Styracosaurus
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[[WP:UNDO|Undid]] revision 225148438 by [[Special:Contributions/Ruasonnaryt|Ruasonnaryt]] ([[User talk:Ruasonnaryt|talk]])
{{Taxobox
| name = ''Styracosaurus''
| image = Styracosaurus.jpg
| image_width = 250px
| image_caption = ''Styracosaurus albertensis'' skull, [[American Museum of Natural History]].
| fossil_range = [[Late Cretaceous]]
| regnum = [[Animal]]ia
| phylum = [[Chordate|Chordata]]
| classis = [[Reptile|Sauropsida]]
| superordo = [[Dinosaur]]ia
| ordo = [[Ornithischia]]
| subordo = [[Cerapoda]]
| infraordo = [[Ceratopsia]]
| familia = [[Ceratopsidae]]
| subfamilia = [[Centrosaurinae]]
| genus = '''''Styracosaurus'''''
| genus_authority = [[Lawrence Lambe|Lambe]], 1913
| subdivision_ranks = [[Species]]
| subdivision =
*''S. albertensis'' <small>Lambe, 1913 ([[Type (zoology)|type]])</small>
*''S. ovatus'' <small>[[Charles W. Gilmore|Gilmore]], 1930</small>
}}
'''''Styracosaurus''''' ({{pronEng|st<s>ɪ</s>ˌrækəˈsɔrəs}}, meaning "spiked lizard" from [[Ancient Greek|Greek]] ''styrax/στυραξ'' 'spike at the butt-end of a spear-shaft' and ''saurus/σαυρος'' 'lizard')<ref name="Liddell">{{cite book|author=Liddell & Scott|year=1980|title=Greek-English Lexicon, Abridged Edition |publisher=Oxford University Press, Oxford, UK|id=ISBN 0-19-910207-4}}</ref> was a [[genus]] of [[herbivore|herbivorous]] [[ceratopsia]]n [[dinosaur]] from the [[Cretaceous]] [[Period (geology)|Period]] ([[Campanian]] [[faunal stage|stage]]), about 76.5 to 75.0 [[million years ago]]. It had four to six long horns extending from its [[neck frill]], a smaller horn on each of its cheeks, and a single horn protruding from its nose, which may have reached dimensions of around 60 [[centimeter]]s (2 [[foot (unit of length)|ft]]) long and 15 centimeters (6 [[inch|in]]) wide. The function or functions of the horns and frills have been the subject of debate for many years.
''Styracosaurus'' was a large dinosaur, reaching lengths of 5.5 [[metre|meters]] (18 ft) and weighing nearly 3 [[ton]]s. It stood about 1.8 meters (6 ft) tall. ''Styracosaurus'' possessed four short legs and a bulky body. Its tail was rather short. It also had a beak and flat cheek teeth, indicating that its diet was herbivorous. Like other ceratopsians, this dinosaur may have been a [[herd animal]], traveling in large groups, as suggested by bonebeds.
Named by [[Lawrence Lambe]] in 1913, ''Styracosaurus'' is a member of the [[Centrosaurinae]]. Two [[species]], ''S. albertensis'' and ''S. ovatus'' are currently assigned to ''Styracosaurus''. Other species assigned to the genus have since been reassigned elsewhere.
==Description==
[[Image:Human-styracosaurus size comparison.svg|thumb|left|200px|''Styracosaurus'' compared in size with a human.]]
