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Ceratopsians
Fossil range: Jurassic - Late Cretaceous
Triceratops skull
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Sauropsida
Superorder: Dinosauria
Order: Ornithischia
Suborder: Cerapoda
Infraorder: Ceratopsia
Marsh, 1890
Families

Ceratopsia or Ceratopia (pronounced /ˌsɛrəˈtɒpsiə/, /ˌsɛrəˈtoʊpiə/; Greek: "horned faces") is a group of herbivorous, beaked dinosaurs which thrived in what are now North America and Asia, during the Cretaceous Period, although ancestral forms lived earlier, in the Jurassic. The Jurassic is a geologic period and system that extends from about Ma (million years ago to  Ma that is from the end of the Triassic to the beginning Late Cretaceous (100mya - 65mya refers to the second half of the Cretaceous Period, named after the famous white Chalk cliffs of southern England Triceratops (traɪˈsɛrətɒps is an extinct Genus of herbivorous ceratopsid Dinosaur which lived during the late Maastrichtian Chordates ( Phylum Chordata) are a group of Animals that includes the Vertebrates together with several closely related Invertebrates Reptiles, or members of the class Reptilia are air-breathing Cold-blooded Vertebrates that have skin covered in scales as opposed to hair or feathers Ornithischia (ɔrnɪˈθɪskiə) or Predentata is an extinct order of beaked herbivorous Dinosaurs The name ornithischia Cerapoda (siːˈrɒpədə is a Clade or suborder of the order Ornithischia. Othniel Charles Marsh ( October 29, 1831 &ndash March 18, 1899) was one of the pre-eminent Paleontologists of the 19th century who In Biological classification, family ( Latin The Archaeoceratopsidae constitutes a family of primitive Ceratopsian Dinosaur from the Early Cretaceous of China Ceratopsidae (sometimes spelled Ceratopidae) is a speciose group of Marginocephalian Dinosaurs including Triceratops and Styracosaurus Chaoyangsauridae is a family of Dinosaurs They were the first Marginocephalian dinosaurs to appear on the planet about 150 million years ago in the The family Leptoceratopsidae, its name derived from the type genus Leptoceratops, is a group of several small neoceratopsian genera which appear not to belong to the A protoceratopsid is a Dinosaur of the family Protoceratopsidae. The Psittacosauridae were a group of Ceratopsian dinosaurs The family Psittacosauridae was first named by Osborn in 1923 The Ancient Greek language is the historical stage in the development of the Hellenic language family spanning the Archaic (c Herbivory is a form of Predation in which an Organism, known as a herbivore, consumes principally Autotrophs ref name=Campbell>Campbell The Cretaceous (kriːˈteɪʃəs, usually abbreviated 'K' for its German translation "Kreide" is a geologic period and system, reaching from the end of The Jurassic is a geologic period and system that extends from about Ma (million years ago to  Ma that is from the end of the Triassic to the beginning Early members such as Psittacosaurus were small and bipedal. Psittacosaurus ( or, from the Greek for ' Parrot Lizard ' is a Genus of Psittacosaurid Ceratopsian Bipedalism is a form of Terrestrial locomotion where an organism moves by means of its two rear limbs Later members, including ceratopsids like Centrosaurus and Triceratops, became very large quadrupeds and developed elaborate facial horns and a neck frill. Centrosaurus (ˌsɛtroʊˈsɔrəs SEN-tro-SAW-rus, meaning "pointed lizard" (from Greek kentron/κεντρον = "point or Triceratops (traɪˈsɛrətɒps is an extinct Genus of herbivorous ceratopsid Dinosaur which lived during the late Maastrichtian Quadrupedalism (from Latin meaning "four legs" is a form of land animal locomotion using four legs. A horn is a pointed projection of the Skin on the head of various Mammals consisting of a covering of horn ( Keratin and other Proteins While the frill might have served to protect the vulnerable neck from predators, it may also have been used for display, thermoregulation, the attachment of large neck and chewing muscles or some combination of the above. Display is a form of animal behaviour, linked to survival of the species in various ways Thermoregulation is the ability of an Organism to keep its body temperature within certain boundaries even when temperature surrounding is very different Ceratopsians ranged in size from 1 meter (3 ft) and 23 kilograms (50 lb) to over 9 meters (30 ft) and 5,400 kg (12,000 lb). The metre or meter is a unit of Length. It is the basic unit of Length in the Metric system and in the International A foot (plural feet or foot; symbol or abbreviation ft or sometimes &prime – the prime symbol) is a non-SI unit The pound or pound-mass (abbreviation lb, lbm, or sometimes in the United States #) is a unit of Mass

Triceratops is by far the best-known ceratopsian to the general public. It is traditional for ceratopsian genus names to end in "-ceratops", although this is not always the case. A genus (plural genera from Γένος Latin genus "descent family type gender" is a low-level Taxonomic One of the first named genera was Ceratops itself, which lent its name to the group, although it is considered a nomen dubium today as it has no distinguishing characteristics that are not also found in other ceratopsians. Ceratops (meaning "horn face" was a Ceratopsian Dinosaur which lived during the Late Cretaceous. In zoological nomenclature, a nomen dubium ( Latin for "doubtful name" plural nomina dubia) is a scientific name that is [1]

Contents

Anatomy

Skulls of different members of the Ceratopsidae.
Skulls of different members of the Ceratopsidae.

