Tienshanosaurus 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 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 Late Jurassic

Jurassic

The Jurassic is a geologic period and system that extends from about Mya to  Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...

. It was a sauropod which lived in what is now 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...

.

On 11 September 1928 Chinese geology

Geology

Geology is the science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which it evolves. Geology gives insight into the history of the Earth, as it provides the primary evidence for plate tectonics, the evolutionary history of life, and past climates...

 professor Yuan Fu ("P.L. Yüan") discovered in Xinjiang

Xinjiang

Xinjiang is an autonomous region of the People's Republic of China. It is the largest Chinese administrative division and spans over 1.6 million km2...

 the remains of about thirty adult and three juvenile sauropods, which he uncovered during the following weeks. The finds, including a fossilized egg, were sent to Beijing

Beijing

Beijing , also known as Peking , is the capital of the People's Republic of China and one of the most populous cities in the world, with a population of 19,612,368 as of 2010. The city is the country's political, cultural, and educational center, and home to the headquarters for most of China's...

 where they ultimately became part of the collection of the Institute of Vertebrate Paleontology and Paleoanthropology

Institute of Vertebrate Paleontology and Paleoanthropology

The Institute of Vertebrate Paleontology and Paleoanthropology of China is a prominent research institution and collections repository for fossils, including many dinosaur and pterosaurand cat poo specimens...

. In 1937 paleontologist Yang Zhongjian

Yang Zhongjian

Yang Zhongjian , courtesy name Keqiang , also known as C.C. Young, was one of China's foremost paleontologists. He has been called the 'Father of Chinese vertebrate paleontology'...

 ("C.C. Young") named 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...

 Tienshanosaurus chitaiensis. The generic name, suggested by Yuan, refers to the Tian Shan

Tian Shan

The Tian Shan , also spelled Tien Shan, is a large mountain system located in Central Asia. The highest peak in the Tian Shan is Victory Peak , ....

, the "heavenly mountains". The specific name refers to the location Chitai or Qitai.

The holotype

Holotype

A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...

, IVPP AS 40002-3, was found near Paikushan, Luanshantze, in sandstone

Sandstone

Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...

 of the Shishugou Formation

Shishugou Formation

The Shishugou Formation is a geological formation in Xinjiang, China, whose strata date back to the Late Jurassic period. Dinosaur remains are among the fossils that have been recovered from the formation....

 dating from the Oxfordian. It consists of elements of the postcrania

Postcrania

Postcrania[p] in zoology and vertebrate paleontology refers to all or part of the skeleton apart from the skull. Frequently, fossil remains, e.g...

. A considerable part of the skeleton is known but not the skull or the lower jaws. The body length has been estimated at twelve metres.

In 1991 Ralph Molnar

Ralph Molnar

Ralph E. Molnar is a paleontologist who had been Curator of Mammals at the Queensland Museum and more recently associated with the Museum of Northern Arizona. He is also a research associate at the Texas natural Science Centre. He co-authored descriptions of the dinosaurs Muttaburrasaurus, Kakuru,...

 renamed Euhelopus zdanskyi Tienshanosaurus zdanskyi, despite the species having priority over T. chitaiensis, made possible by the fact that Euhelopus

Euhelopus

Euhelopus is a genus of sauropod dinosaur that lived during the Early Cretaceous, between 130 and 112 million years ago . It lived in what is now Shandong Province in China. A large herbivore, it weighed approximately 15-20 tons and attained an adult length of 15m...

is a renaming of the earlier Helopus. This has not been accepted; this same is true for Valérie Martin-Rolland's 1999 renaming of T. chitaiensis into Euhelopus chitaiensis.

Due to the fragmentary nature of the material and a limited description, it has not been easy to establish the affinities of Tienshanosaurus. Originally classified in the Helopodinae, it has been assigned to many groups, among them the Astrodontidae, Euhelopodinae, Euhelopodidae

Euhelopodidae

Euhelopodidae is a family of sauropod dinosaurs which includes the genus Euhelopus. The family name was first proposed by American paleontologist Alfred Sherwood Romer in 1956. The four genera Chiayusaurus, Omeisaurus, Tienshanosaurus, and Euhelopus were the original proposed euhelopodines...

, Brachiosauridae

Brachiosauridae

Brachiosauridae are a family of dinosaurs, whose members are known as brachiosaurids. They were herbivorous quadrupeds with longer forelegs than hind legs - the name derives from the Greek for arm lizard - and long necks...

, Camarasauridae, and Mamenchisauridae

Mamenchisauridae

Mamenchisauridae is an extinct family of sauropod dinosaurs. The family was first named by Chinese paleontologists C.C. Young and H.C. Chao in 1972, in a paper describing Mamenchisaurus. Other mamenchisaurids may include Bellusaurus, Chuanjiesaurus, Eomamenchisaurus, Hudiesaurus, Klamelisaurus,...

. Modern authors have concluded that it cannot be further determined than Eusauropoda incertae sedis

Incertae sedis

, is a term used to define a taxonomic group where its broader relationships are unknown or undefined. Uncertainty at specific taxonomic levels is attributed by , , and similar terms.-Examples:*The fossil plant Paradinandra suecica could not be assigned to any...

and is a nomen dubium

Nomen dubium

In zoological nomenclature, a nomen dubium is a scientific name that is of unknown or doubtful application...

.