''Pentaceratops'' ("five-horned 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 ...
of herbivorous
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 k ...
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 ...
from the late
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 ...
Period of what is now
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
. Fossils of this animal were first discovered in 1921, but the genus was named in 1923 when its
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 ...
, ''Pentaceratops sternbergii'', was described. ''Pentaceratops'' lived around 76–73
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). ...
, its remains having been mostly found in the
Kirtland Formation in the
San Juan Basin
The San Juan Basin is a geologic structural basin located near the Four Corners region of the Southwestern United States. The basin covers 7,500 square miles and resides in northwestern New Mexico, southwestern Colorado, and parts of Utah a ...
in
New Mexico
)
, population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano)
, seat = Santa Fe
, LargestCity = Albuquerque
, LargestMetro = Tiguex
, OfficialLang = None
, Languages = English, Spanish ( New Mexican), Navajo, Ker ...
. About a dozen skulls and skeletons have been uncovered, so anatomical understanding of ''Pentaceratops'' is fairly complete. One exceptionally large specimen later became its own genus, ''
Titanoceratops'', due to its more derived morphology, similarities 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 ...
,'' and lack of unique characteristics shared with ''Pentaceratops''.
''Pentaceratops'' was about 6 meters (20 feet) long, and has been estimated to have weighed around . It had a short nose horn, two long brow horns, and long horns on the
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.
Anatomy ...
s. Its skull had a very long frill with triangular hornlets on the edge.
Discoveries and species
![Pentaceratops sternbergii (1)](https://upload.wikimedia.org/wikipedia/commons/f/f3/Pentaceratops_sternbergii_%281%29.jpg)
The first specimens were collected by
Charles Hazelius Sternberg
Charles Hazelius Sternberg (June 15, 1850 – July 20, 1943) was an American fossil collector and paleontologist. He was active in both fields from 1876 to 1928, and collected fossils for Edward Drinker Cope and Othniel C. Marsh, and for the ...
in the
San Juan Basin
The San Juan Basin is a geologic structural basin located near the Four Corners region of the Southwestern United States. The basin covers 7,500 square miles and resides in northwestern New Mexico, southwestern Colorado, and parts of Utah a ...
in
New Mexico
)
, population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano)
, seat = Santa Fe
, LargestCity = Albuquerque
, LargestMetro = Tiguex
, OfficialLang = None
, Languages = English, Spanish ( New Mexican), Navajo, Ker ...
. Sternberg worked in commission for the Swedish
Uppsala University
Uppsala University ( sv, Uppsala universitet) is a public university, public research university in Uppsala, Sweden. Founded in 1477, it is the List of universities in Sweden, oldest university in Sweden and the Nordic countries still in opera ...
. In 1921 he recovered a skull and a rump, specimens PMU R.200 and PMU R.286, at the
Meyers Creek near the Kimbetoh Wash in a layer of the
Kirtland Formation. He sent these fossils to paleontologist
Carl Wiman. In 1922 Sternberg decided to work independently and began a dig north of Tsaya Trading Post, in the Fossil Forest of
San Juan County. Here he discovered a complete skeleton, which he sold to the
American Museum of Natural History
The American Museum of Natural History (abbreviated as AMNH) is a natural history museum on the Upper West Side of Manhattan in New York City. In Theodore Roosevelt Park, across the street from Central Park, the museum complex comprises 26 inter ...
. The museum then sent out a team headed by
Charles Mook
Charles is a masculine given name predominantly found in English and French speaking countries. It is from the French form ''Charles'' of the Proto-Germanic name (in runic alphabet) or ''*karilaz'' (in Latin alphabet), whose meaning was " ...
and
Peter Kaisen to assist Sternberg in securing this specimen; subsequent digging by Sternberg in 1923 brought the total of AMNH specimens to four. The rump of the main specimen was discarded by the museum because it had insufficient value as a display.
