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Qianxisaurus, new eosauropterygian from Triassic of China



From: Ben Creisler
bcreisler@gmail.com

A new taxon from China:


Yen-Nien Cheng, Xiao-Chun Wu, Tamaki Sato & Hsi-Yin Shan (2012)
A new eosauropterygian (Diapsida, Sauropterygia) from the Triassic of China
Journal of Vertebrate Paleontology 32(6): 1335-1349
DOI:10.1080/02724634.2012.695983
http://www.tandfonline.com/doi/full/10.1080/02724634.2012.695983


A new Middle Triassic sauropterygian, Qianxisaurus chajiangensis, gen.
et sp. nov., is described on the basis of a skeleton from the Zhuganpo
Member (Ladinian) of the Falang Formation, Xingyi, southwestern
Guizhou Province, China. It is primarily characterized by a premaxilla
with eight teeth, marginal teeth with a slightly constricted peduncle
and short conical crown, snout longer than the rest of skull,
postorbital with a truncated dorsal process and forked posterior
process, a very small supratemporal fenestra, a short retroarticular
process posteriorly truncated and lacking a dorsal concavity, an
elongate trunk with 28 vertebrae, a stout sacrum with four vertebrae,
a longitudinal groove on proximodorsal surface of the dorsal ribs, and
a coracoid with a narrow lateral portion and a foot-shaped medial
portion. Q. chajiangensis appears similar to the European
pachypleurosaurs, but a global phylogenetic analysis failed to support
close relationships with these taxa. Instead, Q. chajiangensis is an
eosauropterygian and most probably the sister group of a clade
consisting of the European pachypleurosaurs and the Nothosauroidea.
The discovery of Q. chajiangensis certainly enriches our knowledge of
the early history of the Eosauropterygia and leads to a better
understanding of the phylogenetic relationships among known
eosauropterygians.