Individuals of the ''Styracosaurus'' genus were approximately 5.5 m (18 ft) long as adults and weighed around 2.7 tons.<ref name="Lambert">Lambert, D. (1993). ''The Ultimate Dinosaur Book.'' Dorling Kindersley: New York, 152–167. ISBN 1-56458-304-X.</ref> The skull was massive, with a large [[naris|nostril]], a tall straight nose horn, and a parietosquasomal frill (a [[neck frill]]) crowned with at least four large spikes. Each of the four longest frill spines was comparable in length to the nose horn, at 50 to 55 centimeters long (19.7 to 21.7 in).<ref name="Dodson">{{cite book| last = Dodson| first = P.| authorlink =Peter Dodson | title = The Horned Dinosaurs: A Natural History| publisher = Princeton University Press| date = 1996| location = Princeton| pages = 165–169| isbn = 0-691-05900-4}}</ref> The nasal horn is estimated at 57 centimeters long (19.7 in) in the [[holotype|type]] specimen,<ref name=LL13>{{cite journal |last=Lambe |first=L.M. |year=1913 |title=A new genus and species from the Belly River Formation of Alberta |journal=Ottawa Naturalist |volume=27 |pages=109–116}}</ref> but the horn is only partially complete. Based on other nasal horn cores from ''Styracosaurus'' and ''[[Centrosaurus]]'', this horn may have come to a rounded point at around half of that length.<ref name=RHR07>{{cite journal |last=Ryan |first=Michael J. |coauthors=Holmes, Robert; and Russell, A.P. |year=2007 |title=A revision of the late Campanian centrosaurine ceratopsid genus ''Styracosaurus'' from the Western Interior of North America |journal=Journal of Vertebrate Paleontology |volume=27 |issue=4 |pages=94–962 |doi=10.1671/0272-4634(2007)27[944:AROTLC]2.0.CO;2 }}</ref>
Aside from the large nasal horn and four long frill spikes, the cranial ornamentation was variable. Some individuals had small hook-like projections and knobs at the [[anatomical terms of location|posterior]] margin of the frill, similar to but smaller than those in ''Centrosaurus''. Others had less prominent tabs. Some, like the type individual, had a third pair of long frill spikes. Others had much smaller projections. Second species ''S. ovatus'' had only four large spikes, but the inner pair curved toward each other, the opposite of what is seen in the much better known ''S. albertensis''. Other small points are found on the side margins of some but not all specimens. Modest pyramid-shaped brow horns were present in subadults, but were replaced by pits in adults.<ref name=RHR07/> Like most ceratopsids, ''Styracosaurus'' had large [[fenestrae]] (skull openings) in its frill. The front of the mouth had a toothless beak.
[[Image:Styracosaurus dinosaur.png|left|thumb|Artist's impression of ''Styracosaurus'']]
The bulky body of ''Styracosaurus'' resembled that of a [[rhinoceros]]. It had powerful shoulders which may have been useful in intraspecies combat. ''Styracosaurus'' had a relatively short tail. Each toe bore a hooflike [[ungual]] which was sheathed in horn.<ref name="Lambert"/>
Various limb positions have been proposed for ''Styracosaurus'' and ceratopsids in general, including forelegs which were held underneath the body, or, alternately, held in a sprawling position. The most recent work has put forward an intermediate crouched position as most likely.<ref name=TH07>{{cite web |url=http://palaeo-electronica.org/2007_1/step/index.html |title=Forelimb stance and step cycle in ''Chasmosaurus irvinensis'' (Dinosauria:Neoceratopsia |accessdate=2007-05-28 |author=Thompson, Stefan |coauthors= and Holmes, Robert |year=2007 |month=April |format=HTML |publisher=Palaeontologia Electronica }}</ref> [[Paleontologist]]s [[Gregory Paul]] and Per Christiansen of the Zoological Museum of the [[University of Copenhagen]] in [[Denmark]] proposed that large ceratopsians such as ''Styracosaurus'' were able to run at speeds exceeding that of an [[elephant]], based on possible ceratopsian [[fossil trackway|trackway]]s which did not exhibit signs of sprawling forelimbs.<ref>{{cite journal| last = Paul| first = Gregory| authorlink =| coauthors = Per Christiansen| title = Forelimb posture in neoceratopsian dinosaurs: implications for gait and locomotion | journal = Paleobiology| volume = 26| issue = 3| pages = 450–465| publisher = BioOne|date=September 2000| url = http://www.bioone.org/perlserv/?request=get-document&doi=10.1666%2F0094-8373(2000)026%3C0450%3AFPINDI%3E2.0.CO%3B2 |id ={{doi| id = 10.1666/0094-8373(2000)026%3C0450:FPINDI%3E2.0.CO;2 | label = 10.1666/0094-8373(2000)026<0450:FPINDI>2.0.CO;2 }} | accessdate = 2007-02-25| doi = 10.1666/0094-8373(2000)026<0450:FPINDI>2.0.CO;2| format = subscription required| year = 2000 }}</ref>
