''Mosaiceratops'' is a genus of

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 Jurassic. ...

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

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

. ''Mosaiceratops'' lived in the upper

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 th ...

in what is now the

Henan Province Henan (; or ; ; alternatively Honan) is a landlocked province of China, in the central part of the country. Henan is often referred to as Zhongyuan or Zhongzhou (), which literally means "central plain" or "midland", although the name is al ...

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 ...

. 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 126 and 101 million years ago. It is notable for being the most species-rich non-avian dinosaur gen ...

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

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 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 ...

''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 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 of the ...

''mosaicus'' and Greek ''keras'', "horn" and ''ops'', "face". The specific name honours the Japanese paleontologist Yoichi Azuma, the discoverer of ''

Archaeoceratops ''Archaeoceratops'', meaning "ancient horned face", is a genus of basal neoceratopsian dinosaur from the Early Cretaceous (Aptian stage) of north central China. It appears to have been bipedal and quite small, reaching in length and in body m ...

''. ''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 ICS' geologic timescale, the second age in the Late Cretaceous Epoch, or a stage in the Upper Cretaceous Series. It spans the time between 93.9 ± 0.8 Ma and 89.8 ± 1 Ma (million years ago). The Turonian is preceded by t ...

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 ...

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

pelvis The pelvis (plural pelves or pelvises) is the lower part of the trunk, between the abdomen and the thighs (sometimes also called pelvic region), together with its embedded skeleton (sometimes also called bony pelvis, or pelvic skeleton). The ...

bones and leg bones (

femur The femur (; ), or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates with ...

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

fibula The fibula 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. Its upper extremity is ...

ischium The ischium () form ...

, ilium, some

phalanges The phalanges (singular: ''phalanx'' ) are digital bones in the hands and feet of most vertebrates. In primates, the thumbs and big toes have two phalanges while the other digits have three phalanges. The phalanges are classed as long bones. ...

and

metatarsal The metatarsal bones, or metatarsus, are a group of five long bones in the foot, located between the tarsal bones of the hind- and mid-foot and the phalanges of the toes. Lacking individual names, the metatarsal bones are numbered from the med ...

calcaneum In humans and many other primates, the calcaneus (; from the Latin ''calcaneus'' or ''calcaneum'', meaning heel) or heel bone is a bone of the tarsus of the foot which constitutes the heel. In some other animals, it is the point of the hock. ...

and

astragalus ''Astragalus'' is a large genus of over 3,000 species of herbs and small shrubs, belonging to the legume family Fabaceae and the subfamily Faboideae. It is the largest genus of plants in terms of described species. The genus is native to tempe ...

), twenty-four

vertebrae The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic i ...

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

humerus The humerus (; ) 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 and ulna, and consists of three sections. The humeral upper extremity consists of a roun ...

, a

radius In classical geometry, a radius ( : radii) of a circle or sphere is any of the line segments from its center to its perimeter, and in more modern usage, it is also their length. The name comes from the latin ''radius'', meaning ray but also the ...

and the anterior part of an articulated

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, the ...

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 v ...

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 ancestral co ...

. The articulated skull preserves the

rostral bone 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 Jurassic. ...

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 mammal has b ...

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 ...

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. It is connected to the quadratojugal and maxilla, as well as other bones, which may vary by species. Anato ...

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 anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower tooth, teeth in place. The mandible sits beneath the maxilla. It is the only movabl ...

surangular The suprangular or surangular 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, splenial and articular. It is often a mu ...

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 art ...

, 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 fossils are part of the collection of the

Zhejiang Museum of Natural History The Zhejiang Museum of Natural History is a museum that mainly focuses on exhibitions, collections and analysis on specimens of life science and earth science. The museum is one of the earliest museums of natural history created by Chinese peopl ...

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 refer to: Healthcare *Lateral (anatomy), an anatomical direction *Lateral cricoarytenoid muscle *Lateral release (surgery), a surgical procedure on the side of a kneecap Phonetics *Lateral cons ...

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 ...

, 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, and ...

, 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 an ...

''.

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 herbivore, herbivorous Chasmosaurinae, chasmosaurine Ceratopsidae, ceratopsid dinosaur that first appeared during the late Maastrichtian stage of the Late Cretaceous Period (geology), period, about 68 m ...

'' 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 ''Yinlong'' (, meaning "hidden dragon") is a genus of basal ceratopsian dinosaur from the Late Jurassic Period of central Asia. It was a small, primarily bipedal herbivore. Discovery and species A coalition of American and Chinese paleontologis ...

'', 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 Ceratopsians Late Cretaceous dinosaurs of Asia Fossil taxa described in 2015 Paleontology in Henan Ornithischian genera

Discovery

Description

Classification

See also

References