The Creatures of 'Primeval' -- Giant Sea Snakes and Prehistoric Penguins

Yes, the monsters of "Primeval" are real, for the most part. And every week, KCET is educating you -- and horrifying you -- about the once-real prehistoric monsters featured on the show. Watch "Primeval" every Wednesday at 8 p.m. and then check in online to learn more!

Last week's "Primeval," which starred giant spiders and giant centipedes, clearly sought to make you fear the skittering, multi-legged creatures hiding in the dark corners of your basement. This week? A new element to fear: water.

This week's episode starts on a grabby note with a swimmer taking a leap of the high-dive at the local pool... and being swallowed whole by a towering aquatic snake. Surely, this public pool-dwelling nightmare is an embellished version of a real-life monster, no?

Rendering of a basal mosasaur, via Wikipedia under Creative Commons

No. The creature in question is a mosasaur, a slithery sea-dwelling dinosaur that could stretch as long as 56 feet, snout-to-tail. Picture a monitor lizard on a scale that doesn't bode well for your longevity and you'll get the picture quickly enough. But "Primeval" didn't depict the mosasaur exactly as it looked -- or at least as we're pretty sure it looked. Rather than a crusty, crocodile-like body, it was probably smooth-skinned, like a snake. In fact, it's possible that modern snakes and mosasaurs share a common lineage.

What "Primeval" got right, however, was the mosasaur's ability to swallow prey whole -- like the ill-fated fellow at the beginning of the episode. In fact, according to Wikipedia, a mosasaur skeleton found in South Dakota included bonus fossils, unchewed, in its gut. How thoughtful of this mosasaur, to preserve his lunch for the benefit of future generations of scientists!

By the way, the mosa in the creature's name refers to France's Meuse River, because the first-ever discovered skeleton of this animal was found in 1764 near the Dutch city of Maastricht -- "crossing at the Meuse."

Perhaps even more interesting than a giant, jaw-snapping sea snake is the bizarre aquatic bird glimpsed in this episode: hesperornis.
On "Primeval," they look like prehistoric, toothed ostriches, but in reality they were much more like seals, to the point that these six-foot-tall creatures couldn't even actually stand upright on their hind legs and instead, they just flopped around on land in an ungainly fashion. In the water, however, they could move like a shot, with their legs exerting underwater a level of power they weren't capable of on land.

Rendering of a hesperornis, via Wikipedia under Creative Commons

Notably, paleontologists once mistakenly thought that the birds could stand upright. In fact, the man who first discovered hesperornis -- Othniel Charles Marsh, a dinosaur grand poobah of the 19th century -- named the creature Hersperornis regalis, or "regal western bird" as a result of his perceived stature. And while he may have been way off about how this creature acted on land, he did wisely use the hesperornis as proof of an evolutionary link between reptiles and birds. Scientists continue to make similar arguments today.

And as for Helen Cutter's evaluation of the hesperornis -- "Scary up close but cumbersome, and very stupid" -- we'll just have to wait for science to find a way to let us observe the birds firsthand.