Liopleurodon

Genus:

Liopleurodon

Genus author:

Sauvage, 1873

Classification:

Age:

Callovian, Middle Jurassic

Location:

Peterborough, England. Also known from Bedfordshire (UK), Cambridgeshire (UK), France (near Boulogne) and possibly Chile.

Referred material (sp.):

sp.

Type species:

Liopleurodon ferox

Species:

L. ferox

Species author:

Sauvage, 1873

Type specimen:

the holotype is only a single tooth

Age:

Callovian, Middle Jurassic

Geological formation:

Oxford Clay Formation

Type location:

Peterborough, England. Also known from Bedfordshire (UK), Cambridgeshire (UK), France (near Boulogne) and possibly Chile.

Referred material:

Known from several partial skeletons and skulls

Species:

L. pachydeirus

Species author:

(Seeley, 1869)

Type specimen:

Associated cervical vertebrae

Age:

Callovian, Middle Jurassic

Geological formation:

Oxford Clay Formation

Type location:

Great Gransden, UK

Referred material:

Liopleurodon is a pliosaur that hardly needs introduction since appearing as the villain in the BBC’s ‘Walking with Dinosaurs’ TV series. This led to popular misconceptions about the size of Liopleurodon, which is known to have reached adult sizes in the region of seven metres long, nowhere near the gargantuan 25m estimate proposed by the series and later perpetuated elsewhere.

Liopleurodon differs from Pliosaurus in the following characters: relatively short mandibular symphysis with 5-7 teeth adjacent to it), each lower jaw ramus contains 25-28 teeth, the teeth have fewer longitudinal ridges on outer (labial) surface relative to the inner (lingual) surface, and relatively longer epipodial bones in the limbs. According to the classification of Tarlo (1960), the teeth of Callovian species of Liopleorodon (L. ferox) are circular in cross section, whereas they are trihedral (triangular in cross section) in later Kimmeridgian species (L. rossicus, L. macromerus). A similar trend occurs in the closely related genus Pliosaurus. However, revision of Jurassic pliosaurid taxonomy is underway and the relationships of Jurassic pliosaurus are still poorly understood. The species macromerus, previosuly included by some authors in Pliosaurus and by others in Liopleurodon, may turn out to be a distict genus.

Also, Liopleurodon was in no way magical, Charlie.

Liopleurodon ferox

L. ferox is the most common species of Liopleurodon from the Oxford Clay, but then a lot of isolated material is referred to it by default.

Mounted skeleton of *Liopleurodon ferox* in the Tubingen Museum, Germany.

Close up of the skull of the mounted skeleton of *Liopleurodon ferox* in the Tubingen Museum, Germany. Photo by Markus Felix Bühler

Skull of *Liopleurodon ferox* in dorsal and ventral view. From Andrews (1897).

Skull of *Liopleurodon ferox* in lateral view and posterior view. From Noe et. al. (2003).

Associated skeleton referred to *Liopleurodon ferox* (from Tarlo, 1960).

Skeleton and muscular reconstruction of *Liopleurodon ferox* in lateral view. From Newman and Tarlo (1967). This reconstruction is probably a composite of several specimens of *Liopleurodon* and *Pliosaurus*.

Skeleton of *Liopleurodon ferox* in dorsal view. From Newman and Tarlo (1967). This reconstruction is probably a composite of several specimens of *Liopleurodon* and *Pliosaurus*.

Liopleurodon pachydeirus

According to Tarlo (1960), L. pachydeirus differs from L. ferox in the morphology of its teeth and cervical vertebrae. L. pachydeirus has enamel ridges closely packed on inner surface and 6-7 evenly spaced ridges on outer surface, cervical vertebrae with faint ventral keel (Tarlo, 1960).