Liopleurodon: Prehistoric Animal of the Week

Liopleurodon was a predatory marine reptile that swam in the oceans that once covered Europe during the Jurassic Period 155 million years ago.

Liopleurodon ferox life reconstruction by Christopher DiPiazza.

This prehistoric sea monster became popular by the hit BBC series "Walking with Dinosaurs" in which Liopleurodon played the roll of a total badass, killing and eating pretty much every other animal it coexisted with during the course of just one episode.  In the show it was portrayed as being over 80 feet long when in reality Liopleurodon actually only measured a little over 22 feet. (Much smaller, yes, but still not an animal I would want to meet while swimming!)  Liopleurodon also is a bit of an internet star since it was featured in a viral video on youtube called "Charlie the Unicorn".

During the year 2007 I, too was guilty of saying "Magical Liopleurodon!" in a high-pitched whisper at least once and thought i was funny.  Still do, actually.  Don't judge me.

Liopleurodon belongs to a large order of animals called Plesiosauria.  Plesiosaurs were not actual dinosaurs but marine reptiles characterized by having four paddle-shaped flippers, short, robust bodies, and short tails.  Like all reptiles, they would have had lungs and would have needed to surface for breathing, much like modern sea turtles and whales do.  They existed in the ocean from the early Jurassic and persisted from there until the Late Cretaceous when the sudden mass extinction that also killed most of the dinosaurs occurred.  Some of them had extremely long necks with tiny heads while others, like Liopleurodon had short necks with huge heads complete with powerful jaws filled with interlocking cone-shaped teeth.

Skeletal mount of Liopleurodon ferox from the Tubingen Museum in Germany.

Liopleurodon would have been able to swim quickly at least in short bursts to ambush prey thanks to large muscles attached to he base of each of its flippers.  Also, like all plesiosaurs, the bones on the underside of Lioplurodon's body, called gastralia (belly ribs), as well as its sternum (breast bone), scapulae (shoulder bones) and pelvis (hips) were all wide, flat and almost fused together.  This would have made its body stable and rigid which is important for any animal that uses its limbs to swim.  This same morphology is present in modern turtles.  Liopleurodon had eyes that were fixed looking above it which gives clues as to how it probably hunted.  It may have swam in deeper, darker water, out of sight from its prey swimming above.  At the right moment it would have used its powerful flippers to give it a short-lived, but powerful, burst of speed, ambushing from the black depths below like a giant scaly torpedo with teeth.  Modern Great White Sharks hunt in a similar manner. 

That's it for this week!  Special thanks to paleontologist, Dr. Adam Stuart Smith, who is an expert on plesiosaurs and contributed information to today's post.  He also provided input when I was painting the reconstruction you now see at the top of the post for scientific accuracy. (yay!)  Tune in next week for a special Saint Patrick's Day prehistoric beast! 

References

NOE, LESLIE F.; JEFF LISTON and MARK EVANS (2003). "The first relatively complete exoccipital-opisthotic from the braincase of the Callovian pliosaur, Liopleurodon". Geological Magazine (UK: Cambridge University Press) 140 (4): 479–486. doi:10.1017/S0016756803007829

 Halstead, L. B. (1989). Plesiosaur locomotion. Journal of the Geological Society, London 146, 37-40.

Smith, Adam. "Liopleurodon Sauvage, 1873." The Plesiosaur Directory. N.p., n.d. Web. Mar. 2013.