Ceratopsians are easily recognized by features of the skull. On the tip of a ceratopsian upper jaw is the rostral bone, a unique bone found nowhere else in the animal kingdom. The rostral bone is the edentulous (toothless dorsal component of the skeleton of the Beak, unique to (an ' Autapomorphy ' of the Ceratopsian Dinosaurs Along with the predentary bone, which forms the tip of the lower jaw in all ornithischians, the rostral forms a superficially parrot-like beak. The predentary is an 'extra' bone in the front of the lower jaw, which extended the dentary (the main lower jaw bone Ornithischia (ɔrnɪˈθɪskiə) or Predentata is an extinct order of beaked herbivorous Dinosaurs The name ornithischia Parrots are birds of the roughly 350 Species in 85 genera comprising the order Psittaciformes, found in most warm and tropical regions Also, the jugal bones below the eye are very tall and flare out sideways, making the skull appear somewhat triangular when viewed from above. The jugal is a Skull bone found in most Reptiles Amphibians and Birds In Mammals the jugal is often called the malar or A triangle is one of the basic Shapes of Geometry: a Polygon with three corners or vertices and three sides or edges which are Line This triangular appearance is accentuated, in later ceratopsians, by the rearwards extension of the parietal and squamosal bones of the skull roof, to form the neck frill. The parietal bones are bones in the Human Skull and form by their union the sides and roof of the Cranium. The squamosal is a bone of the head of higher Vertebrates It is the principal component of the cheek region in the skull lying below the temporal series and [2][3]

Systematics

Ceratopsia was coined by Othniel Charles Marsh in 1890 to include dinosaurs possessing certain characteristic features, including horns, a rostral bone, teeth with two roots, fused neck vertebrae, and a forward-oriented pubis. Othniel Charles Marsh ( October 29, 1831 &ndash March 18, 1899) was one of the pre-eminent Paleontologists of the 19th century who The rostral bone is the edentulous (toothless dorsal component of the skeleton of the Beak, unique to (an ' Autapomorphy ' of the Ceratopsian Dinosaurs For the bone in many mammals often called the penis bone see Baculum The android pubic bone is the Ventral and Anterior Marsh considered the group distinct enough to warrant its own suborder within Ornithischia. [4] The name is derived from the Greek κερας/keras meaning 'horn' and οψις/opsis meaning 'face'. The Ancient Greek language is the historical stage in the development of the Hellenic language family spanning the Archaic (c As early as the 1960s, it was noted that the name Ceratopsia is actually incorrect linguistically and that it should be Ceratopia. Linguistics is the scientific study of Language, encompassing a number of sub-fields [5] However, this spelling, while technically correct, has been used only rarely in the scientific literature, and the vast majority of paleontologists continue to use Ceratopsia. Palaeontology redirects here For the Scientific journal, see Palaeontology (journal. As the ICZN does not govern taxa above the level of superfamily, this is unlikely to change. "ICZN" redirects here It is also sometimes used for the International Code of Zoological Nomenclature in error Taxonomic rank ( rank, category, taxonomic category is an abstract term used in the Scientific classification, or Taxonomy, of organisms

Taxonomy

An early ceratopsian: Psittacosaurus life restoration from the Natural History Museum, London. Note that Psittacosaurus has since been discovered to have had a row of large "bristles" along the top of the tail.
An early ceratopsian: Psittacosaurus life restoration from the Natural History Museum, London. Psittacosaurus ( or, from the Greek for ' Parrot Lizard ' is a Genus of Psittacosaurid Ceratopsian The Natural History Museum is one of three large Museums on Exhibition Road, South Kensington, London (the others are the Science Museum London ( ˈlʌndən is the capital and largest urban area in the United Kingdom. Note that Psittacosaurus has since been discovered to have had a row of large "bristles" along the top of the tail. [6]
A typical protoceratopsid: Protoceratops skeleton at the Wyoming Dinosaur Center.
A typical protoceratopsid: Protoceratops skeleton at the Wyoming Dinosaur Center. Protoceratops (meaning 'First Horned Face' derived from Greek proto-/πρωτο- 'first' cerat-/κερατ- 'horn' The Wyoming Dinosaur Center is located in Thermopolis, Wyoming and is one of the few Dinosaur Museums in the world to have its own excavation
A derived ceratopsid: Triceratops model at the Royal Belgian Institute of Natural Sciences.
A derived ceratopsid: Triceratops model at the Royal Belgian Institute of Natural Sciences. Triceratops (traɪˈsɛrətɒps is an extinct Genus of herbivorous ceratopsid Dinosaur which lived during the late Maastrichtian The Royal Belgian Institute of Natural Sciences is a Museum in the Belgian capital of Brussels dedicated to natural history

