cuvier.

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