Leptoceratops: Difference between revisions
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==Classification== |
==Classification== |
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[[File:Leptoceratops gracilis skeletal.jpg|thumb|Skeletal reconstruction]] |
[[File:Leptoceratops gracilis skeletal.jpg|thumb|Skeletal reconstruction]] |
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''Leptoceratops'' was first named as a primitive member of [[Ceratopsia]] outside the family [[Ceratopsidae]], with Brown suggesting that it and ''[[Brachyceratops]]'' may form their own family.<ref name="brown1914"/> This was not followed by Hungarian palaeontologist [[Franz Nopcsa]], who instead placed ''Leptoceratops'' within its own subfamily of Ceratopsidae separate from ''Brachyceratops'' but joining ''[[Protoceratops]]'', [[Leptoceratopsinae]].<ref name="nopcsa1923">{{cite journal|last=Nopcsa|first=F.|year=1923|title=Die Familien der Reptilien|journal=Fortschritte der Geologie und Palaeontologie|volume=2|pages=1-210}}</ref><ref name="nopcsa1928">{{cite journal|last=Nopcsa|first=F.|year=1928|title=The genera of reptiles|journal=Palaeobiologica|volume=1|pages=163-188}}</ref><ref name="nopcsa1929">{{cite journal|last=Nopcsa|first=F.|year=1929|title=Dinosaurierreste aus Siebenbürgen V|journal=Geologica Hungarica. Series Palaeontologica|volume=4|pages=1-76}}</ref> A similar classification was supported by American palaeontologist [[Alfred Romer]], who placed ''Leptoceratops'' separately within the new family [[Leptoceratopsidae]] in 1927, which joined Ceratopsidae and [[Protoceratopsidae]] within Ceratopsia.<ref name="romer1927">{{cite journal|last=Romer|first=A.S.|year=1927|title=The pelvic musculature of ornithischian dinosaurs|journal=Acta Zoologica|volume=8|pages=225-275}}</ref> The description of new material of ''Leptoceratops'' was its classification change, with a similarity to ''Protoceratops'' recognized and the two genera, as well as ''Montanoceratops'' after its separation, united within Protoceratopsidae.<ref name="sternberg1951"/><ref name="brown1942"/><ref name="gilmore1939"/> |
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''Leptoceratops'' belonged to the Ceratopsia, a group of herbivorous dinosaurs with [[parrot]]-like beaks that thrived in [[North America]] and [[Asia]] during the Cretaceous Period. Although traditionally allied with the [[Protoceratopsidae]], it is now placed in its own family, [[Leptoceratopsidae]], along with dinosaurs such as ''[[Udanoceratops]]'' and ''[[Prenoceratops]]''. The relationships of Leptoceratops to [[Ceratopsidae|ceratopsids]] are not entirely clear. Although most studies suggest that they lie outside the protoceratopsids and ceratopsids, some studies suggest that they may be allied with Ceratopsidae. The absence of [[premaxilla]]ry teeth is one feature that supports this arrangement.<ref>{{Citation |last=Ott |first=Christopher J. |title=Cranial Anatomy and Biogeography of the First Leptoceratops gracilis (Dinosauria: Ornithischia) Specimens from the Hell Creek Formation, Southeast Montana |url=http://dx.doi.org/10.2307/j.ctt1zxz1md.16 |work=Horns and Beaks |pages=213–234 |publisher=Indiana University Press |doi=10.2307/j.ctt1zxz1md.16 |access-date=2022-07-30}}</ref><ref>{{Cite book |last=Auteur. |first=Royal Tyrrell Museum Ceratopsian Symposium (2007 : Drumheller, Alta.). |url=http://worldcat.org/oclc/758756959 |title=New perspectives on horned dinosaurs the Royal Tyrrell Museum Ceratopsian Symposium |date=2010 |publisher=Indiana University Press |isbn=978-0-253-35358-0 |oclc=758756959}}</ref><ref>{{Citation |title=22. Basal Ceratopsia |date=2019-12-31 |url=http://dx.doi.org/10.1525/9780520941434-028 |work=The Dinosauria, Second Edition |pages=478–493 |publisher=University of California Press |doi=10.1525/9780520941434-028 |isbn=9780520941434 |s2cid=241167251 |access-date=2022-07-30 |last1=Hailu |first1=You |last2=Dodson |first2=Peter }}</ref><ref>{{Cite journal |last1=Campione |first1=Nicolas E. |last2=Holmes |first2=Robert |date=2006-12-11 |title=The anatomy and homologies of the ceratopsid syncervical |url=http://dx.doi.org/10.1671/0272-4634(2006)26[1014:taahot]2.0.co;2 |journal=Journal of Vertebrate Paleontology |volume=26 |issue=4 |pages=1014–1017 |doi=10.1671/0272-4634(2006)26[1014:taahot]2.0.co;2 |s2cid=86242702 |issn=0272-4634}}</ref> |
