Coahuilaceratops Temporal range: Late Cretaceous ~ | |
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Skull of Coahuilaceratops | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Clade: | Dinosauria |
Clade: | † Ornithischia |
Clade: | † Neornithischia |
Clade: | † Ceratopsia |
Family: | † Ceratopsidae |
Subfamily: | † Chasmosaurinae |
Genus: | † Coahuilaceratops Loewen et al., 2010 |
Species: | †C. magnacuerna |
Binomial name | |
†Coahuilaceratops magnacuerna Loewen et al., 2010 | |
Coahuilaceratops (meaning "horned face from Coahuila") is a genus of chasmosaurine ceratopsian dinosaur that lived during the early Maastrichtian age of the Late Cretaceous epoch, about 71.5 to 70.5 million years ago in what is now northern Mexico. [1] It contains a single species, Coahuilaceratops magnacuerna. [2]
Fossils of Coahuilaceratops were discovered by Claudio de Leon near the town of Porvenir de Jalpa in the south of Coahuila, Mexico in 2001 and excavated in 2003. [3] The deposits where the remains were found were originally assigned to the Cerro del Pueblo Formation [2] (upper Campanian; ca. 73–72.5 Ma), but in a 2024 stratigraphic revision they were assigned to the overlying Cerro Huerta Formation (lower Maastrichtian; about 71.5–70.5 million years). This makes Coahuilaceratops the first dinosaur described from the Cerro Huerta Formation. The lower Maastrichtian age of the deposits is consistent with the relatively derived phylogenetic position of Coahuilaceratops. [1]
Over the course of two years, the Coahuilaceratops fossils were prepared by volunteer preparator Jerry Golden at the Natural History Museum of Utah. [3] The holotype CPC 276 is represented mainly by unarticulated bones of the skull of an adult individual: rostral bone, left premaxilla, right maxilla, fused nasal bones, incomplete left and right supraorbital horncores, part of the parietosquasomal frill, predentary, both dentaries, and unprepared postcranial material. Another specimen, CPC 277, contains unarticulated juvenile skeletal elements, including predentary, dentary, and unprepared postcranial material. [2]
The name of the dinosaur was mentioned in the press in 2008 as an informal designation ( nomen nudum ). [4] Coahuilaceratops magnacuerna was formally described by paleontologists Mark A. Loewen, Scott D. Sampson, Eric K. Lund, Andrew A. Farke, Martha C. Aguillón Martínez , Claudio A. de Leon, Rubén A. Rodríguez de la Rosa, Michael A. Getty, and David A. Eberth in 2010. The generic name combines "Coahuila", the state of origin, with the Ancient Greek suffix "-ceratops", meaning "horned face", which is common for ceratopsians. The specific name refers to the large size of horns and comes from the Latin word "magna", meaning "great", and the Spanish word "cuerna", meaning "horn". [2]
According to estimates given in a press release from the Natural History Museum of Utah (2010), an adult Coahuilaceratops was about 22 ft (6.7 m) long, 6 to 7 ft (1.8 to 2.1 m) tall at the shoulders and hips, with a 6 ft (1.8 m) skull and 3 to 4 ft (0.91 to 1.22 m) horns, and probably weighed about four to five tons. [3] Gregory S. Paul estimated its length at 4 meters (13 ft) m and weight at 1 metric ton (1.1 short tons) ton in 2016 and 1.5 metric tons (1.7 short tons) tons in 2024. [5] [6]
Although the horns of Coahuilaceratops are not completely preserved, their absolute size is comparable to the size of the horns of the largest chasmosaurines, such as Triceratops and Torosaurus . The hyperrobust morphology of the horns of Coahuilaceratops (relative lack of constriction in the distal region) is more reminiscent of large specimens of Pentaceratops than of Agujaceratops . [2]
In the phylogenetic analysis performed by the authors of the Coauilaceratops description, Loewen et al. (2010), it was found in a polytomy with Anchiceratops and Arrhinoceratops , with which it was found in a sister clade of Triceratopsini. [2] Triceratopsins include Triceratops and all taxa closer to Triceratops than to Anchiceratops and Arrhinoceratops. [7]
According to analysis conducted by Brown & Henderson (2015), Coahuiceratops is a sister genus of Bravoceratops within a clade that includes a number of other non-triceratopsin chasmosaurines, with Anchiceratops and Arrhinoceratops still forming a sister clade of Triceratopsini. [8] One of the Mallon al. (2016) analyzes confirmed that Coahuilaceratops and Bravoceratops are sister taxa, but the study authors had to remove the fragmentary Bravoceratops from the analysis to obtain more meaningful results. [9] Dalman et al. (2022) found Coahuilaceratops in a polytomy with Bravoceratops and Sierraceratops . The researchers suggested that a clade containing these three genera was endemic to southern Laramidia. [10]
Loewen et al. (2010) [2] | Brown & Henderson (2015) [8] | Dalman et al. (2022) [10] |
Torosaurus is a genus of herbivorous chasmosaurine ceratopsian dinosaur that lived during the late Maastrichtian age of the Late Cretaceous period, between 68 and 66 million years ago, though it is possible that the species range might extend to as far back as 69 million years ago. Fossils have been discovered across the Western Interior of North America, from as far north as Saskatchewan to as far south as Texas.
