"Gadolosaurus" is the informal name given to 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 ornithopod

Ornithopod

Ornithopods or members of the clade Ornithopoda are a group of ornithischian dinosaurs that started out as small, bipedal running grazers, and grew in size and numbers until they became one of the most successful groups of herbivores in the Cretaceous world, and dominated the North American...

 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 late Cretaceous

Late Cretaceous

The Late Cretaceous is the younger of two epochs into which the Cretaceous period is divided in the geologic timescale. Rock strata from this epoch form the Upper Cretaceous series...

-age rocks in Mongolia

Mongolia

Mongolia is a landlocked country in East and Central Asia. It is bordered by Russia to the north and China to the south, east and west. Although Mongolia does not share a border with Kazakhstan, its western-most point is only from Kazakhstan's eastern tip. Ulan Bator, the capital and largest...

. Though the name was made public in 1979, it has never been formally described, and the name is considered a nomen nudum

Nomen nudum

The phrase nomen nudum is a Latin term, meaning "naked name", used in taxonomy...

. The name "Gadolosaurus" first appeared in a book by Japanese paleontologist Tsunemasa Saito. It came from a caption to a photo of a juvenile

Juvenile (organism)

A juvenile is an individual organism that has not yet reached its adult form, sexual maturity or size. Juveniles sometimes look very different from the adult form, particularly in terms of their colour...

 dinosaur skeleton; this small individual was only about a meter long (39 inches). The skeleton was part of an Soviet

Soviet Union

The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....

 exhibition of fossils in Japan

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

. Apparently, the name comes from a Japanese

Japanese language

is a language spoken by over 130 million people in Japan and in Japanese emigrant communities. It is a member of the Japonic language family, which has a number of proposed relationships with other languages, none of which has gained wide acceptance among historical linguists .Japanese is an...

 phonetic translation of the Cyrillic

Cyrillic alphabet

The Cyrillic script or azbuka is an alphabetic writing system developed in the First Bulgarian Empire during the 10th century AD at the Preslav Literary School...

 word "gadrosavr", or hadrosaur, and was never meant by the Russians to establish a new generic name.

Because it is an informal name, with a suspect history, it has not attracted much professional attention. However, it has appeared in many popular dinosaur books, with varying identifications. Donald F. Glut

Donald F. Glut

Donald F. Glut is an American writer, motion picture director, screenwriter, amateur paleontologist, musician and actor....

 in 1982 reported it as either an iguanodont or hadrosaur, with no crest or boot on the ischium (both characteristics of the crested lambeosaurine

Lambeosaurinae

Lambeosaurinae is a group of crested hadrosaurid dinosaurs.-Classification:Lambeosaurines have been split into Parasaurolophini and Corythosaurini . Corythosaurini and Parasaurolophini as terms entered the formal literature in Evans and Reisz's 2007 redescription of Lambeosaurus magnicristatus...

 duckbills), and suggested it could be the juvenile of a previously named genus like Tanius

Tanius

Tanius is a genus of hadrosauroid dinosaur. It lived in the Late Cretaceous of the People's Republic of China.The type species, named and described in 1929 by Carl Wiman, is Tanius sinensis. The generic name honours the Chinese paleontologist Tan Xichou...

or Shantungosaurus

Shantungosaurus

Shantungosaurus, meaning "Shandong Lizard", is a genus of saurolophine hadrosaurid dinosaurs found in the Late Cretaceous Wangshi Formation of the Shandong Peninsula in China.-Description:...

. David Lambert in 1983 classified it as an iguanodont, but changed his mind by 1990, when it was listed as a synonym

Synonym (taxonomy)

In scientific nomenclature, a synonym is a scientific name that is or was used for a taxon of organisms that also goes by a different scientific name. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies...

 of Arstanosaurus

Arstanosaurus

Arstanosaurus was a genus of hadrosaurid dinosaur from the Santonian-Campanian-age Upper Cretaceous Bostobinskaya Formation, Kazakhstan. It has had a confusing history, being considered both a hadrosaurid and a ceratopsid, or both at the same time .-History:The genus was based on a maxilla , with...

. What may be the same animal is mentioned but not named by David B. Norman

David B. Norman

David Bruce Norman is a British paleontologist, currently Director of the Sedgwick Museum, Cambridge University. He is a fellow at Christ's College, Cambridge where he teaches geology in the Natural Sciences tripos. He is a member of the Palaeontological Association. He has studied Iguanodon...

 and Hans-Dieter Sues

Hans-Dieter Sues

Hans-Dieter Sues is a German-born paleontologist who is Senior Scientist and Curator of Vertebrate Paleontology at the National Museum of Natural History of the Smithsonian Institution in Washington, DC. He received his education at Johannes Gutenberg-Universität Mainz , University of Alberta, and...

 in 2000; this material, from the Soviet-Mongolian expeditions of the 1970s, had been listed as Arstanosaurus in the Russian Academy of Sciences

Russian Academy of Sciences

The Russian Academy of Sciences consists of the national academy of Russia and a network of scientific research institutes from across the Russian Federation as well as auxiliary scientific and social units like libraries, publishers and hospitals....

, but is currently under study for a future description, and more bones have been found in the intervening years. These bones were found at Baishin Tsav and were assigned a tentative Cenomanian

Cenomanian

The Cenomanian is, in the ICS' geological timescale the oldest or earliest age of the Late Cretaceous epoch or the lowest stage of the Upper Cretaceous series. An age is a unit of geochronology: it is a unit of time; the stage is a unit in the stratigraphic column deposited during the corresponding...

age.

External links

• "Gadolosaurus" at Thescelosaurus!
• "Gadolosaurus"