Plesiosaur

Plesiosaur Temporal range: Middle Triassic to Upper Cretaceous
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Superorder:	Sauropterygia
Order:	Plesiosauria
Suborder:	Plesiosauroidea Pliosauroidea Gray, 1825

The plesiosaurs were an order of large, carnivorous marine reptiles. They flourished from 203 million years ago (mya) to 66 mya.

In 1719, William Stukeley described the first partial skeleton of a plesiosaur. The great-grandfather of Charles Darwin, Robert Darwin of Elston told him about it.^[1]

Mary Anning was the first to discover a fairly complete plesiosaur. She found it on the 'Jurassic Coast' of Dorset, England in the winter of 1820/21. The fossil was missing its skull, but in 1823 she found another one, this time complete with its skull. The name Plesiosaurus was given to it by the Rev. William Conybeare.

The earliest plesiosaur remains are from the Middle Triassic period.^[2]p128 The group was important through the Jurassic and Cretaceous. They had two large pairs of paddles, short tails, short or long necks, and broad bodies. They died out at the K/T extinction event, 65 million years ago.^[3][4]

1. ↑ Stukeley W. 1719. An account of the impression of the almost entire sceleton of a large animal in a very hard stone, lately presented the Royal Society, from Nottinghamshire. Philosophical Transactions, 30: 963-968.
2. ↑ Benton M.J. 1990. The reign of the reptiles. Quarto N.Y.
3. ↑ Carroll R.L. 1988. Vertebrate paleontology and evolution. Freeman N.Y.
4. ↑ Tutin S. & Butler R. 2017. The completeness of the fossil record of plesiosaurs, marine reptiles from the Mesozoic. Acta Palaeontologica Polonica. doi: 10.4202/app.00355.2017