''Beishanlong'' 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 ...

of giant

ornithomimosauria Ornithomimosauria ("bird-mimic lizards") are theropod dinosaurs which bore a superficial resemblance to the modern-day ostrich. They were fast, omnivorous or herbivorous dinosaurs from the Cretaceous Period (geology), Period of Laurasia (now Asia ...

theropod Theropoda (; ), whose members are known as theropods, is a dinosaur clade that is characterized by hollow bones and three toes and claws on each limb. Theropods are generally classed as a group of saurischian dinosaurs. They were ancestrally c ...

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 ...

from the

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 ...

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 ...

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 (, ; 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 ...

. 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 ...

is ''Beishanlong grandis'', described and named online in 2009 by a team of Chinese and American paleontologists, and formally published in January

2010 File:2010 Events Collage New.png, From top left, clockwise: The 2010 Chile earthquake was one of the strongest recorded in history; The Eruption of Eyjafjallajökull in Iceland disrupts air travel in Europe; A scene from the opening ceremony of ...

by the same Peter Makovicky, Li Daiqing,

Gao Keqin Gao , or Gawgaw/Kawkaw, is a city in Mali and the capital of the Gao Region. The city is located on the River Niger, east-southeast of Timbuktu on the left bank at the junction with the Tilemsi valley. For much of its history Gao was an impor ...

, Matthew Lewin, Gregory Erickson and Mark Norrell. The generic name combines a references to the Bei Shan, the "North Mountains", with a Chinese ''long'', "dragon". The specific name means "large" in

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

, in reference to the body size. ''Beishanlong'' lived in the late Aptian stage, with its fossils being uncovered in layers of the

Xinminpu Group The Xīnmínbǎo Group () is a group of geological formations in north central China. They occur across a large depression between the Altai mountains of Mongolia to the north and the Qilian mountains of the Qinghai Plateau to the south, in the ...

, in the

Xiagou Formation The Xiagou Formation is the middle strata of the Xinminbao Group. It is named for its type site in Xiagou, in the Changma Basin of Gansu Province, northwestern China and is considered Early Cretaceous in age. It is known outside the specialized ...

. The

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

is FRDC-GS GJ (06) 01-18, found in 2006, consisting of a partial skeleton lacking the skull. The

paratype In zoology and botany, a paratype is a specimen of an organism that helps define what the scientific name of a species and other taxon actually represents, but it is not the holotype (and in botany is also neither an isotype nor a syntype). Of ...

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'' ( ) is a genus of theropod dinosaur that lived in what is now Mongolia during the Late Cretaceous period, about seventy million years ago (mya). Several fossils in various stages of growth were discovered by Polish-Mongolian exped ...

'', which have been estimated to reach 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." A

histological Histology, also known as microscopic anatomy or microanatomy, is the branch of biology which studies the microscopic anatomy of biological tissues. Histology is the microscopic counterpart to gross anatomy, which looks at larger structures vis ...

study of the bone structure of the

fibula The fibula or calf bone is a leg bone on the lateral side of the tibia, to which it is connected above and below. It is the smaller of the two bones and, in proportion to its length, the most slender of all the long bones. Its upper extremity is ...

found thirteen or fourteen growth lines, indicating the individual was subadult, though growth had already slowed. The size of this subadult individual is estimated at in length and in body mass.Paul, G.S., 2010, ''The Princeton Field Guide to Dinosaurs'', Princeton University Press p. 112 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 ("bird-mimic lizards") are theropod dinosaurs which bore a superficial resemblance to the modern-day ostrich. They were fast, omnivorous or herbivorous dinosaurs from the Cretaceous Period (geology), Period of Laurasia (now Asia ...

, in a more basal position. ''Beishanlong'' was closely related to fellow ornithomimosaurian ''

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 restr ...

''. Together they formed a

polytomy An internal node of a phylogenetic tree is described as a polytomy or multifurcation if (i) it is in a rooted tree and is linked to three or more child subtrees or (ii) it is in an unrooted tree and is attached to four or more branches. A tr ...

with the main ornithomimosaurian branch just below ''

Garudimimus ''Garudimimus'' (meaning "Garuda mimic") is a genus of ornithomimosaur that lived in Asia during the Late Cretaceous. The genus is known from a single specimen found in 1981 by a Soviet-Mongolian paleontological expedition in the Bayan Shireh Fo ...

''. In 2014 Yuong-Nam Lee ''et al.'' recovered ''Beishanlong'' as a member of

Deinocheiridae Deinocheiridae is a family (biology), family of ornithomimosaurian dinosaurs, living in Asia and the Americas from the Albian until the Maastrichtian. The family was originally named by Halszka Osmólska and Roniewicz in 1970 in paleontology, 197 ...

basal to a

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

containing ''Garudimimus'' and ''

Deinocheirus ''Deinocheirus'' ( ) is a genus of large ornithomimosaur that lived during the Late Cretaceous around 70 million years ago. In 1965, a pair of large arms, shoulder girdles, and a few other bones of a new dinosaur were first discovered in the Ne ...

''.Yuong-Nam Lee, Rinchen Barsbold, Philip J. Currie, Yoshitsugu Kobayashi, Hang-Jae Lee, Pascal Godefroit, François Escuillié & Tsogtbaatar Chinzorig (2014) "Resolving the long-standing enigmas of a giant ornithomimosaur ''Deinocheirus mirificus''". ''Nature'' (advance online publication) .

References

External links

"Field Museum palaeontologist leads study on two new dinosaurs from China"
ScienceCentric.com {{Portalbar, Dinosaurs, Cretaceous Early Cretaceous dinosaurs of Asia Ornithomimosaurs Fossil taxa described in 2010 Taxa named by Mark Norell Paleontology in Gansu

Discovery and naming

Description

Classification

See also

References

External links