Following Marsh, Ceratopsia has usually been classified as a suborder within the order Ornithischia, though occasionally it has been reduced to the level of infraorder. [7]

Following is a list of ceratopsian genera by classification and location:

There are several fragmentary Asian forms which may or may not be valid: Asiaceratops, Kulceratops, Microceratus, and Turanoceratops. Yinlong (meaning "hidden dragon" is a Genus of basal Ceratopsian Dinosaur from the Late Jurassic Period Xinjiang ( Uyghur: شىنجاڭ Shinjang;; Postal map spelling: Sinkiang; Turkish: Sincan, Sincan Uygur Özerk Chaoyangsauridae is a family of Dinosaurs They were the first Marginocephalian dinosaurs to appear on the planet about 150 million years ago in the Xuanhuaceratops is a Genus of Dinosaur from the Late Jurassic Period ( Postal map spelling: Hopeh) is a northern province of the People's Republic of China. Chaoyangsaurus (" Chaoyang lizard" was a Marginocephalian Dinosaur from the Late Jurassic of China. ( is a northeastern province of the People's Republic of China. The Psittacosauridae were a group of Ceratopsian dinosaurs The family Psittacosauridae was first named by Osborn in 1923 Psittacosaurus ( or, from the Greek for ' Parrot Lizard ' is a Genus of Psittacosaurid Ceratopsian Hongshanosaurus (hɒŋˌʃænəˈsɔrəs hawng-SHAN-o-SAWR-us "Red Hill lizard" is a Genus of Psittacosaurid Ceratopsian Yamaceratops is a Genus of Dinosaur from the Early Cretaceous. Auroraceratops, meaning "dawn horned face" is a Genus of basal neoceratopsian Dinosaur, from the Early Cretaceous The Archaeoceratopsidae constitutes a family of primitive Ceratopsian Dinosaur from the Early Cretaceous of China Archaeoceratops, meaning "ancient horned face" was a Genus of basal neoceratopsian Dinosaur from the Early Cretaceous ( is a province located in the northwest of the People's Republic of China. Liaoceratops, meaning "Liao Horned Face" is a newly discovered Dinosaur believed to be an early cousin to the horned Ceratopsians It lived The family Leptoceratopsidae, its name derived from the type genus Leptoceratops, is a group of several small neoceratopsian genera which appear not to belong to the Bainoceratops was a Dinosaur from the late Campanian in the Late Cretaceous. Cerasinops was a small Ceratopsian Dinosaur. It lived during the Campanian of the late Cretaceous Period. Montana ( is a state in the Western United States. One-third of the state in the western part contains numerous mountain ranges (approximately 77 named of the northern Leptoceratops (meaning 'lean-horned face' and derived from Greek lepto-/λεπτο- meaning 'small' 'insignificant' 'slender' 'meagre' or 'lean' cerat-/κερατ- Alberta (ælˈbɝtə is one of Canada's prairie provinces. It became a province on September 1 1905 The State of Wyoming ( is a sparsely populated state in the western region of the United States. Montanoceratops (meaning "Montana horned face" was a small Ceratopsian Dinosaur. Montana ( is a state in the Western United States. One-third of the state in the western part contains numerous mountain ranges (approximately 77 named of the northern Prenoceratops, (meaning 'bent or prone-horned face' and derived from Greek prene-/πρηνη- meaning 'bent forwards' or 'prone' Udanoceratops (meaning 'Udan horn face' derived from the Greek ceras/κέρας meaning 'horn' and -ops/ωψ meaning 'face' A protoceratopsid is a Dinosaur of the family Protoceratopsidae. Graciliceratops is a Ceratopsian Dinosaur first described by paleontologist Paul Sereno in 2000 Bagaceratops, meaning "small-horned face" ( Mongolian Baga = "small" Greek ceratops = "horn face" Breviceratops (meaning "short horn face" was a Ceratopsian Dinosaur from Late Cretaceous Mongolia. Lamaceratops,"Lama Horned Face" is a Dinosaur from the Late Cretaceous period Magnirostris, from the latin "magnus" 'large' and "rostrum" 'beak' is the name given to a Genus of Dinosaur Inner Mongolia ( Mongolian:, Öbür mongɣul; occasionally romanized to Nei Mongol is the Mongol Platyceratops is a Dinosaur from the Late Cretaceous, during the Campanian Age, about 75-72 million years ago Protoceratops (meaning 'First Horned Face' derived from Greek proto-/πρωτο- 'first' cerat-/κερατ- 'horn' Zuniceratops (' Zuni -horned face' was a Ceratopsian Dinosaur from the mid Turonian of the Late Cretaceous Period New Mexico ( is a state located in the southwestern region of the United States of America. Ceratopsidae (sometimes spelled Ceratopidae) is a speciose group of Marginocephalian Dinosaurs including Triceratops and Styracosaurus Asiaceratops (meaning "Asian horned face" was a Genus of Ceratopsian Dinosaur. Kulceratops is a Genus of Ceratopsian Dinosaur from the Early Cretaceous. Microceratus (meaning "small-horned" is a Genus of small Ceratopsian Dinosaur that lived in the Cretaceous period in Turanoceratops ("Turan horn face" is a Genus of Ceratopsian Dinosaur. Possible ceratopsians from the Southern Hemisphere include the Australian Serendipaceratops, known from an ulna, and Notoceratops from Argentina is known from a single toothless jaw (which has been lost). For a topic outline on this subject see List of basic Australia topics. Serendipaceratops is a Genus of early Ceratopsian Dinosaur from the early Cretaceous Period of Australia. The ulna ( elbow bone) is a long bone prismatic in form placed at the medial side of the Forearm, parallel with the radius. Notoceratops ("southern horned face" Tapia 1918 is the name given to a dubious genus of Dinosaur from the Late Cretaceous of Patagonia For a topic outline on this subject see List of basic Argentina topics. [8]