The species was named and described by
Henry Fairfield Osborn in 1923, as ''Pentaceratops sternbergii''. The generic name means "five-horned face", derived from the
Greek ''penta'' (πέντα, meaning five), ''keras'' (κέρας, horn) and ''-ops'' (ὤψ, face),
in reference to its two long epijugal bones, spikes which protrude out sidewards from under its eyes, in addition to the three more obvious horns as with ''
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 ...
''. Osborn obligingly gave it the specific name ''sternbergii'' to honor its discoverer.
[H.F. Osborn, 1923, "A new genus and species of Ceratopsia from New Mexico, ''Pentaceratops sternbergii'', ''American Museum Novitates'' 93: 1-3] The name had been suggested to Osborn by
William Diller Matthew; the specific epithet served as a consolation to the almost bankrupt Sternberg whose 1923 fossils were initially not acquired by the museum that had to use its 1923/1924 budget to process the finds of the great Asian expeditions by
Roy Chapman Andrews
Roy Chapman Andrews (January 26, 1884 – March 11, 1960) was an American explorer, adventurer and naturalist who became the director of the American Museum of Natural History. He led a series of expeditions through the politically disturbed C ...
.
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 ...
was the skull discovered by Sternberg in 1922, specimen AMNH 6325. It was found in a layer of the
Fruitland Formation, dating from the
Campanian, about seventy-five million years old. The other three AMNH specimens were AMNH 1624, a smaller skull; AMNH 1622, a pair of brow horns; and AMNH 1625, a piece of skull frill.
In 1930, Wiman named a second species of ''Pentaceratops'': ''P. fenestratus''. It was based on Sternberg's 1921 specimens and the specific name referred to a hole in the left
squamosal.
[C. Wiman, 1930, "Über Ceratopsia aus der Oberen Kreide in New Mexico", ''Nova Acta Regiae Societatis Scientiarum Upsaliensis, Series 4'' 7(2): 1-19] This was later considered to be the same species as ''Pentaceratops sternbergii'' and thus a
junior synonym
The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently.
* In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linna ...
, the hole being the likely effect of an injury.
In 1929 Sternberg's son,
George Fryer Sternberg, discovered specimen USNM V12002, a right squamosal. ''Pentaceratops'' proved to be a quite common fossil in the Fruitland and Kirtland formations. It has even been used as a
guide fossil
Biostratigraphy is the branch of stratigraphy which focuses on correlating and assigning relative ages of rock Stratum, strata by using the fossil assemblages contained within them.Hine, Robert. “Biostratigraphy.” ''Oxford Reference: Dictiona ...
: the appearance of ''Pentaceratops sternbergii'' in the fossil record marks the end of the
Judithian
The Judithian was a North American faunal stage lasting from 83.5 to 70.6 million years ago. It overlaps with the Campanian global stage.
Fauna
Dinosaur faunas of the Judithian age may represent the peak of dinosaur evolution in North America. H ...
land vertebrate age and the start of the
Kirtlandian
Dinosaur paleobiogeography is the study of dinosaur geographic distribution, based on evidence in the fossil record.
Late Cretaceous North America
Thomas M. Lehman, in a study of Late Cretaceous dinosaur distribution, concluded that they were "r ...
.
Subsequent finds include specimens MNA Pl. 1668, MNA Pl. 1747, NMMNH P-27468 and USNM 2416, partial skeletons with skull; YPM 1229, a skeleton lacking the skull; UALP 13342 and UKVP 16100, skulls; UNM B-1701, USNM 12741, USNM 12743, USNM 8604, SMP VP-1596, SMP VP-1488, SMP VP-1500 and SMP VP-1712, fragmentary skulls. Apart from the San Juan Basin finds, a juvenile specimen of ''Pentaceratops'', SDMNH 43470, was found in the
Williams Fork Formation of
Colorado
Colorado (, other variants) is a state in the Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the western edge of t ...
in 2006.
