Cryptoclidus (/krɪptoʊˈklaɪdəs/ krip-toh-KLY-dəs) is a genus of plesiosaur reptile from the Middle Jurassic period of England, France, and Cuba.

Discovery

Skeleton AMNH 995

Cryptoclidus was a plesiosaur whose specimens include adult and juvenile skeletons, and remains which have been found in various degrees of preservation in England, Northern France, Russia, and South America. Its name, meaning "hidden clavicles", refer to its small, practically invisible clavicles buried in its front limb girdle.

The type species was initially described as Plesiosaurus eurymerus. The specific name "wide femur" refers to the forelimb, which was mistaken for a hindlimb at the time. It was moved to its own genus Cryptoclidus by Seeley (1892).

Fossils of Cryptoclidus have been found in the Oxford Clay of Cambridgeshire, England. The dubious species Cryptoclidus beaugrandi is known from Kimmeridgian-age deposits in Boulogne-sur-Mer, France. Cryptoclidus vignalensis, which is now considered undiagnostic, hails from the Jagua Formation of western Cuba.

In 2016, there was a report about a fragmentary Cryptoclidus postcranial skeleton from the Callovian deposits of Nikitino village in Spassky District, Ryazan Oblast, Russia, but later Zverkov et al. defined it as an intedermitate cryptoclidid.

Description

Life reconstruction of C. eurymerus

Cryptoclidus was a medium-sized plesiosaur, with the largest individuals measuring up to 4 m (13 ft) long and weighing about 737–756 kg (1,625–1,667 lb). The fragile build of the head and teeth preclude any grappling with prey, and suggest a diet of small, soft-bodied animals such as squid and shoaling fish. Cryptoclidus may have used its long, intermeshing teeth to strain small prey from the water, or perhaps sift through sediment for buried animals.

The size and shape of the nares and nasal openings have led Brown and Cruickshank (1994) to argue that they were used to sample seawater for smells and chemical traces.

Classification

Life restoration of C. oxoniensis, currently considered a dubious species synonymous with C. eurymerus
Cast of a fossil skeleton, University of Tübingen, with the fore and hindlimbs swapped

The cladogram below follows the topology from Benson et al. (2012) analysis.

