Cryptoclidus


Genus

Cryptoclidus

Author

Seeley, 1892

Classification

Sauropterygia
Eosauropterygia
Eusauropterygia
Pistosauroidea
Pistosauria
Plesiosauria
Plesiosauroidea
Cryptoclididae

Age

Late Jurassic and Lower Cretaceous

Location

Peterborough, Cambridgeshire and Bedfordshire, UK; Normandy, France

Type species

C. eurymerus

Other species

C. richardsoni

Referred material

To be compiled

Cryptoclidus, often wrongly spelled ‘Cryptocleidus’ after Andrews (1909), is a moderately sized (up to 3 metres long) plesiosaur known from a large number of individuals from the Oxford Clay Formation. Fossils of Cryptoclidus are relatively common, which provided a complete ontogenetic sequence from very young to old adult individuals. This makes Cryptoclidus one of the most studied and most understood of all plesiosaurs.

Full skeletal reconstructions of Cryptoclidus can be seen in many major museums including the Musee Palaeontologique in Paris, France; the Natural History Museum, London, England; the Hunterian Museum, Glasgow, Scotland; and the American Museum of Natural History, New York, USA.

The genus has diagnostic teeth with reduced ornamentation. Each premaxilla contains six teeth. Cryptoclidus lacks suborbital fenestrae on its palate and has a large anterior interpterygoid vacuity. A small foramen is located along the postorbital-squamosal junction in C. eurymerus.

Cryptoclidus used its numerous sharp teeth to catch squid and fish, or perhaps to sift silty sediments for benthic animals such as crustaceans.

C. richardsoni differs from C. eurymerus only in the form of the humerus, which is more greatly expanded distally. The genus and species ‘Apractocleidus teretipes‘ was introduced by Smellie (1916) for a specimen now regarded as an old-adult specimen of Cryptoclidus.

C. eurymerus

Species

C. eurymerus

Author

(Phillips, 1871)

Classification

Sauropterygia
Eosauropterygia
Eusauropterygia
Pistosauroidea
Pistosauria
Plesiosauria
Plesiosauroidea
Cryptoclididae
Cryptoclidus

Age

Callovian, Late Jurassic

Formation

Lower Oxford Clay, Upper Jurassic

Type location

Peterborough, England

Type specimen

NHMUK 22656, complete skeleton.

Referred material

To be compiled

C. richardsoni

Species

C. richardsoni

Author

Lydekker, 1889

Classification

Sauropterygia
Eosauropterygia
Eusauropterygia
Pistosauroidea
Pistosauria
Plesiosauria
Plesiosauroidea
Cryptoclididae
Cryptoclidus

Age

To compile

Formation

Lower Oxford Clay Formation, Late Jurassic of

Type location

Dorset

Type specimen

To comile

Referred material

To compile