![Pentaceratops fossil airlift](https://upload.wikimedia.org/wikipedia/commons/3/35/Pentaceratops_fossil_airlift.jpg)
Sometimes the identification of a specimen as ''Pentaceratops'' has proven to be highly contentious. In 1998
Thomas Lehman described OMNH 10165, a very large skull and its associated
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 ...
found in New Mexico in 1941. The skull is presently on display at the
Sam Noble Oklahoma Museum of Natural History
Sam, SAM or variants may refer to:
Places
* Sam, Benin
* Sam, Boulkiemdé, Burkina Faso
* Sam, Bourzanga, Burkina Faso
* Sam, Kongoussi, Burkina Faso
* Sam, Iran
* Sam, Teton County, Idaho, United States, a populated place
People and fictio ...
, and is the largest ''Pentaceratops'' exemplar known, with the distinction of having produced the largest known
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 ...
of any land
vertebrate
Vertebrates () comprise all animal taxa within the subphylum Vertebrata () ( chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, ...
.
[Lehman, T.M., 1998, "A gigantic skull and skeleton of the horned dinosaur ''Pentaceratops sternbergi'' from New Mexico: Journal of Paleontology, 72(5): 894-906] However, in 2011, the skeleton was renamed as a separate genus, ''
Titanoceratops'', due to its more derived morphology, similarities 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 ...
,'' and lack of unique characteristics shared with ''Pentaceratops''.
In 2014
Nicholas Longrich named a new species: ''Pentaceratops aquilonius'', "the northern one," based on fragmentary fossils discovered during the 1930s near
Manyberries
Manyberries is a hamlet in Alberta, Canada within the County of Forty Mile No. 8. It is located approximately south of Medicine Hat, at the eastern end of Highway 61 (the Red Coat Trail).
Climate
Manyberries experiences a semi-arid climate ( ...
in
Alberta
Alberta ( ) is one of the thirteen provinces and territories of Canada. It is part of Western Canada and is one of the three prairie provinces. Alberta is bordered by British Columbia to the west, Saskatchewan to the east, the Northwest Ter ...
,
Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...
. The species has been described as having a first epiparietal pointing upwards instead of forwards. In 2016, Mallon ''et al.'' found ''P. aquilonius'' to be morphologically similar to ''
Spiclypeus shipporum
''Spiclypeus'' (meaning "spike shield") is an extinct genus of chasmosaurine ceratopsian dinosaur known from the Late Cretaceous Judith River Formation (late Campanian stage) of Montana, United States.
Discovery
In 2000, Bill D. Shipp, a nuclea ...
'', with it possibly being the same species, and considered ''P. aquilonius'' a ''
nomen dubium
In binomial nomenclature, a ''nomen dubium'' (Latin for "doubtful name", plural ''nomina dubia'') is a scientific name that is of unknown or doubtful application.
Zoology
In case of a ''nomen dubium'' it may be impossible to determine whether a s ...
''.
Description
![Pentaceratops BW](https://upload.wikimedia.org/wikipedia/commons/f/fb/Pentaceratops_BW.jpg)
''Pentaceratops'' was a large
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 k ...
; Dodson estimated the body length at . The skull length of AMNH 1624 is while PMU R.200 has a length of .
In 2016
Paul estimated its length at 5.5 meters (18 ft) and its weight at 2.5 metric tons (2.75 short tons). The nose horn of ''Pentaceratops'' is small and pointing upward and backward. The brow horns are very long and curving strongly forward. The somewhat upward tilted frill of ''Pentaceratops'' is considerably longer than that of ''
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 ...
'', with two large holes (parietal
fenestrae
A fenestra (fenestration; plural fenestrae or fenestrations) is any small opening or pore, commonly used as a term in the biological sciences. It is the Latin word for "window", and is used in various fields to describe a pore in an anatomical st ...
) in it. It is rectangular, adorned by large triangular
osteoderm
Osteoderms are bony deposits forming scales, plates, or other structures based in the dermis. Osteoderms are found in many groups of extant and extinct reptiles and amphibians, including lizards, crocodilians, frogs, temnospondyls (extinct amp ...
s: up to twelve episquamosals at the
squamosal and three epiparietals at the
parietal bone
The parietal bones () are two bones in the Human skull, skull which, when joined at a fibrous joint, form the sides and roof of the Human skull, cranium. In humans, each bone is roughly quadrilateral in form, and has two surfaces, four borders, an ...
