Centrosaurinae

{{Short description|Extinct subfamily of dinosaurs}} {{Automatic taxobox | name = Centrosaurines | taxon = Centrosaurinae | fossil_range = Late Cretaceous, {{fossil_range|82|68|ref=<ref name="dalman2021">{{cite journal | last1=Dalman | first1=Sebastian G. | last2=Lucas | first2=Spencer G. | last3=Jasinki | first3=Steven G. | last4=Lichtig | first4=Asher J. | last5=Dodson | first5=Peter | url=https://www.researchgate.net/publication/351466021 | title=The oldest centrosaurine: a new ceratopsid dinosaur (Dinosauria: Ceratopsidae) from the Allison Member of the Menefee Formation (Upper Cretaceous, early Campanian), northwestern New Mexico, USA | journal=PalZ | year=2021 | volume=95 | issue=2 | pages=291–335 | doi=10.1007/s12542-021-00555-w | bibcode=2021PalZ...95..291D |issn=0031-0220| s2cid=234351502 }}</ref><ref>{{cite journal |last1=Fiorillo |first1=Anthony R. |last2=Tykoski |first2=Ronald S. |name-list-style=and |year=2012 |title=A new Maastrichtian species of the centrosaurine ceratopsid ''Pachyrhinosaurus'' from the North Slope (Prince Creek Formation: Maastrichtian) of Alaska |journal=Acta Palaeontologica Polonica |volume=57 |issue=3 |pages=561–573 |doi=10.4202/app.2011.0033 |doi-access=free}}</ref>}} | image = Paläontologisches Museum in München Monoclonius.JPG | image_caption = ''Centrosaurus "nasicornus"'' skeleton, Palaeontological Museum Munich | authority = Lambe, 1915 | type_species = {{extinct}}''Centrosaurus apertus'' | type_species_authority = Lambe, 1904 | subdivision_ranks = Subgroups | subdivision = *{{extinct}}''Brachyceratops''? *{{extinct}}''Diabloceratops'' *{{extinct}}''Machairoceratops'' *{{extinct}}''Menefeeceratops'' *{{extinct}}''Monoclonius'' *{{extinct}}''Sinoceratops'' *{{extinct}}''Wendiceratops'' *{{extinct}}''Xenoceratops'' *{{extinct}}'''Albertaceratopsini''' Loewen ''et al.'', 2024 **{{extinct}}''Albertaceratops'' **{{extinct}}''Lokiceratops'' **{{extinct}}''Medusaceratops'' *{{extinct}}'''Nasutoceratopsini''' Ryan ''et al.'', 2017 **{{extinct}}''Avaceratops'' **{{extinct}}''Crittendenceratops'' **{{extinct}}''Furcatoceratops'' **{{extinct}}''Nasutoceratops'' **{{extinct}}''Yehuecauhceratops''? *{{extinct}}'''Eucentrosaura''' Chiba ''et al.'', 2018 **{{extinct}}'''Centrosaurini''' Ryan ''et al.'', 2017 ***{{extinct}}''Centrosaurus'' ***{{extinct}}''Coronosaurus'' ***{{extinct}}''Spinops'' ***{{extinct}}''Styracosaurus''? **{{extinct}}'''Pachyrhinosaurini''' Sternberg, 1950 ***{{extinct}}''Einiosaurus'' ***{{extinct}}''Stellasaurus'' ***{{extinct}}''Styracosaurus''? ***{{extinct}}'''Pachyrostra''' Fiorillo & Tykoski, 2012 ****{{extinct}}''Achelousaurus'' ****{{extinct}}''Pachyrhinosaurus'' | synonyms = * Pachyrhinosaurinae Sternberg, 1950 * Monocloniinae Nopcsa, 1923 }}