Anchiceratops is an extinct genus of chasmosaurine ceratopsid dinosaur that lived approximately 72 to 71 million years ago during the latter part of the Cretaceous Period in what is now Alberta, Canada. Anchiceratops was a medium-sized, heavily built, ground-dwelling, quadrupedal herbivore that could grow up to an estimated 4.3 metres (14 ft) long. Its skull featured two long brow horns and a short horn on the nose. The skull frill was elongated and rectangular, its edges adorned by coarse triangular projections. About a dozen skulls of the genus have been found.
Arrhinoceratops is a genus of herbivorous ceratopsian dinosaur. The name was coined as its original describer concluded it was special because the nose-horn was not a separate bone, however further analysis revealed this was based on a misunderstanding. It lived during the latest Campanian/earliest Maastrichtian stage of the Late Cretaceous, predating its famous relative Triceratops by a few million years, although it was contemporary with Anchiceratops. Its remains have been found in Canada.
The Horseshoe Canyon Formation is a stratigraphic unit of the Western Canada Sedimentary Basin in southwestern Alberta. It takes its name from Horseshoe Canyon, an area of badlands near Drumheller.
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 the Cretaceous–Paleogene extinction event. Broadly, the most distinguishing features of chasmosaurines are prominent brow horns and long frills lacking long spines; centrosaurines generally had short brow horns and relatively shorter frills, and often had long spines projecting from their frills.
Eotriceratops is a genus of herbivorous ceratopsian dinosaurs which lived in the area of North America during the late Cretaceous period. The only named species is Eotriceratops xerinsularis.
Velafrons is a genus of lambeosaurine hadrosaurid dinosaur from the Late Cretaceous of Mexico. It is known from a mostly complete skull and partial skeleton of a juvenile individual, with a bony crest on the forehead. Its fossils were found in the late Campanian-age Cerro del Pueblo Formation, near Rincon Colorado, Coahuila, Mexico. The type specimen is CPC-59, and the type species is V. coahuilensis.
Ojoceratops is a genus of ceratopsian dinosaur which lived in what is now New Mexico, United States. Ojoceratops fossils have been recovered from strata of the Ojo Alamo Formation, dating to the late Cretaceous period. The type species is Ojoceratops fowleri.
Tatankaceratops is a controversial genus of herbivorous ceratopsian dinosaur. It is a small chasmosaurine ceratopsian which lived during the Late Cretaceous period in what is now South Dakota. It is known from a single partial skull which was collected from the Hell Creek Formation, dating to 66 million years ago. Tatankaceratops was described by Christopher J. Ott and Peter L. Larson in 2010 and the type species is Tatankaceratops sacrisonorum. Tatankaceratops is known from one specimen housed at the Black Hills Institute, BHI 6226.
Kosmoceratops is a genus of ceratopsid dinosaur that lived in North America about 76–75.9 million years ago during the Late Cretaceous period. Specimens were discovered in Utah in the Kaiparowits Formation of the Grand Staircase–Escalante National Monument in 2006 and 2007, including an adult skull and postcranial skeleton and partial subadults. In 2010, the adult was made the holotype of the new genus and species Kosmoceratops richardsoni; the generic name means "ornate horned face", and the specific name honors Scott Richardson, who found the specimens. The find was part of a spate of ceratopsian discoveries in the early 21st century, and Kosmoceratops was considered significant due to its elaborate skull ornamentation.
Vagaceratops is a genus of herbivorous ceratopsian dinosaur. It is a chasmosaurine ceratopsian which lived during the Late Cretaceous period in what is now Alberta. Its fossils have been recovered from the Upper Dinosaur Park Formation. It is sometimes included in the genus Chasmosaurus as Chasmosaurus irvinensis instead of being recognized as its own genus.
