''Monkonosaurus'' (meaning " Monkon lizard") is a

dubious Doubt is a mental state in which the mind remains suspended between two or more contradictory propositions, unable to be certain of any of them. Doubt on an emotional level is indecision between belief and disbelief. It may involve uncertainty ...

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

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 ...

from the

Late Jurassic The Late Jurassic is the third epoch of the Jurassic Period, and it spans the geologic time from 163.5 ± 1.0 to 145.0 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic strata.Owen 1987. In European lithostratigraphy, the name ...

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 ...

-aged Loe-ein Formation of

Tibet Tibet (; ''Böd''; ) is a region in East Asia, covering much of the Tibetan Plateau and spanning about . It is the traditional homeland of the Tibetan people. Also resident on the plateau are some other ethnic groups such as Monpa people, ...

(or the

Lura Formation of

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 ...

). Some sources place it as alive during the Oxfordian -

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 113.0 ± 1.0 Ma to 100.5 ± 0.9 M ...

stages, around 163 - 100 million years ago, although ''Monkonosaurus'' was probably only alive during the

(163 – 152.1 ± 0.9 million years ago), making it among the earliest known stegosaurs along with ''

Chungkingosaurus ''Chungkingosaurus'', meaning "Chongqing Lizard", is a genus of herbivorous dinosaur from the Late Jurassic Upper Shaximiao Formation in what is now China. It is a member of the Stegosauria. Description According to Dong e.a. the ''Chungkingo ...

'' and '' Bashanosaurus''.

Discovery and naming

The genus was formalized by

Zhao Xijin Zhao Xijin (赵喜进; born c. 1935 died July 21, 2012) was a Chinese paleontologist notable for having named numerous dinosaurs. He was a professor at Beijing's Institute of Vertebrate Paleontology and Paleoanthropology. Biography Zhao Xijin was ...

in 1986.X. Zhao. 1986. eptilia ''Ching-kuo Ti Pao o Hsi'' 'The Cretaceous System of China. The Stratigraphy of China.''12:67-73 The generic name refers to

Markam County Markam County, (; ) is a county under the jurisdiction of the Chamdo in the Tibet Autonomous Region, bordering the provinces of Sichuan to the east and Yunnan to the south. It is the easternmost county-level division of the Tibet A.R. Climate ...

, also known as ''Monko''.Chao S., 1983. "Phylogeny and Evolutionary Stages of Dinosauria", ''Acta Palaeontologia Polonica'' 28 (1/2): 295-306 Zhao at the time gave neither a description, meaning the name remained a ''

nomen nudum In taxonomy, a ''nomen nudum'' ('naked name'; plural ''nomina nuda'') is a designation which looks exactly like a scientific name of an organism, and may have originally been intended to be one, but it has not been published with an adequate descr ...

'', nor a specific name. The latter was provided in 1986 when 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 ...

''Monkonosaurus lawulacus'' was named, the epithet referring to the Lawushan, the Lawu mountains. The first description was provided in 1990 by

Dong Zhiming Dong Zhiming (Chinese: 董枝明, Pinyin: ''Dǒng Zhimíng''; born January 1937) is a Chinese vertebrate paleontologist formerly employed at the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) in Beijing. He began working at the ...

.Dong, Z., 1990, "Stegosaurs of Asia", In: Carpenter, K. and Currie J. (eds.). ''Dinosaur Systematics''. Cambridge: Cambridge University Press. pp 255-268 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 ...

, IVPP V 6975, was found in a layer of the Loe-ein Formation dating probably from the

, or from the

Lura Formation.Weishampel, David B; et al. (2004). "Dinosaur distribution (Early Cretaceous, Asia)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 563-570. . It consists of a partial skeleton lacking the skull. It contains a pelvis with sacrum, two vertebrae and three back plates. The fragmentary condition of this single skeleton places doubt on the validity of this genus, with some studies concluding it is 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 ...

''.

Description

''Monkonosaurus'' was about long when fully grown. The ilium has a length of 905 millimetres. The sacrum consists of five sacral vertebrae.

Classification

Zhao (1983) placed ''Monkonosaurus'' in the Oligosacralosauroidea. Later researchers considered it an indeterminate member of the

Stegosauridae Stegosauridae is a family of thyreophoran dinosaurs (armoured dinosaurs) within the suborder Stegosauria. The clade is defined as all species of dinosaurs more closely related to ''Stegosaurus'' than ''Huayangosaurus''.David B. Weishampel, Peter ...

References

Stegosaurs Late Jurassic dinosaurs of Asia Fossil taxa described in 1986 Taxa named by Zhao Xijin Paleontology in Tibet Early Cretaceous dinosaurs of Asia Ornithischian genera {{stegosaur-stub

Discovery and naming

Description

Classification

See also

References