''Stegosaurides'' (meaning "''

Stegosaurus ''Stegosaurus'' (; ) is a genus of herbivorous, four-legged, armored dinosaur from the Late Jurassic, characterized by the distinctive kite-shaped upright plates along their backs and spikes on their tails. Fossils of the genus have been foun ...

''-shaped") 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 herbivorous

thyreophora Thyreophora ("shield bearers", often known simply as "armored dinosaurs") is a group of armored ornithischian dinosaurs that lived from the Early Jurassic until the end of the Cretaceous. Thyreophorans are characterized by the presence of body ...

n (perhaps

ankylosaurid Ankylosauridae () is a family of armored dinosaurs within Ankylosauria, and is the sister group to Nodosauridae. The oldest known Ankylosaurids date to around 122 million years ago and went extinct 66 million years ago during the Cretaceous–Pal ...

or possibly

stegosauria Stegosauria is a group of herbivorous ornithischian dinosaurs that lived during the Jurassic and early Cretaceous periods. Stegosaurian fossils have been found mostly in the Northern Hemisphere, predominantly in what is now North America, Europe, ...

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 ...

. It lived during the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...

. Its fossils were found in the

Xinminbao Group The Xīnmínbǎo Group () is a group of geological formations in north central China. They occur across a large depression (geology), depression between the Altai mountains of Mongolia to the north and the Qilian Shan, Qilian mountains of the Qing ...

near Heishan in

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 ...

Province in

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 ...

. These fossils consist of fragmentary material, including dermal spine elements. The genus is occasionally misspelled as "Stegosauroides".

Discovery and species

In 1930,

Anders Birger Bohlin Dr. Anders Birger Bohlin (26 March 1898 – 28 November 1990) was a Swedes, Swedish palaeontologist. As well as his work on dinosaurs and prehistoric mammals, Bohlin was part of the group that established the existence of Peking Man ''(Sinanthr ...

during the Swedish-Chinese expedition of

Sven Hedin Sven Anders Hedin, KNO1kl RVO,Wennerholm, Eric (1978) ''Sven Hedin – En biografi'', Bonniers, Stockholm (19 February 1865 – 26 November 1952) was a Swedish geographer, topographer, explorer, photographer, travel writer and illustrator ...

excavated fossils at Hui-Hui-Pu, between the Heishan en Ku’an-t’ai-shan mountain ranges, near Xinminbao, in the west of Gansu. These included two vertebrae of about eleven centimetres in length and a dermal spine base.B. Bohlin, (1953), ''Fossil reptiles from Mongolia and Kansu. Reports from the Scientific Expedition to the North-western Provinces of China under Leadership of Dr. Sven Hedin. VI. Vertebrate Palaeontology 6.'' The Sino-Swedish Expedition Publications 37, 113 pp 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 ''Stegosaurides excavatus'', formally described by Bohlin in 1953. The generic name combines ''

'' with the Greek ''~eides'', "-shaped", in reference to the presumed similarity with the vertebrae of ''Stegosaurus''. The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

means "hollowed out" 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 ...

and refers to two large depressions, one each on either side of the spine base. It is currently considered a ''

nomen dubium In binomial nomenclature, a ''nomen dubium'' (Latin for "doubtful name", plural ''nomina dubia'') is a scientific name that is of unknown or doubtful application. Zoology In case of a ''nomen dubium'' it may be impossible to determine whether a s ...

'' as the material is so limited.

Phylogeny

Bohlin placed ''Stegosaurides'' in the

Stegosauria Stegosauria is a group of herbivorous ornithischian dinosaurs that lived during the Jurassic and early Cretaceous periods. Stegosaurian fossils have been found mostly in the Northern Hemisphere, predominantly in what is now North America, Europe, ...

. However, later authors often presumed it represented a member of the

Ankylosauria Ankylosauria is a group of herbivorous dinosaurs of the order Ornithischia. It includes the great majority of dinosaurs with armor in the form of bony osteoderms, similar to turtles. Ankylosaurs were bulky quadrupeds, with short, powerful limbs. ...

, in an indeterminate position. The fossils resemble vertebrae of both groups in having strongly elevated diapophyses, but are more ankylosaur-like in that the

neural arch The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic i ...

is moderately tall. Uncertainty over the precise age of the Xinminbao Group adds to the difficulty of determining the affinities. Usually it is given as

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 ...

when both stegosaurs and ankylosaurs were present, but sometimes as

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the ...

when stegosaurs were probably extinct.

Notes

{{Taxonbar, from=Q1956529 Ankylosaurs Early Cretaceous dinosaurs of Asia Fossil taxa described in 1953 Taxa named by Birger Bohlin Paleontology in Gansu Nomina dubia Ornithischian genera

Discovery and species

Phylogeny

See also

Notes