Editing Plesiosaurus (section)

{{Short description|Extinct genus of reptiles}}
{{speciesbox
| name = ''Plesiosaurus''
| fossil_range = [[Early Jurassic]], {{Fossil range|199.5|192.9}}|
| image = Plesiosaurus dolichodeirus NHM.jpg
| image_upright = 1.1
| image_caption = ''Plesiosaurus'' [[type specimen]] at [[Natural History Museum, London|Natural History Museum]] (specimen NHMUK OR 22656)
| display_parents = 3
| genus = Plesiosaurus
| parent_authority = [[Henry De la Beche|De la Beche]] & [[William Daniel Conybeare|Conybeare]], 1821
| authority = Conybeare, 1824
| species = dolichodeirus
}}

'''''Plesiosaurus''''' (Greek: ''{{lang|grc|πλησίος}}'' (''{{lang|grc-Latn|plesios}}''), near to + ''{{lang|grc|σαῦρος}}'' (''{{lang|grc-Latn|sauros}}''), lizard) is a genus of extinct, large marine [[sauropterygia]]n [[reptile]] that lived during the [[Early Jurassic]]. It is known by nearly complete skeletons from the [[Lias Group|Lias]] of England. It is distinguishable by its small head, long and slender neck, broad turtle-like body, a short tail, and two pairs of large, elongated paddles. It lends its name to the order [[Plesiosauria]], of which it is an early, but fairly typical member. It contains only one species, the [[type species|type]], '''''Plesiosaurus dolichodeirus'''''.  Other species once assigned to this genus, including ''P. brachypterygius'', ''P. guilielmiimperatoris'', and ''P. tournemirensis'' have been reassigned to new genera, such as ''[[Hydrorion]]'', ''[[Seeleyosaurus]]'' and ''[[Occitanosaurus|Microcleidus]]''.