. These are largest at the rear corners of the frill, and are separated by a large U-shaped notch at the midline, a feature not recognized until 1981 when specimen UKVP 16100 was described.
[Rowe, T., Colbert, E.H. and Nations, J.D., 1981, "The occurrence of ''Pentaceratops'' with a description of its frill", In: Lucas, S.G., Rigby, J.K. and Kues, B.S. (eds.) ''Advances in San Juan Basin Paleontology'', University of New Mexico Press, Alburquerque p. 29-48] Within the notch the first epiparietals point forwards. The very thick jugal and the squamosal do not touch each other, a possible
autapomorphy
In phylogenetics, an autapomorphy is a distinctive feature, known as a derived trait, that is unique to a given taxon. That is, it is found only in one taxon, but not found in any others or outgroup taxa, not even those most closely related to t ...
.
The torso of ''Pentaceratops'' is tall and wide. The rear dorsal vertebrae bear long spines from which ligaments possibly ran to the front, to balance the high frill. The
prepubis is long. The
is long and strongly curves forward. In smaller specimens the thigh bone bows outwards.
[Paul, G.S., 2010, ''The Princeton Field Guide to Dinosaurs'', Princeton University Press p. 272]
Classification
Osborn originally assigned ''Pentaceratops'' to
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. ...
. Within this group ''Pentaceratops'' belonged to the
Ceratopsinae or
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 ...
. It appears to be most closely related to ''
Utahceratops
''Utahceratops'' is an extinct genus of ceratopsian dinosaur that lived approximately 76.4~75.5 million years ago during the Late Cretaceous period in what is now Utah. ''Utahceratops'' was a large-sized, robustly-built, ground-dwelling, quadru ...
''. Their
clade
A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...
was perhaps more derived than the earlier genus ''
Chasmosaurus
''Chasmosaurus'' ( ) is a genus of ceratopsid dinosaur from the Upper Cretaceous Period of North America. Its name means 'opening lizard', referring to the large openings ( fenestrae) in its frill (Greek ''chasma'' meaning 'opening' or 'hollow' ...
'' but more basal than ''
Anchiceratops
''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-size ...
'', the latter representing a line of which ''Triceratops'' was a member, which lived a few million years later, right at the end of the Cretaceous period, when all ceratopsians died out.
The
cladogram of the
phylogeny
A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree showing the evolutionary relationships among various biological spec ...
of ''Pentaceratops'' according to a study by
Scott Sampson ''et al.'' in 2010 found that the genus was most closely related to ''Utahceratops'', from a similar age and region.
The below cladogram follows Longrich (2014), who named a new species of ''Pentaceratops'', and included nearly all chasmosaurine species.
![Pentaceratops_Size](https://upload.wikimedia.org/wikipedia/commons/a/a5/Pentaceratops_Size.svg)
Longrich stated that the holotype and referred specimen of ''P. aquilonius'' fall within the diagnosis of ''Pentaceratops'', and were recovered very close to the type species in the phylogeny. He noted that the placement of ''Utahceratops'' does not make the genus
paraphyletic
In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ...
, as there is no requirement that genera are
monophyletic
In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ...
. The Williams Fork chasmosaur differs from the ''Pentaceratops'' and ''Utahceratops'' species, and might require a new specific or generic name.
Paleobiology
''Pentaceratops'', like all ceratopsians, was an
herbivore
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 ...
. During the Cretaceous, flowering plants were "geographically limited on the landscape" and so it is likely that this dinosaur fed on the predominant plants of the era:
fern
A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes except t ...
s,
cycads
Cycads are seed plants that typically have a stout and woody (ligneous) trunk with a crown of large, hard, stiff, evergreen and (usually) pinnate leaves. The species are dioecious, that is, individual plants of a species are either male or ...
and
conifers
Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single extant class, Pinopsida. All extan ...
