Liopleurodon
Liopleurodon (/ˌlaɪoʊˈplʊərədɒn/; meaning 'smooth-sided teeth') is a genus of large, carnivorous marine reptile belonging to the Pliosauroidea, a clade of short-necked plesiosaurs. The two species of Liopleurodon lived from the Callovian Stage of the Middle Jurassic to the Kimmeridgian stage of the Late Jurassic Period (c. 166 to 155 mya). It was the apex predator of the Middle to Late Jurassic seas that covered Europe. The largest species, L. ferox, is estimated to have grown up to 6.4 metres (21 ft) in length.[1]
The name "Liopleurodon" (meaning "smooth-sided tooth") derives from Ancient Greek words: λεῖος leios, "smooth"; πλευρά pleurá, "side" or "rib"; and ὀδόν odṓn, "tooth".
The genus name Liopleurodon was coined by Henri Émile Sauvage in 1873. Sauvage named three species which he assigned to this genus, each based on a single tooth. One tooth, its crown[2]: 133 measuring 7.5 centimetres (3.0 in) long, was found near Boulogne-sur-Mer, France in layers dating from the Callovian,[2]: 32 and was named Liopleurodon ferox. Another from Charly, France, measuring 7 centimetres (2.8 in) long and with a crown length of 5.5 centimetres (2.2 in), was named Liopleurodon grossouvrei. The third, discovered near Caen, France was originally attributed to Poikilopleuron bucklandi by Eudes Deslongchamps. While the tooth could have come from the megalosaur, Sauvage considered this identity unsubstantiated, and assigned it to the species Liopleurodon bucklandi. Sauvage did not ascribe the genus to any particular group of reptiles in his descriptions.[3]
Liopleurodon fossils have been found mainly in England and France. Fossil specimens that are contemporary (Callovian-Kimmeridgian) with those from England and France referrable to Liopleurodon are known from Germany.[4][5]
Currently, there are two recognized species within Liopleurodon. From the Callovian-Kimmeridgian of England and France L. ferox is well known; while also from the Callovian-Kimmeridgian of England is the rarer L. pachydeirus, described by Seeley (1869) as a species of Pliosaurus (1869).[6] Only L. ferox is known from more or less complete skeletons. Liopleurodon grossouvrei, although synonymized with Pliosaurus andrewsi by most authors, may be a distinct genus in its own right given differences from P. andrewsi and Liopleurodon type species.[7]
Liopleurodon ferox first came to the public attention in 1999 when it was featured in an episode of the BBC television series Walking with Dinosaurs, which depicted it as an enormous 25 m (82 ft) long and 150 t (330,000 lb) predator; this was based on very fragmentary remains, and considered to be an exaggeration for Liopleurodon,[8] with the calculations of 20-metre specimens generally considered dubious.[9]
,_London_(1910)_(20864103542).jpg/440px-thumbnail.jpg)
,_London_(1910)_(20864103542).jpg){kind=link}