'''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 Alberta, Montana, and Alaska) but isolated taxa have been found in China and Utah as well.<ref name=":3">{{Cite journal|last1=Sampson|first1=Scott D.|last2=Lund|first2=Eric K.|last3=Loewen|first3=Mark A.|last4=Farke|first4=Andrew A.|last5=Clayton|first5=Katherine E.|date=2013-09-07|title=A remarkable short-snouted horned dinosaur from the Late Cretaceous (late Campanian) of southern Laramidia|journal=Proc. R. Soc. B|language=en|volume=280|issue=1766|article-number=20131186|doi=10.1098/rspb.2013.1186|issn=0962-8452|pmc=3730592|pmid=23864598}}</ref>

Defining features of centrosaurines include a large nasal horn, short supratemporal horns, and an ornamented frill projecting from the back of the skull.<ref name=":0">{{Cite journal|last1=Sampson|first1=Scott D.|last2=Ryan|first2=Michael J.|last3=Tanke|first3=Darren H.|date=1997-11-01|title=Craniofacial ontogeny in centrosaurine dinosaurs (Ornithischia: Ceratopsidae): taxonomic and behavioral implications|journal=Zoological Journal of the Linnean Society|volume=121|issue=3|pages=293–337|doi=10.1111/j.1096-3642.1997.tb00340.x|issn=0024-4082|doi-access=free}}</ref> With the exception of ''Centrosaurus apertus'', all adult centrosaurines have spike-like ornaments midway up the skull.<ref name=":1">{{Cite journal|last=Ryan|first=Michael J.|date=2007-03-01|title=A new basal centrosaurine ceratopsid from the oldman formation, southeastern alberta|journal=Journal of Paleontology|volume=81|issue=2|pages=376–396|doi=10.1666/0022-3360(2007)81[376:ANBCCF]2.0.CO;2|s2cid=130607301 |issn=0022-3360}}</ref> Morphometric analysis shows that centrosaurines differ from other ceratopsian groups in skull, snout, and frill shapes.<ref>{{Cite journal|last1=Maiorino|first1=Leonardo|last2=Farke|first2=Andrew A|last3=Kotsakis|first3=Tassos|last4=Piras|first4=Paolo|date=2017|title=Macroevolutionary patterns in cranial and lower jaw shape of ceratopsian dinosaurs (Dinosauria, Ornithischia): phylogeny, morphological integration, and evolutionary rates|url=http://www.evolutionary-ecology.com/issues/v18/n02/ccar3008.pdf|archive-url=https://web.archive.org/web/20200226224023/http://www.evolutionary-ecology.com/issues/v18/n02/ccar3008.pdf|url-status=usurped|archive-date=February 26, 2020|journal=Evolutionary Ecology Research|volume=18|pages=123–167}}</ref> There is evidence to suggest that male centrosaurines had an extended period of adolescence, and sexual ornamentation did not appear until adulthood.<ref name=":0" />