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Recognition that ''Leptoceratops'' and other early ceratopsians were not all united within Protoceratopsidae began with the descriptions of new genera from Asia since 1975 and the introduction of [[phylogenetics]] to ceratopsian classification.<ref name="makovicky2002">{{cite journal|last=Makovicky|first=P.J.|year=2002|title=Taxonomic revision and phylogenetic relationships of basal Neoceratopsia (Dinosauria: Ornithischia)|journal=Unpublished dissertation, Columbia University|pages=1-279}}</ref> American palaeontologist [[Paul C. Sereno]] suggested in 1986 that Protoceratopsidae as traditionally used is [[paraphyletic]], instead forming a successive acquisition of features closer to Ceratopsidae.<ref name="sereno1986">{{cite journal |last1=Sereno |first1=P.C. |title=Phylogeny of the Bird-Hipped Dinosaurs (Ornithischia) |journal=National Geographic Research |date=1986 |volume=2 |issue=2 |pages=234–256}}</ref> This was supported by multiple phylogenetic analyses, where ''Leptoceratops'' was either unrelated to other forms,<ref name="zhao1999">{{cite journal|last=Zhao|first=X.|last2=Cheng|first2=Z.|last3=Xu|first3=X.|year=1999 |title=The earliest ceratopsian from the Tuchengzi Formation of Liaoning, China|journal=Journal of Vertebrate Paleontology|volume=19|issue=4|pages=681–691|doi=10.1080/02724634.1999.10011181}}</ref> within Protoceratopsidae,<ref name="chinnery1998">{{cite journal|last=Chinnery|first=B.J.|last2=Weishampel|first2=D.B.|year=1998|title=''Montanoceratops cerorhynchus'' (Dinosauria: Ceratopsia) and relationships among basal neoceratopsians|journal=Journal of Vertebrate Paleontology|volume=18|issue=3|pages=569-585|doi=10.1080/02724634.1998.10011085}}</ref> or outside Protoceratopsidae but forming a clade with taxa like ''Montanoceratops'', ''[[Udanoceratops]]'', or ''[[Asiaceratops]]''.<ref name="sereno2000">{{cite book|last=Sereno|first=P.C.|year=2000|chapter=The fossil record, systematics and evolution of pachycephalosaurs and ceratopsians from Asia|editor-last=Benton|editor-first=M.J.|editor2-last=Shiskin|editor2-first=M.A.|editor3-last=Unwin|editor3-first=D.M.|editor4-last=Kurochkin|editor4-first=E.N.|title=The Age of Dinosaurs in Russia and Mongolia|publisher=Cambridge University Press|pages=480-516|isbn=0-521-55476-4}}</ref><ref name="makovicky2001">{{cite book|last=Makovicky|first=P.J.|chapter=A ''Montanoceratops cerorhynchus'' (Dinosauria: Ceratopsia) Braincase from the Horseshoe Canyon Formation of Alberta|editor-last=Tanke|editor-first=D.H.|editor2-last=Carpenter|editor2-first=K.|title=Mesozoic Vertebrate Life: New Research Inspired by the Paleontology of Philip J. Currie|publisher=Indiana University Press|pages=243-262|isbn=0-253-33907-3}}</ref> The latter hypothesis gained support as studies progressed, with the name Leptoceratopsidae adopted for the group and its taxonomic content expanding to include a diverse variety of Late Cretaceous early ceratopsians, including both existing and newly described genera.<ref name="chinnery2007"/><ref name="ryan2012"/><ref name="makovicky2002"/><ref name="xu2002">{{cite journal|last=Xu|first=X.|last2=Makovicky|first2=P.J.|last3=Wang|first3=X.|last4=Norell|first4=M.A.|last5=You|first5=H.|year=2002|title=A ceratopsian dinosaur from China and the early evolution of Ceratopsia|journal=Nature|volume=416|pages=314–317|doi=10.1038/416314a}}</reF><ref name="you2003">{{cite journal|last1=You|first1=H.|last2=Dodson|first2=P.|year=2003|title=Redescription of neoceratopsian dinosaur ''Archaeoceratops'' and early evolution of Neoceratopsia|journal=Acta Palaeontologica Polonica|volume=48|issue=2|pages=261–272}}</ref><ref name="xu2010">{{cite journal|last=Xu|first=X.|last2=Wang|first2=K. |last2=Zhao|first3=X.|last4=Sullivan|first4=C.|last5=Chen|first5=S.|year=2010|title=A New Leptoceratopsid (Ornithischia: Ceratopsia) from the Upper Cretaceous of Shandong, China and Its Implications for Neoceratopsian Evolution |journal=PLoS ONE |volume=5 |issue=11 |pages=e13835 |doi=10.1371/journal.pone.0013835}}</ref> |