==Classification==
''Styracosaurus'' is a member of the [[Centrosaurinae]], a subfamily of large North American [[Ceratopsia|horned dinosaurs]] characterized by their "prominent nasal horns, subordinate brow horns, short [[squamosal]]s in a short frill, a tall, deep face relative to the ceratopines, and a projection into the rear of the nasal fenestra."<ref name="Tweet">{{cite web| last =Tweet| first =J.| authorlink =| coauthors =| title =Centrosaurinae| work =Thescelosaurus| publisher =Qwest.net| date =2007| url =http://www.users.qwest.net/~jstweet1/centrosaurinae.htm| format =| doi =| accessdate =2007-04-22}}</ref> Other members of the [[clade]] include ''[[Centrosaurus]]'' (from which the group takes its name),<ref name="Dodson90">{{cite book |last=Dodson |first=P. |year=1990 |chapter=On the status of the ceratopsids ''Monoclonius'' and ''Centrosaurus'' |editor=Carpenter, K.; and Currie, P.J. (eds.) |title=Dinosaur Systematics: Perspectives and Approaches |publisher=Cambridge University Press |location=Cambridge |pages=231–243 |isbn=0-521-36672-0}}</ref><ref name="RyanRussell03">{{cite journal| last =Ryan| first =M.J.| authorlink =| coauthors =A.P. Russell| title =New centrosaurine ceratopsids from the late Campanian of Alberta and Montana and a review of contemporaneous and regional patterns of centrosaurine evolution| journal =Journal of Vertebrate Paleontology | volume =23| issue =3| pages =| publisher =| date =2003 }}</ref> ''[[Pachyrhinosaurus]]'',<ref name="Dodson90"/><ref name="RyanRussell05">{{cite journal| last =Ryan| first =M.J.| authorlink =| coauthors =A.P. Russell| title =A new centrosaurine ceratopsid from the Oldman Formation of Alberta and its implications for centrosaurine taxonomy and systematics| journal =Canadian Journal of Earth Sciences | volume =42| issue =| pages =1369–1387| publisher =| date =2005| doi =10.1139/e05-029}}</ref> ''[[Avaceratops]]'',<ref name="Dodson90"/> ''[[Einiosaurus]]'',<ref name="RyanRussell05"/><ref name="Ryan07"/> ''[[Albertaceratops]]'',<ref name="Ryan07">{{cite journal| last =Ryan| first =M.J.| authorlink =| coauthors =| title =A new basal centrosaurine ceratopsid from the Oldman Formation, southeastern Alberta| journal =Journal of Paleontology| volume =81| issue =2| pages =376–396 | publisher =| date =2007| url =| doi =10.1666/0022-3360(2007)81[376:ANBCCF]2.0.CO;2| id =| accessdate =| year =2007 }}</ref> ''[[Achelousaurus]]'',<ref name="RyanRussell05"/> ''[[Brachyceratops]]'',<ref name ="Dino2">Dodson, P., Forster, C. A, and Sampson, S. D. (2004) ''Ceratopsidae''. In: Weishampel, D. B., Dodson, P., and Osmólska, H. (eds.), ''The Dinosauria'' (second edition). University of California Press:Berkeley, pp. 494–513. ISBN 0-520-24209-2.</ref> and ''[[Monoclonius]]'',<ref name="Dodson90"/> although these last two are [[nomen dubium|dubious]]. Because of the variation between species and even individual specimens of centrosaurines, there has been much debate over which genera and species are valid, particularly whether ''Centrosaurus'' and/or ''Monoclonius'' are valid genera, undiagnosable, or possibly members of the opposite sex. In 1996, [[Peter Dodson]] found enough variation between ''Centrosaurus'', ''Styracosaurus'', and ''Monoclonius'' to warrant separate genera, and that ''Styracosaurus'' resembled ''Centrosaurus'' more closely than either resembled ''Monoclonius''. Dodson also believed one species of ''Monoclonius'', ''M. nasicornis'', may actually have been a female ''Styracosaurus''.<ref name="Dodson1">Dodson, P. (1996). ''The Horned Dinosaurs: A Natural History''. Princeton University Press: Princeton, New Jersey, p. 197–199. ISBN 0-691-02882-6.</ref> His assessments have been partially followed, with other researchers not accepting ''Monoclonius nasicornis'' as a female ''Styracosaurus'', or ''Monoclonius'' as a valid genus.<ref name=RE05>{{cite book |last=Ryan |first=Michael J. |coauthors=and Evans, David C. |editors=Currie, Phillip J., and Koppelhus, Eva |title=Dinosaur Provincial Park: A Spectacular Ancient Ecosystem Revealed |chapter=Ornithischian Dinosaurs |year=2005 |publisher=Indiana University Press |location=Bloomington |pages=312–348 |isbn=0-253-34595-2 }}</ref><ref name=RHR07/> While [[sexual dimorphism]] has been proposed for an earlier ceratopsian ''[[Protoceratops]]'',<ref>{{cite journal | last = Dodson | first = P. | title = Quantitative aspects of relative growth and sexual dimorphism in ''Protoceratops'' | journal = Journal of Paleontology | volume = 50 | pages = 929–940 | doi =}}