Pistosauria"Pistosaurus postcranium" Pistosaurus Yunguisaurus liae Augustasaurus hagdorni Plesiosauria Bobosaurus forojuliensis NHMUK 49202 [now Anningasaura lymense] Rhomaleosauridae Neoplesiosauria Pliosauridae Thalassiodracon hawkinsii Hauffiosaurus spp. Attenborosaurus conybeari advanced pliosaurids (Peloneustes) Plesiosauroidea Eoplesiosaurus antiquior Plesiosaurus dolichodeirus Plesiopterys wildi Cryptoclidus eurymerus Microcleididae Eretmosaurus rugosus Westphaliasaurus simonsensii Seeleyosaurus guilelmiimperatoris Microcleidus tournemiensis Microcleidus brachypterygius Microcleidus homalospondylus
"Pistosaurus postcranium"
Pistosaurus
Yunguisaurus liae
Augustasaurus hagdorni Plesiosauria Bobosaurus forojuliensis NHMUK 49202 [now Anningasaura lymense] Rhomaleosauridae Neoplesiosauria Pliosauridae Thalassiodracon hawkinsii Hauffiosaurus spp. Attenborosaurus conybeari advanced pliosaurids (Peloneustes) Plesiosauroidea Eoplesiosaurus antiquior Plesiosaurus dolichodeirus Plesiopterys wildi Cryptoclidus eurymerus Microcleididae Eretmosaurus rugosus Westphaliasaurus simonsensii Seeleyosaurus guilelmiimperatoris Microcleidus tournemiensis Microcleidus brachypterygius Microcleidus homalospondylus
Augustasaurus hagdorni
PlesiosauriaBobosaurus forojuliensis NHMUK 49202 [now Anningasaura lymense] Rhomaleosauridae Neoplesiosauria Pliosauridae Thalassiodracon hawkinsii Hauffiosaurus spp. Attenborosaurus conybeari advanced pliosaurids (Peloneustes) Plesiosauroidea Eoplesiosaurus antiquior Plesiosaurus dolichodeirus Plesiopterys wildi Cryptoclidus eurymerus Microcleididae Eretmosaurus rugosus Westphaliasaurus simonsensii Seeleyosaurus guilelmiimperatoris Microcleidus tournemiensis Microcleidus brachypterygius Microcleidus homalospondylus
Bobosaurus forojuliensis
NHMUK 49202 [now Anningasaura lymense] Rhomaleosauridae Neoplesiosauria Pliosauridae Thalassiodracon hawkinsii Hauffiosaurus spp. Attenborosaurus conybeari advanced pliosaurids (Peloneustes) Plesiosauroidea Eoplesiosaurus antiquior Plesiosaurus dolichodeirus Plesiopterys wildi Cryptoclidus eurymerus Microcleididae Eretmosaurus rugosus Westphaliasaurus simonsensii Seeleyosaurus guilelmiimperatoris Microcleidus tournemiensis Microcleidus brachypterygius Microcleidus homalospondylus
NHMUK 49202 [now Anningasaura lymense]
Rhomaleosauridae Neoplesiosauria Pliosauridae Thalassiodracon hawkinsii Hauffiosaurus spp. Attenborosaurus conybeari advanced pliosaurids (Peloneustes) Plesiosauroidea Eoplesiosaurus antiquior Plesiosaurus dolichodeirus Plesiopterys wildi Cryptoclidus eurymerus Microcleididae Eretmosaurus rugosus Westphaliasaurus simonsensii Seeleyosaurus guilelmiimperatoris Microcleidus tournemiensis Microcleidus brachypterygius Microcleidus homalospondylus
Rhomaleosauridae
NeoplesiosauriaPliosauridae Thalassiodracon hawkinsii Hauffiosaurus spp. Attenborosaurus conybeari advanced pliosaurids (Peloneustes) Plesiosauroidea Eoplesiosaurus antiquior Plesiosaurus dolichodeirus Plesiopterys wildi Cryptoclidus eurymerus Microcleididae Eretmosaurus rugosus Westphaliasaurus simonsensii Seeleyosaurus guilelmiimperatoris Microcleidus tournemiensis Microcleidus brachypterygius Microcleidus homalospondylus
PliosauridaeThalassiodracon hawkinsii Hauffiosaurus spp. Attenborosaurus conybeari advanced pliosaurids (Peloneustes)
Thalassiodracon hawkinsii
Hauffiosaurus spp. Attenborosaurus conybeari advanced pliosaurids (Peloneustes)
Hauffiosaurus spp.
Attenborosaurus conybeari advanced pliosaurids (Peloneustes)
Attenborosaurus conybeari
advanced pliosaurids (Peloneustes)
PlesiosauroideaEoplesiosaurus antiquior Plesiosaurus dolichodeirus Plesiopterys wildi Cryptoclidus eurymerus Microcleididae Eretmosaurus rugosus Westphaliasaurus simonsensii Seeleyosaurus guilelmiimperatoris Microcleidus tournemiensis Microcleidus brachypterygius Microcleidus homalospondylus
Eoplesiosaurus antiquior
Plesiosaurus dolichodeirus Plesiopterys wildi Cryptoclidus eurymerus Microcleididae Eretmosaurus rugosus Westphaliasaurus simonsensii Seeleyosaurus guilelmiimperatoris Microcleidus tournemiensis Microcleidus brachypterygius Microcleidus homalospondylus
Plesiosaurus dolichodeirus
Plesiopterys wildi Cryptoclidus eurymerus Microcleididae Eretmosaurus rugosus Westphaliasaurus simonsensii Seeleyosaurus guilelmiimperatoris Microcleidus tournemiensis Microcleidus brachypterygius Microcleidus homalospondylus
Plesiopterys wildi Cryptoclidus eurymerus
Plesiopterys wildi
Cryptoclidus eurymerus
MicrocleididaeEretmosaurus rugosus Westphaliasaurus simonsensii Seeleyosaurus guilelmiimperatoris Microcleidus tournemiensis Microcleidus brachypterygius Microcleidus homalospondylus
Eretmosaurus rugosus
Westphaliasaurus simonsensii
Seeleyosaurus guilelmiimperatoris Microcleidus tournemiensis Microcleidus brachypterygius Microcleidus homalospondylus
Seeleyosaurus guilelmiimperatoris
Microcleidus tournemiensis Microcleidus brachypterygius Microcleidus homalospondylus
Microcleidus tournemiensis
Microcleidus brachypterygius Microcleidus homalospondylus
Microcleidus brachypterygius
Microcleidus homalospondylus

See also

Further reading

  • Z. Gasparini and L. Spaletti. 1993. First Callovian plesiosaurs from the Neuquen Basin, Argentina. Ameghiniana 30(3):245-254

External links