Pleurosaurids Temporal range: Early Jurassic - Late Jurassic, 183–145 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Fossil of Pleurosaurus
Fossil of Palaeopleurosaurus
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	Rhynchocephalia
Suborder:	Sphenodontia
Family:	†Pleurosauridae Lydekker, 1888
Genera
†Palaeopleurosaurus †Pleurosaurus †?Derasmosaurus †?Vadasaurus

Pleurosauridae is an extinct family of sphenodontian reptiles, known from the Jurassic of Europe. Members of the family had long-snake like bodies with reduced limbs that were adapted for aquatic life in marine environments. It contains two genera, Palaeopleurosaurus, which is known from the Early Jurassic (Toarcian) Posidonia Shale of Germany, as well as Pleurosaurus from the Late Jurassic of Germany and France. Paleopleurosaurus is more primitive than the later Pleurosaurus, with a skull similar to those of other sphenodontians, while that of Pleurosaurus is highly modified relative to other sphendontians. They likely swam via anguilliform locomotion.^[1] Vadasaurus and Derasmosaurus from the Late Jurassic and Early Cretaceous of Europe have been placed as part of this family in some studies, but lack the body elongation that typifies the other two genera.^[2][3]

v t e Rhynchocephalia
Kingdom: Animalia Phylum: Chordata Class: Reptilia Superorder: Lepidosauria Sauropsida see Sauropsida Lepidosauromorpha see Lepidosauromorpha Rhynchocephalia see below↓ Rhynchocephalia
†Gephyrosauridae? Gephyrosaurus Penegephyrosaurus Deltadectes Sphenodontia †Diphydontosaurus †Godavarisaurus †Micromenodon †Pelecymala †Rebbanasaurus †Sphenocondor Incertae sedis †Paleollanosaurus †Whitakersaurus Acrosphenodontia †Planocephalosaurus †Godavarisaurus? Eusphenodontia †Lanceirosphenodon †Microsphenodon †Opisthiamimus †Polysphenodon †Clevosauridae Brachyrhinodon Clevosaurus Polysphenodon? Neosphenodontia †Colobops? †Homoeosaurus †Lanceirosphenodon? †Pamizinsaurus †Rebbanasaurus? †Sphenocondor? †Theretairus †Zapatadon †Kallimodon †Leptosaurus †Sapheosauridae Piocormus Sapheosaurus Oenosaurus "Eupropalinal sphenodonts" †Lamarquesaurus †Sigmala †Tingitana †Vadasaurus †Pleurosauridae? Palaeopleurosaurus Pleurosaurus Tingitana? Vadasaurus? Sphenodontidae †Ankylosphenodon †Cynosphenodon †Derasmosaurus †Kawasphenodon? †Navajosphenodon †Pamizinsaurus? Sphenodon †Sphenofontis †Sphenovipera? †Theretairus? †Tika †Zapatadon? †Opisthodontia Fraserosphenodon Kawasphenodon? Opisthias Pelecymala? Trullidens Pleurosauridae? Sapheosaurs? Eilenodontinae Eilenodon Kaikaifilusaurus Patagosphenos Priosphenodon Sphenotitan? Toxolophosaurus