Stratum.black
Plesiosaurus — Plesiosaurus
Plesiosaurus — Creator:Dmitry Bogdanov, Wikimedia Commons, CC BY 3.0

Marine reptile

Plesiosaurus

Plesiosaur

Plesiosaurus dolichodeirus is the long-necked marine reptile first found complete by Mary Anning at Lyme Regis in 1823. Genuine Plesiosaurus material is limited to the Dorset and Somerset Lias; the name is also loosely applied by dealers to plesiosaur teeth and vertebrae from Morocco (Zarafasaura) and Kansas (Elasmosaurus). Lyme plesiosaur skeletons come to market rarely and attract national interest.

PhylumChordata
ClassReptilia
OrderPlesiosauria
FamilyPlesiosauridae
GroupMarine reptile
Rank (PBDB)genus· Paleobiology Database
Authorde la Beche and Conybeare 1821· Paleobiology Database
Classification (PBDB)Chordata › Reptilia › Plesiosauria › NO_FAMILY_SPECIFIED· Paleobiology Database
Range (PBDB)206–66 Ma· Paleobiology Database
PBDB occurrences55· Paleobiology Database

Photographs

Plesiosaurus — Plesiosaurus dolichodeirus Conybeare, 1824, Figured (NHMUK PV R 1313)
Plesiosaurus dolichodeirus Conybeare, 1824, Figured (NHMUK PV R 1313) — © The Trustees of the Natural History Museum, London, Natural History Museum (London) Data Portal, CC BY 4.0
Plesiosaurus — Plesiosaurus dolichodeirus Conybeare, 1824, Figured (NHMUK PV OR 36183)
Plesiosaurus dolichodeirus Conybeare, 1824, Figured (NHMUK PV OR 36183) — © The Trustees of the Natural History Museum, London, Natural History Museum (London) Data Portal, CC BY 4.0
Plesiosaurus — Plesiosaurus dolichodeirus Conybeare, 1824, Figured (NHMUK PV OR 33287)
Plesiosaurus dolichodeirus Conybeare, 1824, Figured (NHMUK PV OR 33287) — © The Trustees of the Natural History Museum, London, Natural History Museum (London) Data Portal, CC BY 4.0

Age

Formations

Elsewhere

Cite this article

Stratum Study. "Plesiosaurus" (Taxon). Stratum Study pack 2026.09, as of 2026-09-19. https://stratum.black/study/taxa/plesiosaurus. Accessed 2026-09-20.

BibTeX · CSL-JSON

@misc{stratum-plesiosaurus,
  title        = {Plesiosaurus},
  author       = {{Stratum Study}},
  howpublished = {\url{https://stratum.black/study/taxa/plesiosaurus}},
  year         = {2026},
  note         = {Taxon article, Stratum Study pack 2026.09, as of 2026-09-19; sources: stratum, pbdb, wikidata, commons, nhm. Accessed 2026-09-20.}
}

Citations carry the pack version and the article's as-of date so they resolve to the same text later. The facts themselves belong to the sources listed below; cite those for the science.