Gobisaurus is an extinct 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 basal ankylosaurid ankylosaur from the Upper Cretaceous

Cretaceous

The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...

 (Turonian

Turonian

The Turonian is, in the ICS' geologic timescale, the second age in the Late Cretaceous epoch, or a stage in the Upper Cretaceous series. It spans the time between 93.5 ± 0.8 Ma and 89.3 ± 1 Ma...

) Ulansuhai Formation

Ulansuhai Formation

The Ulansuhai Formation is a geological formation in Inner Mongolia, north China. Dinosaur remains are among the fossils that have been recovered from the formation....

 (Nei Mongol Zizhiqu) 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...

. 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...

 (IVPP V12563) consists of a skull and as yet undescribed postcranial remains. It was first named by Matthew K. Vickaryous, Anthony P. Russell, Philip J. Currie and Xi-Jin Zhao in 2001

2001 in paleontology

-Newly named insects:-Newly named bony fishes:-Newly named amphibians:-Newly named turtles:-Ichthyosaurs:-Newly named basal lepidosauromorphs:-Newly named plesiosaurs:-Newly named sphenodonts:-Newly named basal archosauromorphs:...

 and 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 Gobisaurus domoculus.

This is a large ankylosaur, with a skull measuring 46 centimetres (18.1 in) in length and 45 centimetres (17.7 in) across. The name means "Gobi (Desert) lizard," referring to its discovery by the Sino-Soviet Expeditions (1959–1960) in the Gobi Desert

Gobi Desert

The Gobi is a large desert region in Asia. It covers parts of northern and northwestern China, and of southern Mongolia. The desert basins of the Gobi are bounded by the Altai Mountains and the grasslands and steppes of Mongolia on the north, by the Hexi Corridor and Tibetan Plateau to the...

. The 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...

 is monotypic

Monotypic

In biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...

, containing only G. domoculus.

Gobisaurus and Shamosaurus

Gobisaurus domoculus shares many cranial

Skull

The skull is a bony structure in the head of many animals that supports the structures of the face and forms a cavity for the brain.The skull is composed of two parts: the cranium and the mandible. A skull without a mandible is only a cranium. Animals that have skulls are called craniates...

 similarities with Shamosaurus scutatus, including a rounded squamosal, large elliptical orbital fenestrae

Fenestrae

Fenestræ is a Latin word that means "window".* In histology, fenestræ are small pores in endothelial cells that allow for rapid exchange of molecules between sinusoid blood vessels and surrounding tissue...

 and external nares, a deltoid

Kite (geometry)

In Euclidean geometry a kite is a quadrilateral whose four sides can be grouped into two pairs of equal-length sides that are next to each other. In contrast, a parallelogram also has two pairs of equal-length sides, but they are opposite each other rather than next to each other...

 dorsal

Dorsum (biology)

In anatomy, the dorsum is the upper side of animals that typically run, fly, or swim in a horizontal position, and the back side of animals that walk upright. In vertebrates the dorsum contains the backbone. The term dorsal refers to anatomical structures that are either situated toward or grow...

 profile with a narrow rostrum

Rostrum (anatomy)

The term rostrum is used for a number of unrelated structures in different groups of animals:*In crustaceans, the rostrum is the forward extension of the carapace in front of the eyes....

, quadratojugal protuberances, and caudolaterally directed paroccipital processes. But the two taxa may be distinguished by differences in the length of the maxillary tooth row, an unfused basipterygoid-pterygoid process in Gobisaurus, the presence on an elongate vomerine premaxillary process in Gobisaurus, and the presence of cranial sculpting in Shamosaurus, but not in Gobisaurus. Vickaryous et al., 2004 found that a clade formed by Shamosaurus

Shamosaurus

Shamosaurus is an extinct genus of basal ankylosaurid ankylosaur from Early Cretaceous deposits of Höövör, Mongolia. Shamosaurus is known from the holotype PIN N 3779/2 complete skull and jaw and the paratypes include partial skeleton remains and an armor. It was collected from the...

and Gobisaurus is "nested deep within the ankylosaurid lineage as the first successive outgroup

Outgroup

In cladistics or phylogenetics, an outgroup is a group of organisms that serves as a reference group for determination of the evolutionary relationship among three or more monophyletic groups of organisms....

 to (the subfamily) Ankylosaurinae".