Tonganosaurus

• Sichuan, People's Republic of China ( Yimen Formation)

• Tonganosaurus hei

Tonganosaurus is a genus of sauropod dinosaur from the Jurassic of China.

She is known only by a single incomplete skeleton, which comes from the south of Sichuan province from the Yimen lineup. Like all sauropods, there was a four-legged herbivores. Tonganosaurus will be provided to Mamenchisauridae; like other members of this group showed Tonganosaurus a very long neck in proportion. Because of its high geological age of this Fund is to understand the early evolution of meaning.

The genus was described in 2010 by Kui Li and colleagues with the only kind Tonganosaurus hot first time scientifically.

Characteristics and systematics

The largest anatomical similarities showed Tonganosaurus with the Middle Jurassic Omeisaurus: Both genera were distinguished among others by long and thin neck vertebrae with low spinous processes, well-developed Pleurocoele ( lateral openings ) to the period prior to the sacral vertebrae, and front legs, 80% of length of the hind legs accounted for. Unlike Omeisaurus the vertebrae that lie before the sacral vertebrae, however, were simply structured, while they were more complex in Omeisaurus.

The systematic position of Omeisaurus is controversial. Kui Li and colleagues ( 2010), however, follow authors who classify this genus within the Mamenchisauridae. Based on this assignment, they classify the presumably closely related Tonganosaurus also within this group. A phylogenetic analysis of the relationships is still pending.

Fund and naming

The finding comes from the layers of Yimen lineup in the district Tong'an in southern Sichuan. Known are 20 vertebrae, the shoulder girdle, front and rear legs, ischium, metatarsus, a claw, and other vertebral and rib fragments. This is the first discovery of a sauropod from the Jurassic of China since the discovery of the described Gongxianosaurus 1998.

The genus name Tonganosaurus has the locality Tong'an, while the second part of the species name ( hei ) the dinosaur researchers Hey Xinluhai honors.