Centrosaurinae was named by paleontologist Lawrence Lambe in 1915, with ''Centrosaurus'' as the type genus. It is defined in the ''PhyloCode'' as "the largest clade containing ''Centrosaurus apertus'', but not ''Chasmosaurus belli'' and ''Triceratops horridus''.<ref name="madziaea21">{{cite journal |last1=Madzia |first1=D. |last2=Arbour |first2=V.M. |last3=Boyd |first3=C.A. |last4=Farke |first4=A.A. |last5=Cruzado-Caballero |first5=P. |last6=Evans |first6=D.C. |title=The phylogenetic nomenclature of ornithischian dinosaurs |journal=PeerJ |date=2021 |volume=9 |article-number=e12362 |doi=10.7717/peerj.12362|doi-access=free |pmid=34966571 |pmc=8667728 }}</ref> The centrosaurines are further divided into three tribes: the '''Nasutoceratopsini''', the '''Centrosaurini''', and the '''Pachyrhinosaurini''' by Ryan ''et al'' (2016).<ref name=":2">{{Cite journal|last1=Ryan|first1=Michael J.|last2=Holmes|first2=Robert|last3=Mallon|first3=Jordan|last4=Loewen|first4=Mark|last5=Evans|first5=David C.|date=2016-10-27|title=A basal ceratopsid (Centrosaurinae: Nasutoceratopsini) from the Oldman Formation (Campanian) of Alberta, Canada|journal=Canadian Journal of Earth Sciences|volume=54|issue=1|pages=1–14|doi=10.1139/cjes-2016-0110|issn=0008-4077|doi-access=free}}</ref> '''Nasutoceratopsini''' is defined as "the largest clade containing ''Nasutoceratops titusi'', but not ''Centrosaurus apertus''. The remaining two tribes belong to the clade '''Eucentrosaura''', defined as "the smallest clade containing ''Centrosaurus apertus'' and ''Pachyrhinosaurus canadensis''".<ref name="madziaea21"/> '''Centrosaurini''' is defined as "the largest clade containing ''Centrosaurus apertus'', but not ''Pachyrhinosaurus canadensis''" while '''Pachyrhinosaurini''' has the opposite definition consisting of "the largest clade containing ''Pachyrhinosaurus canadensis'', but not ''Centrosaurus apertus''".<ref name="madziaea21"/> Most recently, Mark Loewen and colleagues in 2024 named the tribe '''Albertaceratopsini''' in their description of the new species ''Lokiceratops rangiformis''. It is defined as "all taxa more closely related to ''Albertaceratops nesmoi'' than to ''Centrosaurus apertus''".<ref name="Lokiceratops">{{Cite journal |last1=Loewen |first1=Mark A. |last2=Sertich |first2=Joseph J. W. |last3=Sampson |first3=Scott |author-link3=Scott D. Sampson |last4=O'Connor |first4=Jingmai K. |author-link4=Jingmai O'Connor |last5=Carpenter |first5=Savhannah |last6=Sisson |first6=Brock |last7=Øhlenschlæger |first7=Anna |last8=Farke |first8=Andrew A. |last9=Makovicky |first9=Peter J. |last10=Longrich |first10=Nick |last11=Evans |first11=David C. |author-link11=David C. Evans (paleontologist) |date=20 June 2024 |title=''Lokiceratops rangiformis'' gen. et sp. nov. (Ceratopsidae: Centrosaurinae) from the Campanian Judith River Formation of Montana reveals rapid regional radiations and extreme endemism within centrosaurine dinosaurs |journal=PeerJ |language=en |volume=12 |article-number=e17224 |doi=10.7717/peerj.17224 |issn=2167-8359 |doi-access=free|pmid=38912046 |pmc=11193970 }}</ref>

==Classification== The classification of centrosaurines and the relationships among the various species is complicated by a wide degree of variation between individuals and growth stages. Some features that have traditionally been used to classify these dinosaurs, like the number and arrangement of frill ornaments or spikes, have been discovered to be more variable than previously thought. For example, the cladogram presented below follows a 2016 phylogenetic analysis by Chiba ''et al.'' (2017).<ref>{{Cite journal|author1=Kentaro Chiba |author2=Michael J. Ryan |author3=Federico Fanti |author4=Mark A. Loewen |author5=David C. Evans |year=2018 |title=New material and systematic re-evaluation of ''Medusaceratops lokii'' (Dinosauria, Ceratopsidae) from the Judith River Formation (Campanian, Montana) |journal=Journal of Paleontology |volume=92 |issue= 2|pages= 272–288|doi=10.1017/jpa.2017.62 |bibcode=2018JPal...92..272C |s2cid=134031275 }}</ref> These authors treated the species ''Rubeosaurus ovatus'' as distinct from ''Styracosaurus albertensis'', and recovered several distinct clades within Centrosaurini, which together formed a sister group to the Pachyrhinosaurini:

