Liopleurodon
Live reconstruction of Liopleurodon ferox
Liopleurodon (Size: Leios = smooth, pleuron = page, odon = tooth) is a genus of Pliosaur (extinct, diapside reptiles), from the Middle Jurassic of Europe, which is known by good fossil record.
- 4.1 Outer systematics
- 4.2 Internal systematics
Features
Skull and teeth
Liopleurodon had a wedge-shaped and flattened skull. On each ramus Liopleurodon had 25 to 28 teeth. A characteristic that is different from L. ferox Pliosaurus is a symphysis in front of the skull, which is longer than that of Pliosaurus. In this part of the skull (above the symphysis ) are 6-7 longer canine teeth that are round in cross section. The teeth in the rear part of the cranium, are more triangular in cross-section. The teeth are sharp, are sawn on one side and plain on the other. You have a deep root, comparable to today's killer whales, or saltwater crocodiles.
Size
Liopleurodon reached an average length of 5 to 7 m. The copy of " Peterborough " is estimated to be 6.39 m, where the skull length was 1.26 meters. This length calculation is based on the assumption of a skull: body ratio of 1:5,19, based on the proportions of the individual GPIT1754 / 2 This one has a skull length of 0.94 m and a total length of 4.88 m.
The largest skull of Liopleurodon can be assigned is 154 inches long. The length of the entire animal was estimated to be slightly more than 10 m, based on the assumption that the cranial 1/7 of the overall length by weight. However, the proportions used for this estimate is probably wrong. Instead, a ratio of 1:4 or 1:5 was adopted. Copies of this order have a weight of 2.5 to 5 tonnes, with average specimens came to about 500 to 750 kilograms. Other models for the estimation of the weight, however, assume that an approximately 5 meter individual already could just weigh a ton.
Pliosaurus macromerus, with an almost 3 m long lower jaw, Liopleurodon was also assigned, but this is not tenable. In Tübingen, a 4.5 m long copy is issued.
Discovery history
Liopleurodon was first described in 1873 by Henri -Émile Sauvage based on three teeth. One was found near Boulogne -sur -Mer in northern France and Liopleurodon ferox ( ferox = wild) assigned. The tooth is 75 mm long. The others were in the department of Cher and the Calvados found. The tooth Cher is 70 mm long and was assigned to L. grossouvrei. Sauvage described the Calvados from as L. buck landi. Only the teeth ferox L. and L. were assigned grossouvrei described by Sauvage. Sauvage not examined the relationships of Liopleurodon. Later (1909 ) was brought to the tooth with skeletal material of an adult animal from the Callovian ( Clay Formation) at Peterborough in England in connection and found a kinship with Pliosaurus. This material was not found, the validity of the taxon was controversial.
Nutrition
Liopleurodon was probably a Spitzenprädator with strong jaws that were well adapted to strong bite.
Bite marks of Liopleurodon were found on bones of the Plesiosaur Cryptocleidus. Generally, Liopleurodon, seen because of sawn and sharp teeth, as a hunter of meaty prey. Worn teeth indicate the hunting of large prey.
Pliosaur be regarded as swimmers who use a four - fin principle and do in the deep sea cephalopods, reptiles and fish hunting.
In addition Pliosaur be seen as prehistoric equivalent of toothed whales.
System
Outer systematics
Liopleurodon is a representative of Pliosauridae family, a group within the Pliosaur, the ( possibly from the Cretaceous ) is known from the Jurassic of Europe and North America.
Liopleurodon was within the group to the basal representatives from the Middle Jurassic. These differ from their relatives from the Upper Jurassic, among other things by the number of tooth sockets and lower cranial, or body length.
A study from 2013 summarizes Liopleurodon, Simolestes, Peloneustes, Pliosaurus and Brachaucheininae together as Thalassophonea.
Inside systematics
Currently there are two types that can be assigned to the genus Liopleurodon:
- Liopleurodon ferox ( type species; England and France)
- Liopleurodon pachydeirus (England)
Differs from L. ferox by features in teeth and cervical vertebrae.
- Undefined type ( Germany, North Rhine -Westphalia)
Sometimes the kind Pliosaurus rossicus Liopleurodon is attributed (L. rossicus ), but in a phylogenischen analysis from the year 2013, this species are listed separately because P. rossicus has a short symphysis with only six tooth sockets.
Popularity
In the BBC television series "Dinosaurs - In the Realm of the Giants " was shown with a length of 25 meters and a weight of 150 tons a Liopleurodon, based on the assumption of a 18 -meter-long Liopleurodon, which was held for juvenile. This quantity is, however, criticized because this specimen likely was not a Liopleurodon, but a distinguished taxon called "Monster of Aramberri ". In addition, it is assumed that the animal was smaller than expected ( 15 meters) and probably fully grown.