Yuzhoupliosaurus is an extinct genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of plesiosaur

Plesiosaur

Plesiosauroidea is an extinct clade of carnivorous plesiosaur marine reptiles. Plesiosauroids, are known from the Jurassic and Cretaceous Periods...

 from the Middle Jurassic

Middle Jurassic

The Middle Jurassic is the second epoch of the Jurassic Period. It lasted from 176-161 million years ago. In European lithostratigraphy, rocks of this Middle Jurassic age are called the Dogger....

 of China

China

Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

. The genus is known only from a lower jaw

Jaw

The jaw is any opposable articulated structure at the entrance of the mouth, typically used for grasping and manipulating food. The term jaws is also broadly applied to the whole of the structures constituting the vault of the mouth and serving to open and close it and is part of the body plan of...

, a vertebra, and fragments of a pectoral girdle. It is believed this genus lived in fresh water.

Etymology

The Genus was named after Yuzhou

Yuzhou

Yuzhou is a county-level city in Xuchang, central Henan province in the People's Republic of China...

 (禹州), the previous name of Chungking- a major city on the Yangtze River

Yangtze River

The Yangtze, Yangzi or Cháng Jiāng is the longest river in Asia, and the third-longest in the world. It flows for from the glaciers on the Tibetan Plateau in Qinghai eastward across southwest, central and eastern China before emptying into the East China Sea at Shanghai. It is also one of the...

, and where the first fossil of Yuzhoupliosaurus was found.

Description

Paleontologists believe Yuzhoupliosaurus to have been approximatively 4 meters long. The lower jaw contains five pairs of large teeth and 23 or 234 smaller teeth. The cervical vertebra are considered "high and short". The anterior cervical rib

Rib

In vertebrate anatomy, ribs are the long curved bones which form the rib cage. In most vertebrates, ribs surround the chest, enabling the lungs to expand and thus facilitate breathing by expanding the chest cavity. They serve to protect the lungs, heart, and other internal organs of the thorax...

s are double-headed while the posterior cervical ribs are single-headed. The coracoids are elongated and the clavicles are well developed.