''Shantungosaurus'' (meaning "''Shandong Lizard''") is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of very large

saurolophine Saurolophinae is a subfamily (biology), subfamily of hadrosaurid dinosaurs. It has since the mid-20th century generally been called the Hadrosaurinae, a group of largely non-crested hadrosaurs related to the crested sub-family Lambeosaurinae. How ...

hadrosaurid Hadrosaurids (), also hadrosaurs or duck-billed dinosaurs, are members of the ornithischian family Hadrosauridae. This group is known as the duck-billed dinosaurs for the flat duck-bill appearance of the bones in their snouts. The ornithopod fami ...

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

found in the Late

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

Wangshi Group of the

Shandong Shandong is a coastal Provinces of China, province in East China. Shandong has played a major role in Chinese history since the beginning of Chinese civilization along the lower reaches of the Yellow River. It has served as a pivotal cultural ...

Peninsula in

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

, containing a single species, ''Shantungosaurus giganteus''. The

stratigraphic Stratigraphy is a branch of geology concerned with the study of rock layers (strata) and layering (stratification). It is primarily used in the study of sedimentary and layered volcanic rocks. Stratigraphy has three related subfields: lithost ...

interval of ''Shantungosaurus'' ranges from the top of the Xingezhuang Formation to the middle of the Hongtuya Formation, middle to late

Campanian The Campanian is the fifth of six ages of the Late Cretaceous epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campa ...

in age. ''Shantungosaurus'' is so far the largest hadrosauroid taxon in the world, with size estimates around in length and in body mass.

History of discovery

First described in 1973, ''Shantungosaurus'' is known from over five incomplete skeletons that were unearthed from 1964 to 1968. Chinese scientist Xing Xu and his colleagues indicate that ''Shantungosaurus'' is very similar to and shares many unique characters with '' Edmontosaurus'', forming a node of an '' Edmontosaurus''–''Shantungosaurus'' clade between

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

and

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

, based on the new materials recovered in

. Remains of several individuals, including skull bones, limb bones, and

vertebra Each vertebra (: vertebrae) is an irregular bone with a complex structure composed of bone and some hyaline cartilage, that make up the vertebral column or spine, of vertebrates. The proportions of the vertebrae differ according to their spina ...

e, were found in Shandong,

. These specimens were classified in the new genus and species ''Zhuchengosaurus maximus'' in 2007. However, further study showed that the supposedly distinct features of ''Zhuchengosaurus'' were simply a result of different growth stages.Ji, Y., Wang, X., Liu, Y., and Ji, Q. (2011). "Systematics, behavior and living environment of ''Shantungosaurus giganteus'' (Dinosauria: Hadrosauridae)." ''Acta Geologica Sinica (English Edition)'', 85(1): 58-65.

Description

''Shantungosaurus giganteus'' is one of the largest known

ornithischia Ornithischia () is an extinct clade of mainly herbivorous dinosaurs characterized by a pelvic structure superficially similar to that of birds. The name ''Ornithischia'', or "bird-hipped", reflects this similarity and is derived from the Greek ...

ns. The

type Type may refer to: Science and technology Computing * Typing, producing text via a keyboard, typewriter, etc. * Data type, collection of values used for computations. * File type * TYPE (DOS command), a command to display contents of a file. * ...

skull is long, and the composite skeleton mounted at the Chinese Academy of Geological Sciences in

Beijing Beijing, Chinese postal romanization, previously romanized as Peking, is the capital city of China. With more than 22 million residents, it is the world's List of national capitals by population, most populous national capital city as well as ...

measures in length. Another mounted skeleton, originally referred to as ''Zhuchengosaurus maximus'', measures in length. The largest individuals may have weighed as much as . In 2012, Butler and Barrett estimated its maximum length up to . In 2016, Gregory S. Paul suggested that previous studies have overestimated the size of this dinosaur, moderating it at in length and in body mass, which still makes this dinosaur the largest hadrosaur. Like all hadrosaurs its beak was toothless, but its jaws were packed with around 1,500 tiny chewing teeth. A large hole near its

nostril A nostril (or naris , : nares ) is either of the two orifices of the nose. They enable the entry and exit of air and other gasses through the nasal cavities. In birds and mammals, they contain branched bones or cartilages called turbinates ...

s may have been covered by a loose flap of skin, which could be inflated to make sounds.

Classification

Recent maximum parsimony-based

phylogenetic analyses In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as Computational phylogenetics, phylogenetic inference. It infers the relationship among organ ...

of Hadrosauroidea from Xing and colleagues recovered a stable sister group relationship between '' Edmontosaurus'' and ''Shantungosaurus''. ''Shantungosaurus'' is the single hadrosaurid from the Zhucheng area that is considered valid. ''Zhuchengosaurus'' and ''Huaxiaosaurus'', both of which are known from the same region, have been interpreted by the analyses as junior synonyms of ''Shantungosaurus''. All unequivocal morphological discrepancies among these three taxa could be attributed to intraspecific variation (ontogenetic and polymorphic variation) and post-depositional distortion. The following

cladogram A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ...

is the result of Prieto-Márquez ''et al.'' in 2016. It shows the position of ''Shantungosaurus'' as

sister group In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...

of ''Edmontosaurus'' in the Edmontosaurini clade:

References

Sources

* * {{Taxonbar, from=Q131158 Saurolophinae Dinosaur genera Campanian dinosaurs Fossil taxa described in 1973 Dinosaurs of China

History of discovery

Description

Classification

See also

References

Sources