{{clade| style=font-size:85%; line-height:85% |label1='''Centrosaurinae''' |1={{clade |1={{clade |1=''Diabloceratops eatoni'' |2=''Machairoceratops cronusi'' }} |2={{clade |label1 =Nasutoceratopsini |1={{clade |1=''Avaceratops lammersi'' (ANSP 15800) |2=MOR 692 50px |3=CMN 8804 |4=''Nasutoceratops titusi'' 50px |5=Malta new taxon }} |2={{clade |1=''Xenoceratops foremostensis'' |2={{clade |1={{clade |1=''Sinoceratops zhuchengensis'' |2=''Wendiceratops pinhornensis'' 50px}} |2=''Albertaceratops nesmoi'' 50px |3=''Medusaceratops lokii'' |label4 ='''Eucentrosaura''' |4={{clade |label1 =Centrosaurini |1={{clade |1={{clade |1=''Rubeosaurus ovatus'' |2=''Styracosaurus albertensis'' }} |2={{clade |1=''Coronosaurus brinkmani'' |2={{clade |2=''Spinops sternbergorum'' 50px |1=''Centrosaurus apertus'' }} }} }} |label2 =Pachyrhinosaurini |2={{clade |1=''Einiosaurus procurvicornis'' 50px |label2 =Pachyrostra |2={{clade |1=''Achelousaurus horneri'' |2={{clade |1=''Pachyrhinosaurus canadensis'' 50px |2={{clade |1=''Pachyrhinosaurus lakustai'' |2=''Pachyrhinosaurus perotorum'' }} }} }} }} }} }} }} }} }} }}

However, subsequent studies have cast doubt on the usefulness of minor variations in frill spike arrangement for classifying centrosaurines. In particular, large sample sizes of the species ''Centrosaurus apertus'' and ''Styracosaurus albertensis'' have shown a higher than predicted amount of variation. In 2020, Holmes et al. explored what the effect of recognizing such diversity would have on centrosaur classification. They used the same data as Chiba ''et al.'''s 2017 study, but treated ''Rubeosaurus'' as a synonym of ''Styracosaurus'', dropping it from their taxon list. The resulting cladogram (below) found Centrosaurini as a polytomy, a grouping with no discernable sister group relationships within it. The authors concluded that this meant the variation present within these species made it difficult to find any real resolution among them, and may even provide support for the hypothesis that centrosaurines evolved primarily via anagenesis (a single lineage changing through time) rather than cladogenesis (multiple branching lineages with shared common ancestors).<ref>{{cite journal|vauthors=Holmes RB, Persons WS, Rupal, BS, Qureshi, AJ, Currie PJ|year=2020|title=Morphological variation and asymmetrical development in the skull of ''Styracosaurus albertensis'' | journal=Cretaceous Research|volume=107|article-number=104308|doi=10.1016/j.cretres.2019.104308|bibcode=2020CrRes.10704308H |s2cid=210260909}}</ref>

{{clade| style=font-size:85%; line-height:85% |label1='''Centrosaurinae''' |1={{clade |1={{clade |1='''Nasutoceratopsini''' }} |2={{clade |1=''Coronosaurus brinkmani'' |2=''Centrosaurus apertus'' |3=''Spinops sternbergorum'' 50px |4=''Styracosaurus albertensis'' |label5 ='''Pachyrhinosaurini''' |5={{clade |1=''Einiosaurus procurvicornis'' 50px |label2 =Pachyrostra |2={{clade |1=''Achelousaurus horneri'' |2=''Pachyrhinosaurus'' 50px }} }} }} }} }}

Pachyrhinosaurini was defined in 2012 by Fiorillo & Tykoski. It was defined as all centrosaurine ceratopsids more closely related to ''Pachyrhinosaurus canadensis'' than to ''Centrosaurus apertus''. It was defined during the description of ''Pachyrhinosaurus perotorum'', a species from Alaska.<ref name="fiorillo2001">{{cite journal |last1=Fiorillo |first1=Anthony R. |last2=Gangloff |first2=Roland A. |name-list-style=amp |year=2001 |title=Theropod teeth from the Prince Creek Formation (Cretaceous) of northern Alaska, with speculations on Arctic dinosaur paleoecology |journal=Journal of Vertebrate Paleontology |volume=20 |issue=4 |pages=675–682 |doi=10.1671/0272-4634(2000)020[0675:TTFTPC]2.0.CO;2 |s2cid=130766946}}</ref> The substituent clade Pachyrostra, compromising centrosaurs with bossed instead of horned noses, is defined as "the least inclusive clade including both ''Pachyrhinosaurus canadensis'' and ''Achelousaurus horneri''.<ref name=madzia2021>{{Cite journal |last1=Madzia |first1=Daniel |last2=Arbour |first2=Victoria M. |last3=Boyd |first3=Clint A. |last4=Farke |first4=Andrew A. |last5=Cruzado-Caballero |first5=Penélope |last6=Evans |first6=David C. |date=2021-12-09 |title=The phylogenetic nomenclature of ornithischian dinosaurs |journal=PeerJ |language=en |volume=9 |article-number=e12362 |doi=10.7717/peerj.12362 |issn=2167-8359 |pmc=8667728 |pmid=34966571 |doi-access=free }}</ref>