</ref> there is no firm evidence for sexual dimorphism in any ceratopsids.<ref name = "Forster90">Forster, C. A. (1990). The cranial morphology and systematics of ''Triceratops'', with a preliminary analysis of ceratopsian phylogeny. Ph.D. Dissertation. University of Pennsylvania, Philadelphia. 227 pp.</ref><ref name="TML98">{{cite journal|last=Lehman|first=T. M.|year=1998|title=A gigantic skull and skeleton of the horned dinosaur ''Pentaceratops sternbergi'' from New Mexico|journal=Journal of Paleontology|volume=72|issue=5|pages=894–906}}</ref><ref name=SRT97>{{cite journal |last=Sampson |first=S. D. |coauthors=Ryan, M.J.; and Tanke, D.H. |year=1997 |title=Craniofacial ontogeny in centrosaurine dinosaurs (Ornithischia: Ceratopsidae): taphonomic and behavioral phylogenetic implications |journal=Zoological Journal of the Linnean Society |volume=121 |pages=293–337}}</ref>
===Origins===
[[Image:Styracosaurus BW.jpg|thumb|Restoration of ''Styracosaurus albertensis''.]]
The evolutionary origins of ''Styracosaurus'' were not understood for many years because fossil evidence for early ceratopsians was sparse. The discovery of ''[[Protoceratops]]'', in 1922, shed light on early ceratopsid relationships,<ref name="Dodson2">Dodson, P. (1996). ''The Horned Dinosaurs: A Natural History''. Princeton University Press: Princeton, New Jersey, p. 244. ISBN 0-691-02882-6.</ref> but several decades passed before additional finds filled in more of the blanks. Fresh discoveries in the late 1990s and 2000s, including ''[[Zuniceratops]]'', the earliest known ceratopsian with brow horns, and ''[[Yinlong]]'', the first known [[Jurassic]] ceratopsian, indicate what dinosaurs related to the ancestors of ''Styracosaurus'' may have looked like. These new discoveries have been important in illustrating the origins of horned dinosaurs in general, and suggest that the group originated during the Jurassic in [[Asia]], and the appearance of truly horned ceratopsians by the beginning of the late Cretaceous in North America.<ref name ="Dino2">Dodson, P., Forster, C. A, and Sampson, S. D. (2004) ''Ceratopsidae''. In: Weishampel, D. B., Dodson, P., and Osmólska, H. (eds.), ''The Dinosauria'' (second edition). University of California Press:Berkeley, pp. 494–513. ISBN 0-520-24209-2.</ref>
==Discoveries and species==
The first [[fossil]] remains of ''Styracosaurus'' were collected in [[Alberta]], [[Canada]] by [[Charles Mortram Sternberg|C.M. Sternberg]] (from an area now known as the [[Dinosaur Provincial Park]], in a [[geological formation|formation]] now called the [[Dinosaur Park Formation]]) and named by [[Lawrence Lambe]] in 1913. This quarry was revisited in 1935 by a [[Royal Ontario Museum]] crew who found the missing lower jaws and most of the skeleton. These fossils indicate that ''S. albertensis'' was around 5.5 to 5.8 meters in length and stood about 1.65 meters high at the hips.<ref name="Dodson"/> An unusual feature of this first skull is that the smallest frill spike on the left side is partially overlapped at its base by the next spike. It appears that the frill suffered a break at this point in life and was shortened by about 6 centimeters (2 in). The correct shape of this area is unknown because the corresponding area of the right side of the frill was not recovered.<ref name=RHR07/>