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[[File:Ferrisaurus model front.jpg|thumb|upright|Life-sized model of leptoceratopsid ''[[Ferrisaurus]]'']] |
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All previously published neoceratopsian phylogenetic analyses were incorporated into the analysis of Eric M. Morschhauser and colleagues in [[2019 in paleontology|2019]], along with all previously published diagnostic species excluding the incomplete juvenile ''[[Archaeoceratops yujingziensis]]'' and the problematic genera ''[[Bainoceratops]]'', ''[[Lamaceratops]]'', ''[[Platyceratops]]'' and ''[[Gobiceratops]]'' that are very closely related to and potentially synonymous with ''[[Bagaceratops]]''. While there were many unresolved areas of the strict consensus, including all of Leptoceratopsidae, a single most parsimonious tree was found that was most consistent with the relative ages of the taxa included, which is shown below, restricted to Leptoceratopsidae.<ref name="Morschhauser 2019">{{cite journal |last1=Morschhauser |first1=E.M. |last2=You |first2=H. |last3=Li |first3=D. |last4=Dodson |first4=P. |year=2019 |title=Phylogenetic history of Auroraceratops rugosus (Ceratopsia: Ornithischia) from the Lower Cretaceous of Gansu Province, China |journal=Journal of Vertebrate Paleontology |volume=38 |issue=Supplement |pages=117–147 |doi=10.1080/02724634.2018.1509866 |s2cid=202867827}}</ref> Further phylogenetic analysis also adding the new leptoceratopsid taxa ''[[Ferrisaurus]]'' and ''[[Gremlin slobodorum]]'' have also been conducted, but the inclusion of these taxa and the fragmentary nature of many early ceratopsians results in there being very little resolution of leptoceratopsid relationships.<ref name="arbour2019">{{cite journal|last1=Arbour|first1=V. M.|last2=Evans|first2=D. C.|date=2019|title=A new leptoceratopsid dinosaur from Maastrichtian-aged deposits of the Sustut Basin, northern British Columbia, Canada|journal=PeerJ|volume=7|pages=e7926|doi=10.7717/peerj.7926}}</ref><ref name="ryan2023">{{cite book |last1=Ryan |first1=M.J. |last2=Micucci |first2=L. |last3=Rizo |first3=H. |last4=Sullivan |first4=C. |last5=Lee |first5=Y.-N. |last6=Evans |first6=D.C. |year=2023 |chapter=A New Late Cretaceous leptoceratopsid (Dinosauria: Ceratopsia) from the Oldman Formation (Campanian) of Alberta, Canada |editor-last1=Lee |editor-first1=Y.-N. |title=Windows into Sauropsid and Synapsid Evolution: Essays in Honor of Prof. Louis L. Jacobs |publisher=Dinosaur Science Center Press |isbn=978-89-5708-358-1 |pages=151–165}}</ref> |
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{{clade| style=font-size:85%; line-height:85%; |
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|label1=[[Leptoceratopsidae]] |
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|1={{clade |
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|1=''[[Helioceratops brachygnathus]]'' |
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|2={{clade |
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|1='''''Leptoceratops gracilis''''' |
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|2={{clade |
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|1={{clade |
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|1=''[[Ischioceratops zhuchengensis]]'' |
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|2={{clade |
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|1=''[[Prenoceratops pieganensis]]'' |
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|2={{clade |
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|1=''[[Udanoceratops tchizhovi]]'' |
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|2=''[[Zhuchengceratops inexpectus]]'' }} }} }} |
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|2={{clade |