==Biogeography== [[File:Nasutoceratopsini de Aldama Chihuahua.jpg|200px|thumb|Skull of an unnamed nasutoceratopsin exhibited in the Museo del Mamuth in Chihuahua City, from the municipality of Aldama]] Centrosaurine fossils have mostly been found in Western North America (Alberta, Montana, and Alaska).<ref name=":3" /> In the United States, two taxa, ''Diabloceratops and Machairoceratops'', have been found as far south as Utah. ''Yehuecauhceratops,'' a nasutoceratopsin from Coahuila, Mexico, is the southernmost occurrence of a centrosaurine in North America.<ref name=":3" /> No centrosaurine fossils had been uncovered outside Western North America until the 2010 discovery of ''Sinoceratops'' in the Shandong Province of China.<ref name=":4" /> However, some authors question the placement of ''Sinoceratops'' within Centrosaurinae. All other Late Cretaceous dinosaur groups from North America have also been found in Asia, so the initial absence of Asian centrosaurines had been surprising.<ref name=":4" /> The current evidence suggests that Centrosaurinae originated in Laramidia 90-80 million years ago,<ref name=":3" /> with the discovery of the oldest known centrosaurine, ''Menefeeceratops'' further proving this.<ref>{{cite book |last1=Williamson |first1=TE |year=1997 |chapter=A new Late Cretaceous (early Campanian) vertebrate fauna from the Allison Member, Menefee Formation, San Juan Basin, New Mexico |editor-last1=Lucas |editor-first1=SG |editor-last2=Estep |editor-first2=JW |editor-last3=Williamson |editor-first3=TE |editor-last4=Morgan |editor-first4=GS |title=New Mexico's Fossil Record 1. Albuquerque: New Mexico Museum of Natural History and Science Bulletin 11 |pages=51–59 |chapter-url=https://books.google.com/books?id=YWcdCgAAQBAJ&q=Williamson%2C+TE+%281997%29.++A+new+Late+Cretaceous+%28early+Campanian%29+vertebrate+fauna+from+the+Allison+Member%2C+Menefee+Formation%2C+San+Juan+Basin%2C+New+Mexico&pg=PA51 |access-date=21 April 2021}}.</ref><ref name="dalman2021"/> This means ''Sinoceratops'' would have migrated to China from North America.<ref name=":2" /> Some hypothesize that centrosaurines originated in southern Laramidia and later radiated north.<ref>{{Cite journal|last1=Lund|first1=Eric K.|last2=O'Connor|first2=Patrick M.|last3=Loewen|first3=Mark A.|last4=Jinnah|first4=Zubair A.|date=2016-05-18|title=A New Centrosaurine Ceratopsid, Machairoceratops cronusi gen et sp. nov., from the Upper Sand Member of the Wahweap Formation (Middle Campanian), Southern Utah|journal=PLOS ONE|volume=11|issue=5|article-number=e0154403|doi=10.1371/journal.pone.0154403|issn=1932-6203|pmc=4871575|pmid=27192148|bibcode=2016PLoSO..1154403L|doi-access=free}}</ref>

