''Sinoceratops'' is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

ceratopsia Ceratopsia or Ceratopia ( or ; Greek: "horned faces") is a group of herbivorous, beaked dinosaurs that thrived in what are now North America, Europe, and Asia, during the Cretaceous Period, although ancestral forms lived earlier, in the Jurassi ...

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 ...

that lived approximately 73

million years ago The abbreviation Myr, "million years", is a unit of a quantity of (i.e. ) years, or 31.556926 teraseconds. Usage Myr (million years) is in common use in fields such as Earth science and cosmology. Myr is also used with Mya (million years ago). ...

during the latter part of 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 ...

Period in what is now

Shandong province Shandong ( , ; ; alternately romanized as Shantung) is a coastal province of the People's Republic of China and is part of the East China region. Shandong has played a major role in Chinese history since the beginning of Chinese civilizati ...

in China. It was named in

2010 File:2010 Events Collage New.png, From top left, clockwise: The 2010 Chile earthquake was one of the strongest recorded in history; The Eruption of Eyjafjallajökull in Iceland disrupts air travel in Europe; A scene from the opening ceremony of ...

by Xu Xing ''et al.'' for three skulls from

Zhucheng Zhucheng () is a county-level city in the southeast of Shandong province, People's Republic of China. It is under the administration of Weifang city and had at the 2010 census a population of 1,086,222 even though its built-up (''or metro'') area ...

, China. The name of its type species ''Sinoceratops zhuchengensis'' means "Chinese horned face from Zhucheng", after the location of its discovery. ''Sinoceratops'' was a medium-sized, averagely-built, ground-dwelling,

quadrupedal Quadrupedalism is a form of locomotion where four limbs are used to bear weight and move around. An animal or machine that usually maintains a four-legged posture and moves using all four limbs is said to be a quadruped (from Latin ''quattuo ...

herbivore A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthp ...

. It could grow up to an estimated in length and weigh up to . It was the first

ceratopsid Ceratopsidae (sometimes spelled Ceratopidae) is a family of ceratopsian dinosaurs including ''Triceratops'', '' Centrosaurus'', and '' Styracosaurus''. All known species were quadrupedal herbivores from the Upper Cretaceous. All but one species ar ...

dinosaur discovered in China, and the only ceratopsid known from Asia. All other centrosaurines, and all chasmosaurines, are known from fossils discovered in North America, except for possibly ''

Turanoceratops ''Turanoceratops'' ("Turan horned face") is a genus of herbivorous ceratopsian dinosaur from the late Cretaceous Bissekty Formation of Uzbekistan. The fossils dated from the mid-late Turonian stage, roughly 90 million years ago. The skull bore a ...

''. ''Sinoceratops'' is also significant because it is one of the largest known centrosaurines, and is much larger than any other known

basal Basal or basilar is a term meaning ''base'', ''bottom'', or ''minimum''. Science * Basal (anatomy), an anatomical term of location for features associated with the base of an organism or structure * Basal (medicine), a minimal level that is nec ...

members of this group. ''Sinoceratops'' was discovered in the Hongtuya Formation, which was deposited during the late Cretaceous. It lived alongside leptoceratopsids, saurolophines, and tyrannosaurines. The most common creature in the formation was ''

Shantungosaurus ''Shantungosaurus'' (meaning "''Shandong Lizard''") is a genus of very large saurolophine hadrosaurid dinosaur found in the Late Cretaceous Wangshi Group of the Shandong Peninsula in China, containing a single species, ''Shantungosaurus giganteus ...

'', to which most of the material has been assigned. The animals living alongside ''Sinoceratops'' and ''Shantungosaurus'' were '' Zhuchengceratops'', '' Zhuchengtitan'', and ''

Zhuchengtyrannus ''Zhuchengtyrannus'' (meaning "Zhucheng tyrant") is a genus of tyrannosaurid theropod dinosaur known from the Campanian stage of the Late Cretaceous of Shandong Province, China. It belongs to the subfamily Tyrannosaurinae, and contains a singl ...

''.

Discovery

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 seve ...

specimen ZCDM V0010, consisting of a partial

skull The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, t ...

, including a

braincase In human anatomy, the neurocranium, also known as the braincase, brainpan, or brain-pan is the upper and back part of the skull, which forms a protective case around the brain. In the human skull, the neurocranium includes the calvaria or skul ...

, was in the summer of 2008 recovered at the Hongtuya Formation of the

Wangshi Group The Wangshi Group () is a geological Group in Shandong, China whose strata date back to the Coniacian to Campanian stages of the Late Cretaceous.Shandong, China. The specimen was collected in fluvial sediments that were deposited during 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. Campani ...

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 interv ...

stages 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 * St ...

of the

period, approximately 72–66 million years ago. Two other specimens have been recovered from the same formation. Specimen ZCDM V0011 is a partial skull that consists of the skull roof and most of the braincase, and ZCDM V0012 represents a partial braincase. The genus name ''Sinoceratops'' means "Chinese horned face", and is derived from the word ''Sino-'' referring to China from

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 ...