Phylogeny

An Illustration of 18 species of basal ceratopsia to scale
An Illustration of 18 species of basal ceratopsia to scale

Paleontologists today agree on the overall structure of the ceratopsian family tree, although there are differences on individual taxa. There have been several cladistic studies performed on basal ceratopsians since 2000. Cladistics is the hierarchical classification of Species based on evolutionary ancestry None have used every taxon listed above and many of the differences between the studies are still unresolved.

In clade-based phylogenetic taxonomy, Ceratopsia is often defined to include all marginocephalians more closely related to Triceratops than to Pachycephalosaurus. A clade is a taxonomic group comprising a single Common ancestor and all the descendants of that ancestor Phylogenetic nomenclature (PN is an alternative to rank-based nomenclature. Marginocephalia ("fringed heads" is a Clade of Ornithischian Dinosaurs that includes the thick-skulled pachycephalosaurids, and horned Pachycephalosaurus (ˌpækiˌsɛfələˈsɔrəs meaning "thick headed lizard" from Greek pachy-/παχυ- "thick" [9] Under this definition, the most basal known ceratopsians are Yinlong, from the Late Jurassic Period, along with Chaoyangsaurus and the family Psittacosauridae, from the Early Cretaceous Period, all of which were discovered in northern China or Mongolia. In Phylogenetics, a basal Clade is the earliest clade to branch in a larger clade it appears at the base of a cladogram Yinlong (meaning "hidden dragon" is a Genus of basal Ceratopsian Dinosaur from the Late Jurassic Period The Jurassic is a geologic period and system that extends from about Ma (million years ago to  Ma that is from the end of the Triassic to the beginning Chaoyangsaurus (" Chaoyang lizard" was a Marginocephalian Dinosaur from the Late Jurassic of China. The Psittacosauridae were a group of Ceratopsian dinosaurs The family Psittacosauridae was first named by Osborn in 1923 The Cretaceous (kriːˈteɪʃəs, usually abbreviated 'K' for its German translation "Kreide" is a geologic period and system, reaching from the end of China ( Wade-Giles ( Mandarin) Chung¹kuo² is a cultural region, an ancient Civilization, and depending on perspective a National Mongolia (mɒŋˈɡoʊliə, literally Mongol country/nation,) is a Landlocked Country in East The rostral bone and flared jugals are already present in all of these forms, indicating that even earlier ceratopsians remain to be discovered.

The clade Neoceratopsia includes all ceratopsians more derived than psittacosaurids. A clade is a taxonomic group comprising a single Common ancestor and all the descendants of that ancestor In Phylogenetics, a trait is derived if it is present in an organism but was absent in the last common ancestor of the group being considered Another subset of neoceratopsians is called Coronosauria, which currently includes all ceratopsians more derived than Auroraceratops. Auroraceratops, meaning "dawn horned face" is a Genus of basal neoceratopsian Dinosaur, from the Early Cretaceous Coronosaurs show the first development of the neck frill and the fusion of the first several neck vertebrae to support the increasingly heavy head. A vertebra (plural vertebrae) is an individual Irregular bone in the spinal or Vertebral column ( aka ischis a flexuous and flexible column Within Coronosauria, three groups are generally recognized, although the membership of these groups varies somewhat from study to study and some animals may not fit in any of them. One group can be called Protoceratopsidae and includes Protoceratops and its closest relatives, all Asian. A protoceratopsid is a Dinosaur of the family Protoceratopsidae. Protoceratops (meaning 'First Horned Face' derived from Greek proto-/πρωτο- 'first' cerat-/κερατ- 'horn' Another group, Leptoceratopsidae, includes mostly North American animals that are more closely related to Leptoceratops. The family Leptoceratopsidae, its name derived from the type genus Leptoceratops, is a group of several small neoceratopsian genera which appear not to belong to the Leptoceratops (meaning 'lean-horned face' and derived from Greek lepto-/λεπτο- meaning 'small' 'insignificant' 'slender' 'meagre' or 'lean' cerat-/κερατ- The Ceratopsoidea includes animals like Zuniceratops which are more closely related to the family Ceratopsidae. Zuniceratops (' Zuni -horned face' was a Ceratopsian Dinosaur from the mid Turonian of the Late Cretaceous Period Ceratopsidae (sometimes spelled Ceratopidae) is a speciose group of Marginocephalian Dinosaurs including Triceratops and Styracosaurus This last family includes Triceratops and all the large North American ceratopsians and is further divided into the subfamilies Centrosaurinae and Ceratopsinae (also known as Chasmosaurinae).

