''Mosaiceratops'' is a genus of

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

n, described by Zheng, Jin & Xu in 2015 and found in the Xiaguan Formation of

Neixiang County Neixiang County () is a CPRC, county under the jurisdiction of Nanyang, Henan, Nanyang City, in the southwest of Henan province, China. It has an area of and a population of 610,000 as of 2002. Neixiang is best known because it has China's best ...

. ''Mosaiceratops'' lived in the upper

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

in what is now the

Henan Province Henan; alternatively Honan is a province in Central China. Henan is home to many heritage sites, including Yinxu, the ruins of the final capital of the Shang dynasty () and the Shaolin Temple. Four of the historical capitals of China, Luo ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

. Although phylogenetic analyses have found ''Mosaiceratops'' to be the most basal neoceratopsian, the authors noted that several features in the premaxilla and nasal bones are shared with ''

Psittacosaurus ''Psittacosaurus'' ( ; "parrot lizard") is a genus of extinct ceratopsian dinosaur from the Early Cretaceous of what is now Asia, existing between 125 and 105 million years ago. It is notable for being the most species-rich non-avian dinosaur ...

'', indicating that neoceratopsians evolved premaxillary teeth twice and that ''Psittacosaurus'' is not as primitive as previously thought.Zheng, W., Jin, X., & Xu, X. (2015)
A psittacosaurid-like basal neoceratopsian from the Upper Cretaceous of central China and its implications for basal ceratopsian evolution
. ''Scientific reports'', 5. article number 14190: 1-9; doi:10.1038/srep14190

Discovery

On the westbank of the river Tuanhe in Neixiang in Henan the skeleton was discovered of a small ceratopian. The fossil was prepared by Sheng Yiming and Yu Chaohe. In 2015, the

type species In International_Code_of_Zoological_Nomenclature, 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 spe ...

''Mosaiceratops azumai'' was named and described by Zheng Wenjie, Jin Xingsheng and Xu Xing. The generic name ''Mosaiceratops'' means "mosaic horned face", which refers to the mosaic of features normally found on basal neoceratopsians, psittacosaurids and other basal ceratopsians, especially the lack of premaxillary teeth. It is a combination of

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

''mosaicus'' and Greek ''keras'', "horn" and ''ops'', "face". The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

honours the Japanese paleontologist Yoichi Azuma, the discoverer of '' Archaeoceratops''. ''Mosaiceratops'' was one of eighteen dinosaur taxa from 2015 to be described in open access or free-to-read journals. The holotype, ZMNH M8856, was found in a layer of the Xiaguan Formation dating from the

Turonian The Turonian is, in the International Commission on Stratigraphy, ICS' geologic timescale, the second age (geology), age in the Late Cretaceous epoch (geology), Epoch, or a stage (stratigraphy), stage in the Upper Cretaceous series (stratigraphy), ...

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. Campa ...

. It is an incomplete and disarticulated skeleton with skull. It includes

pelvis The pelvis (: pelves or pelvises) is the lower part of an Anatomy, anatomical Trunk (anatomy), trunk, between the human abdomen, abdomen and the thighs (sometimes also called pelvic region), together with its embedded skeleton (sometimes also c ...

bones and leg bones (

femur The femur (; : femurs or femora ), or thigh bone is the only long bone, bone in the thigh — the region of the lower limb between the hip and the knee. In many quadrupeds, four-legged animals the femur is the upper bone of the hindleg. The Femo ...

tibia The tibia (; : tibiae or tibias), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two Leg bones, bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outsi ...

fibula The fibula (: fibulae or fibulas) or calf bone is a leg bone on the lateral side of the tibia, to which it is connected above and below. It is the smaller of the two bones and, in proportion to its length, the most slender of all the long bones. ...

ischium The ischium (; : is ...