Titanoceratops is a controversial genus of herbivorous ceratopsian dinosaur. It was a giant chasmosaurine ceratopsian that lived in the Late Cretaceous period in what is now New Mexico. Titanoceratops was named for its large size, being one of the largest known horned dinosaurs and the type species was named T. ouranos, after Uranus (Ouranos), the father of the Greek titans. It was named in 2011 by Nicholas R. Longrich for a specimen previously referred to Pentaceratops. Longrich believed that unique features found in the skull reveal it to have been a close relative of Triceratops, classified within the subgroup Triceratopsini. However, other researchers have expressed skepticism, and believe "Titanoceratops" to simply be an unusually large, old specimen of Pentaceratops.
Nasutoceratops is genus of ceratopsid dinosaur that lived in North America during the Late Cretaceous period, about 76.0–75.5 million years ago. The first known specimens were discovered in Utah in the Kaiparowits Formation of the Grand Staircase–Escalante National Monument (GSENM) from 2006 onwards, including a subadult skull with a partial postcranial skeleton and rare skin impressions and two other partial skulls. In 2013, the subadult was made the holotype of the new genus and species Nasutoceratops titusi; the generic name means "large-nosed horned face", and the specific name honors the paleontologist Alan L. Titus for his work at the GSENM. The dinosaur was noted for its large nose in news reports, and later featured in Jurassic World films.
Coronosaurus is a genus of centrosaurine ceratopsian dinosaurs which lived in the Late Cretaceous, in the middle Campanian stage. Its remains, two bone beds, were discovered by Phillip J. Currie in the Oldman Formation of Alberta, Canada, and its type and only species, Coronosaurus brinkmani, was first described in 2005, as a new species within the genus Centrosaurus. Later studies questioned the presence of a direct relationship, and in 2012 it was named as a separate genus. Coronosaurus means "crowned lizard", coming from "corona", Latin for crown, and "sauros", Greek for lizard; this name refers to the unique, crown-like shape of the horns on the top of its frill.
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.
Mercuriceratops is an extinct genus of herbivorous chasmosaurine ceratopsid dinosaur known from the Late Cretaceous of Alberta, Canada and Montana, United States. It contains a single species, Mercuriceratops gemini.
This timeline of ceratopsian research is a chronological listing of events in the history of paleontology focused on the ceratopsians, a group of herbivorous marginocephalian dinosaurs that evolved parrot-like beaks, bony frills, and, later, spectacular horns. The first scientifically documented ceratopsian fossils were described by Edward Drinker Cope starting in the 1870s; however, the remains were poorly preserved and their true nature was not recognized. Over the next several decades, Cope named several such genera and species. Cope's hated rival, Othniel Charles Marsh, also described ceratopsian remains. In 1887, Marsh mistook a Triceratops horn for one belonging to a new species of prehistoric Bison. Marsh also named the eponymous genus Ceratops in 1888. The next year, he named the most famous ceratopsian, Triceratops horridus. It was the discovery of Triceratops that illuminated the ceratopsian body plan, and he formally named the Ceratopsia in 1890.
Regaliceratops is a monospecific genus of chasmosaurine ceratopsid dinosaur from Alberta, Canada that lived during the Late Cretaceous in what is now the St. Mary River Formation. The type and only species, Regaliceratops peterhewsi, is known only from an adult individual with a nearly complete skull lacking the lower jaw, which was nicknamed "Hellboy". Regaliceratops was named in 2015 by Caleb M. Brown and Donald M. Henderson. Regaliceratops has an estimated length of 5 metres (16 ft) and body mass of 2 metric tons. The skull of Regaliceratops displays features more similar to centrosaurines, which suggests convergent evolution in display morphology in ceratopsids.
Yehuecauhceratops is a genus of horned centrosaurine ceratopsid dinosaur from the Late Cretaceous of Coahuila, Mexico. It contains a single species, Y. mudei, described from two partial specimens by Rivera-Sylva et al. in 2016 and formally named by Rivera-Sylva et al. in 2017. It was a small centrosaurine with a body length of 3 metres (9.8 ft), making it smaller than Agujaceratops and Coahuilaceratops, the other two ceratopsids in its environment; the three may have been ecologically segregated. A ridge bearing a single roughened projection near the bottom of the squamosal bone, which probably supported a small horn, allows Yehuecauhceratops to be distinguished from other centrosaurines. Its affinities to nasutoceratopsin centrosaurines, such as Avaceratops and Nasutoceratops, are supported by various morphological similarities to the former.