''Sina'', the country of its discovery, and the

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

words ''keras'' (κέρας) meaning "horn", and ''ops'' (ωψ) meaning "face". ''Sinoceratops'' was described and named by

paleontologist Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of foss ...

Xu Xing and colleagues, in

. 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 ''Sinoceratops zhuchengensis''. The specific name refers to the location of its discovery, the city of

which also financed the excavations. The discovery was significant, because it represented the first ceratopsid known from China, and possibly the only ceratopsid from Asia. The only other possible Asian ceratopsid is ''

'', however, its position within the Ceratopsidae is contested.

Description

Sinoceratops_Size_Comparison_by_PaleoGeek

''Sinoceratops'' was a large

n, with an estimated length of and body mass of . It has a short, hooked horn on its nose (called a nasal horn), no horns above its eyes (brow horns), and a short

neck frill A neck frill is the relatively extensive margin seen on the back of the heads of reptiles with either a bony support such as those present on the skulls of dinosaurs of the suborder Marginocephalia or a cartilaginous one as in the frill-neck ...

with a series of forward-curving hornlets that gave the frill a crown-like appearance. Inside this row of hornlets there is a series of low knobs on the top of the frill, which are not seen in any other horned dinosaur. ''Sinoceratops'' is a member of the short-frilled ceratopsids, the Centrosaurinae.

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 seve ...

specimen ZCDM V0010 consists of a partial skull with most elements of the skull roof and partial braincase. The skull of ''Sinoceratops'' is estimated to be long making it one of the largest known centrosaurine skulls. Features that differentiate an animal from most or all others are called a diagnosis. Some, but not all, of the features in a diagnosis are also

autapomorphies In phylogenetics, an autapomorphy is a distinctive feature, known as a derived trait, that is unique to a given taxon. That is, it is found only in one taxon, but not found in any others or outgroup taxa, not even those most closely related to t ...

. An autapomorphy is a distinctive anatomical feature that is unique to a given organism. According to Xu ''et al.'' (2010), ''Sinoceratops'' can be distinguished based on the following diagnostic characteristics: there are at least ten robust, strongly curved hornlike processes along the rear margin of the combined parietals, while at the same time at least four hornlike processes on the combined

squamosal The squamosal is a skull bone found in most reptiles, amphibians, and birds. In fishes, it is also called the pterotic bone. In most tetrapods, the squamosal and quadratojugal bones form the cheek series of the skull. The bone forms an ancestral co ...

s are present; there is a large accessory fenestra in front of the

antorbital fenestra An antorbital fenestra (plural: fenestrae) is an opening in the skull that is in front of the eye sockets. This skull character is largely associated with archosauriforms, first appearing during the Triassic Period. Among extant archosaurs, birds ...

(differing from all other known centrosaurines); the external margin of the parietals is only weakly undulating (differing from all other known centrosaurines); and the presence of broad-based epoccipitals (differing from all other known centrosaurines).

Classification

''Sinoceratops'' was assigned to the

taxon In biology, a taxon ( back-formation from '' taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular n ...

Centrosaurinae, as a

member by Xu et al. (2010) based on characteristics present in the skull. ''Sinoceratops'' bears several characteristics that resemble features in chasmosaurines, blurring the distinction between the Centrosaurinae and Chasmosaurinae. According to Xu e.a. the basal position of ''Sinoceratops'' indicates that ceratopids originated in Asia. ''Sinoceratops'' however, shares a number of features with advanced centrosaurines such as ''Centrosaurus'' and ''Styracosaurus'' that are not seen in primitive centrosaurines like ''

Diabloceratops ''Diabloceratops'' is an extinct genus of centrosaurine ceratopsian dinosaur that lived approximately 81.4-81 million years ago during the latter part of the Cretaceous Period in what is now Utah, in the United States. ''Diabloceratops'' was ...

'', including a well-developed nose horn and reduced brow horns. The implication might be that this genus represents a lineage that invaded Asia from North America through

Beringia Beringia is defined today as the land and maritime area bounded on the west by the Lena River in Russia; on the east by the Mackenzie River in Canada; on the north by 72 degrees north latitude in the Chukchi Sea; and on the south by the tip ...

. The

cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to ...

below represents a phylogenetic analysis by Chiba ''et al.'' (2017):

Paleoecology

''Sinoceratops'' is known from the Hongtuya Formation of southern China. It is known from skull material. Alongside it, in the formation, lived ''

'', a very common hadrosaurid to which most of the material has been assigned, ''

'', an Asian tyrannosaurid related to ''

Tarbosaurus ''Tarbosaurus'' ( ; meaning "alarming lizard") is a genus of tyrannosaurid dinosaur that flourished in Asia about 70 million years ago, at the end of the Late Cretaceous Period, considered to contain a single known species, ''Tarbosauru ...

'', '' Zhuchengceratops'', an Asian leptoceratopsid, and ''

Huaxiaosaurus ''Shantungosaurus'' (meaning "''Shandong Lizard''") is a genus of very large saurolophine hadrosaurid dinosaur found in the Late Cretaceous Wangshi Group of the Shandong Peninsula in China, containing a single species, ''Shantungosaurus gigan ...

'', a possible older individual of ''Shantungosaurus''.

References

External links