View source for Plesiosaurus

{{speciesbox
| name = ''Plesiosaurus''
| fossil_range = [[Early Jurassic]], {{Fossil range|199.6|175.6}}
| image = Plesiosauria.png
| image_upright = 1.1
| image_caption = The ''Plesiosaurus'' model.
| display_parents = 3
| genus = Plesiosaurus
| parent_authority = [[William Daniel Conybeare|Conybeare]], 1821
| authority = Conybeare, 1824
| species = dolichodeirus
}}
[[File:Anning Plesiosaur.png|thumb|right|230px|Illustration of one of Anning's finds: ''Plesiosaurus macrocephalus'']]

'''''Plesiosaurus''''' was a large [[fossil]] [[Ocean|marine]] [[reptile]], a genus in the [[Order (biology)|order]] [[Plesiosauria]]. 

The first specimen discovered by [[Mary Anning]] in 1820-21 was missing its [[skull]]. She found it on the '[[Jurassic Coast]]' of [[Lyme Regis]], [[Dorset]], England. In 1823 she found another one, this time complete with its skull. The name ''Plesiosaurus'' was given by the Rev. William Conybeare.

''Plesiosaurus'' was a [[predator]], living mostly on [[fish]] and [[belemnite]]s. It would [[swim]] through [[school]]s of [[fish]] and use its long [[neck]] and sharp [[teeth]] to [[snap]] them up.

''Plesiosaurus'' was a fairly typical member of its order, and measured around 3 to 5 metres (10 to 16 ft) in total length. The snout was short, but the jaws were able to open very wide, and had a series of conical teeth in sockets. The neck was quite long, and the short tail was used for steering. Like all plesiosaurs, it used its large paddles to swim.

Only two [[species]] are known, and the genus existed for about 25 million years from the beginning of the [[Jurassic]] period.

Scientists have wondered whether ancient reptiles like pleisiosaurs were [[warm-blooded]] or [[cold-blooded]]. Scientists from the University of Plymouth studied many animals of different sizes from insects to whales that dive and hold their breath. They found that larger animals can hold their breath longer than smaller animals because they can store more oxygen. They also found this difference was much bigger for warm-blooded animals than for cold-blooded animals. They said this could be why whales became so large. They think since plesiosaurs were also large, like whales, they were more likely to be warm-blooded than cold-blooded.<ref name="Plymouth">{{cite press release|author=University of Plymouth|publisher=Eurekalert.org|title=Scientists reveal new fundamental principles governing diving in animals |url=https://www.eurekalert.org/pub_releases/2020-05/uop-srn052620.php|date=May 26, 2020|accessdate=June 1, 2020}}</ref><ref name="Diving">{{cite journal|doi=10.1098/rspb.2020.0488 |publisher=Proceedings of the Royal Society B|title=Universal metabolic constraints shape the evolutionary ecology of diving in animals|date=May 27, 2020|author1=Wilco C. E. P. Verberk|author2=Piero Calosi|author3=François Brischoux|author4=John I. Spicer|author5=Theodore Garland|author6=David T. Bilton|journal=Proceedings of the Royal Society B: Biological Sciences|volume=287|issue=1927|pmid=32453989|pmc=7287373}}</ref>

Scientists also looked at the phosphate molecules inside plesiosaurs' teeth and saw the oxygen isotopes that suggested they had been warm-blooded.<ref name="Diving" />
 
==References==

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[[Category:Plesiosaurs]]