Auroraceratops
Encyclopedia
Auroraceratops, meaning "dawn horned face", is a 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
Basal (phylogenetics)
In phylogenetics, a basal clade is the earliest clade to branch in a larger clade; it appears at the base of a cladogram.A basal group forms an outgroup to the rest of the clade, such as in the following example:...

 neoceratopsian dinosaur
Dinosaur
Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...

, from the Early Cretaceous
Early Cretaceous
The Early Cretaceous or the Lower Cretaceous , is the earlier or lower of the two major divisions of the Cretaceous...

 (Aptian
Aptian
The Aptian is an age in the geologic timescale or a stage in the stratigraphic column. It is a subdivision of the Early or Lower Cretaceous epoch or series and encompasses the time from 125.0 ± 1.0 Ma to 112.0 ± 1.0 Ma , approximately...

 age) of north central 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 etymology
Etymology
Etymology is the study of the history of words, their origins, and how their form and meaning have changed over time.For languages with a long written history, etymologists make use of texts in these languages and texts about the languages to gather knowledge about how words were used during...

 of the generic name refers to its status as an early ceratopsian and also to Dawn Dodson, wife of Peter Dodson
Peter Dodson
Peter Dodson is an American paleontologist who has published many papers and written and collaborated on books about dinosaurs. An authority on Ceratopsians, he has also authored several papers and textbooks on hadrosaurs and sauropods, and is a co-editor of The Dinosauria, widely considered the...

, one of the palaeontologists who described it.

Discovery and species

The only known specimen was found in the Xinminbao Group
Xinminbao Group
The Xinminbao 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 Gonpoquan and Suanjingze basins, and also in the...

, Gongpoquan Basin
Basin (geology)
A structural basin is a large-scale structural formation of rock strata formed by tectonic warping of previously flat lying strata. Structural basins are geological depressions, and are the inverse of domes. Some elongated structural basins are also known as synclines...

 of the Mazong Shan
Mazong Shan
The Mazong Shan is a minor mountain range of northern Gansu, between the Altay range to the north and the Qilian range to the south. The Mazong Shan peak rises to 2584 m....

 area of Gansu Province, north central China. 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...

, A. rugosus, was described by You, Li, Ji, Lamanna, and Dodson in 2005. The specific descriptor, "rugosus", Latin for "rough", refers to the various rugose areas on the surface of both skull and jaw, namely the wrinkled expansion of the lacrimal bone
Lacrimal bone
The lacrimal bone, the smallest and most fragile bone of the face, is situated at the front part of the medial wall of the orbit. It has two surfaces and four borders.-Lateral or orbital surface:...

 distinctive of this animal. Auroraceratops is the second basal neoceratopsian to be found in the Mazong Shan area, after Archaeoceratops.

The type
Biological type
In biology, a type is one particular specimen of an organism to which the scientific name of that organism is formally attached...

 specimen, IG-2004-VD-001, consists of a nearly complete subadult skull lacking the rostral bone
Rostral bone
The rostral bone is the edentulous dorsal component of the skeleton of the beak, unique to the ceratopsian dinosaurs. Othniel Charles Marsh recognized and named this bone, which acts as a mirror image of the predentary bone on the lower jaw....

 and parietal
Parietal
Parietal may refer to:*Parietal placentation*Parietal lobe of the brain*Parietal bone of the skull*Parietal scales of a snake lie in the general region of the parietal bone*Parietal cell in the stomach*Parietal pleura...

 crest.

Description

Though most other neoceratopsians are characterized by a long, narrow snout, Auroraceratops has a shorter wider one. The 20 cm (8 in) skull itself is rather flat and wide. The premaxilla
Premaxilla
The incisive bone is the portion of the maxilla adjacent to the incisors. It is a pair of small cranial bones at the very tip of the jaws of many animals, usually bearing teeth, but not always. They are connected to the maxilla and the nasals....

e have at least two pairs of striated fang-like teeth. Paired rugose areas, very probably covered in keratin
Keratin
Keratin refers to a family of fibrous structural proteins. Keratin is the key of structural material making up the outer layer of human skin. It is also the key structural component of hair and nails...

 in life, are in front of the eyes and on the jugal
Jugal
The jugal is a skull bone found in most reptiles, amphibians, and birds. In mammals, the jugal is often called the malar or Zygomatic. It is connected to the quadratojugal and maxilla, as well as other bones, which may vary by species....

 with corresponding areas on the lower jaw. These roughened knobs were likely to have been used for inter- and intra-specific interactions
Display (zoology)
Display is a form of animal behaviour, linked to survival of the species in various ways. One example of display used by some species can be found in the form of courtship, with the male usually having a striking feature that is distinguished by colour, shape or size, used to attract a female...

. While they would not have been much use as a physical defense against predators, another possible function for these structures would be in pushing or butting contests between members of the same species either for mating rights or social disputes.

Auroraceratops is a rather derived moderate-sized basal neoceratopsian that adds diversity to that clade
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...

, displaying skull features not present in Archaeoceratops
Archaeoceratops
Archaeoceratops, meaning "ancient horned face", is a genus of basal neoceratopsian dinosaur from the Early Cretaceous of north central China. It appears to have been bipedal and quite small with a comparatively large head...

or Liaoceratops
Liaoceratops
Liaoceratops, meaning "Liao Horned Face", is a ceratopsian dinosaur believed to be an early relative of the horned ceratopsids. It lived in the early Cretaceous, some 130 million years ago. It was discovered in China by a team of American and Chinese scientists...

.
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