The evolution of plesiosaur and pliosaur morphotypes in the Plesiosauria (Reptilia: Sauropterygia)

@inproceedings{OKeefe2002TheEO,
  title={The evolution of plesiosaur and pliosaur morphotypes in the Plesiosauria (Reptilia: Sauropterygia)},
  author={F. Robin O'Keefe},
  booktitle={Paleobiology},
  year={2002}
}
  • F. O'Keefe
  • Published in Paleobiology 21 December 2002
  • Geography, Environmental Science
Abstract The dichotomy between short-necked, large-headed “pliosaurs” and long-necked, small-headed “plesiosaurs” has formed the basis of plesiosaur taxonomy for over one hundred years. Recent work has cast doubt on the taxonomic validity of this dichotomy, suggesting that the pliosaur morphotype may have evolved independently in more than one clade. This paper quantifies the variation in body proportion in the clade Plesiosauria using principal component analysis and demonstrates that the… 

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TLDR
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The first phylogenetic analysis dedicated to in-group relationships of pliosaurs allows us to hypothesise a number of well-supported lineages that correlate with marine biogeography and the palaeoecology of these reptiles.

The Anatomy and Taxonomy of Macroplata tenuiceps (Sauropterygia, Plesiosauria) from the Hettangian (Lower Jurassic) of Warwickshire, United Kingdom

ABSTRACT A detailed re-description and revised diagnosis is given for Macroplata tenuiceps Swinton, 1930, a plesiosaurian known from a single almost complete specimen (BMNH R5488) from the Blue

Viviparity and K-Selected Life History in a Mesozoic Marine Plesiosaur (Reptilia, Sauropterygia)

TLDR
Quantitative analysis indicates that plesiosaurs gave birth to large, probably single progeny, and the combination of viviparity, large offspring size, and small brood number differs markedly from the pattern seen in other marine reptiles but does resemble the K-selected strategy of all extant marine mammals and a few extant lizards.

THE ANATOMY AND TAXONOMY OF MACROPLAT A TENUICEPS (SAUROPTERYGIA, PLESIOSAURIA) FROM THE HETTANGIAN (LOWER JURASSIC) OF WARWICKSHIRE,

A detailed re-description and revised diagnosis is given for Macroplata tenuiceps Swinton, 1930, a ple- siosaurian known from a single almost complete specimen (BMNH R5488) from the Blue Lias

A NEW OXFORDIAN PLIOSAURID (PLESIOSAURIA, PLIOSAURIDAE) IN THE CARIBBEAN SEAWAY

TLDR
A phylogenetic analysis suggests that Gallardosaurus forms a clade with Peloneustes, the most common pliosaurid genus occurring in the Oxford Clay, and that it would have played the role of an active predator taking advantage of nectonic fish recorded in the area.

A new genus of pliosaur (Reptilia: Sauropterygia) from the Lower Jurassic of Holzmaden, Germany

TLDR
The known geographical distribution of Rhomaleosaurus, which previously extended across the Ger- man and English palaeobiogeographical zones, is reduced to the English zone as a consequence of the referral of SMNS 12478 to a new genus, Meyerasaurus gen. nov.

Cranial Anatomy of Thalassiodracon hawkinsii (Reptilia, Plesiosauria) from the Early Jurassic of Somerset, United Kingdom

TLDR
The relatively long neck and small skull of Thalassiodracon indicate that the robust skeleton and macropredaceous habits of rhomaleosaurids and pliosaurids were derived independently.

Osteology of the Cryptocleidoid Plesiosaur Tatenectes laramiensis, with Comments on the Taxonomic Status of the Cimoliasauridae

TLDR
New fossil material of Tatenectes is described, and the phylogenetic position of this genus is reevaluate based on all known material, with TatenECTes as being most closely related to the Oxford Clay taxon Kimmerosaurus.

Plasticity and Convergence in the Evolution of Short-Necked Plesiosaurs

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