Pleurosaurus, from Ancient Greek πλευρά ( pleurá), meaning "rib" or "side", and σαυρος ( sauros), meaning "lizard", is an extinct genus of aquatic belonging to the order Rhynchocephalia. Pleurosaurus fossils have primarily been discovered in the Solnhofen Limestone of Bavaria, Germany and the Canjuers lagerstatte near Canjuers, France, both dating to the Late Jurassic. It contains two species, P. goldfussi and P. ginsburgi.[Dupret, V. (2004). The pleurosaurs: anatomy and phylogeny. Revue de Paléobiologie, 9: 61-80.[1]]
History of discovery
Pleurosaurus was first described from the Solnhofen Limestone by Christian Erich Hermann von Meyer in 1834, based on the species
Pleurosaurus goldfussi. In 1970 fossils were reported from the lithographic limestones in a quarry near the village of
Aiguines in the
Canjuers plateau, France. In 1974,
Pleurosaurus ginsburgi was described based on MNHN 1983-4-CNJ 67, a mostly complete skeleton found at the Aiguines quarry.
is one of two unambiguous members of the family
Pleurosauridae, alongside
Palaeopleurosaurus from the Early Jurassic of Germany.
In 2012, fragmentary remains likely belonging to
P. goldfussi were reported from central Poland.
Description
Pleurosaurus is one of the few known
aquatic animal sphenodontians. It reached a maximum body length of .
[Michael Benton, Vertebrate Paleontology 2009 p. 455 (3rd Edition)] The body and especially the tail were elongated, while the limbs were comparatively short. The elongated triangular skull was highly modified from those present in other rhynchocephalians.
Pleurosaurus swam via undulating its tail from side to side (anguilliform locomotion), while it probably used its limbs to steer. It lived in shallow marine environments, and was probably
Piscivore.
and
Pleurosaurus ginsburgi are distinguished by differing skull proportions, different numbers of presacral vertebrae (50 in
P. goldfussi vs 57 in
P. ginsburgi), and considerably shorter forelimbs on
P. ginsburgi.
