Liopleurodon

***Liopleurodon*** is a genus of carnivorous marine reptiles from Jurassic Europe. Scientists believe that two species of *Liopleurodon*, *L. ferox* and *L. pachydeirus*, lived during the Jurassic Period, around 160-150 million years ago. It was a strong swimmer and likely one of the greatest predators of its time. It was about 23 feet (7 metres) long and it weighed about 2 tons. Its skull alone was 5 feet (1 metre) long.

## Description

### Size

To estimate the maximum size of *Liopleurodon* has been a controversial subject. The palaeontologist L. B. Tarlo thought that the full body length of a pliosaur (including *Liopleurodon*) can be guessed from its skull length. Tarlo claimed that the skull of a pliosaur is typically 1/7 of the total length. The largest known skull belonging to *L. ferox* is 34 ft long. Based on Tarlo's hypothesis, this specimen would be around 34 ft long. But, the case of *Kronosaurus* exposed some doubts of the accuracy of Tarlo's suggestion.

New research on pliosaur anatomy has cast doubt on Tarlo's hypothesis of the size of pliosaurs and showed that pliosaur skulls were typically just 1/5 of the body length. An exceptionally well-preserved skeleton of *L. ferox* is in the Institut und Museum für Geologie und Paläontologie der Universität Tübingen in Germany. This specimen is around 15 ft long.
Fossil remains of another specimen identified as *L. ferox* have been excavated from an Oxford Clay formation near Peterborough. This specimen has been estimated to be 21 ftt in length with a skull length of about 4.1 ft and is thought to be an adult. An adult *L. ferox* would have averaged 16-23 long.

Some fossils dug up from the Kimmeridge Clay formation in England show a much larger taxon, possibly up to 49 ft long, but these have not been assigned to the *Liopleurodon* genus.

Part of a jaw bone that measures 9.43 ft is at the Oxford University Museum of Natural History: it is estimated that the total length of the jaw is more than 9.43 ft. The was first assigned to the *Stretosaurus* genus (as *Stretosaurus macromerus*), but is now thought to come from the *Liopleurodon* genus and has been renamed *L. macromerus*. The genus *Stretosaurus* later became a junior synonym of *Liopleurodon*, but it has been re-classified as *Pliosaurus macromerus*.

## Classification

Now, there are three recognized species within *Liopleurodon*. *L. ferox* is well known, the rarer *L. pachydeirus*, described by Seeley as a *Pliosaurus* (1869),and *L. rossicus*, known from the early Volga Beds of Russia. This species was first described by Novozhilov (in 1948) as being from *Pliosaurus*, and is the type species of the genus *Strongylokroptaphus*. Just *L. ferox* is known from more or less complete skeletons.

## History

The genus name *Liopleurodon* was coined by Henri Émile Sauvage in 1873 based on too poor remains made up of three 70 mm teeth. One tooth, found near Boulogne-sur-Mer, France in layers, was named *Liopleurodon ferox*, one from Charly, France was named *Liopleurodon grossouvrei*, while a third found near Caen, France was first described as *Poikilopleuron bucklandi* and ascribed by Sauvage to the species *Liopleurodon bucklandi*. Sauvage did not ascribe the genus to any particular group of reptiles in his descriptions.

Most Liopleurodon fossils have been found in England and France, with one younger species known from Russia. Fossil specimens of the same time are known from Germany.

## Paleobiology

Four strong fin-like limbs suggest that *Liopleurodon* was a mighty swimmer. Its four-flipper mode of propulsion is feature of all plesiosaurs. A study that used a swimming robot has shown that while this form of force is not especially efficient, it provides very good acceleration - a desirable trait in an ambush predator. Studies of the skull have shown that it likely could scan the water with its nose to check the source of some smells.

## Appearance in other media

### *Jurassic Park*

* Liopleurodon is a Legendary reef creature that can be created in Jurassic World: The Game. It was added as a part of the March 16th, 2016 update.

### *The Land Before Time*

* A Liopleurodon is the main antagonist in The Land Before Time IX: Journey to the Big Water and along with other swimming carnivores, such as Cretoxyrhina, are called Swimming Sharpteeth or Sharptooth Swimmers.

## References

Template:References

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4. ↑ Tarlo, L. B. (1959) "Stretosaurus gen. nov., a giant pliosaur from the Kimeridge Clay"
5. ↑ Halstead, L. B. (1989). Plesiosaur locomotion. Journal of the Geological Society, London 146, 37-40.
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7. ↑ Seeley, H.G. (1869). *Index to the Fossil remains of Aves, Ornithosauria, and Reptilia, from the Secondary System of Strata arranged in the Woodwardian Museum of the University of Cambridge*.
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11. ↑ Sachs, S. (1997). "Mesozoische Reptilien aus Nordrhein-Westfalen." Pp. 22-27 in Sachs, S., Rauhut, O.W.M. and Weigert, A. (eds.), *Terra Nostra. 1. Treffen der deutschsprachigen Paläoherpetologen Düsseldorf*.
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13. ↑ Template:Cite news
14. ↑ Carpenter, K. (1997). "Comparative cranial anatomy of two North American Cretaceous plesiosaurs." Pp. 191-216 in Callaway, J.M. and Nicholls, E.L. (eds.), *Ancient Marine Reptiles*. Academic Press.