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Contact

About the author
Email: plesiosauria@gmail.com
Follow: @adamstuartsmith

Higher taxa

  • Sauropterygia
  • Eosauropterygia
  • Eusauropterygia
  • Pachypleurosauria
  • Nothosauria
  • Pistosauroidea
  • Pistosauria
  • Plesiosauria
  • Pliosauroidea
  • Plesiosauroidea

Families

  • Aristonectidae
  • Brachauchenidae
  • Cimoliasauridae
  • Cryptoclididae
  • Elasmosauridae
  • Leptocleididae
  • Microcleididae
  • Plesiosauridae
  • Pliosauridae
  • Polycotylidae
  • Rhomaleosauridae

Genera

The genera section is under construction, active pages are indicated by an asterisk

  • A
  • Albertonectes
  • Alexeyisaurus
  • Alzadosaurus
  • Anningasaura
  • Aphrosaurus
  • * 'Apractocleidus'
  • * Archaeonectrus
  • * Aristonectes
  • * Attenborosaurus
  • Augustasaurus
  • Avalonnectes
  • B
  • Bathyspondylus
  • Bishanopliosaurus
  • * Bobosaurus
  • Borealonectes
  • Brachauchenius
  • * Brancasaurus
  • C
  • Callawayasaurus
  • 'Cimoliasaurus'
  • Colymbosaurus
  • * Cryptoclidus
  • D
  • Dolichorhynchops
  • E
  • * Edgarosaurus
  • * Elasmosaurus
  • Eoplesiosaurus
  • Eopolycotylus
  • * Eretmosaurus
  • Eromangasaurus
  • Eurycleidus
  • F
  • Fresnosaurus
  • Futabasaurus
  • G
  • Gallardosaurus
  • Georgiasaurus
  • H
  • Hauffiosaurus
  • Hydralmosaurus
  • Hydrorion
  • Hydrotherosaurus
  • I
  • J
  • K
  • * Kaiwhekea
  • * Kimmerosaurus
  • * Kronosaurus
  • L
  • * Leptocleidus
  • Leurospondylus
  • * Libonectes
  • * Liopleurodon
  • Lusonectes
  • M
  • * Macroplata
  • Manemergus
  • * Maresaurus
  • Marmornectes
  • Mauisaurus
  • Megalneusaurus
  • * Meyerasaurus
  • Microcleidus
  • Morenosaurus
  • * 'Morturneria'
  • Muraenosaurus
  • N
  • Nichollssaura
  • O
  • * Occitanosaurus
  • 'Ogmodirus'
  • Opallionectes
  • P
  • * Pachycostasaurus
  • Pahasapasaurus
  • Palmulasaurus
  • Pantosaurus
  • * Peloneustes
  • Pistosaurus
  • Plesiopleurodon
  • Plesiopterys
  • * Plesiosaurus
  • Pliosaurus
  • Polycotylus
  • Polyptychodon
  • Q
  • R
  • * Rhomaleosaurus
  • S
  • Seeleyosaurus
  • Scanisaurus
  • * Simolestes
  • Sthenarosaurus
  • Stratesaurus
  • 'Stretosaurus'
  • Strongylokrotaphus
  • Styxosaurus
  • Sulcusuchus
  • T
  • Tatenectes
  • Terminonatator
  • * Thalassiodracon
  • * Thalassomedon
  • 'Thaumatosaurus'
  • *Thililua
  • Trememesacleis'
  • *Tricleidus
  • Trinacromerum
  • Tuarangisaurus
  • U
  • Umoonasaurus
  • V
  • Vinialesaurus
  • W
  • Wapuskanectes
  • Westphaliasaurus
  • Woolungasaurus
  • X
  • Y
  • Yuzhoupliosaurus
  • Z
  • Zarafasaura

Thalassomedon Welles, 1943

The holotype of Thalassomedon was discovered by R. L. Landberg in 1939 in Baca County, Colorado. Thalassomedon has a short and deep atlas-axis and 62 cervical vertebrae, and there is no pectoral or pelvic bar in the adult condition (Carpenter, 1999). The species name haningtoni is sometimes wrongly spelled 'hanningtoni' (as in Carpenter 1999) or 'haringtoni' (asin the AMNH exhibit pictured above). The three dimensional skull used in the mounted skeletons of this taxon in the AMNH (American Museum of Natural History, New York) and DMNH (Denver Museum of Natural History) is a reconstruction based on the crushed holotype specimen. Carpenter (1999) synonymized Alzadosaurus with Thalassomedon. Thalassomedon haningtoni Welles, 1943, is the type and only known species of this genus.

Classification

Sauropterygia --> Eosauropterygia --> Eusauropterygia --> Pistosauroidea --> Plesiosauria --> Plesiosauroidea --> Elasmosauridae

Thalassomedon haningtoni Welles, 1943

Material

Holotype Material - DMNH 1588, an almost complete skeleton and crushed skull.

Age and Location

Graneros Shale (Lower Cenomanian), near Pritchet, northwestern Baca County, Colorado, USA.

Thalassomedon images

A mounted cast of the holotype of Thalassomedon in the American Museum of Natural History seen from the front, from below showing the pectoral girdle and pelvic girdle, and from the side (AMNH 29878).
Model of Thalassomedon, including detail of the head by Hirokazu Tokugawa (used with kind permission of Hirokazu Tokugawa, see his other models at http://www2.neweb.ne.jp/wc/A-fragi)

References

under construction

Popular pages

Liopleurodon

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Further reading

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The skeletons in the site header are (from left to right): Kronosaurus (in the Museum of Comparative Zoology, Harvard University, Cambridge), Thalassomedon (in the American Museum of Natural History, New York), Cryptoclidus (In the Hunterian Museum and Art Gallery, Glasgow), Rhomaleosaurus (in the Natural History Museum, London), Dolichorhynchops (in the Smithsonian Institution's National Museum of Natural History, Washington) and Thalassiodracon (in the Natural History Museum, London).

©2011 Copyright Adam S. Smith. This site opened in June 2001. Last updated April 2013.