==Body size== Compared to their sister group, Chasmosaurinae, centrosaurines are relatively small. The primitive ''Sinoceratops'' is an exception, with an estimated skull length of {{Convert|180|cm|in}}.<ref name=":4">{{Cite journal|last1=Xu|first1=Xing|last2=Wang|first2=KeBai|last3=Zhao|first3=XiJin|last4=Li|first4=DunJing|date=2010-06-01|title=First ceratopsid dinosaur from China and its biogeographical implications|journal=Chinese Science Bulletin|language=en|volume=55|issue=16|pages=1631–1635|doi=10.1007/s11434-009-3614-5|bibcode=2010ChSBu..55.1631X|s2cid=128972108|issn=1001-6538}}</ref> By contrast, the skull length of ''Albertoceratops'' was more typical for this group at only {{Convert|67|cm|in}}.<ref name=":1" /> In general, centrosaurines were about the size of a rhinoceros with body lengths ranging from {{Convert|2.5-8|m|ft}}.<ref>{{Cite book|title=Dinosaurs: the most complete, up-to-date encyclopedia for dinosaur lovers of all ages|last=Rey|first=Luis V.|date=2007|publisher=Random House|isbn=978-0-375-82419-7|oclc=930042495|url-access=registration|url=https://archive.org/details/dinosaursmostcom00holt}}</ref>

==Reproduction== [[File:Pachyrhinosaurus perotorum ontogeny with updated epiparietals.png|thumb|Hypothesised ontogenic development of ''Pachyrhinosaurus perotorum'']] Possible neonate sized centrosaurine fossils have been documented in the scientific literature.<ref name="hadro-egg-intro-207" /> Research indicates that centrosaurines did not achieve fully developed mating signals until nearly fully grown.<ref name="socioecology-retarded-270" /><ref name=":0" /> Scott D. Sampson found commonality between the slow growth of mating signals in centrosaurines and the extended adolescence of animals whose social structures are ranked hierarchies founded on age-related differences.<ref name="socioecology-retarded-270" /> In these sorts of groups, young males are typically sexually mature for several years before actually beginning to breed, when their mating signals are most fully developed.<ref name="socioecology-correlates-265" /> Females, by contrast, do not have such an extended adolescence.<ref name="socioecology-correlates-265" />

==See also== {{Portal|Dinosaurs}} * Timeline of ceratopsian research

==Footnotes== {{Reflist|3|refs=  <ref name="hadro-egg-intro-207">"Abstract," Tanke and Brett-Surman (2001). Page 207.</ref> <ref name="socioecology-retarded-270">"Retarded Growth of Mating Signals," Sampson (2001); page 270.</ref> <ref name="socioecology-correlates-265">"Sociological Correlates in Extant Vertebrates," Sampson (2001); page 265.</ref> }}

==References== * {{cite journal | last1 = Sampson | first1 = S. D. | year = 1995b | title = Two new horned dinosaurs from the Upper Cretaceous Two Medicine Formation of Montana; with a phylogenetic analysis of the Centrosaurinae (Ornithischia: Ceratopsidae) | journal = Journal of Vertebrate Paleontology | volume = 15 | issue = 4| pages = 743–760 | doi=10.1080/02724634.1995.10011259| bibcode = 1995JVPal..15..743S }} * Sampson, S. D., 2001, Speculations on the socioecology of Ceratopsid dinosaurs (Orinthischia: Neoceratopsia): In: Mesozoic Vertebrate Life, edited by Tanke, D. H., and Carpenter, K., Indiana University Press, pp. 263–276. * Tanke, D.H. and Brett-Surman, M.K. 2001. Evidence of Hatchling and Nestling-Size Hadrosaurs (Reptilia:Ornithischia) from Dinosaur Provincial Park (Dinosaur Park Formation: Campanian), Alberta, Canada. pp. 206–218. In: Mesozoic Vertebrate Life—New Research Inspired by the Paleontology of Philip J. Currie. Edited by D.H. Tanke and K. Carpenter. Indiana University Press: Bloomington. xviii + 577 pp.

Category:Centrosaurinae Category:Dinosaur subfamilies Category:Late Cretaceous dinosaurs