Chiayusaurus

Chiayusaurus (meaning "Chia-yu-kuan lizard", after where it was found) was a genus of sauropod dinosaur known from teeth found in China and possibly also South Korea. Two species have been named for this obscure genus, although only the type, "C. lacustris", is seen as valid today. It was originally named as "Chiayüsaurus", but the ICZN does not permit special characters, so it has become "Chiayusaurus". The old name can still be seen in older sources, though.
History and taxonomy.
Birger Bohlin based "Chiayusaurus" on a tooth crown in the IVPP. This tooth was found in the ?Tithonian-age ?Upper Jurassic Keilozo (now Kalazha) Formation of Xinjiang, China. This spatulate tooth crown was long, and was not unlike that of the younger genus "Asiatosaurus". 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 1997, Lee, Yang, and Park described a new species from South Korea 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-Albian-age Lower Cretaceous Hasandong Formation of Namdo, Gyeongsang. 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, 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.
Paleobiology.
As a sauropod, "Chiayusaurus" would have been a large, quadrupedal herbivore.