Anshunsaurus (Thalattosauria) redescribed

[Ben Creisler <bscreisler@yahoo.com>]

From: Ben Creisler
bscreisler@yahoo.com
 
 
A new paper about a Triassic marine reptile:
 
 
 
 
 
Long, C., Xiaohong, C., Baomin, Z. and Yongjian, C. (2011)
New Study of Anshunsaurus huangnihensis Cheng, 2007 (Reptilia: Thalattosauria): 
Revealing its Transitional Position in Askeptosauridae. 
Acta Geologica Sinica (English Edition) 85: 1231–1237.
doi: 10.1111/j.1755-6724.2011.00584.x
http://onlinelibrary.wiley.com/doi/10.1111/j.1755-6724.2011.00584.x/abstract
 
 
The skull of Anshunsaurus huangnihensis Cheng, 2007, especially the skull roof, 
is described in detail in this paper. Compared to other genera and species of 
Askeptosauroidea, Anshunsaurus huangnihensis has some important transitional 
characters from Askeptosaurus italicus to Anshunsaurus huangguoshuensis: the 
rostral length related to the skull length between Askeptosaurus italicus and 
Anshunsaurus huangguoshuensis; the postfrontal existing but distinctly reduced; 
the posterolateral process relatedly short and overlapping the parietal. The 
phylogenetic analysis weakly supports the evolutional progress from 
Anshunsaurus huangnihensis to Anshunsaurus huangguoshuensis. The skeletal 
ratios indicated that the node among the Askeptosauridae ingroup. The 
evolutional direction of Askeptosauridae should be from Askeptosaurus italicus 
to Anshunsaurus huangguoshuensis. The skeletal ratios indicated that the 
evolutional progress is Askeptosaurus italicus --
 Anshunsaurus huangnihensis -- Anshunsaurus huangguoshuensis. In biogeography 
provinces, the Askeptosauroidea taxa from south China have a close relationship 
with those from western Tethys; however, Xinpusaurus from the Late Triassic is 
more related to those from the eastern Pacific.