Leshansaurus
Encyclopedia
Leshansaurus is a 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 theropod dinosaur
Dinosaur
Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...

 from the Mid
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....

 to Late Jurassic Dashanpu Formation
Dashanpu Formation
The Dashanpu Formation is a Mid to Late Jurassic rock formation in China, most notable for the wealth of dinosaurs that have been excavated from the area...

  of what is now China. It was described in 2009 by a team of Chinese paleontologists. The type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...

 is L. qianweiensis. Fossils of Leshansaurus were discovered in strata from the Shangshaximiao Formation, a formation rich in dinosaur fossils. Li et al. referred this taxon
Taxon
|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...

 to Sinraptoridae
Sinraptoridae
Sinraptorids were a family of carnivorous theropod dinosaurs. They tended to be large predators, some growing to sizes of . Sinraptorids are carnosaurs, and many were initially classified within Megalosauridae or Allosauridae prior to recent analysis...

 – a group of carnosauria
Carnosauria
Carnosauria is a group of large predatory dinosaurs that lived during the Jurassic and Cretaceous periods. While it originally contained a wide assortment of giant theropods that were not closely related, the group has since been defined to encompass only the allosaurs and their closest kin...

n theropods, but it may it belong to Megalosauridae instead.

Discovery and naming

The holotype (QW 200701) was found in 2007. It is a fairly complete skeleton consisting of a partial skull and lower jaws, seven cervical vertebrae, twelve dorsal vertebrae, five sacral vertebrae, two caudal vertebrae, and much of the hind limbs and hands. A second specimen (QW 200702), an isolated femur from a juvenile, has been designated as the paratype.

Leshansaurus has an elongated skull that is broader towards the front. The femur has a length of 62 centimeters, and the tibia has a length of 52 centimeters. Its autapomorphies (unique characteristics) are the property of a sharp central ridge on the supraoccipitalis (the bone above the occipital), elongated frontal bones that are 2.86 times as long as they are wide, slender basipterygoid projections on the basisphenoid, a bone of the palate, an atlas intercentrum that is horseshoe-shaped in cross-section, slender diapophyses, Thin protrusions on the dorsal vertebrae and sacral vertebrae, the possession of a clear keel at the bottom of the sacral vertebrae, and an ilium with a distinct ridge along the middle edge of the hip joint.

Leshansaurus was described in 2009 by Li Fei
Li Fei
Consort Li was a consort of the Xianfeng Emperor who ruled China during the Qing Dynasty from 1850 till 1861.-Biography:...

, Peng Guangzhao, Ye Yong, Jiang Shan, and Huang Daxi. The generic epithet refers to Leshan
Leshan
-Administrative divisions:-Transport:There is a passenger rail line that serves the Mianyang–Chengdu–Leshan inter-city area.The Chengdu-Leshan Highway with a total length of 160 kilometers, was finished on January 14th, 2000...

, a nearby city in Sichuan
Sichuan
' , known formerly in the West by its postal map spellings of Szechwan or Szechuan is a province in Southwest China with its capital in Chengdu...

, 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...

, and the specific epithet refers to Qianwei, the county in which the fossils were found.

Phylogeny

The describers placed Leshansaurus in Sinraptoridae, but they did not carry out a cladistic analysis.

Features

Leshansaurus was a medium-sized theropod that would have had a length of 6 to 7 meters, and a hip height of about one and a half meters.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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