Tricuspisaurus

{{Short description|Extinct genus of reptiles}} {{Automatic taxobox | taxon = Tricuspisaurus | fossil_range = Late Triassic, {{fossilrange|205.6|201.6}} | authority = Robinson, 1957 | type_species = {{extinct}}'''''Tricuspisaurus thomasi''''' | type_species_authority = Robinson, 1957 }}

'''''Tricuspisaurus''''' is an extinct genus of reptile originally described as a trilophosaurid;<ref name="RPL57" /> it was later considered likely to be a procolophonid,<ref name="SO93" /><ref name="FNC97" /><ref name="Hetal06" /> but recent analyses have affirmed the original classification.<ref name=":0">{{Cite journal|last1=Skinner|first1=Matthew|last2=Whiteside|first2=David I.|last3=Benton|first3=Michael J.|date=2020 |title=Late Triassic island dwarfs? Terrestrial tetrapods of the Ruthin fissure (South Wales, UK) including a new genus of procolophonid|url=https://linkinghub.elsevier.com/retrieve/pii/S0016787820300365|journal=Proceedings of the Geologists' Association|language=en|volume=131|issue=5|pages=535–561|doi=10.1016/j.pgeola.2020.04.005|bibcode=2020PrGA..131..535S |s2cid=221878712|url-access=subscription}}</ref> Fossils are known from the Ruthin Quarry in Glamorgan, Wales, one of several Late Triassic to Early Jurassic British fissure deposits. Like some trilophosaurs, it has an edentulous, or toothless beak. ''Tricuspisaurus'' gets its name from its heterodont dentition, which includes ''tricuspid'' teeth, or teeth with three cusps. The type species, ''T. thomasi'', was named in 1957 along with the possible trilophosaur ''Variodens inopinatus'' from Somerset, England.<ref name=RPL57>{{cite journal |last=Robinson |first=P.L. |year=1957 |title=An unusual sauropsid dentition |journal=Zoological Journal of the Linnean Society |volume=43 |issue=291 |pages=283–293 |doi=10.1111/j.1096-3642.1957.tb01554.x}}</ref>

Although originally classified as a trilophosaur, ''Tricuspisaurus'' was reclassified as a procolophonid in 1993 by paleontologists Hans-Dieter Sues and Paul E. Olsen.<ref name=SO93>{{cite journal |last=Sues |first=H.-D. |author2=Olsen, P.E. |year=1993 |title=A new procolophonid and a new tetrapod of uncertain, possibly procolophonian affinities from the Upper Triassic of Virginia |journal=Journal of Vertebrate Paleontology |volume=13 |issue=3 |pages=282–286 |doi=10.1080/02724634.1993.10011510|bibcode=1993JVPal..13..282S }}</ref> This was due to similarities between its tricuspid teeth and those of the newly described procolophonid ''Xenodiphyodon''. Along with ''Tricuspisaurus'', ''Variodens'' and ''Trilophosaurus jacobsi'' were also considered to be procolophonids.<ref name="FNC97">{{cite book|last=Fraser|first=N.C.|title=In the Shadow of the Dinosaurs: Early Mesozoic Tetrapods|publisher=Cambridge University Press|year=1994|isbn=9780521458993|editor1=Fraser, N.C. |editor2=Sues, H.-D. |location=Cambridge and New York|pages=214–225|chapter=Assemblages of small tetrapods from British Late Triassic fissure deposits}}</ref> More recently described cranial material from ''T. jacobsi'' indicates that it is still likely to be a trilophosaur.<ref name=Hetal06>{{cite journal |last=Heckert |first=A.B. |author2=Lucas, S.G. |author3=Rinehart, L.F. |author4=Spielmann, J.A. |author5=Hunt, A.P. |author6= Kahle, R. |year=2006 |title=Revision of the archosauromorph reptile ''Trilophosaurus'', with a description of the first skull of ''Trilophosaurus jacobsi'', from the Upper Triassic Chinle Group, West Texas, USA |journal=Palaeontology |volume=49 |issue=3 |pages=621–640 |doi=10.1111/j.1475-4983.2006.00556.x|bibcode=2006Palgy..49..621H |url=http://libres.uncg.edu/ir/asu/f/Heckert_Andrew_2006_Revision_of_the_Archosauromorph_orig.pdf.X.pdf |doi-access=free }}</ref><ref name=":0" />

==References== {{Reflist}}

Category:Trilophosauridae Category:Late Triassic reptiles of Europe Category:Prehistoric reptile genera