Xu/Makovicky/Chinnery Phylogeny:

Xu Xing of the Chinese Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) in Beijing, along with Peter Makovicky, formerly of the American Museum of Natural History (AMNH) in New York City and others, published a cladistic analysis in the 2002 description of Liaoceratops. Xu Xing ( is a famed Chinese paleontologist who has named many dinosaurs including the new Jurassic Ceratopsian Yinlong The Institute of Vertebrate Paleontology and Paleoanthropology (abbreviated to IVPP) is a prominent research institution and collections repository for Chinese The American Museum of Natural History ( AMNH) located on the Upper West Side, Manhattan, New York, USA is one of the largest and most The City of New York [10] This analysis is very similar to one published by Makovicky in 2001. [11] Makovicky, who currently works at the Field Museum of Natural History in Chicago, also included this analysis in his 2002 doctoral thesis. The Field Museum of Natural History is located in Chicago, Illinois, USA. Chicago (ʃɪˈkɑːgoʊ is the largest City by population in the state of Illinois and the American Midwest of the United States. "PhD" redirects here for other uses see PhD (disambiguation. Xu and other colleagues added Yinlong to this analysis in 2006. [12]

Brenda Chinnery, formerly of the Museum of the Rockies in Bozeman, Montana, independently described Prenoceratops in 2005 and published a new phylogeny. The Museum of the Rockies, affiliated with Montana State University in Bozeman and the Smithsonian Institution, is located in Bozeman, Montana Bozeman is a city in and the County seat of Gallatin County, Montana, United States, in the southwestern part of the state Montana ( is a state in the Western United States. One-third of the state in the western part contains numerous mountain ranges (approximately 77 named of the northern [13] In 2006, Makovicky and Mark Norell of the AMNH incorporated Chinnery's analysis into their own and also added Yamaceratops, although they were not able to include Yinlong. [14] The cladogram presented below is a combination of Xu, Makovicky, and their colleagues' most recent work.

Ceratopsia 

 Yinlong

 void 
 void 

 Chaoyangsaurus


 IVPP V12722 (Xuanhuaceratops)


 void 

 Psittacosauridae

 Neoceratopsia 

 Liaoceratops

 void 

 Yamaceratops

 void 

 Archaeoceratops

 Coronosauria 
 Leptoceratopsidae 

 Montanoceratops

 void 

 Udanoceratops


 Leptoceratops


 Prenoceratops



 void 

 Graciliceratops

 void 
 Protoceratopsidae 

 Bagaceratops


 Protoceratops


 void 

 Zuniceratops


 Ceratopsidae












Chaoyangsaurus is recovered in a more basal position than Psittacosauridae, although Chinnery's original analysis finds it within Neoceratopsia. Yinlong (meaning "hidden dragon" is a Genus of basal Ceratopsian Dinosaur from the Late Jurassic Period Chaoyangsaurus (" Chaoyang lizard" was a Marginocephalian Dinosaur from the Late Jurassic of China. Xuanhuaceratops is a Genus of Dinosaur from the Late Jurassic Period The Psittacosauridae were a group of Ceratopsian dinosaurs The family Psittacosauridae was first named by Osborn in 1923 Ceratopsia or Ceratopia (ˌsɛrəˈtɒpsiə/ /ˌsɛrəˈtoʊpiə Greek: "horned faces" is a group of herbivorous, beaked Dinosaurs Liaoceratops, meaning "Liao Horned Face" is a newly discovered Dinosaur believed to be an early cousin to the horned Ceratopsians It lived Yamaceratops is a Genus of Dinosaur from the Early Cretaceous. Archaeoceratops, meaning "ancient horned face" was a Genus of basal neoceratopsian Dinosaur from the Early Cretaceous The family Leptoceratopsidae, its name derived from the type genus Leptoceratops, is a group of several small neoceratopsian genera which appear not to belong to the Montanoceratops (meaning "Montana horned face" was a small Ceratopsian Dinosaur. Udanoceratops (meaning 'Udan horn face' derived from the Greek ceras/κέρας meaning 'horn' and -ops/ωψ meaning 'face' Leptoceratops (meaning 'lean-horned face' and derived from Greek lepto-/λεπτο- meaning 'small' 'insignificant' 'slender' 'meagre' or 'lean' cerat-/κερατ- Prenoceratops, (meaning 'bent or prone-horned face' and derived from Greek prene-/πρηνη- meaning 'bent forwards' or 'prone' Graciliceratops is a Ceratopsian Dinosaur first described by paleontologist Paul Sereno in 2000 A protoceratopsid is a Dinosaur of the family Protoceratopsidae. Bagaceratops, meaning "small-horned face" ( Mongolian Baga = "small" Greek ceratops = "horn face" Protoceratops (meaning 'First Horned Face' derived from Greek proto-/πρωτο- 'first' cerat-/κερατ- 'horn' Zuniceratops (' Zuni -horned face' was a Ceratopsian Dinosaur from the mid Turonian of the Late Cretaceous Period Ceratopsidae (sometimes spelled Ceratopidae) is a speciose group of Marginocephalian Dinosaurs including Triceratops and Styracosaurus Protoceratopsidae is considered to be the sister group of Ceratopsoidea. The fragmentary Asiaceratops was included in these studies and is found to have a variable position, either as a basal neoceratopsian or as a leptoceratopsid, most likely due to the amount of missing information. Removal of Asiaceratops stabilizes the entire cladogram.

