Thalattosauroidea

Thalattosauroidea
Temporal range: Triassic
Life restoration of Nectosaurus halinus (left) and Thalattosaurus alexandrae (right)
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Thalattosauria
Superfamily: Thalattosauroidea
Merriam, 1904
Subtaxa

Thalattosauroidea is a superfamily of thalattosaurs, a Triassic group of marine reptiles. It was named in 1904 by paleontologist John Campbell Merriam to include the genus Thalattosaurus from California. Thalattosauroids are one of two groups of Thalattosauria, the other being Askeptosauroidea. Thalattosauroids make up the "traditional" thalattosaurs with large downturned snouts, short necks, and long, paddle-like tails.

Classification

Thalattosauria includes North American genera such as Thalattosaurus and Nectosaurus as well as recently described Chinese forms such as Xinpusaurus. A 1999 study of thalattosaurs, which established much of the currently accepted phylogeny of the group, referred to Thalattosauroidea as Thalattosauria, while calling the larger group Thalattosauriformes. More recent phylogenetic studies have came upon the same conclusions, but refer to the group as Thalattosauroidea in order to contrast it with another superfamily of thalattosaurs, Askeptosauroidea.[1][2] Below is a cladogram from Wu et al. (2009) showing the phylogenetic relationships of Thalattosauroidea:[3]

Thalattosauria

Askeptosauroidea


 Thalattosauroidea 


Nectosaurus



Xinpusaurus



Kössen-Form





Agkistrognathus




Paralonectes




Thalattosaurus


 Claraziidae 

Clarazia



Hescheleria








References

  1. ^ Rieppel, O.; Liu, J.; and Bucher, H. (2000). "The first record of a thalattosaur reptile from the Late Triassic of southern China (Guizhou Province, PR China)". Journal of Vertebrate Paleontology 20 (3): 507–514. doi:10.1671/0272-4634(2000)020[0507:TFROAT]2.0.CO;2. 
  2. ^ Liu, J.; and Rieppel, O. (2005). "Restudy of Anshunsaurus huangguoshuensis (Reptilia: Thalattosauria) from the Middle Triassic of Guizhou, China". American Museum Noviates 3488: 1–34. ISSN 0003-0082. http://digitallibrary.amnh.org/dspace/bitstream/2246/5657/1/N3488.pdf. 
  3. ^ Wu, X.-C.; Cheng, Y.-N.; Sato, T.; and Shan, H.-Y. (2009). "Miodentosaurus brevis Cheng et al., 2007 (Diapsida: Thalattosauria): its postcranial skeleton and phylogenetic relationships". Vertebrata PalAsiatica 47 (1): 1–20. http://www.ivpp.ac.cn/cbw/gjzdwxb/xbwzxz/200902/W020090813372748918302.pdf.