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|1=''[[Koreaceratops hwaseongensis]]'' |
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|2={{clade |
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|1=''[[Montanoceratops cerorhynchus]]'' |
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|2={{clade |
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|1=''[[Cerasinops hodgskissi]]'' |
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|2={{clade |
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|1=''[[Gryphoceratops morrisoni]]'' |
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|2=''[[Unescoceratops kopelhusae]]'' }} }} }} }} }} }} }} }} |
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==Biology== |
==Biology== |
Revision as of 20:39, 15 August 2024
Leptoceratops Temporal range: Late Cretaceous (Maastrichtian),
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Fossils CMN 8888 and CMN 8887 at the Canadian Museum of Nature, Ottawa | |
Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Clade: | Dinosauria |
Clade: | †Ornithischia |
Clade: | †Neornithischia |
Clade: | †Ceratopsia |
Family: | †Leptoceratopsidae |
Genus: | †Leptoceratops Brown, 1914[1] |
Species: | †L. gracilis
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Binomial name | |
†Leptoceratops gracilis Brown, 1914[1]
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Leptoceratops (meaning 'Thin-horned face' and derived from Greek lepto-/λεπτο- meaning 'small', 'insignificant', 'slender', 'meagre' or 'lean', kerat-/κερατ- meaning 'horn' and -ops/ωψ meaning face),[2] is a genus of leptoceratopsid ceratopsian dinosaurs from the late Cretaceous Period (late Maastrichtian age, 68.8-66 Ma ago[3]) of what is now Western North America. Their skulls have been found in Alberta, Canada and Wyoming.[4]
Discovery and species
![](/upwiki/wikipedia/commons/thumb/d/d3/Leptoceratops_gracilis.jpg/170px-Leptoceratops_gracilis.jpg)
A 1910 expedition by the American Museum of Natural History discovered two specimens of ceratopsian from the Edmontonian age of the Cretaceous along the Red Deer River in Alberta, Canada. The two individuals were found together in a weathered-out cow trail that had destroyed and fragmented some of the material, so that only parts of each skeleton were recovered. The individual preserving a partial skull, collected and accessioned as AMNH specimen 5205, was designated as the holotype of the new taxon Leptoceratops gracilis when it was described in 1914 by American palaeontologist Barnum Brown. AMNH 5205 preserved parts of the skull and jaws, a complete right forelimb, partial hindlimbs, and a series of 24 vertebrae from the tail, as well as two other isolated vertebrae. The second individual, also included under AMNH 5205 despite being slightly larger, also preserved part of the forelimb, as well as four presacral, three sacral, and one caudal vertebrae.[1] The locality that Leptoceratops was first found in, originally described as the Edmonton Formation only, was identified in 1951 by Canadian palaeontologist Charles M. Sternberg as being from the Upper Edmonton member based on location information given, as the exact quarry was lost. Sternberg in the same publication described three skeletons of Leptoceratops from the Edmonton Formation, including one fully complete individual. The specimens were discovered towards the end of the 1947 field season, where Sternberg located a skull, jaw, and most of a skeleton of a first specimen, Canadian Museum of Nature number 8889, student assistant T. P. Chammery found a smaller individual missing most of the head and a partial left hand (CMN 8888), and a third complete individual directly beside the latter was uncovered during excavation (CMN 8887). CMN 8888 and 8887 were 15 m (50 ft) above the base of the Upper Edmonton member, and CMN 8889 was an additional 1.5 m (5 ft) above them.[5] These specimens were complete enough to allow Canadian palaeontologist Dale A. Russell to describe and published a complete skeleton of Leptoceratops based only on the CMN individuals.[6] Newer geology has separated the Edmonton Formation into four formations as the Edmonton Group, with Leptoceratops known from the uppermost named the Scollard Formation, which was deposited at the end of the Maastrichtian. Within the Scollard Formation, Leptoceratops was known in 2013 from nine specimens found in the lower portion, with an estimated range of 65.5-66.1 million years old (0.5 my older with recalibration).[7] Along with the described types and plesiotypes, known Leptoceratops specimens from the Scollard also includes the partial skeletons Royal Tyrrell Museum of Palaeontology 93.95.1 and 95.86.1.[8]
