Plesiosauroidea

Reconstructed skeleton of Plesiosaurus, copyright Kumiko.

Belongs within: Eusauropterygia.

The Plesiosauroidea are a clade of mostly long-necked (sometimes extraordinarily so) marine reptiles known from the Jurassic and Cretaceous periods.

<==Plesiosauroidea
    |--Plesiosaurus de la Beche & Conybeare 1821 H02, D07 [Plesiosauridae]
    |    |--P. brachypterygius Huene 1923 H02
    |    |--P. dolichodeirus Conybeare 1824 DV06
    |    |--P. eurymerus D07
    |    |--P. guilelmiimperatoris D07
    |    |--P. macrocephalus D07
    |    |--P. megdeirus D07
    |    `--P. winspitensis D07
    `--Euplesiosauria [Tricleidida] H02
         |  i. s.: Muraenosaurus Seeley 1874 H02, DV06
         |           |--M. beloclis D07
         |           |--M. elasmosauroides D07
         |           |--M. leedsii D07
         |           `--M. purbecki D07
         |         Alzadasaurus H02
         |         Thalassomedon H02
         |--Elasmosauridae H02
         |    |  i. s.: ‘Plesiosaurus australis Owen 1861 (n. d.) CF02
         |    |         ‘Plesiosaurus’ crassicostatus Owen 1870 (n. d.) CF02
         |    |         ‘Plesiosaurus’ holmesi Hector 1874 (n. d.) CF02
         |    |         ‘Plesiosaurus’ hoodi Owen 1870 (n. d.) CF02
         |    |         ‘Plesiosaurus’ mackayi Hector 1874 (n. d.) CF02
         |    |--Mauisaurus haasti Hector 1874 (see below for synonymy) CF02
         |    |--Tuarangisaurus keyesi Wiffen & Moisley 1986 CF02
         |    |--Occitanosaurus Bardet et al. 1999 H02
         |    |    `--*O. tournemirensis (Sciau, Crochet & Mattei 1990) [=Plesiosaurus tournemirensis] H02
         |    |--Hydrotherosaurus Welles 1943 H02, D07
         |    |    `--H. alexandrae D07
         |    `--Elasmosaurus Cope 1868 D07
         |         |--E. morgani D07
         |         |--E. platyurus D07
         |         |--E. serpentines D07
         |         `--E. snowii D07
         |--Microcleidus H02
         `--+--Cryptoclididae [Cryptocleidoidea] H02
            |    |--Kaiwhekea Cruickshank & Fordyce 2002 CF02
            |    |    `--*K. katiki Cruickshank & Fordyce 2002 CF02
            |    |--Mortuneria Chatterjee & Creisler 1994 CF02
            |    |    `--M. seymourensis CF02
            |    |--Aristonectes Cabrera 1941 CF02
            |    |    `--A. parvidens CF02
            |    |--Colymbosaurus Seeley 1874 [incl. Kimmerosaurus Brown 1981] CF02
            |    |    `--C. trochanterius CF02
            |    |--Cryptoclidus Seeley 1892 CF02
            |    |    |--C. eurymerus CF02
            |    |    |--C. oxoniensis N85
            |    |    `--C. richardsoni D07
            |    `--Tricleidus Andrews 1909 CF02
            |--Cimoliosaurus F71 [Cimoliasauridae H02]
            |    |--C. australis F71
            |    |--C. maccoyi Etheridge 1904 F71
            |    `--C. sutherlandi F71
            `--Polycotylidae H02
                 |--Polycotylus tenuis Hector 1874 (n. d.) CF02
                 |--Dolichorhynchus H02
                 |--Trinacromerum Cragin 1888 DV06
                 |--Plesiopleurodon wellesi H02
                 `--Edgarosaurus Druckenmiller 2002 H02
                      `--E. muddi Druckenmiller 2002 H02

Mauisaurus haasti Hector 1874 [incl. M. brachiolatus Hector 1874, Cimoliosaurus caudalis Hutton 1894] CF02

*Type species of generic name indicated

REFERENCES

[CF02] Cruickshank, A. R. I., & R. E. Fordyce. 2002. A new marine reptile (Sauropterygia) from New Zealand: further evidence for a Late Cretaceous austral radiation of cryptoclidid plesiosaurs. Palaeontology 45 (3): 557–575.

[DV06] Dalla Vecchia, F. M. 2006. A new sauropterygian reptile with plesiosaurian affinity from the Late Triassic of Italy. Rivista Italiana di Paleontologia e Stratigrafia 112 (2): 207–225.

[D07] Dixon, D. 2007. The Complete Illustrated Encyclopedia of Dinosaurs & Prehistoric Creatures. Hermes House: London.

[F71] Fletcher, H. O. 1971. Catalogue of type specimens of fossils in the Australian Museum, Sydney. Australian Museum Memoir 13: 1–167.

[H02] Haubold, H. 2002. Literaturbericht: Ichthyosaurier und Sauropterygier. Zbl. Geol. Paläont. Teil II 5-6: 367–403.

[N85] Norman, D. 1985 (reprinted 2000). The Illustrated Encyclopedia of Dinosaurs. Salamander Books: London.