Peterborough, Cambridgeshire and Bedfordshire, UK; Normandy, France
Referred material (sp.):
To be compiled
Type species:
C. eurymerus
Species:
C. eurymerus
Species author:
(Phillips, 1871)
Type specimen:
NHMUK 22656, complete skeleton.
Age:
Callovian, Late Jurassic
Geological formation:
Oxford Clay Formation
Type location:
Peterborough, England
Referred material:
To be compiled
Species:
C. richardsoni
Species author:
Lydekker, 1889
Type specimen:
To compile
Age:
To compile
Geological formation:
To compile
Type location:
Dorset
Referred material:
To compile
Cryptoclidus, often wrongly spelled ‘Cryptocleidus’ after Andrews (1909), is a moderately sized plesiosaur up to 3 metres long. It is known from a large number of individual specimens from the Oxford Clay Formation. Fossils of Cryptoclidus are relatively common, and provide a complete ontogenetic sequence from very young to old adult individuals. This makes Cryptoclidus one of the most studied and best understood of all plesiosaurs.
Full mounted skeletons of Cryptoclidus can be seen in several major museums including the Musee Palaeontologique, Paris; the Natural History Museum, London; the Hunterian Museum, Glasgow; and the American Museum of Natural History, New York.
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 its humerus, which is more 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.
Referred specimen of Cryptoclidus in the Tubingen Museum, Germany.Referred specimen of Cryptoclidus in the Tubingen Museum, Germany.Reconstruction of the skeleton of Cryptocidus from Andrews (1910)Reconstruction of the skeleton of Cryptoclidus is dorsal view from Gregory (1951)Skull of Cryptoclidus in lateral view. From Brown (1981).Skeleton of Cryptoclidus in lateral view. From Brown (1981).Cryptoclidus eurymerus. Postcard from the Paris Musee de PaleontologieAdult Cryptoclidus, American Museum of Natural History, New York.Adult Cryptoclidus, American Museum of Natural History, New York. Photo by Adam S. SmithAdult Cryptoclidus, American Museum of Natural History, New York. Photo by Adam S. SmithAdult individual of Cryptoclidus in the Natural History Museum, London.Young individual of Cryptoclidus in the Natural History Museum, London.Young individual of Cryptoclidus in the Natural History Museum, London.Young individual of Cryptoclidus in the Natural History Museum, London. Photo by Adam S. Smith 2005.Cryptoclidus (the type specimen of ‘Apractocleidus’, V.1091, with the tail of V.1104 and a replica head) in the Hunterian Museum, Glasgow, Scotland. Photo by Adam S. Smith. 2007.Cryptoclidus excavtionCryptoclidus excavtion3D ‘bust’ of a Cryptoclidus head in the York Museum, UK.3D ‘bust’ of a Cryptoclidus head in the York Museum, UK. Cryptoclidus painting by Zdenek Burian.Cryptoclidus illustration by Zdenek Burian.Cryptoclidus on land, as depicted in ‘Walking with Dinosaurs’. From Martill and Naish 2000.
