Tonganosaurus

Tonganosaurus
Temporal occurrence
	Lower Jurassic
	201.3 to 174.1 million years
Locations
	Sichuan , People's Republic of China ( Yimen Formation );
Systematics
	Dinosaur (dinosauria)
	Lizard dinosaur (Saurischia)
	Sauropods (Sauropoda)
	Eusauropoda
	Tonganosaurus
Scientific name
	Tonganosaurus
	Li et al., 2010
Art
	Tonganosaurus hot;

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

It is known only from a single, incomplete skeleton, which comes from the south of the Sichuan province from the Yimen formation . As with all sauropods, it was a four-legged herbivore. Tonganosaurus is placed among the Mamenchisauridae ; like other representatives of this group, Tonganosaurus had a relatively very long neck. Because of its great geological age, this find is important for understanding early evolution.

The genus was first scientifically described in 2010 by Kui Li and colleagues with the only species Tonganosaurus hei .

Features and systematics

Tonganosaurus showed the greatest anatomical similarities with the Central Jurassic Omeisaurus : Both genera were characterized, among other things, by long and thin cervical vertebrae with low spinous processes , well-developed pleurocoels (lateral openings) on the vertebrae lying in front of the sacrum , and forelegs that were 80% of the length of the hind legs. In contrast to Omeisaurus , the vertebral bodies of the vertebrae lying in front of the sacrum were simply structured, while in Omeisaurus they were more complex.

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

Find and naming

The find comes from the layers of the Yimen Formation in the Tong'an district in southern Sichuan. Twenty vertebrae, the shoulder girdle, front and rear legs, ischium, metatarsal bones, a claw and other vertebrae and rib fragments are known. It is the first discovery of a sauropod from the Lower Jurassic of China since the discovery of the Gongxianosaurus described in 1998 .

The genus name Tonganosaurus points to the locality Tong'an , while the second part of the species name ( hei ) honors the dinosaur researcher He Xinlu .

Individual evidence

↑ Li-Da Xing, Martin G. Lockley, Zhong-Dong Li, Hendrik Klein, Jian-Ping Zhang, Gerard D. Gierliński, Yong Ye, W. Scott Persons IV, Long Zhou: Middle Jurassic theropod trackways from the Panxi region, Southwest China and a consideration of their geologic age. In: Palaeoworld. Vol. 22, No. 1/2, 2013, ISSN 1871-174X , pp. 36-41, doi : 10.1016 / j.palwor.2012.11.002 .
↑ ^a ^b ^c ^d ^e Kui Li, Chun-Yan Yang, Jian Liu, Zhen-Xin Wang: [A new sauropod from the Lower Jurassic of Huili, Sichuan, China]. In: Vertebrata PalAsiatica. Vol. 48, No. 3, 2010, ZDB -ID 2485763-4 , pp. 185–202, digital version (PDF; 10.45 MB) , (in Chinese language and writing).

[xing_12-1] Li-Da Xing, Martin G. Lockley, Zhong-Dong Li, Hendrik Klein, Jian-Ping Zhang, Gerard D. Gierliński, Yong Ye, W. Scott Persons IV, Long Zhou: Middle Jurassic theropod trackways from the Panxi region, Southwest China and a consideration of their geologic age. In: Palaeoworld. Vol. 22, No. 1/2, 2013, ISSN 1871-174X , pp. 36-41, doi : 10.1016 / j.palwor.2012.11.002 .

[li_10-2] Kui Li, Chun-Yan Yang, Jian Liu, Zhen-Xin Wang: [A new sauropod from the Lower Jurassic of Huili, Sichuan, China]. In: Vertebrata PalAsiatica. Vol. 48, No. 3, 2010, ZDB -ID 2485763-4 , pp. 185–202, digital version (PDF; 10.45 MB) , (in Chinese language and writing).