CARL MARSHALL: Predator X vs Liopleurodon.

Predator X vs Liopleurodon.
For the last three weeks my family and I have been watching "Planet Dinosaur" on BBC1, this edition (4 of 6) of the documentary series was looking at the Dinosaur "Allosaurus" and an new colossal marine Pleosaur known informally as "Predator X". Well as soon as I saw the mighty P. x in motion I got a sudden feeling that I had seen this massive creature before on another documentary called "Walking with Dinosaurs" that aired in 1999 and also in Nigel Marven's "Sea Monsters" in 2003 and that its name was Liopleurodon (smooth sided tooth). Well, I remembered buying a copy of "Sea Monsters", so went to find my copy and get to the bottom of this..

I found it - Liopleurodon, according to the book this monstrous reptile was alive in the mid to late Jurassic (160 -155 mya) and was a colossal 25 meters long (80 feet). So why were the producers of this series making such a fuss out of P.x which came in at 15 meters (49 feet) when an even bigger monster Liopleurodon (from the same clade) had already been discovered- Well after some more research the truth came to light.

Walking with Dinosaurs and Sea Monsters did not tell us the whole truth.

Liopleurodon never reached 25 meters (80 feet), as far as my research implies the largest specimen found was named Liopleurodon ferox and was a (still respectful) 6.50 meters (21 feet) in length, discovered near Peterborough in England. The Liopleurodon Genus was first named by Henri - Emile Sauvage in 1873 with the discovery of L. ferox and eventually contained two more species L. pachydeirus ( European) and L. rossicus (Russian). There was another discovered but wasn't placed into the Liopleurodon genus. The maximum length for Liopleurodon has been a debatable subject for some time, Palaeontologist L.B Tarlo stated that the total length of any Pleosaur ( including Liopleurodon ) could be obtained from skull length eg. a skull at 1.5 meters (4.92 feet) means a Pleosaur at 10.5 meters (34.44feet)

But even these dated ratios do not explane the body length depicted by both "Walking with Dinosaurs and "Sea Monsters".

Predator X.

Discovered in 2006 and excavated in 2008 "Predator X" is the largest Pliosaur ever discovered. It was found in Svalbard near the Arctic by Dr Hurrum of the Natural History Museum at the University of Olso and is estimated at a massive 15 meters (49 feet) long. 20,000 fragments were discovered.

One resource states that P. x had a bite eleven times more powerful than Tyrannosaurus rex-

P. x : 33,000 lb per square inch.
T.rex : 3,000 lb per square inch.
Crocodile :2,500 lb per square inch.


However I have also found information that says that P.x had a bite force ten times more powerful than extant animals but only four times the bite pressure of T. rex.

But whatever the outcome Liopleurodon did not reach lengths anywhere near the 25 meters (80 feet) that "Walking with Dinosaurs" and "Sea Monsters" have claimed, and it seems these two documentary's are actually sisters and have seriously damaged there credibility with these statements.

I believe the largest marine reptile was an Ichthyosaur at an enormous 22.86 meters (75 feet) that lived about 210 mya, so far I don't think it has yet been given a Bi-nominal name.

However I am not a Palaeontologist, I work with modern Reptiles so if anybody reading this has more reliable information about this debate please do comment.