Makovicky's latest analysis includes IVPP V12722 ("Xuanhuasaurus"), a Late Jurassic ceratopsian from China that at the time was awaiting publication, but has since been published as Xuanhuaceratops. Xuanhuaceratops is a Genus of Dinosaur from the Late Jurassic Period Kulceratops and Turanoceratops are considered nomina dubia in this study. Makovicky believes Lamaceratops, Magnirostris, and Platyceratops to be junior synonyms of Bagaceratops, and Bainoceratops to be synonymous with Protoceratops. In Scientific nomenclature, synonyms are different Scientific names used for a single Taxon.

You/Dodson Phylogeny:

You Hailu of Beijing's Chinese Academy of Geological Sciences, was a co-author with Xu and Makovicky in 2002 but, in 2003, he and Peter Dodson from the University of Pennsylvania published a separate analysis. Peter Dodson is an American paleontologist who has published many papers and written and collaborated on books about Dinosaurs Dodson described Avaceratops The University of Pennsylvania (also known as Penn) is a private University located in Philadelphia, Pennsylvania, USA. [15] The two presented this analysis again in 2004. [2] In 2005, You and three others, including Dodson, published on Auroraceratops and inserted this new dinosaur into their phylogeny. [16]

Ceratopsia 

 Psittacosauridae

 Neoceratopsia 

 Chaoyangsaurus

 void 

 Liaoceratops

 void 

 Archaeoceratops

 void 

 Auroraceratops

 Coronosauria 
 Protoceratopsidae 

 Bagaceratops


 Protoceratops


 void 
 Leptoceratopsidae 

 Montanoceratops


 Leptoceratops



 Ceratopsidae









In contrast to the previous analysis, You and Dodson find Chaoyangsaurus to be the most basal neoceratopsian, more derived than Psittacosaurus, while Leptoceratopsidae, not Protoceratopsidae, is recovered as the sister group of Ceratopsidae. The Psittacosauridae were a group of Ceratopsian dinosaurs The family Psittacosauridae was first named by Osborn in 1923 Ceratopsia or Ceratopia (ˌsɛrəˈtɒpsiə/ /ˌsɛrəˈtoʊpiə Greek: "horned faces" is a group of herbivorous, beaked Dinosaurs Chaoyangsaurus (" Chaoyang lizard" was a Marginocephalian Dinosaur from the Late Jurassic of China. Liaoceratops, meaning "Liao Horned Face" is a newly discovered Dinosaur believed to be an early cousin to the horned Ceratopsians It lived Archaeoceratops, meaning "ancient horned face" was a Genus of basal neoceratopsian Dinosaur from the Early Cretaceous Auroraceratops, meaning "dawn horned face" is a Genus of basal neoceratopsian Dinosaur, from the Early Cretaceous A protoceratopsid is a Dinosaur of the family Protoceratopsidae. Bagaceratops, meaning "small-horned face" ( Mongolian Baga = "small" Greek ceratops = "horn face" Protoceratops (meaning 'First Horned Face' derived from Greek proto-/πρωτο- 'first' cerat-/κερατ- 'horn' The family Leptoceratopsidae, its name derived from the type genus Leptoceratops, is a group of several small neoceratopsian genera which appear not to belong to the Montanoceratops (meaning "Montana horned face" was a small Ceratopsian Dinosaur. Leptoceratops (meaning 'lean-horned face' and derived from Greek lepto-/λεπτο- meaning 'small' 'insignificant' 'slender' 'meagre' or 'lean' cerat-/κερατ- Ceratopsidae (sometimes spelled Ceratopidae) is a speciose group of Marginocephalian Dinosaurs including Triceratops and Styracosaurus This study includes Auroraceratops but lacks seven taxa found in Xu and Makovicky's work, so it is unclear how comparable the two studies are. Asiaceratops and Turanoceratops are each considered nomen dubium and not included. Along with Dong Zhiming, You described Magnirostris in 2003, but to date has not included it any of his cladograms. Dong Zhiming (1937- Chinese: 董枝明 Pinyin: Dǒng Zhimíng) from the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP [17]

