{{Short description|Extinct family of reptiles}} {{Automatic taxobox | fossil_range = Triassic, <br>{{fossil range|Anisian|Rhaetian}}<ref>{{Cite journal|author1=David I. Whiteside, FLS |author2=Christopher J. Duffin, FLS |year=2017 |title=Late Triassic terrestrial microvertebrates from Charles Moore's ''"Microlestes"'' quarry, Holwell, Somerset, UK |journal=Zoological Journal of the Linnean Society |volume=179 |issue=3 |pages=677–705 |doi=10.1111/zoj.12458 |doi-access=free }}</ref> | image = Trilophosaurus buettneri - AMNH - DSC06265.JPG | image_upright = 1.15 | image_caption = Mounted skeleton of ''Trilophosaurus'' | parent_authority = Romer, 1956 | taxon = Trilophosauridae | authority = Gregory, 1945 | subdivision_ranks = Genera | subdivision = * {{extinct}}''Anisodontosaurus''? * {{extinct}}''Coelodontognathus''? * {{extinct}}''Doniceps''? * {{extinct}}''Rutiotomodon'' * {{extinct}}''Spinosuchus'' * {{extinct}}''Teraterpeton'' * {{extinct}}''Tricuspisaurus'' * {{extinct}}''Trilophosaurus'' * {{extinct}}''Variodens'' * {{extinct}}''Vitalia''? | synonyms = Teraterpetidae <small>Sues, 2003</small> }}
'''Trilophosaurs''' are lizard-like Triassic allokotosaur reptiles related to the archosaurs. The best known genus is ''Trilophosaurus'', a herbivore up to {{convert|2.5|m|ft|abbr=off}} long. It had a short, unusually heavily built skull, equipped with massive, broad flattened cheek teeth with sharp shearing surfaces for cutting up tough plant material. Teeth are absent from the premaxilla and front of the lower jaw, which in life were probably equipped with a horny beak. thumb|left|Size comparison of ''Trilophosaurus buettneri'' The skull is also unusual in that the lower temporal opening is missing, giving the appearance of a euryapsid skull, and originally the Trilophosaurs were classified with placodonts and sauropterygia. Carroll (1988) suggests that the lower opening may have been lost to strengthen the skull.<ref>{{cite book|author-link=Robert L. Carroll|last=Carroll|first=R. L.|title=Vertebrate Paleontology and Evolution|url=https://archive.org/details/vertebratepaleon0000carr|url-access=registration|place=New York|publisher=W.H. Freeman & Co.|year=1988|page=[https://archive.org/details/vertebratepaleon0000carr/page/266 266]}}</ref>
Trilophosaurs are so far known only from the Late Triassic of North America and Europe.
Below is a cladogram showing the phylogenetic relationships of Trilophosauridae within Archosauromorpha as recovered by Nesbitt ''et al.'' (2015).<ref name="nesbitt2015">{{cite journal |last1=Nesbitt |first1=S.J. |last2=Flynn |first2=J.J. |last3=Pritchard |first3=A.C. |last4=Parrish |first4=M.J. |last5=Ranivoharimanana |first5=L. |last6=Wyss |first6=A.R. |title=Postcranial osteology of Azendohsaurus madagaskarensis (?Middle to Upper Triassic, Isalo Group, Madagascar) and its systematic position among stem archosaur reptiles |journal=Bulletin of the American Museum of Natural History |issue=398 |year=2015 |doi=10.5531/sd.sp.15 |pages=1–126 |issn=0003-0090 |hdl=2246/6624 |hdl-access=free }}</ref>
{{clade| style=font-size:80%;line-height:80% |label1=Sauria |1={{clade |1='''Lepidosauromorpha''' |label2=Archosauromorpha |2={{clade |1=''Protorosaurus speneri'' |2={{clade |label1=Tanystropheidae |1={{clade |1=''Macrocnemus bassanii'' |2={{clade |1={{clade |1=''Langobardisaurus pandolfii'' |2=''Tanytrachelos ahynis''}} |2={{clade |1=''Amotosaurus rotfeldensis'' |2=''Tanystropheus longobardicus''}} }} }} |label2=Crocopoda <small>sensu Ezcurra (2016)</small> |2={{clade |label1=Rhynchosauria |1={{clade |1=''Mesosuchus browni'' |2={{clade |1=''Rhynchosaurus articeps'' |2=''Teyumbaita sulcognathus''}} }} |2={{clade |label2=Allokotosauria |2={{clade |1=''Pamelaria dolichotrachela'' |2={{clade |label1=Azendohsauridae |1={{clade |1=''Azendohsaurus laaroussii'' |2=''Azendohsaurus madagaskarensis''}} |label2='''Trilophosauridae''' |2={{clade |1=''Teraterpeton hrynewichorum'' |2={{clade |1=''Trilophosaurus buettneri'' |label2=''Spinosuchus caseanus'' |2={{clade |1=''"Trilophosaurus" jacobsi'' |2=''Spinosuchus caseanus'' holotype}} }} }} }} }} |1={{clade |1='''Archosauriformes''' |2=''Prolacerta broomi''}} }} }} }} }} }} }}
==References== {{Reflist}}
== Sources == * Benton, M. J. (2000), ''Vertebrate Paleontology'', 2nd ed. Blackwell Science Ltd, p. 144
== External links == * [https://web.archive.org/web/20060313165417/http://www.palaeos.com/Vertebrates/Units/270Archosauromorpha/270.200.html Archosauromorpha: Rhynchosaurs and ''Trilophosaurus''] at Palaeos * [https://ucmp.berkeley.edu/taxa/verts/archosaurs/trilophosauria.php Trilophosauria. Beaked, lizard-like reptiles]. UC Museum of Paleontology. [https://web.archive.org/web/20190206192559/https://ucmp.berkeley.edu/taxa/verts/archosaurs/trilophosauria.php Archive copy] from 6 February 2019.
{{Allokotosauria|R.}} {{Taxonbar|from=Q133273}}
Category:Trilophosauridae Category:Allokotosauria Category:Prehistoric reptile families Category:Triassic reptiles Category:Anisian first appearances Category:Rhaetian extinctions