. It would have used its sharp ceratopsian beak to bite off the branches which were then shredded - leaves, needles and all - by the tooth batteries, providing a self-sharpening continuous cutting edge in both upper and lower jaws. Ultimately the plant material was digested by the large gut.
Paleoecology
''Pentaceratops'' lived around 76–73
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). ...
, its remains having been mostly found in the
Kirtland Formation in the
San Juan Basin
The San Juan Basin is a geologic structural basin located near the Four Corners region of the Southwestern United States. The basin covers 7,500 square miles and resides in northwestern New Mexico, southwestern Colorado, and parts of Utah a ...
in
New Mexico
)
, population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano)
, seat = Santa Fe
, LargestCity = Albuquerque
, LargestMetro = Tiguex
, OfficialLang = None
, Languages = English, Spanish ( New Mexican), Navajo, Ker ...
. Other dinosaurs that shared its
habitat
In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...
include ''
Parasaurolophus cyrtocristatus
''Parasaurolophus'' (; meaning "near crested lizard" in reference to '' Saurolophus)'' is a genus of herbivorous hadrosaurid ornithopod dinosaur that lived in what is now North America and possibly Asia during the Late Cretaceous Period, ab ...
'', the pachycephalosaur ''
Sphaerotholus'', the armored dinosaur ''
Nodocephalosaurus
''Nodocephalosaurus'' (meaning "knob headed lizard") is a monospecific genus of ankylosaurid dinosaur from New Mexico that lived during the Late Cretaceous (late Campanian to early Maastrichtian stage, 73.49 to 73.04 Ma) in what is now the De-na- ...
'' and the
tyrannosauroid
Tyrannosauroidea (meaning 'tyrant lizard forms') is a superfamily (or clade) of coelurosaurian theropod dinosaurs that includes the family Tyrannosauridae as well as more basal relatives. Tyrannosauroids lived on the Laurasian supercontinent b ...
''
Bistahieversor
''Bistahieversor'' (meaning "Bistahi destroyer"), also known as the "Bisti Beast", is a genus of eutyrannosaurian tyrannosauroid dinosaur; the genus contains only a single known species, ''B. sealeyi'', described in 2010, from the Late Cretaceo ...
''.
See also
*
Timeline of ceratopsian research
*
Ah-Shi-Sle-Pah Wilderness Study Area
Ah-Shi-Sle-Pah Wilderness is located in San Juan County, New Mexico, between Chaco Canyon and the De-Na-Zin Wilderness. Its name is a phonetic transliteration of Navajo " áshįįh łibá" meaning "salt, it is grey (grey salt)". The wilderness ...
, the
type locality for ''Pentaceratops fenestratus''
References
Sources
*
*
* Lehman, T. M., 2001, Late Cretaceous dinosaur provinciality: In: Mesozoic Vertebrate Life, edited by Tanke, D. H., and Carpenter, K., Indiana University Press, pp. 310–328.
*
* Sullivan, R.M., and Lucas, S.G. 2006.
The Kirtlandian land-vertebrate "age" – faunal composition, temporal position and biostratigraphic correlation in the nonmarine Upper Cretaceous of western North America" New Mexico Museum of Natural History and Science, Bulletin 35:7-29.
*
* Lucas, S.G., Sullivan, R.M., Hunt, A.P., 2006, Re-evaluation of ''Pentaceratops'' and ''Chasmosaurus'' (Ornithischia, Ceratopsidae) in the Upper Cretaceous of the Western Interior: New Mexico Museum of Natural History and Science, Bulletin 35
External links
*
*
*
{{Taxonbar, from=Q131253
Chasmosaurines
Late Cretaceous dinosaurs of North America
Fossil taxa described in 1923
Taxa named by Henry Fairfield Osborn
Kirtland fauna
Paleontology in New Mexico
Campanian genus first appearances
Campanian genus extinctions
Ornithischian genera