Brown collected additional remains referred to Leptoceratops in 1916 from the St. Mary River Formation of Montana, AMNH 5464. This specimen, including a very good skeleton and a fragmentary skull, was prepared in 1918 at the AMNH and then mounted in 1935 to be put on display, with the fragmentary skull being completely modelled out of plaster for the mount. Differences in the skull from the first Leptoceratops specimens lead Brown and Erich M. Schlaijker to describe the specimen in 1942 as a new species, Leptoceratops cerorhynchus. The description of the material alongside the anatomy of the other specimens known lead to Brown and Schlaijker concluding that Leptoceratops was a very close relative of Protoceratops that together should be united within Protoceratopsidae.[9] Comparisons between the St. Mary River specimen and the skeletons collected by Sternberg in Alberta showed that L. cerorhynchus should be given its own genus separate from Leptoceratops, which Sternberg named Montanoceratops in 1951.[5]
![](/upwiki/wikipedia/commons/thumb/3/33/Leptoceratops_skull_Royal_Tyrrell.jpg/220px-Leptoceratops_skull_Royal_Tyrrell.jpg)
American palaeontologist Charles W. Gilmore led three expeditions of the US Geological Survey to the Two Medicine Formation of Montana in 1913, 1928 and 1935, discovering two specimens in the third expedition he described as Leptoceratops. The material, fragmentary but showing clear similarities to the earlier-known remains, also included a complete foot for the first time, along with other materials that supplemented the known anatomical regions. The separate stratigraphic position from both the Alberta and St. Mary River material suggested that Gilmore's specimens, United States National Museum numbers 13863 and 13864, could belong to a distinct species, but the fragmentary nature meant he did not give it a name and left it as indeterminate.[10] These specimens were later removed from Leptoceratops by Sternberg in 1951,[5] and then later referred to its close relative Cerasinops when it was named in 2007 by American palaeontologists Brenda J. Chinnery and John R. Horner for an 80% complete skeleton also found in the Two Medicine Formation.[11]
A Leptoceratops locality was found in 1962 within the Lance Formation of Wyoming by Michael Ramus, where a single individual was collected, Princeton University number 18133. This specimen preserves a nearly complete hindlimb, pelvis, and tail alongside some isolated teeth. Described in 1978 by American palaeontologist John Ostrom, the skeleton is extremely similar to the material assigned to Leptoceratops from Alberta, while also displaying differences to both Montanoceratops and other former Leptoceratops material from Montana. An isolated tooth from the Pinyon Conglomerate of Teton County, Wyoming was also referred to Leptoceratops, but not L. gracilis, by Ostrom.[12]
Leptoceratops was first found in the Hell Creek Formation of Montana, equivalent in age to the Scollard and Lance Formations of Alberta and Wyoming, in 1992 with the discovery of a partial rear skull by Brig Konecke. The skull, University of Wisconsin-Madison Geology Museum number 200, was prepared in 1998 to show the first complete unfused braincase to be described. An isolated tooth, UWGM-201, was also found. UWGM-200 was found within a 1 m (3.3 ft) cross-bedded sandstone containing unionid bivalve shells from the upper Hell Creek, and UWGM-201 was found 75 m (246 ft) below the K-T boundary in the middle Hell Creek.[13]