, ilium, some

phalanges The phalanges (: phalanx ) are digit (anatomy), digital bones in the hands and foot, feet of most vertebrates. In primates, the Thumb, thumbs and Hallux, big toes have two phalanges while the other Digit (anatomy), digits have three phalanges. ...

and

metatarsal The metatarsal bones or metatarsus (: metatarsi) are a group of five long bones in the midfoot, located between the tarsal bones (which form the heel and the ankle) and the phalanges ( toes). Lacking individual names, the metatarsal bones are ...

calcaneum In humans and many other primates, the calcaneus (; from the Latin ''calcaneus'' or ''calcaneum'', meaning heel; : calcanei or calcanea) or heel bone is a bone of the tarsus of the foot which constitutes the heel. In some other animals, it is t ...

and

astragalus Astragalus may refer to: * ''Astragalus'' (plant), a large genus of herbs and small shrubs *Astragalus (bone) The talus (; Latin for ankle or ankle bone; : tali), talus bone, astragalus (), or ankle bone is one of the group of foot bones known ...

), twenty-four

vertebrae Each vertebra (: vertebrae) is an irregular bone with a complex structure composed of bone and some hyaline cartilage, that make up the vertebral column or spine, of vertebrates. The proportions of the vertebrae differ according to their spinal ...

(three cervicals, three dorsals and eighteen caudals), a dorsal rib, a

humerus The humerus (; : humeri) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius (bone), radius and ulna, and consists of three sections. The humeral upper extrem ...

, a

radius In classical geometry, a radius (: radii or radiuses) of a circle or sphere is any of the line segments from its Centre (geometry), center to its perimeter, and in more modern usage, it is also their length. The radius of a regular polygon is th ...

and the anterior part of an articulated

skull The skull, or cranium, is typically a bony enclosure around the brain of a vertebrate. In some fish, and amphibians, the skull is of cartilage. The skull is at the head end of the vertebrate. In the human, the skull comprises two prominent ...

with a disarticulated

postorbital bone The ''postorbital'' is one of the bones in vertebrate skulls which forms a portion of the dermal skull roof and, sometimes, a ring about the orbit. Generally, it is located behind the postfrontal and posteriorly to the orbital fenestra. In some ...

and

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 ancestra ...

. The articulated skull preserves the

rostral bone Ceratopsia or Ceratopia ( or ; Ancient Greek, Greek: "horned faces") is a group of herbivore, herbivorous, beaked dinosaurs that thrived in what are now North America, Asia and Europe, during the Cretaceous Period (geology), Period, although ance ...

premaxilla The premaxilla (or praemaxilla) is one of a pair of small cranial bones at the very tip of the upper jaw of many animals, usually, but not always, bearing teeth. In humans, they are fused with the maxilla. The "premaxilla" of therian mammals h ...

maxilla In vertebrates, the maxilla (: maxillae ) 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 two maxil ...

jugal bone The jugal is a skull bone found in most reptiles, amphibians and birds. In mammals, the jugal is often called the malar or zygomatic bone, zygomatic. It is connected to the quadratojugal and maxilla, as well as other bones, which may vary by spe ...

quadratojugal The quadratojugal is a skull bone present in many vertebrates, including some living reptiles and amphibians. Anatomy and function In animals with a quadratojugal bone, it is typically found connected to the jugal (cheek) bone from the front and ...

dentary In jawed vertebrates, the mandible (from the Latin ''mandibula'', 'for chewing'), lower jaw, or jawbone is a bone that makes up the lowerand typically more mobilecomponent of the mouth (the upper jaw being known as the maxilla). The jawbone ...

surangular The surangular or suprangular is a jaw bone found in most land vertebrates, except mammals. Usually in the back of the jaw, on the upper edge, it is connected to all other jaw bones: dentary, angular bone, angular, splenial and articular. It is o ...

angular bone The angular is a large bone in the lower jaw (mandible) of amphibians and reptiles (birds included), which is connected to all other lower jaw bones: the dentary (which is the entire lower jaw in mammals), the splenial, the suprangular, and the ...

, the anterior section of the

prefrontal bone The prefrontal bone is a bone separating the lacrimal and frontal bones in many tetrapod skulls. It first evolved in the sarcopterygian clade Rhipidistia, which includes lungfish and the Tetrapodomorpha. The prefrontal is found in most modern and ...

, and the anterior part of the

nasal bone The nasal bones are two small oblong bones, varying in size and form in different individuals; they are placed side by side at the middle and upper part of the face and by their junction, form the bridge of the upper one third of the nose. Eac ...