[[Barnum Brown]] and [[Erich Maren Schlaikjer]], working for the [[American Museum of Natural History]] in New York, collected a nearly complete articulated skeleton with a partial skull in 1915. These fossils were also found in the Dinosaur Park Formation, near [[Steveville, Alberta|Steveville]], Alberta. Brown and Schlaikjer compared the finds, and, though they allowed that both specimens were from the same general locality and geological formation, they considered the specimen sufficiently distinct from the [[holotype]] to warrant erecting a new species, and described the fossils as ''Styracosaurus parksi'', named in honor of [[William Parks]].<ref name="Brown">{{cite journal| last = Brown| first = Barnum| authorlink =| coauthors = Erich Maren Schlaikjer| title = The skeleton of ''Styracosaurus'' with the description of a new species| journal = American Museum novitates| volume = no. 955| pages = 12| publisher = New York City : The American Museum of Natural History| date = 1937| url = http://digitallibrary.amnh.org/dspace/handle/2246/2191| accessdate =2007-03-29}}</ref> Among the differences between the specimens cited by Brown and Schlaikjer were a [[jugal|cheekbone]] quite different from that of ''S. albertensis'', and smaller [[tail]] [[vertebra]]e. ''S. parksi'' also had a more robust jaw, a shorter [[dentary]], and the frill differed in shape from that of the type species.<ref name="Brown"/> However, much of the skull consisted of plaster reconstruction, and the original 1937 paper did not illustrate the actual skull bones.<ref name="Dodson"/> It is now accepted as a specimen of ''S. albertensis''.<ref name=Dino2/><ref name=RHR07/>
In the summer of 2006, [[Darren Tanke]] of the [[Royal Tyrrell Museum of Palaeontology]] in [[Drumheller, Alberta|Drumheller]], Alberta relocated the long lost ''S. parksi'' site.<ref name=RHR07/> Pieces of the skull, evidently abandoned by the 1915 crew, were found in the quarry. These were collected and it is hoped more pieces will be found, perhaps enough to warrant a redescription of the skull and test whether ''S. albertensis'' and ''S. parksi'' are the same. The Tyrrell Museum has also collected several partial ''Styracosaurus'' skulls.<ref name=EG05/> At least one confirmed bonebed (bonebed 42) in Dinosaur Provincial Park has also been explored (other proposed ''Styracosaurus'' bonebeds instead have fossils from a mix of animals, and nondiagnostic ceratopsian remains). Bonebed 42 is known to contain numerous pieces of skulls such as horncores, jaws and frill pieces.<ref name=RHR07/>
A third species, ''S. ovatus'', from the [[Two Medicine Formation]] of [[Montana]], was described by [[Charles W. Gilmore|Gilmore]] in 1930. The fossil material is limited, with the best being a portion of the [[parietal]] bone of the frill, but one unusual feature is that the pair of spikes closest to the midline converge towards the midline, rather than away from it as in ''S. albertensis''. There also may only have been two sets of spikes on each side of the frill, instead of three. The spikes are much shorter than in ''S. albertensis'', with the longest only 295 millimeters (11.6 in) long.<ref name="Gilmore1930">{{cite journal |last=Gilmore |first=Charles W. |authorlink=Charles W. Gilmore |year=1930 |title=On dinosaurian reptiles from the Two Medicine Formation of Montana |journal=Proceedings of the United States National Museum |volume=77 |issue=16 |pages=1–39 }}</ref> Recent review of styracosaur skull remains by Ryan, Holmes, and Russell finds it to be a distinct species.<ref name=RHR07/>
Several other species which were assigned to ''Styracosaurus'' have since been assigned to other genera. ''S. sphenocerus'', described by [[Edward Drinker Cope]] in 1890 as a species of ''[[Monoclonius]]'' and based on a [[nasal bone]] with a broken ''Styracosaurus''-like straight nose horn, was attributed to ''Styracosaurus'' in 1915.<ref name="Lambe">{{cite journal|last=Lambe|first=L. M.|year=1915|title=On ''Eoceratops canadensis'', gen. nov., with remarks on other genera of Cretaceous horned dinosaurs|journal=Canada Geological Survey Bulletin, Geological Series|volume=12|issue=24|pages=1–49}}</ref> "S. makeli", mentioned informally by amateur [[paleontologist]]s Stephen and Sylvia Czerkas in 1990 in a caption to an illustration, is an early name for ''[[Einiosaurus]]''.<ref name=DFG97a>{{cite book|chapter=Einiosaurus |last=Glut |first=Donald F. |title=Dinosaurs: The Encyclopedia |year=1997 |publisher=McFarland & Co |location=Jefferson, North Carolina|pages=396–398 |isbn=0-89950-917-7}}</ref> "S. borealis" is an early informal name for ''S. parksi''.<ref name=DFG97b>{{cite book|chapter=Styracosaurus |last=Glut |first=Donald F. |title=Dinosaurs: The Encyclopedia |year=1997 |publisher=McFarland & Co |location=Jefferson, North Carolina|pages=865–868 |isbn=0-89950-917-7}}</ref>
