Plesiosauridae

The Plesiosauridae are a monophyletic family of plesiosaurs named by John Edward Gray in 1825.^[1][2]

Plesiosaurids Temporal range: 199.6–174.7 Ma PreꞒ Ꞓ O S D C P T J K Pg N Early Jurassic - Late Cretaceous?
Plesiosaurus skeleton
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Superorder:	†Sauropterygia
Order:	†Plesiosauria
Superfamily:	†Plesiosauroidea
Family:	†Plesiosauridae Gray, 1825
Genera
†Eretmosaurus †Hydrorion †Leurospondylus? †Plesiosaurus