ON THE CRANIAL ANATOMY OF THE POLYCOTYLID PLESIOSAURS, INCLUDING NEW MATERIAL OF POLYCOTYLUS LATIPINNIS, COPE, FROM ALABAMA

@inproceedings{OKeefe2004ONTC,
  title={ON THE CRANIAL ANATOMY OF THE POLYCOTYLID PLESIOSAURS, INCLUDING NEW MATERIAL OF POLYCOTYLUS LATIPINNIS, COPE, FROM ALABAMA},
  author={F. Robin O'Keefe},
  year={2004}
}
Abstract The cranial anatomy of plesiosaurs in the family Polycotylidae (Reptilia: Sauropterygia) has received renewed attention recently because various skull characters are thought to indicate plesiosauroid, rather than pliosauroid, affinities for this family. New data on the cranial anatomy of polycotylid plesiosaurs is presented, and is shown to compare closely to the structure of cryptocleidoid plesiosaurs. The morphology of known polycotylid taxa is reported and discussed, and a… 

OF THE SHOULDER IN POLYCOTYLUS LATIPINNUS ( PLESIOSAURIA : POLYCOTYLIDAE ) AND ITS BEARING ON PLESIOSAUR VIVIPARITY

Comparison of the fetal material with a juvenile polycotylid specimen and with adult material of Dolichorhynchops osborni demonstrates that the elements identified as fetal humeri are in fact scapulae, and that the fetal clavicles were misidentified as the scapula.

Braincase of a Polycotylid Plesiosaur (Reptilia: Sauropterygia) from the Upper Cretaceous of Manitoba, Canada

A virtual reconstruction of the braincase of a polycotylid plesiosaur referable to Dolichorhynchops from the Niobrara Formation was created by using a three-dimensional scanning technique that produces accurate reconstruction of missing or damaged elements and demonstrates the three- dimensional relationships among the elements.

Revision of polycotylid plesioaur systematics (sauropterygia plesiosauria) and description of the axial osteology of a juvenile polycotylid

A phylogenetic analysis incorporating a large taxon sampling from the Polycotylidae was used to parse out the evolutionary relationships among the taxa, and revealed that the two Wallace Ranch specimens form a well-supported clade, and feature a mosaic of character states found in currently described species, and may represent a new species.

Cranial Anatomy and Taxonomy of Dolichorhynchops Bonneri New Combination, a Polycotylid (Sauropterygia: Plesiosauria) from the Pierre Shale of Wyoming and South Dakota

This analysis reveals a stable sister-taxon relationship with Dolichorhynchops osborni, and a wide-ranging homoplasy among characters previously diagnostic among polycotylid genera challenges the alpha taxonomy of forms from the western interior seaway.

On the skull of a pliosaur (Plesiosauria; Pliosauridae) from the Upper Cretaceous (Early Turonian) of the North American Western Interior

Abstract A partial pliosaur skull reveals anatomical features poorly known for Plesiosauria. The specimen lacks recorded contextual information, however preservational character and nannofossil

Ontogeny of Polycotylid Long Bone Microanatomy and Histology

Comparison with the geologically oldest plesiosaur confirms that rapid growth evolved in the Triassic, although histological details differ, and the degree to which the polycotylid ontogenetic pattern is generalizable to other plesioaurs is currently unknown.

Revision of Sulcusuchus erraini (Sauropterygia, Polycotylidae) from the Upper Cretaceous of Patagonia, Argentina

Sulcusuchus erraini, from the upper Campanian–lower Maastrichtian of Patagonia, Argentina, is the only polycotylid from the Southern Hemisphere for which the skull and mandible are known and several hypotheses about the identity of the structures that could have been housed in the rostral and mandibular grooves are evaluated.

Polycotylus latipinnis Cope (Plesiosauria, Polycotylidae), a Nearly Complete Skeleton from the Niobrara Formation (Early Campanian) of Southwestern South Dakota

Cladistic analysis indicates that Polycotylus nests firmly within derived polycotylidae as a potential sister taxon to Dolichorhynchops osborni and Trinacromerum, despite a ‘primitive’ presacral vertebral count.
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References

SHOWING 1-10 OF 33 REFERENCES

AN EARLY POLYCOTYLID PLESIOSAUR (REPTILIA: SAUROPTERYGIA) FROM THE CRETACEOUS OF HOKKAIDO, JAPAN

Abstract A partial skeleton of a short-necked plesiosaur excavated from the Upper Cenomanian of the Middle Yezo Group of Hokkaido, Japan, includes disarticulated vertebrae, the right half of the

OSTEOLOGY OF A NEW PLESIOSAUR FROM THE LOWER CRETACEOUS (ALBIAN) THERMOPOLIS SHALE OF MONTANA

Abstract A new taxon of Cretaceous short-necked plesiosaur, Edgarosaurus muddi, gen. et sp. nov., is described. The specimen consists of a complete skull, 34 vertebrae including the entire series of

A Cladistic Analysis and Taxonomic Revision of the Plesiosauria (Reptilia: Sauropterygia)

The Plesiosauria is found to by polyphyletic due to the inclusion of the Polycotylidae; this second clade is instead a member of the Plesiosauroidea, and thus more closely related to elasmosaurs than to other ‘pliosaurs’.

Preliminary Report on the Osteology and Relationships of a New Aberrant Cryptocleidoid Plesiosaur from the Sundance Formation, Wyoming

The cryptocleidoid plesiosaur Taktwcflts laram.eruiS, new genus, is described from the Redwater Shale: Member of the Sundance fonnation. Narrona County, Wyommg.. The bolotypc of this species was a

Neoteny and the Plesiomorphic Condition of the Plesiosaur Basicranium

The purpose of this paper is to describe the condition of the braincase in stratigraphically early and morphologically primitive plesiosaurs and establish the polarity of characters occurring in more derived plesioaurs.

A juvenile plesiosaur (Plesiosauria: Reptilia) from the Lower Lias (Hettangian: Lower Jurassic) of Lyme Regis, England: a pliosauroid-plesiosauroid intermediate?

A partial skull and skeleton of a small, juvenile plesiosaur from Lyme Regis, England is described and is thought to have been a predator on soft-bodied or lightly armoured prey, such as belemnoids, ammonites or small fish.

A New Marine Reptile (Sauropterygia) from New Zealand: Further Evidence for A Late Cretaceous Austral Radiation of Cryptoclidid Plesiosaurs

Kaiwhekea katiki gen. et sp. nov. represents the first described cryptoclidid plesiosaurian from New Zealand. It is one of the largest cryptoclidids known, at a length of over 6.5 m, and represents

New plesiosaurs from the Upper Cretaceous of Antarctica

  • S. ChatterjeeB. Small
  • Geography, Environmental Science
    Geological Society, London, Special Publications
  • 1989
Abstract New plesiosaur remains from the Upper Cretaceous Lopez de Bertodano Formation (late Campanian-Maastrichtian) of Seymour Island, Antarctic Peninsula include Cryptoclididae and Elasmosauridae.

Muraenosaurus? Reedii, Sp. Nov. and Tricleidus? Laramiensis Knight, American Jurassic Plesiosaurs

The species, judging from the remains at hand, is one of the most primitive found in America and in all probability belongs to a new genus and is provisionally placed with the English genus Muraenosaurus Seeley,' which it closely resembles in several respects.

IV.—On the Structure of the Roof of the Skull and of the Mandible of Peloneustes, with some remarks on the Plesiosaurian Mandible generally

In the course of the preparation of the second part of the Catalogue of the Marine Reptiles of the Oxford Clay in the Collection at the British Museum, it has been necessary to examine in detail the