==Paleobiology==
''Styracosaurus'' and other horned dinosaurs are often depicted in popular culture as [[herd]]ing animals. A bonebed composed of ''Styracosaurus'' remains is known from the [[Dinosaur Park Formation]] of Alberta, about halfway up the formation. This bonebed is associated with different types of [[river]] deposits.<ref name=EG05>{{cite book |last=Eberth |first=David A.|coauthors=and Getty, Michael A. |editors=Currie, Phillip J., and Koppelhus, Eva |title=Dinosaur Provincial Park: A Spectacular Ancient Ecosystem Revealed |chapter=Ceratopsian bonebeds: occurrence, origins, and significance |year=2005 |publisher=Indiana University Press |location=Bloomington |pages=501–536 |isbn=0-253-34595-2 }}</ref><ref>Although this article mentioned two bonebeds, including BB 156, the recent review by Ryan ''et al.'' only accepted BB 42.</ref> The mass deaths may have been a result of otherwise non-herding animals congregating around a waterhole in a period of drought, with evidence suggesting the environment may have been seasonal and semiarid.<ref name=RR90>{{cite journal|last=Rogers|first=R. R.|year=1990|title=Taphonomy of three dinosaur bone beds in the Upper Cretaceous Two Medicine Formation, northwestern Montana: Evidence for drought-related mortality|journal=Palaios|volume=5|pages=394–41|doi=10.2307/3514834}}</ref>
''Styracosaurus'' is known from higher in the formation than the closely-related ''Centrosaurus'', suggesting that ''Styracosaurus'' displaced ''Centrosaurus'' as the environment changed over time.<ref name=RE05>{{cite book |last=Ryan |first=Michael J. |coauthors=and Evans, David C. |editors=Currie, Phillip J., and Koppelhus, Eva |title=Dinosaur Provincial Park: A Spectacular Ancient Ecosystem Revealed |chapter=Ornithischian Dinosaurs |year=2005 |publisher=Indiana University Press |location=Bloomington |pages=312–348 |isbn=0-253-34595-2 }}</ref>
===Dentition and diet===
''Styracosaurus'' were [[herbivore|herbivorous]] dinosaurs; they probably fed mostly on low growth because of the head's position. They may, however, have been able to knock down taller [[plant]]s with their horns, [[beak]], and bulk.<ref>Tait J., and Brown, B. (1928). How the Ceratopsia carried and used their head. ''Transactions of the Royal Society of Canada.'' '''22''':13–23.</ref><ref name ="Dino2"/> The [[jaw]]s were tipped with a deep, narrow beak, believed to have been better at grasping and plucking than biting.<ref name="Ostrom66">{{cite journal|author=Ostrom, J. H.|date=1966| title=Functional morphology and evolution of the ceratopsian dinosaurs| journal=[[Evolution (journal)|Evolution]]| volume=20| issue=3| pages=290–308| doi=10.2307/2406631}}</ref>
Ceratopsid teeth, including those of ''Styracosaurus'', were arranged in groups called batteries. Older teeth on top were continually replaced by the teeth underneath them; this occurred throughout the life of the animal. Unlike [[hadrosaurid]]s, which also had dental batteries, ceratopsid teeth sliced but did not grind.<ref name="Dino2"/> Some scientists have suggested ceratopsids like ''Styracosaurus'' ate [[Arecaceae|palms]] and [[cycad]]s,<ref>Weishampel, D. B. (1984). Evolution of jaw mechanisms in ornithopod dinosaurs. ''Advances in Anatomy, Embryology, and Cell Biology'' '''87''':1–110.</ref> while others have suggested [[fern]]s.<ref>Coe, M. J., Dilcher, D. L., Farlow, J. O., Jarzen, D. M., and Russell, D. A. (1987). Dinosaurs and land plants. In: Friis, E. M., Chaloner, W. G., and Crane, P. R. (eds.) ''The Origins of Angiosperms and their Biological Consequences'' Cambridge University Press, pp. 225–258. ISBN 0-521-32357-6.</ref> Dodson has proposed that Late Cretaceous ceratopsians may have knocked down [[angiosperm]] trees and then sheared off leaves and twigs.<ref name="Dodson3">Dodson, P. (1996). ''The Horned Dinosaurs: A Natural History''. Princeton University Press: Princeton, New Jersey, p. 266. ISBN 0-691-02882-6.</ref>
===Horns and frill===
[[Image:Styracosaurussk.JPG|thumb|''Styracosaurus albertensis'' skull in profile, [[American Museum of Natural History]].]]
