''Qijianglong'' is a genus of herbivorous

mamenchisaurid Mamenchisauridae is a family of sauropod dinosaurs belonging to Eusauropoda known from the Jurassic and Early Cretaceous of Asia and Africa. Some members of the group reached gigantic sizes, amongst the largest of all sauropods. Classification T ...

sauropod Sauropoda (), whose members are known as sauropods (; from '' sauro-'' + '' -pod'', 'lizard-footed'), is a clade of saurischian ('lizard-hipped') dinosaurs. Sauropods had very long necks, long tails, small heads (relative to the rest of their bo ...

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...

from the

Early Cretaceous The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Pro ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

.Wang, J.; Norell, M. A.; Pei, R.; Ye, Y.; Chang, S.-C (2019). Surprisingly young age for the mamenchisaurid sauropods in South China. ''Cretaceous Research'' doi:10.1016/j.cretres.2019.07.006.

Discovery

vertebra The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic ...

of ''Qijianglong'' was first discovered in the early 1990s by farmer Cai Changming of Heba village,

Sichuan Sichuan (; zh, c=, labels=no, ; zh, p=Sìchuān; alternatively romanized as Szechuan or Szechwan; formerly also referred to as "West China" or "Western China" by Protestant missions) is a province in Southwest China occupying most of the ...

, in his backyard. Work at a nearby construction site at

Qijiang District Qijiang District () is a district of Chongqing, China, bordering Guizhou province to the south. The district has an area of 2,748 km2 and a population of 1,213,770 (de facto resident population 825,500 as of 2017.) In October 2011, Qijiang C ...

uncovered a rich fossil quarry in 2006. Its excavation caused an examination of the earlier find which led to the discovery of a skeleton. In 2015, the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

''Qijianglong guokr'' was named and described by

Xing Lida XING is a Hamburg-based career-oriented social networking site, operated by New Work SE (until mid-2019 ''XING SE''). The site is primarily focused on the German-speaking market, alongside XING Spain, and competes with the American platform Li ...

( China University of Geosciences), Tetsuto Miyashita (

University of Alberta The University of Alberta, also known as U of A or UAlberta, is a public research university located in Edmonton, Alberta, Canada. It was founded in 1908 by Alexander Cameron Rutherford,"A Gentleman of Strathcona – Alexander Cameron Rutherfor ...

Zhang Jianping Zhang Jianping (; born April 1956) is a lieutenant general (''zhong jiang'') of the People's Liberation Army Air Force (PLAAF) of China. He has been deputy commander of the PLAAF since 2013, and previously served as commander of the Jinan Militar ...

, Li Daqing, Ye Yong (

Zigong Dinosaur Museum The Zigong Dinosaur Museum () is located near the city of Zigong, Sichuan, China, in the township of Dashanpu. History The museum sits on top of a large concentration of a diverse dinosaur assemblage from the Shaximiao Formation. The museu ...

), Toru Sekiya (

Fukui Prefectural Dinosaur Museum The , located in Katsuyama, Fukui, Japan, is one of the leading dinosaur museums in Asia that is renowned for its exhibits of fossil specimens of dinosaurs and paleontological research. It is sited in the Nagaoyama Park ( Katsuyama Dinosaur For ...

), Wang Fengping and

Philip John Currie Philip John Currie (born March 13, 1949) is a Canadian palaeontologist and museum curator who helped found the Royal Tyrrell Museum of Palaeontology in Drumheller, Alberta and is now a professor at the University of Alberta in Edmonton. In the ...

. The generic name combines the district

Qijiang Qijiang District () is a district of Chongqing, China, bordering Guizhou province to the south. The district has an area of 2,748 km2 and a population of 1,213,770 (de facto resident population 825,500 as of 2017.) In October 2011, Qijiang C ...

with

Mandarin Mandarin or The Mandarin may refer to: Language * Mandarin Chinese, branch of Chinese originally spoken in northern parts of the country ** Standard Chinese or Modern Standard Mandarin, the official language of China ** Taiwanese Mandarin, Stand ...

''long'', "dragon". The specific name ''guokr'', "nutshell", is that of a Chinese scientific

social network A social network is a social structure made up of a set of social actors (such as individuals or organizations), sets of dyadic ties, and other social interactions between actors. The social network perspective provides a set of methods for an ...

. The

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

QJGPM 1001 was found in a layer of the

Suining Formation The Suining Formation () is a geological Formation (geology), formation in China whose strata date back to the Early Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation. A 2019 paper shows zircon dating o ...

, which was seen as dating from the Late Jurassic but is now considered mid-Cretaceous (late Aptian) based on radiometric dating. It consists of a partial skeleton with skull. It includes the rear of the skull, a partial right lower jaw, a complete series of seventeen neck vertebrae, the first six back vertebrae, ribs, the probable tenth tail vertebra, a series of twenty-eight rear tail vertebrae, chevrons, the left pubic bone and two upper pedal phalanges. It likely represents a juvenile individual, large but immature. The holotype of ''Qijianglong'' was about fifteen meters long and had a long neck. The describing authors established several distinguishing traits among which four

autapomorphies In phylogenetics, an autapomorphy is a distinctive feature, known as a derived trait, that is unique to a given taxon. That is, it is found only in one taxon, but not found in any others or outgroup taxa, not even those most closely related to t ...

. On the lower braincase the ''processus basipterygoideus'' has the form of a plate, is oriented along the body axis, and has an additional boss parallel to the ''tubera basilaria''. The neck vertebrae have rear joint processes,

postzygapophyses The articular processes or zygapophyses (Greek ζυγον = "yoke" (because it links two vertebrae) + απο = "away" + φυσις = "process") of a vertebra are projections of the vertebra that serve the purpose of fitting with an adjacent vertebr ...

that next to their normal facets show on the outside an additional finger-shaped extension, stiffening the neck in the horizontal plane but allowing vertical movement. The rear neck vertebrae have pneumatopores, pneumatic openings, in the depression between the diapophysis, the upper rib joint process, and the neural spine. The

pubic bone In vertebrates, the pubic region ( la, pubis) is the most forward-facing (ventral and anterior) of the three main regions making up the coxal bone. The left and right pubic regions are each made up of three sections, a superior ramus, inferior ra ...

has a concave front edge, curving so strongly that its lower end is more directed to the front than to below.

Systematics

''Qijianglong'' was placed in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Mamenchisauridae Mamenchisauridae is a family of sauropod dinosaurs belonging to Eusauropoda known from the Jurassic and Early Cretaceous of Asia and Africa. Some members of the group reached gigantic sizes, amongst the largest of all sauropods. Classification T ...

, in a relatively basal position but above ''

Omeisaurus ''Omeisaurus'' (meaning "Omei lizard") is a genus of sauropod dinosaur from the Middle Jurassic Period (Bathonian-Callovian stage) of what is now China. Its name comes from Mount Emei, where it was discovered in the lower Shaximiao Formation of ...

tianfuensis'' in the evolutionary tree.

References

External links

Qijianglong guokr: New Long-Necked Dinosaur Discovered in China
Jan 29, 2015 by Sci-News.com Mamenchisaurids Fossil taxa described in 2015 Monotypic dinosaur genera Early Cretaceous dinosaurs of Asia Paleontology in Sichuan {{Sauropodomorph-stub