Paleobiology

Biogeography

Ceratopsian fossil discoveries. The presence of Jurassic ceratopsians only in Asia indicates an Asian origin for the group, while the more derived ceratopsids occur only in North America. Questionable remains are indicated with question marks.
Ceratopsian fossil discoveries. The presence of Jurassic ceratopsians only in Asia indicates an Asian origin for the group, while the more derived ceratopsids occur only in North America. Questionable remains are indicated with question marks. The question mark (? also known as an interrogation point, question point, query, or eroteme, is a punctuation mark that replaces

Ceratopsia appears to have originated in Asia, as all of the earliest members are found there. Fragmentary remains, including teeth, which appear to be neoceratopsian, are found in North America from the Albian stage (112 to 100 million years ago), indicating that the group had dispersed across what is now the Bering Strait by the middle of the Cretaceous Period. Albian ( French Albion, from Alba = Aube in France) is a stage of the Cretaceous period. Biological dispersal refers to those processes by which a Species maintains ecosystem The Bering Strait (Берингов пролив Beringov proliv) is a sea Strait between Cape Dezhnev, Russia, the easternmost point (169°43' [18] Almost all leptoceratopsids are North American, aside from Udanoceratops, which may represent a separate dispersal event, back into Asia. Ceratopsids and their immediate ancestors, such as Zuniceratops, are not found in Asia or any other continent and appear to be endemic to western North America. Endemism is the Ecological state of being unique to a place Endemic species are not naturally found elsewhere [2][13] However, if Notoceratops and Serendipaceratops are indeed ceratopsians, this hypothesis will be significantly affected.

Individual variation

Unlike almost all other dinosaur groups, skulls are the most commonly preserved elements of ceratopsian skeletons and many species are known only from skulls. There is a great deal of variation between and even within ceratopsian species. Complete growth series from embryo to adult are known for Psittacosaurus and Protoceratops, allowing the study of ontogenetic variation in these species. An embryo (from Greek:, plural, lit "that which grows" from en- "in" + bryein "to swell be full" is a multicellular Ontogeny, as opposed to Phylogeny, refers to the history of an organism from birth as opposed to its genetic makeup [19][20] Significant sexual dimorphism has been noted in Protoceratops and several ceratopsids. Sexual dimorphism is the systematic difference in form between individuals of different Sex in the same Species. [2][3][21]

Ecological role

Psittacosaurus and Protoceratops are the most common dinosaurs in the different Mongolian sediments where they are found. Sedimentary rock is one of the three main rock types (the others being igneous and Metamorphic rock) [2] Triceratops fossils are far and away the most common dinosaur remains found in the latest Cretaceous rocks in the western United States, making up as much as 5/6ths of the large dinosaur fauna in some areas. FOSSIL is a standard protocol for allowing serial communication for Telecommunications programs under the DOS Operating system. Fauna is all of the Animal life of any particular region or time [22] These facts indicate that some ceratopsians were the dominant herbivores in their environments.

Some species of ceratopsians, especially Centrosaurus and its relatives, appear to have been gregarious, living in herds. A herd is a large group of animals The term is usually applied to mammals particularly Ungulates. This is suggested by bonebed finds with the remains of many individuals of different ages. A bone bed is any geological Stratum or deposit which contains Bones of whatever kind [3] Like modern migratory herds, they would have had a significant effect on their environment, as well as serving as a major food source for predators.

Posture and locomotion

Most restorations of ceratopsians show them with erect hindlimbs but semi-sprawling forelims, which suggest they were not fast movers. But Paul and Christiansen (2000) argued that at least the later ceratopsians had upright forelimbs and the larger species may have been as fast as rhinos, which can run at up to 56 km or 35 miles per hour. Rhinoceros (raɪˈnɒsərəs often colloquially abbreviated rhino, is a name used to group five extant species of Odd-toed ungulates in the family [23]