The large nasal horns and frills of ''Styracosaurus'' are among the most distinctive facial adornments of all dinosaurs. Their function has been the subject of debate ever since the first horned dinosaurs were discovered.
Early in the 20th century, paleontologist [[R. S. Lull]] put forth the [[hypothesis]] that the frills of ceratopsian dinosaurs acted as anchor points for their jaw muscles.<ref name=RSL08>{{cite journal| last =Lull| first=R.S. | authorlink=R. S. Lull | title =The cranial musculature and the origin of the frill in the ceratopsian dinosaurs| journal =American Journal of Science| volume =4| issue =25| pages =387–399| year=1908 }}</ref> He later noted that for ''Styracosaurus'', the spikes would have given it a formidable appearance.<ref name="RSL33">{{cite journal |last=Lull |first=R.S. |authorlink=R. S. Lull |year=1933 |title=A revision of the Ceratopsia or horned dinosaurs |journal=Memoirs of the Peabody Museum of Natural History |volume=3 |issue=3 |pages=1–175}}</ref> In 1996, Dodson supported the idea of muscle attachments in part and created detailed diagrams of possible muscle attachments in the frills of ''Styracosaurus'' and ''Chasmosaurus'', but did not subscribe to the idea that they completely filled in the fenestrae.<ref name="Dodson4">Dodson, P. (1996). ''The Horned Dinosaurs: A Natural History''. Princeton University Press: Princeton, New Jersey, p. 269. ISBN 0-691-02882-6.</ref> C.A. Forster, however, found no evidence of large muscle attachments on the frill bones.<ref name="Forster90">Forster, C. A. (1990). The cranial morphology and systematics of ''Triceratops'', with a preliminary analysis of ceratopsian phylogeny. Ph.D. Dissertation. University of Pennsylvania, Philadelphia. 227 pp. OCLC 61500040 </ref>
It was long believed ceratopsians like ''Styracosaurus'' used their frills and horns in defence against the large predatory dinosaurs of the time. Although pitting, holes, lesions, and other damage on ceratopsid skulls are often attributed to horn damage in combat, a 2006 study found no evidence for horn thrust injuries causing these forms of damage (for example, there is no evidence of infection or healing). Instead, non-pathological bone [[resorption]], or unknown bone diseases, are suggested as causes.<ref name="TF06">Tanke, D. H, and Farke, A. A. (2006). Bone resorption, bone lesions, and extracranial fenestrae in ceratopsid dinosaurs: a preliminary assessment. in: Carpenter, K. (ed.). ''Horns and Beaks: Ceratopsian and Ornithopod Dinosaurs'' Indiana University Press: Bloomington. pp. 319–347. ISBN 0-253-34817-X.</ref>
The large frill on ''Styracosaurus'' and related genera also may have helped to increase body area to [[thermoregulation|regulate body temperature]],<ref>{{cite journal|author=Wheeler, P.E.|date=1978|title=Elaborate CNS cooling structures in large dinosaurs|journal=[[Nature (journal)|Nature]]|issue=275|pages=441–443|doi=10.1038/275441a0|volume=275}}</ref> like the ears of the modern [[elephant]]. A similar theory has been proposed regarding the plates of ''[[Stegosaurus]]'',<ref>{{cite journal|author=Farlow, J. O., Thompson, C. V., and Rosner, D. E.|date=1976| title=Plates of the dinosaur ''Stegosaurus'': Forced convection heat loss fins?| journal=[[Science (magazine)|Science]]| volume=192| pages=1123–1125| doi=10.1126/science.192.4244.1123| pmid=17748675}}</ref> although this use alone would not account for the bizarre and extravagant variation seen in different members of the [[Ceratopsidae]].<ref name="Dino2"/> This observation is highly suggestive of what is now believed to be the primary function, display.
