''Heishansaurus'', meaning "Heishan lizard" after the area 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 ...

where it was discovered, is the name given to a dubious

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

ornithischian Ornithischia () is an extinct order 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 s ...

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 ...

, probably belonging to the

Ankylosauridae 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 ...

. In 1930, Swedish palaeontologist

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 ...

discovered dinosaur fossils, in the context of the Swedish-Chinese expeditions headed by

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 ...

, near Jiayuguan ("Chia-Yu-Kuan"), in the west 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 ...

Province. In 1953, Bohlin named these as 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 ...

''Heishansaurus pachycephalus''. The generic name refers to the Heishan, the "Black Mountains". The specific name ''pachycephalus'', meaning "thick-headed", was inspired by Bohlin's identification of the taxon as a

pachycephalosaur Pachycephalosauria (; from Greek παχυκεφαλόσαυρος for 'thick headed lizards') is a clade of ornithischian dinosaurs. Along with Ceratopsia, it makes up the clade Marginocephalia. With the exception of two species, most pachyc ...

.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 Today this dinosaur is more probably considered an

ankylosaur 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. ...

. The

fossils A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in ...

, from the

Minhe Formation The Minhe Formation () is a geological formation in northwestern China, whose strata date back to the Late Cretaceous period. Dinosaur remains are among the fossils that have been recovered from the formation.Weishampel, David B; et al. (2004). "D ...

dating from the

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 ...

(

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. Campanian s ...

Maastrichtian The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the interval from ...

stage Stage or stages may refer to: Acting * Stage (theatre), a space for the performance of theatrical productions * Theatre, a branch of the performing arts, often referred to as "the stage" * ''The Stage'', a weekly British theatre newspaper * Sta ...

), were fragmentary. The type is the only known specimen. The material consisted of poorly preserved

cranial Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position pro ...

and

postcranial Postcrania (postcranium, adjective: postcranial) in zoology and vertebrate paleontology is all or part of the skeleton apart from the skull. Frequently, fossil remains, e.g. of dinosaurs or other extinct tetrapods, consist of partial or isolated sk ...

fragments plus some

dermal The dermis or corium is a layer of skin between the epidermis (with which it makes up the cutis) and subcutaneous tissues, that primarily consists of dense irregular connective tissue and cushions the body from stress and strain. It is divided in ...

scutes A scute or scutum (Latin: ''scutum''; plural: ''scuta'' "shield") is a bony external plate or scale overlaid with horn, as on the shell of a turtle, the skin of crocodilians, and the feet of birds. The term is also used to describe the anterior po ...

. It contained skull fragments including a

maxilla The maxilla (plural: ''maxillae'' ) in vertebrates is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The t ...

, teeth, vertebrae from the neck, back and tail,

osteoderm Osteoderms are bony deposits forming scales, plates, or other structures based in the dermis. Osteoderms are found in many groups of extant and extinct reptiles and amphibians, including lizards, crocodilians, frogs, temnospondyls (extinct amp ...

s and spikes. Today, the specimen is lost. Of one dorsal vertebra a cast remains, preserved in the

American Museum of Natural History The American Museum of Natural History (abbreviated as AMNH) is a natural history museum on the Upper West Side of Manhattan in New York City. In Theodore Roosevelt Park, across the street from Central Park, the museum complex comprises 26 inter ...

with the inventory number AMNH 2062. Bohlin considered the species to be a member of the pachycephalosaurians because he mistook an osteoderm for the thick skull roof typical of this group. The material is probably

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 ...

. It has been seen as a

junior synonym The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently. * In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linna ...

of ''

Pinacosaurus ''Pinacosaurus'' (meaning "Plank lizard") is a genus of ankylosaurid thyreophoran dinosaur that lived in Asia during the Late Cretaceous (Santonian-Campanian, roughly 75 million to 71 million years ago), mainly in Mongolia and China. The first r ...

'' but the genus is more generally 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 ...

'', especially since Bohlin's description can only be checked by comparison with his published drawings. Arbour, Victoria Megan, 2014. ''Systematics, evolution, and biogeography of the ankylosaurid dinosaurs''. Ph.D thesis, University of Alberta

Notes

References

*Fossil reptiles from Mongolia and Kansu. Bohlin, B. ''Report of the Scientific Expedition to northwest China'', Publ. 37 (6); 1-105 (1953). *A taxonomic review of the Pachycephalosauridae (Dinosauria: Ornithischia). Sullivan, R. ''Late Cretaceous vertebrates from the Western Interior''. Lucas et al. (eds), New Mexico Museum of Natural History and Science Bulletin 35; 347-365 (2006). Ankylosaurs Late Cretaceous dinosaurs of Asia Nomina dubia Fossil taxa described in 1953 {{ornithischian-stub