References

  1. ^ Dodson, P. 1996. The Horned Dinosaurs. Princeton: Princeton University Press. 346pp.
  2. ^ a b c d e You H. & Dodson, P. 2004. Basal Ceratopsia. In: Weishampel, D. B. , Dodson, P. , & Osmolska, H. (Eds. ). The Dinosauria (2nd Edition). Berkeley: University of California Press. Pp. 478-493.
  3. ^ a b c Dodson, P. , Forster, C. A. , & Sampson, S. D. 2004. Ceratopsidae. In: Dodson, P. , Weishampel, D. B. , & Osmolska, H. (Eds. ). The Dinosauria (2nd Edition). Berkeley: University of California Press. Pp. 494-513.
  4. ^ Marsh, O. C. (1890). "Additional characters of the Ceratopsidae, with notice of new Cretaceous dinosaurs. " American Journal of Science, 39: 418-429.
  5. ^ Steel, R. 1969. Ornithischia. In: Kuhn, O. (Ed. ). Handbuch de Paleoherpetologie (Part 15). Stuttgart: Gustav Fischer Verlag. 87pp.
  6. ^ Mayr, Gerald, Peters, D. Stephan, Plodowski, Gerhard & Vogel, Olaf. (2002). Bristle-like integumentary structures at the tail of the horned dinosaur Psittacosaurus. Naturwissenschaften 89: 361–365.
  7. ^ Benton, M. J. (2004). 'Vertebrate Palaeontology, Third Edition. Blackwell Publishing, 472 pp.
  8. ^ Rich, T. H. & Vickers-Rich, P. 2003. Protoceratopsian? ulnae from the Early Cretaceous of Australia. Records of the Queen Victoria Museum. No. 113.
  9. ^ Sereno, P. C. 1998. A rationale for phylogenetic definitions, with applications to the higher-level taxonomy of Dinosauria. Neues Jahrbuch fur Geologie und Palaontologie: Abhandlungen 210: 41-83.
  10. ^ Xu X. , Makovicky, P. J. , Wang X. , Norell, M. A. , You H. 2002. A ceratopsian dinosaur from China and the early evolution of Ceratopsia. Nature 416: 314-317.
  11. ^ Makovicky, P. J. 2001. A Montanoceratops cerorhynchus (Dinosauria: Ceratopsia) braincase from the Horseshoe Canyon Formation of Alberta, In: Tanke, D. H. & Carpenter, K. (Eds. ). Mesozoic Vertebrate Life. Bloomington: Indiana University Press. Pp. 243-262.
  12. ^ Xu X. , Forster, C. A. , Clark, J. M. , & Mo J. 2006. A basal ceratopsian with transitional features from the Late Jurassic of northwestern China. Proceedings of the Royal Society B: Biological Sciences. 273: 2135-2140
  13. ^ a b Chinnery, B. 2005. Description of Prenoceratops pieganensis gen. et sp. nov. (Dinosauria: Neoceratopsia) from the Two Medicine Formation of Montana. Journal of Vertebrate Paleontology 24(3): 572–590.
  14. ^ Makovicky, P. J. & Norell, M. A. 2006. Yamaceratops dorngobiensis, a new primitive ceratopsian (Dinosauria: Ornithischia) from the Cretaceous of Mongolia. American Museum Novitates 3530: 1-42.
  15. ^ You H. & Dodson, P. 2003. Redescription of neoceratopsian dinosaur Archaeoceratops and early evolution of Neoceratopsia. Acta Palaeontologica Polonica 48(2): 261–272.
  16. ^ You H. , Li D. , Lamanna, M. C. , & Dodson, P. 2005. On a new genus of basal neoceratopsian dinosaur from the Early Cretaceous of Gansu Province, China. Acta Geologica Sinica (English edition) 79(5): 593-597.
  17. ^ You H. & Dong Z. 2003. A new protoceratopsid (Dinosauria: Neoceratopsia) from the Late Cretaceous of Inner Mongolia, China. Acta Geologica Sinica (English edition). 77(3): 299-303.
  18. ^ Chinnery, B. J. , Lipka, T. R. , Kirkland, J. I. , Parrish, J. M. , & Brett-Surman, M. K. 1998. Neoceratopsian teeth from the Lower to Middle Cretaceous of North America. In: Lucas, S. G. , Kirkland, J. I. , & Estep, J. W. (Eds. ). Lower and Middle Cretaceous Terrestrial Ecosystems. New Mexico Museum of Natural History and Science Bulletin 14: 297-302.
  19. ^ Erickson, G. M. & Tumanova, T. A. 2000. Growth curve of Psittacosaurus mongoliensis Osborn (Ceratopsia: Psittacosauridae) inferred from long bone histology. Zoological Journal of the Linnean Society of London 130: 551-566.
  20. ^ Dodson, P. 1976. Quantitative aspects of relative growth and sexual dimorphism in Protoceratops. Journal of Paleontology 50: 929-940.
  21. ^ Lehman, T. M. 1990. The ceratopsian subfamily Chasmosaurinae: sexual dimorphism and systematics. In: Carpenter, K. & Currie, P. J. (Eds. ). Dinosaur Systematics: Approaches and Perspectives. Cambridge: Cambridge University Press. Pp. 211-230.
  22. ^ Bakker, R. T. (1986). The Dinosaur Heresies: New Theories Unlocking The Mystery of the Dinosaurs and Their Extinction. William Morrow:New York, p. 438. ISBN 0140100555
  23. ^ Paul, G. S. , and Christiansen, P. (September 2000). "Forelimb posture in neoceratopsian dinosaurs: implications for gait and locomotion" (subscription required). Paleobiology 26 (3): 450. doi:10.1666/0094-8373(2000)026<0450:FPINDI>2.0.CO;2. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.  

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