New Triassic Diapsid reptile found in Southwestern China

November 21, 2011
The holotype of Sinosaurosphargis yunguiensis, gen et sp. nov. (IVPP V 17040), in dorsal view. Credit: LI Chun

Paleontologist LI Chun, Institute of Vertebrate Paleontology and Paleoanthropology (IVPP), Chinese Academy of Sciences, and his research team, reported a new genus and species of marine reptile, Sinosaurosphargis yunguiensis, from the Middle Triassic of Yunnan and Guizhou Provinces, southwestern China, according to a paper published in the Journal of Vertebrate Paleontology, 31(2), 2011.

This new species with closed upper temporal fenestrae has a ventrally open cheek. Its external nares are retracted, and its trunk region is short and of rounded contours. The trunk, neck, and proximal limb segments are covered by shield composed of small osteoderms. The dorsal ribs are broadened and flat, contacting one another along their length. The dorsal vertebrae have elongated, distally expanded transverse processes.

“This new diapsid displays a highly derived postcranial skeletal anatomy convergent on cyamodontid placodonts. It represents the first representative from China of a lineage related to Saurosphargis from the Germanic Muschelkalk, and this find adds further support to the close faunal affinities shared by the Eastern and Western Tethyan realm”, said Dr. Xiao-Chun WU, coauthor, Canadian Museum of Nature, Ottawa.

“Saurosphargis, Sinosaurosphargis, and turtles are the only reptiles known with dorsal ribs transversely broadened to such an extent as to establish an anteroposterior contact with one another, forming a closed dorsal ‘rib basket’ (in turtles in the form of costal plates, integrated into the carapace)”, said Dr. Olivier Rieppel, the corresponding author, curator of the Field Museum, Chicago, “The presence of this rib structure in conjunction with a closed osteoderm covering in Sinosaurosphargis is extremely intriguing, because a derivation of the turtle carapace from an ancestral osteoderm covering has repeatedly been proposed. This scenario of turtle shell evolution conflicts with the absence of osteoderms in the ancestral turtle Odontochelys from the early Late Triassic of southwestern China. However, an alternative interpretation of Odontochelys considers its carapace reduced due to skeletal paedomorphosis as an adaptation to an aquatic mode of life.”

This work was supported mainly by the Major Basic Research Projects of the Ministry of Science and Technology of China, the National Natural Science Foundation of China, and the special grant for fossil excavation and preparation of the

Explore further: Ancient flying dragon discovered in China

Related Stories

New captorhinid reptile found in China

May 23, 2011

A new captorhinid reptile, Gansurhinus qingtoushanensis, gen. et sp. nov., was found from Xidagou Formation (Middle Permian) at Qingtoushan (Dashankou) locality near Yumen, Gansu Province, and from Naobaogou Formation (Late ...

New Eosauropterygian found in Eastern Yunnan, China

June 1, 2011

The marine Triassic deposits in southwestern China have yielded numerous vertebrate fossils (ichthyosaurians, sauropterygians, thalattosaurians, and fishes). A new eosauropterygian, Diandongosaurus acutidentatus gen. et sp. ...

New leuciscin fish found in northern China

June 2, 2011

SU De-Zao, a retired paleoichthyologist of Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, found a new paleogene leuciscin fish, Tianshanicus liui sp. nov., in the Anjihaihe Formation ...

Recommended for you

From a very old skeleton, new insights on ancient migrations

October 9, 2015

Three years ago, a group of researchers found a cave in Ethiopia with a secret: it held the 4,500-year-old remains of a man, with his head resting on a rock pillow, his hands folded under his face, and stone flake tools surrounding ...

Who you gonna trust? How power affects our faith in others

October 6, 2015

One of the ongoing themes of the current presidential campaign is that Americans are becoming increasingly distrustful of those who walk the corridors of power – Exhibit A being the Republican presidential primary, in which ...

Ancient genome from Africa sequenced for the first time

October 8, 2015

The first ancient human genome from Africa to be sequenced has revealed that a wave of migration back into Africa from Western Eurasia around 3,000 years ago was up to twice as significant as previously thought, and affected ...

Mexican site yields new details of sacrifice of Spaniards

October 9, 2015

It was one of the worst defeats in one of history's most dramatic conquests: Only a year after Hernan Cortes landed in Mexico, hundreds of people in a Spanish-led convey were captured, sacrificed and apparently eaten.


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.