''Coahuilaceratops'' (meaning "

Coahuila Coahuila (), formally Coahuila de Zaragoza (), officially the Free and Sovereign State of Coahuila de Zaragoza ( es, Estado Libre y Soberano de Coahuila de Zaragoza), is one of the 32 states of Mexico. Coahuila borders the Mexican states of N ...

horn face") is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

herbivorous 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 mouthpart ...

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. ...

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 ...

. It is a

chasmosaurine Chasmosaurinae is a subfamily of ceratopsid dinosaurs. They were one of the most successful groups of herbivores of their time. Chasmosaurines appeared in the early Campanian, and became extinct, along with all other non-avian dinosaurs, during t ...

ceratopsian 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. ...

which lived during the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger 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 ''creta'', the ...

period Period may refer to: Common uses * Era, a length or span of time * Full stop (or period), a punctuation mark Arts, entertainment, and media * Period (music), a concept in musical composition * Periodic sentence (or rhetorical period), a concept ...

(late

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 ...

stage) in what is now southern

in northern

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

. It is known from 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 several ...

CPC 276, a partial

skeleton A skeleton is the structural frame that supports the body of an animal. There are several types of skeletons, including the exoskeleton, which is the stable outer shell of an organism, the endoskeleton, which forms the support structure inside ...

of an adult individual which includes several skull elements. Another specimen, CPS 277, may represent a juvenile ''Coahuilaceratops''. All specimens of ''Coahuilaceratops'' were collected from a single location in the middle strata of the

Cerro del Pueblo Formation The Cerro del Pueblo Formation is a geological Formation (geology), formation in Coahuila, Mexico whose strata date back to the Late Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation.Weishampel et al., ...

, which dates to between 72.5 and 71.4

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). ...

.Loewen, M.A., Sampson, S.D., Lund, E.K., Farke, A.A., Aguillón-Martínez, M.C., de Leon, C.A., Rodríguez-de la Rosa, R.A., Getty, M.A., Eberth, D.A., 2010, "Horned Dinosaurs (Ornithischia: Ceratopsidae) from the Upper Cretaceous (Campanian) Cerro del Pueblo Formation, Coahuila, Mexico", In: Michael J. Ryan, Brenda J. Chinnery-Allgeier, and David A. Eberth (eds), ''New Perspectives on Horned Dinosaurs: The Royal Tyrrell Museum Ceratopsian Symposium'', Indiana University Press, 656 pp. Coahuilaceratops NT

It was formally described in 2010, though it appeared as an informal designation (''

nomen nudum In taxonomy, a ''nomen nudum'' ('naked name'; plural ''nomina nuda'') is a designation which looks exactly like a scientific name of an organism, and may have originally been intended to be one, but it has not been published with an adequate descr ...

'') as early as 2008. ''Coahuilaceratops'' was named by Mark A. Loewen, Scott D. Sampson, Eric K. Lund, Andrew A. Farke, Martha C. Aguillón Martínez, C.A. de León, R.A. Rodríguez de la Rosa, Michael A. Getty and David A. Eberth 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 ...

and 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 ''Coahuilaceratops magnacuerna''. Although based on incomplete remains, ''Coahuilaceratops'' is thought to possess among the largest horns of any dinosaur currently known, rivaling in absolute size those of larger

chasmosaurines Chasmosaurinae is a subfamily of ceratopsid dinosaurs. They were one of the most successful groups of herbivores of their time. Chasmosaurines appeared in the early Campanian, and became extinct, along with all other non-avian dinosaurs, during t ...

like ''

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 ...

'' and ''

Torosaurus ''Torosaurus'' ("perforated lizard", in reference to the large openings in its frill) is a genus of herbivorous ceratopsid dinosaur that lived during the late Maastrichtian stage of the Cretaceous period, between 68 and 66 million years ago, tho ...

''. Its horns are estimated to have been up to 1.2 m (4 feet) long.http://www.eurekalert.org/pub_releases/2010-05/uou-fhd052510.php eurekalert - First horned dinosaur from Mexico It was a medium-sized ceratopsian, reaching in length and in body mass.

Systematics

''Coahuilaceratops'' is a member of the

Chasmosaurinae Chasmosaurinae is a subfamily of ceratopsid dinosaurs. They were one of the most successful groups of herbivores of their time. Chasmosaurines appeared in the early Campanian, and became extinct, along with all other non-avian dinosaurs, during ...

. Below is a

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 d ...

that represents the findings of Caleb Brown and Donald Henderson (2015), finding ''Coahuilaceratops'' to be the sister taxon to the Texan ''

Bravoceratops ''Bravoceratops'' is a genus of large chasmosaurine ceratopsid dinosaur that lived approximately 70 million years ago, and is known from the Late Cretaceous Javelina Formation in what is now Texas, United States. Discovery and naming ''Bravocer ...

''. This pairing was replicated by Jordan Mallon ''et al.'' in 2016, although ''Bravoceratops'' had to be cut from the analysis to create meaningful results. In 2021, ''

Sierraceratops ''Sierraceratops'' (meaning " Sierra horned face") is a genus of chasmosaurine ceratopsian from the Late Cretaceous Hall Lake Formation of New Mexico, United States. The genus contains a single species, ''Sierraceratops turneri'', known from a p ...

'' was described and found to clade with ''Coahuilaceratops'' and ''Bravoceratops'', and its describers, Sebastian Dalman ''et al.'', suggest they all form a clade unique to southern

Laramidia Laramidia was an island continent that existed during the Late Cretaceous period (99.6–66 Ma), when the Western Interior Seaway split the continent of North America in two. In the Mesozoic era, Laramidia was an island land mass separated from A ...

References

Chasmosaurines Late Cretaceous dinosaurs of North America Cretaceous Mexico Fossils of Mexico Fossil taxa described in 2010 Taxa named by Scott D. Sampson Ornithischian genera {{ceratopsian-stub

Systematics

See also

References