Liopleurodon - Description

Liopleurodon:

Palaeobiology

Four strong paddle-like limbs suggest that Liopleurodon was a powerful swimmer. Its four-flipper mode of propulsion is characteristic of all plesiosaurs. A study involving a swimming robot has demonstrated that although this form of propulsion is not especially efficient, it provides very good acceleration - a desirable character in an ambush predator. Studies of the skull have shown that it could probably scan the water with its nostrils to ascertain the source of certain smells.

Size issue:

Estimating the maximum size of Liopleurodon has become a controversial subject. The paleontologist L. B. Tarlo derived that the total body length of a pliosaur (including Liopleurodon) can be estimated from skull length, in which the skull is approximately one seventh of the entire body. The largest known skull belongs to L. ferox (1.5 meters in length), and according to Tarlo's estimation, this individual would be about 11 m (38 ft) long. However, as with its relative Kronosaurus, there is some uncertainty as to whether Tarlo's estimations are correct.

Recent studies on pliosaurs have cast doubt on Tarlo's estimations, and indicate that pliosaur skulls were about one-fifth of the total body length. Hence, the average size of the L. ferox would have ranged from 7 meters (23 ft) to 10 meters (33 ft) long.

The size estimate of Liopleurodon from the 1999 BBC series Walking with Dinosaurs, which depicts an enormous 25 meter-long Liopleurodon, is not considered to be accurate for any species of Liopleurodon.

Pliosaur remains excavated from Kimmeridge Clay Formatio n of England indicate a much larger taxon, possibly up to 15 meters (49.2 feet long), existed, however they have not been identified as being to Liopleurodon. A mandible on display in the Oxford University Museum of Natural History estimated over 3 meters (preserved 2.875m) was at one time classified as Liopleurodon macromerus. When the mandible was described, it was originally assigned to Stretosaurus (as Stretosaurus macromerus). The genus Stretosaurus later became a junior synonym of Liopleurodon. However, it has been re-classified as Pliosaurus macromerus.

The discovery of a very large pliosaur was announced in 2002, from Mexico, nicknamed the 'Monster of Aramberri'. A cautious estimate placed this juvenile at a bout 15 meters (49.2 ft) long. It was widely reported belonging to Liopleurodon, however no taxonomic conclusions could be made due to poor preservation and fact that the remains were of a partial vertebral column (non-diagnostic). The specimen was dated to the Kimmeridgian age of the La Caja Formation.

In popular culture

In 1999, Liopleurodon was featured in an episode the BBC television series Walking with Dinosaurs. In the program, Liopleurodon was depicted attacking and devouring the theropod dinosaur Eustreptospondylus, before becoming beached during a typhoon and suffocating under its own weight. Two adult Eustreptospondylus who survived the storm feed u pon it. The depiction of Liopleurodon leaping onto the land in order to catch land-based prey is entirely speculative, although the program's producers state that the behavior was inspired by that of orcas.

According to a 2008 article written for About.com, the popularity of Liopleurodon, which had previously been more obscure in popular culture than other well-known pliosaurs such as Kronosaurus, experienced an upsurge following its mention in the online animated short Charlie the Unicorn.