The theory of frill use in sexual display was first proposed in 1961 by Davitashvili. This theory has gained increasing acceptance.<ref name = "Davitashvili61">{{cite book|title=The Theory of sexual selection|year=1961|author=Davitashvili L|pages= 538|publisher=Izdatel'stvo Akademii Nauk SSSR}}</ref><ref name="Forster90"/> Evidence that visual display was important, either in courtship or in other social behavior, can be seen in the fact that horned dinosaurs differ markedly in their adornments, making each species highly distinctive. Also, modern living creatures with such displays of horns and adornments use them in similar behavior.<ref>{{cite journal|author=Farlow, J. O., and Dodson, P.|date=1975|title=The behavioral significance of frill and horn morphology in ceratopsian dinosaurs|journal=[[Evolution (journal)|Evolution]]|volume=29|issue=2|pages=353–361| doi=10.2307/2407222}}</ref>
==In popular culture==
[[Image:Styracosaurus Baltow 20051003 1315.jpg|thumb|left|Model ''Styracosaurus'', Bałtów Jurassic Park, Poland.]]
Because of the distinctive frill and horns of ''Styracosaurus'', depictions of these animals are easily recognizable. The spines, hooks, and horns attached to the head of this dinosaur sparked the imagination of filmmakers during the earliest days of motion pictures, and this has led to its appearance in films ever since. Notable among them are: ''[[The Son of Kong]]'' (1933), where a ''Styracosaurus'' battles the movie's heroes;<ref name="Erickson">{{cite web| last =Erickson| first =G. | authorlink =| coauthors =| title =DVD Savant Review: ''The Son of Kong''| publisher =DVD Talk.com| date =2005| url =http://www.dvdtalk.com/dvdsavant/s1827son.html| accessdate =2007-04-24}}</ref> ''[[The Valley of Gwangi]]'' (1969), where ''Styracosaurus'' is pitted against a carnivorous dinosaur;<ref name="Perez">{{cite web| last =Perez| first =D.| title =The Styracosaurus 1969| publisher =The Seventh Voyage.com| date =2006| url =http://theseventhvoyage.com/Styracosaurus.htm| accessdate =2007-04-23}}</ref> and Disney's [[Computer-generated imagery|CGI]] film ''[[Dinosaur (film)|Dinosaur]]'' (2000), where an [[anthropomorphic]] ''Styracosaurus'' named Eema has a pet ''[[Ankylosaurus]]''.<ref name="Kobak">{{cite web| last =Kobak| first =S.| title =Dinosaur| publisher =Films on Disc|date=2002 |url=http://www.filmsondisc.com/dvdpages/dinosaur_dvd_review.htm| accessdate =2007-04-23}}</ref> The genus also appeared in the novel of ''[[Jurassic Park]]'', in the list of dinosaurs present in the park, but was not seen in the film adaptation.
On the [[television|small screen]], ''Styracosaurus'' has appeared in many cartoons and anime, including ''[[Power Rangers: Dino Thunder]]'' (''[[Bakuryuu Sentai Abaranger]]''), ''[[Dinozaurs]]'', ''[[Dino-Riders]]'', ''[[Dinosaucers]]'',<ref name="Tvcom">{{cite web| last =| first =| authorlink =| coauthors =| title =Dinosaucers Cast and Crew| work =| publisher =TV.com| date =2007| url =http://www.tv.com/dinosaucers/show/9208/cast.html| accessdate =2007-04-28}}</ref> and ''[[Zoids]]''.<ref name="ZT">{{cite web| title =Red Horn| work =Zoids Tribute| publisher =Mopock.com| date =2001| url =http://mopock.com/ZOIDS/photos/RedHorn.html| accessdate =2007-04-28}}</ref> ''Styracosaurus'' has also been featured in various video games, including the popular ''[[Jurassic Park video games|Jurassic Park]]'', ''[[Turok]]'', and ''[[Zoo Tycoon 2: Extinct Animals|Zoo Tycoon]]'' game franchises. It was also a huntable dinosaur in the dinosaur hunting game ''[[Primal Prey]]''.
''Styracosaurus'' has appeared in some dinosaur [[scale model]] lines, such as the [[Carnegie Collection]].
==References==
{{reflist|2}}
==External links==
{{Wikispecies|Styracosaurus}}
{{portalpar|Dinosaurs}}
*[http://www.dinoruss.com/de_4/5a795cb.htm ''Styracosaurus'', from the Dinosaur Encyclopaedia]
{{featured article}}
[[Category:Ceratopsians]]
[[Category:Cretaceous dinosaurs]]
[[Category:Dinosaurs of North America]]
[[ca:Estiracosaure]]
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[[pt:Estiracossauro]]
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