Beishanlong
Encyclopedia
Beishanlong 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 giant ornithomimosauria
Ornithomimosauria
The Ornithomimosauria, ornithomimosaurs or ostrich dinosaurs were theropod dinosaurs which bore a superficial resemblance to modern ostriches. They were fast, omnivorous or herbivorous dinosaurs from the Cretaceous Period of Laurasia...

n theropod 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 Early Cretaceous
Early Cretaceous
The Early Cretaceous or the Lower Cretaceous , is the earlier or lower of the two major divisions of the Cretaceous...

 of 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...

.

Discovery and naming

Three fossils of Beishanlong were in the early twenty-first century found in northwestern China at the White Ghost Castle site, in the province of Gansu
Gansu
' is a province located in the northwest of the People's Republic of China.It lies between the Tibetan and Huangtu plateaus, and borders Mongolia, Inner Mongolia, and Ningxia to the north, Xinjiang and Qinghai to the west, Sichuan to the south, and Shaanxi to the east...

. 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...

 is Beishanlong grandis, described and named online in 2009 by a team of Chinese and American paleontologists, and formally published in January 2010
2010 in paleontology
-Anomalocaridids:-Newly named crustaceans:-Newly named insects:* A new family, Cascopleciidae, is published by Poinar Jr.* A new family of ceraphronoid Hymenopters, Radiophronidae, is published by Ortega-Blanco, Rasnitsyn, and Delclòs....

 by the same Peter Makovicky, Li Daiqing, Gao Keqin, Matthew Lewin, Gregory Erickson and Mark Norrell. The generic name combines a references to the Bei Shan, the "White Mountains", with a Chinese long, "dragon". The specific name means "large" in Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

, in reference to the body size.

Beishanlong lived at the boundary of the Aptian
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 125.0 ± 1.0 Ma to 112.0 ± 1.0 Ma , approximately...

 to Albian
Albian
The Albian is both an age of the geologic timescale and a stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early/Lower Cretaceous epoch/series. Its approximate time range is 112.0 ± 1.0 Ma to 99.6 ± 0.9 Ma...

 stages, around 120 million years ago. Its fossils were uncovered in layers of the Xinminpu Group. 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...

 is FRDC-GS GJ (06) 01-18, found in 2006, consisting of a partial skeleton lacking the skull. The paratype
Paratype
Paratype is a technical term used in the scientific naming of species and other taxa of organisms. The exact meaning of the term paratype when it is used in zoology is not the same as the meaning when it is used in botany...

s consist of two specimens found in 2007: one consisting of remains of hindlimbs, the other, FRDC-GS JB(07)01-01, being a pair of pubes. A fourth fossil found in 1999, IVPP V12756 consisting of foot bones, was tentatively referred to the species.

Description

Beishanlong is of a considerable size, approximating the largest known individuals of Gallimimus
Gallimimus
Gallimimus is a genus of ornithomimid theropod dinosaur from the late Cretaceous period Nemegt Formation of Mongolia. With individuals as long as , it was one of the largest ornithomimosaurs...

, which have been estimated at eight metres. According to the description, Beishanlong "is one of the largest definitive ornithomimosaurs yet described, though histological analysis shows that the holotype individual was still growing at its death." Extrapolating from the sixty-six centimetres long thighbone, the describers estimated the weight at 626 kilogrammes. Gregory S. Paul
Gregory S. Paul
Gregory Scott Paul is a freelance researcher, author and illustrator who works in paleontology, and more recently has examined sociology and theology. He is best known for his work and research on theropod dinosaurs and his detailed illustrations, both live and skeletal...

 in 2010 gave an estimate of seven metres length and five hundred fifty kilogrammes. A histological
Histology
Histology is the study of the microscopic anatomy of cells and tissues of plants and animals. It is performed by examining cells and tissues commonly by sectioning and staining; followed by examination under a light microscope or electron microscope...

 study of the bone structure of the fibula found thirteen or fourteen growth lines, indicating the individual was subadult, though growth had already slowed.

The build of Beishanlong was rather robust. The arms and legs were long, though lacking the extremely elongated hands, feet and claws of later forms.

Classification

Beishanlong was by the describers assigned to the Ornithomimosauria
Ornithomimosauria
The Ornithomimosauria, ornithomimosaurs or ostrich dinosaurs were theropod dinosaurs which bore a superficial resemblance to modern ostriches. They were fast, omnivorous or herbivorous dinosaurs from the Cretaceous Period of Laurasia...

, in a more basal position. Beishanlong was closely related to fellow ornithomimosaurian Harpymimus
Harpymimus
Harpymimus is a basal ornithomimosaurian theropod dinosaur from the Early Cretaceous Period of what is now Mongolia. Unlike later, more derived ornithomimosaurs, Harpymimus still possessed teeth, although they appear to have been restricted to the dentary of the lower jaw.-Discovery and naming:In...

. Together they formed a polytomy
Polytomy
A polytomy , meaning many temporal based branches, is a section of a phylogeny in which the evolutionary relationships can not be fully resolved to dichotomies. In a phylogenetic tree, a polytomy is represented as a node which has more than two immediate descending branches...

 with the main ornithomimosaurian branch just below Garudimimus
Garudimimus
Garudimimus is a basal ornithomimosaurian theropod dinosaur from the Upper Cretaceous of Mongolia.-Discovery and naming:...

.

External links

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