''Chiayusaurus'' (meaning " Chia-yu-kuan

lizard Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia alt ...

", after where it was found) is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

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 ...

known from

teeth A tooth ( : teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tear ...

found in

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 ...

and possibly also

South Korea South Korea, officially the Republic of Korea (ROK), is a country in East Asia, constituting the southern part of the Korea, Korean Peninsula and sharing a Korean Demilitarized Zone, land border with North Korea. Its western border is formed ...

. Two species have been named for this obscure genus, though only the type, ''C. lacustris'', is still seen as valid. It was originally named as ''Chiayüsaurus'', but the

ICZN The International Code of Zoological Nomenclature (ICZN) is a widely accepted convention in zoology that rules the formal scientific naming of organisms treated as animals. It is also informally known as the ICZN Code, for its publisher, the I ...

does not permit special characters, so the name was corrected to ''Chiayusaurus''. The obsolete name can still be seen in older sources, though. As a sauropod, ''Chiayusaurus'' would have been a large, quadrupedal

herbivore A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthpart ...

History and taxonomy

Birger Bohlin Dr. Anders Birger Bohlin (26 March 1898 – 28 November 1990) was a Swedish palaeontologist. As well as his work on dinosaurs and prehistoric mammals, Bohlin was part of the group that established the existence of Peking Man ''(Sinanthropus pek ...

based Brandon Christopher McCartney (born August 17, 1989), professionally known as Lil B and as his alter ego The BasedGod, is an American rapper. Lil B has recorded both solo and with Bay Area group The Pack. His solo work spans several genres, i ...

''Chiayusaurus'' on a tooth crown in the

IVPP The Institute of Vertebrate Paleontology and Paleoanthropology (IVPP; ) of China is a research institution and collections repository for fossils, including many dinosaur and pterosaur specimens (many from the Yixian Formation). As its name suggest ...

. This tooth was found in the

Barremian The Barremian is an age in the geologic timescale (or a chronostratigraphic stage) between 129.4 ± 1.5 Ma (million years ago) and 121.4 ± 1.0 Ma). It is a subdivision of the Early Cretaceous Epoch (or Lower Cretaceous Series). It is preceded ...

-age (

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 ...

)

Xinminbao Group The Xīnmínbǎo Group () is a group of geological formations in north central China. They occur across a large depression (geology), depression between the Altai mountains of Mongolia to the north and the Qilian Shan, Qilian mountains of the Qing ...

Gansu Gansu (, ; alternately romanized as Kansu) is a province in Northwest China. Its capital and largest city is Lanzhou, in the southeast part of the province. The seventh-largest administrative district by area at , Gansu lies between the Tibet ...

. This spatulate tooth crown was long, and was not similar to the younger genus ''

Asiatosaurus ''Asiatosaurus'' (meaning "Asian lizard") is an extinct genus of herbivorous sauropod dinosaur which lived during the Early Cretaceous in Mongolia and China. The type species is known only from teeth, making it difficult to rely on information un ...

''. As it was based on such sparse material, it has largely been ignored or considered to be indistinguishable from other, better-known sauropods. For example, Russell and Zheng found its tooth to be indistinguishable from those of '' Mamenchisaurus''. Bohlin described a larger tooth in the 1953 publication as "Species A. (aff. ''Chiayüsaurus'')", which he thought might belong to 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 ...

. In 1997, Lee, Yang, and Park described a new species from

based on a tooth ( KPE 8001) which they regarded as being identical to "Species A. (aff. ''Chiayüsaurus'')". This new species, ''C. asianensis'', is from the

Aptian The Aptian is an age in the geologic timescale or a stage in the stratigraphic column. It is a subdivision of the Early or Lower Cretaceous Epoch or Series and encompasses the time from 121.4 ± 1.0 Ma to 113.0 ± 1.0 Ma (million years ago), a ...

- Albian-age

Lower Cretaceous Lower may refer to: *Lower (surname) *Lower Township, New Jersey *Lower Receiver (firearms) *Lower Wick Lower Wick is a small hamlet located in the county of Gloucestershire, England. It is situated about five miles south west of Dursley, eight ...

Hasandong Formation The Hasandong Formation () is an Early Cretaceous ( Aptian to Albian) geologic formation in South Korea. It has been dated to the late Aptian and earliest Albian, between 118.0 ± 2.6 Ma and 112.4 ± 1.3 Ma. Dinosaur remains diagnostic ...

of Namdo,

Gyeongsang Gyeongsang ( ko, 경상도, ''Gyeongsang-do''; ) was one of the eight provinces of Korea during the Joseon dynasty. Gyeongsang was located in the southeast of Korea. The provincial capital was Daegu. The region was the birthplace of the Kingdom ...

. The authors rejected the suggestion that Bohlin's two teeth may have differed from being in different places in the jaw, and separated their species on the basis of details of the wear surfaces and placement of ridges. The ''C. asianensis'' tooth crown is long. Both species were reviewed in 2002 by Barrett ''et al.'' They regarded the type tooth of ''C. lacustris'' as nearly identical to teeth of '' Euhelopus'' but were unable to conclusively establish synonymy, finding it to be an indeterminate eusauropod. They found that ''C. lacustris'' and ''C. asianensis'' shared no

special features A feature story is a piece of non-fiction writing about news. A feature story is a type of soft news. The main sub-types are the ''news feature'' and the ''human-interest story''. A feature story is distinguished from other types of non-news ...

, and instead differed. ''C. asianensis'' was regarded as a possible titanosauriform, but still indeterminate. In the most recent review of sauropods, both species were considered to be dubious without comment.

References

{{Taxonbar, from=Q719905 Macronarians Late Jurassic dinosaurs of Asia Early Cretaceous dinosaurs of Asia Taxa named by Birger Bohlin Paleontology in Xinjiang Fossils of South Korea