''Xenoceratops'' (meaning "alien horned face") is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

centrosaurine Centrosaurinae (from the Greek, meaning "pointed lizards") is a subfamily of ceratopsid, a group of large quadrupedal ornithischian dinosaur. Centrosaurine fossil remains are known primarily from the northern region of Laramidia (modern day Alber ...

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 are ...

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutio ...

known from the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...

(middle

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 ...

stage), and is known to have lived in what is currently

Alberta Alberta is a Provinces and territories of Canada, province in Canada. It is a part of Western Canada and is one of the three Canadian Prairies, prairie provinces. Alberta is bordered by British Columbia to its west, Saskatchewan to its east, t ...

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

. The genus has one known species, ''Xenoceratops foremostensis''. Its remains were discovered in the

Foremost Formation The Foremost Formation is a stratigraphic unit of Late Cretaceous (Campanian) age that underlies much of southern Alberta, Canada. It was named for outcrops in Chin Coulee near the town of ForemostGlass, D.J. (editor) 1997. Lexicon of Canadian ...

Discovery

In 1958, Wann Langston, Jr. excavated skull fragments from the

near Foremost, Alberta. The formation is very poorly understood in regards to dinosaur fauna; aside from teeth, only

hadrosaur Hadrosaurids (), also hadrosaurs or duck-billed dinosaurs, are members of the ornithischian family Hadrosauridae. This group is known as the duck-billed dinosaurs for the flat duck-bill appearance of the bones in their snouts. The ornithopod fami ...

skeletons and the

pachycephalosaurid Pachycephalosauria (; from Greek παχυκεφαλόσαυρος for 'thick headed lizards') is a clade of ornithischian dinosaurs. Along with Ceratopsia, it makes up the clade Marginocephalia. With the exception of two species, most pachycepha ...

'' Colepiocephale'' have been reported. Langston stored the fragments in cabinets at the

Canadian Museum of Nature The Canadian Museum of Nature (; CMN) is a national museums of Canada, national natural history museum based in Canada's National Capital Region (Canada), National Capital Region. The museum's exhibitions and public programs are housed in the Vi ...

in Ottawa. Around 2003, David C. Evans and Michael J. Ryan became curious about the specimens, and more thorough investigation was conducted in 2009. They discovered it to be a new species and genus, and it was described in 2012 by Ryan, Evans, and Kieran M. Shepherd. At the time of discovery, ''Xenoceratops foremostensis'' was the oldest known

taxon In biology, a taxon (back-formation from ''taxonomy''; : 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 name and ...

dinosaur in Canada. It is also the first

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

described from the Foremost Formation. ''Xenoceratops'' is named from the Greek ''xenos'', meaning foreign or alien, and ''ceratops'', meaning horned face. The combination is in reference to the lack of

species known from the

. The specific epithet ''foremostensis'' is named after the town of Foremost, Alberta.

Description

''Xenoceratops'' is based on CMN (Canadian Museum of Nature) 53282, a parietal. This is a skull bone that in ceratopsids makes up the

medial Medial may refer to: Mathematics * Medial magma, a mathematical identity in algebra Geometry * Medial axis, in geometry the set of all points having more than one closest point on an object's boundary * Medial graph, another graph that repr ...

(midline) and part of the lateral borders of the distinctive bony frill. Additional skull bones have also been assigned to the genus, including additional parietals, squamosals (bones which make up the rest of the frill's lateral borders), and a partial

nasal Nasal is an adjective referring to the nose, part of human or animal anatomy. It may also be shorthand for the following uses in combination: * With reference to the human nose: ** Nasal administration, a method of pharmaceutical drug delivery * ...

. These bones appear to belong to at least three adult-sized individuals. Another fragmentary skull in the collections of the

Royal Tyrrell Museum of Palaeontology The Royal Tyrrell Museum of Palaeontology (RTMP; often referred to as the Royal Tyrrell Museum) is a palaeontology museum and research facility in Drumheller, Alberta, Canada. The museum was named in honour of Joseph Burr Tyrrell, and is situate ...

is thought to belong to this genus as well. ''Xenoceratops'' can be distinguished from other ceratopsids by details of the frill's bony ornamentation. The two bony projections closest to the midline of the frill are thick knobs, oriented toward the midline. Next to each knob is a single long flattened straight spike pointing laterally and to the rear. The anterior corners of the parietal have a large triangular knob. Unlike most other centrosaurines, the midline bar of the frill has no bumps or other ornamentation. ''Xenoceratops'' probably had a nasal and brow horn configuration comparable to that of other basal centrosaurines. The holotype and associated skull material do not include much of the face, but the Royal Tyrrell skull shows evidence of large brow horns, perhaps similar to those of '' Albertaceratops'' and ''

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'' wa ...

''. Similarly, the form of the nasal bone fragment suggests a long, low structure like that of ''

Medusaceratops ''Medusaceratops'' is an extinct genus of Centrosaurinae, centrosaurine ceratopsian dinosaur known from the Late Cretaceous Judith River Formation (middle Campanian stage) of Montana, northern United States. It contains a single species, ''Medusa ...

''.

Classification

The

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

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

References

{{Taxonbar, from=Q18435 Centrosaurinae Dinosaur genera Campanian dinosaurs Dinosaurs of Canada Fossil taxa described in 2012 Taxa named by David C. Evans

Discovery

Description

Classification

See also

References