An isolated dentary of a protoceratopsian, TMP 95.12.6, was found in 1995 by Canadian palaeontologist Philip J. Currie in the middle Dinosaur Park Formation of Alberta, which is middle Campanian in age. It was first described as Leptoceratops sp. by Michael J. Ryan and Currie in 1998 despite being substantially older than other Leptoceratops material then known, as the only other North American protoceratopsian named, Montanoceratops, showed clear differences in anatomy from the Dinosaur Park specimen.[8] Additional descriptions of other new leptoceratopsids following the description of the specimen led Ryan, Currie and colleagues to redescribe TMP 95.12.6 in 2012 as the new taxon Unescoceratops.[14]
Description
![](/upwiki/wikipedia/commons/thumb/a/a4/Leptoceratops_BW.jpg/220px-Leptoceratops_BW.jpg)
Leptoceratops could probably stand and run on their hind legs: analysis of forelimb function indicates that even though they could not pronate their hands, they could walk on four legs.[15] Paul proposed that Leptoceratops was around 2 m (6.6 ft) long and could have weighed 100 kg (220 lb),[16] but Tereschenko proposed a maximum length of 3–4 m (9.8–13.1 ft).[17]
Classification
![](/upwiki/wikipedia/commons/thumb/6/65/Leptoceratops_gracilis_skeletal.jpg/220px-Leptoceratops_gracilis_skeletal.jpg)
Leptoceratops was first named as a primitive member of Ceratopsia outside the family Ceratopsidae, with Brown suggesting that it and Brachyceratops may form their own family.[1] This was not followed by Hungarian palaeontologist Franz Nopcsa, who instead placed Leptoceratops within its own subfamily of Ceratopsidae separate from Brachyceratops but joining Protoceratops, Leptoceratopsinae.[18][19][20] A similar classification was supported by American palaeontologist Alfred Romer, who placed Leptoceratops separately within the new family Leptoceratopsidae in 1927, which joined Ceratopsidae and Protoceratopsidae within Ceratopsia.[21] The description of new material of Leptoceratops was its classification change, with a similarity to Protoceratops recognized and the two genera, as well as Montanoceratops after its separation, united within Protoceratopsidae.[5][9][10]
Recognition that Leptoceratops and other early ceratopsians were not all united within Protoceratopsidae began with the descriptions of new genera from Asia since 1975 and the introduction of phylogenetics to ceratopsian classification.[22] American palaeontologist Paul C. Sereno suggested in 1986 that Protoceratopsidae as traditionally used is paraphyletic, instead forming a successive acquisition of features closer to Ceratopsidae.[23] This was supported by multiple phylogenetic analyses, where Leptoceratops was either unrelated to other forms,[24] within Protoceratopsidae,[25] or outside Protoceratopsidae but forming a clade with taxa like Montanoceratops, Udanoceratops, or Asiaceratops.[26][27] The latter hypothesis gained support as studies progressed, with the name Leptoceratopsidae adopted for the group and its taxonomic content expanding to include a diverse variety of Late Cretaceous early ceratopsians, including both existing and newly described genera.[11][14][22][28][29][30]
![](/upwiki/wikipedia/commons/thumb/5/5d/Ferrisaurus_model_front.jpg/170px-Ferrisaurus_model_front.jpg)
All previously published neoceratopsian phylogenetic analyses were incorporated into the analysis of Eric M. Morschhauser and colleagues in 2019, along with all previously published diagnostic species excluding the incomplete juvenile Archaeoceratops yujingziensis and the problematic genera Bainoceratops, Lamaceratops, Platyceratops and Gobiceratops that are very closely related to and potentially synonymous with Bagaceratops. While there were many unresolved areas of the strict consensus, including all of Leptoceratopsidae, a single most parsimonious tree was found that was most consistent with the relative ages of the taxa included, which is shown below, restricted to Leptoceratopsidae.[31] Further phylogenetic analysis also adding the new leptoceratopsid taxa Ferrisaurus and Gremlin slobodorum have also been conducted, but the inclusion of these taxa and the fragmentary nature of many early ceratopsians results in there being very little resolution of leptoceratopsid relationships.[32][33]