. The fossils are part of the collection of the

Zhejiang Museum of Natural History The Zhejiang Museum of Natural History () is the provincial natural history museum of the Zhejiang province in China. The Hangzhou branch is located in the West Lake Cultural Square in Hangzhou, which also houses the Wulin building of Zhejiang ...

Description

''Mosaiceratops'' was a relatively small dinosaur, reaching in length and in body mass. It can be distinguished by four autapomorphic, unique derived traits: the presence of an evident groove between the premaxilla and the maxilla in

lateral Lateral is a geometric term of location which may also refer to: Biology and healthcare * Lateral (anatomy), a term of location meaning "towards the side" * Lateral cricoarytenoid muscle, an intrinsic muscle of the larynx * Lateral release ( ...

view; the elongation of the anterior part of the jugal having a parallel upper edge and lower edge; the main body of the jugal below the eye sockets bears two small bumps; in the ilium the extremity of the upper edge of the rear blade is pointed obliquely to above and behind. Mosaiceratops Scale

Furthermore a unique combination is present of traits that in themselves are not unique. The premaxilla is

edentulous Toothlessness or edentulism is the condition of having no teeth. In organisms that naturally have teeth, it is the result of tooth loss. Organisms that never possessed teeth can also be described as edentulous. Examples are the members of the fo ...

, meaning it lacks teeth. The premaxilla is somewhat wider than the maxilla in lateral view (the presence of that trait is

plesiomorphic In phylogenetics, a plesiomorphy ("near form") and symplesiomorphy are synonyms for an ancestral character shared by all members of a clade, which does not distinguish the clade from other clades. Plesiomorphy, symplesiomorphy, apomorphy, an ...

, being shared with ''

''). The nasal bone has a front lower branch extending under the bony nostril. The jugal bone is formed as an inverted T. The postorbital is T-shaped with slender descending and rear branches. The inner branch of the squamosal bone points obliquely to the front and inside. The front branch of the squamosal is not forked. The basal tubers of the occiput are separated by a wide middle notch. More in general, the skull overall is more similar to advanced taxa like '' Aquilops'' or ''

Liaoceratops ''Liaoceratops'', meaning "Liaoning horned face", is a ceratopsian dinosaur believed to be an early relative of the horned ceratopsids. It lived in the Early Cretaceous, 126 million years ago. It was discovered in China by a team of American and ...

''.

Classification

Zheng ''et al.'' (2015), the describers of ''Mosaiceratops'', recovered the genus as the most basal known neoceratopsian, closer to ''

Triceratops ''Triceratops'' ( ; ) is a genus of Chasmosaurinae, chasmosaurine Ceratopsia, ceratopsian dinosaur that lived during the late Maastrichtian age of the Late Cretaceous Period (geology), period, about 68 to 66 million years ago on the island ...

'' than ''Psittacosaurus''. Before the description of ''Mosaiceratops'', the most basal known neoceratopsian was either ''Aquilops'' or ''Liaoceratops'', depending on the analysis. However, they noted that this position was not strongly supported in their phylogenetic analysis, acknowledging the possibility that ''Mosaiceratops'' instead represents the sister taxon to ''Psittacosaurus'' (in which case the name Psittacosauridae would be reinstated). In their description of the postcrania of '' Yinlong'', Han ''et al.'' (2018) noted that the external naris of ''Mosaiceratops'' was not as positioned as high as in ''Psittacosaurus'', and recovered ''Mosaiceratops'' as more derived than ''Liaoceratops'' and ''Aquilops''.Fenglu Han; Catherine A. Forster; Xing Xu; James M. Clark (2017). "Postcranial anatomy of Yinlong downsi (Dinosauria: Ceratopsia) from the Upper Jurassic Shishugou Formation of China and the phylogeny of basal ornithischians". Journal of Systematic Palaeontology. in press. doi:10.1080/14772019.2017.1369185.

References

{{Taxonbar, from=Q21011930 Ceratopsia Dinosaur genera Late Cretaceous dinosaurs Taxa named by Xu Xing Fossil taxa described in 2015 Dinosaurs of China

Discovery

Description

Classification

See also

References