Biology
Behavior
In 2019, fossils from the Hell Creek Formation found three fossil bone beds which revealed that not only was Leptoceratops a social animal, but also raised its young in burrows.[34]
Paleobiology
Leptoceratops, like other ceratopsians, would have been a herbivore. The jaws were relatively short and deep, and the jaw muscles would have inserted over the large parietosquamosal frill, giving Leptoceratops a powerful bite.[35] The teeth are unusual in that the dentary teeth have dual wear facets, with a vertical wear facet where the maxillary teeth sheared past the crown, and a horizontal wear facet where the maxillary teeth crushed against the dentary teeth.[36] This shows that Leptoceratops chewed with a combination of shearing and crushing. Between the shearing/crushing action of the teeth and the powerful jaws, Leptoceratops was probably able to chew extremely tough plant matter.[37] Given its small size and quadrupedal stance, Leptoceratops would have been a low feeder.[38] Flowering plants, also known as angiosperms, were the most diverse plants of the day, although ferns, cycads and conifers may still have been more common in terms of numbers.[39][40] A 2016 study revealed that Leptoceratops was able to chew its food much like several groups of mammals, which meant that it had a diet that consisted of tough, fibrous plant material.[41][42]
References
- ^ a b c d Brown, B. (1914). "Leptoceratops, a new genus of Ceratopsia from the Edmonton Cretaceous of Alberta". Bulletin of the American Museum of Natural History. 33 (36): 567–580.
- ^ Liddell, Henry George and Robert Scott (1980). A Greek-English Lexicon (Abridged ed.). United Kingdom: Oxford University Press. ISBN 0-19-910207-4.
- ^ Holtz, Thomas R. Jr. (2012). Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages (PDF).
- ^ Lyson, Tyler R.; Longrich, Nicholas R. (2010-10-13). "Spatial niche partitioning in dinosaurs from the latest cretaceous (Maastrichtian) of North America". Proceedings of the Royal Society B: Biological Sciences. 278 (1709): 1158–1164. doi:10.1098/rspb.2010.1444. ISSN 0962-8452. PMC 3049066. PMID 20943689.
- ^ a b c d Sternberg, C.M. (1951). "Complete skeleton of Leptoceratops gracilis from the Upper Edmonton member on Red Deer River, Alberta". National Museum of Canada Bulletin. 123: 225–255.
- ^ Russell, D.A. (1969). "A skeletal reconstruction of Leptoceratops gracilis from the upper Edmonton Formation (Cretaceous) of Alberta". Canadian Journal of Earth Sciences. 7: 181–184.
- ^ Eberth, D.A.; Evans, D.C.; Brinkman, D.M.; Therrien, F.; Tanke, D.H.; Russell, L.S. (2013). "Dinosaur biostratigraphy of the Edmonton Group (Upper Cretaceous), Alberta, Canada: evidence for climate influence". Canadian Journal of Earth Sciences. 50 (7): 701–726. doi:10.1139/cjes-2012-0185.
- ^ a b Ryan, M.J.; Currie, P.J. (1998). "First report of protoceratopsians (Neoceratopsia) from the Late Cretaceous Judith River Group, Alberta, Canada". Canadian Journal of Earth Sciences. 35 (7): 820–826. doi:10.1139/e98-033.
- ^ a b Brown, B.; Schlaikjer, E.M. (1942). "The skeleton of Leptoceratops with the description of a new species". American Museum Novitates. 1169: 1–15.
- ^ a b Gilmore, C.W. (1939). "Ceratopsian dinosaurs from the Two Medicine Formation, Upper Cretaceous of Montana". Proceedings of the United States National Museum. 87 (3066): 1–18.
- ^ a b Chinnery, B.J.; Horner, J.R. (2007). "A new neoceratopsian dinosaur linking North American and Asian taxa". Journal of Vertebrate Paleontology. 27 (3): 625–641. doi:10.1671/0272-4634(2007)27[625:ANNDLN]2.0.CO;2.
- ^ Ostrom, J.H. (1978). "Leptoceratops gracilis from the "Lance" Formation of Wyoming". Journal of Paleontology. 52 (3): 697–704.
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Media related to Leptoceratops at Wikimedia Commons
- Timeline of ceratopsian research