{{Short description|Geologic formation in Texas, United States}} {{other uses|Colorado Formation (disambiguation){{!}}Colorado Formation}} {{Infobox rockunit | name = Colorado City Formation | image = | caption = | type = [[Formation (stratigraphy)|Formation]] | age = Late [[Triassic]] | period = Norian | prilithology =[[siltstone]], [[sandstone]] | otherlithology = | namedfor = | namedby = | region = [[Texas]] | country = [[United States]] | coordinates = | unitof = [[Dockum Group]] | subunits = | underlies = possibly [[Cooper Canyon Formation]] | overlies = [[Camp Springs Formation]] | thickness = | extent = | area = | map = | map_caption = }}

The '''Colorado City Formation''' is a [[Late Triassic]] [[Formation (geology)|geologic formation]] in the [[Dockum Group]] of [[Texas]], United States. It has previously been known as the '''Iatan Member''',<ref name=":10">{{Cite journal |last1=Lucas |first1=Spencer G. |last2=Hunt |first2=Adrian P. |last3=Kahle |first3=Robert |date=1993 |title=LATE TRIASSIC VERTEBRATES FROM THE DOCKUM FORMATION NEAR OTIS CHALK, HOWARD COUNTY, TEXAS |url=https://www.researchgate.net/publication/267427539 |journal=New Mexico Geological Society Guidebook, 44th Field Conference, Carlsbad Region |pages=237–244}}</ref> '''Colorado City Member'''<ref>{{Cite journal |last1=Lucas |first1=Spencer G. |last2=Anderson |first2=Orin J. |last3=Hunt |first3=Adrian P. |date=1994 |title=Triassic stratigraphy and correlations, southern High Plains of New Mexico—Texas |url=https://geoinfo.nmt.edu/publications/monographs/bulletins/downloads/150/B150.pdf#page=105 |journal=New Mexico Bureau of Mines & Mineral Resources Bulletin |volume=150 |pages=105–126}}</ref><ref name=":3">{{Cite journal |last1=Heckert |first1=Andrew B. |last2=Lucas |first2=Spencer G. |date=1999-03-15 |title=A new aetosaur (Reptilia: Archosauria) from the Upper Triassic of Texas and the phylogeny of aetosaurs |url=http://www.tandfonline.com/doi/abs/10.1080/02724634.1999.10011122 |journal=Journal of Vertebrate Paleontology |language=en |volume=19 |issue=1 |pages=50–68 |doi=10.1080/02724634.1999.10011122 |issn=0272-4634|url-access=subscription }}</ref> or '''<nowiki/>'Pre-Tecovas Horizon'<ref name=":0">{{Cite journal |last1=Long |first1=Robert A. |last2=Murry |first2=Phillip A. |date=1995 |title=Late Triassic (Carnian and Norian) Tetrapods from the Southwestern United States |url=https://books.google.com/books?id=uYcMNAAACAAJ |journal=New Mexico Museum of Natural History and Science Bulletin |volume=4 |pages=}}</ref>''' (as it is assumed to be older than the [[Tecovas Formation]]).

The Colorado City Formation is mostly restricted to [[Howard County, Texas|Howard]] and [[Borden County, Texas|Borden]] counties. The formation hosts the '''Otis Chalk''' fossil sites, named after a [[ghost town]] in Howard County. Despite their importance, the Otis Chalk localities have been difficult to resolve in the [[stratigraphy]] of Triassic Texas.<ref>{{Cite journal |last=Lehman |first=Thomas M. |date=1994 |title=The saga of the Dockum Group and the case of the Texas/New Mexico boundary fault |url=https://geoinfo.nmt.edu/publications/monographs/bulletins/downloads/150/B150.pdf#page=37 |journal=New Mexico Bureau of Mines & Mineral Resources Bulletin |volume=150 |pages=37–51}}</ref> They occupy a narrow band of sediments between the slightly older [[Camp Springs Formation]] and much younger Cretaceous deposits.

The first major excavations near Otis Chalk were led by [[UMMP]] paleontologists starting in 1927. Several new phytosaur species were discovered during these digs. [[University of Oklahoma]] paleontologists followed with their own expedition in 1931. The vast majority of fossils collected from the formation were recovered during a 1939–1941 state-sponsored [[Works Progress Administration]] paleontological survey. Several sites southeast of [[Big Spring, Texas|Big Spring]] were particularly productive. Fossils collected by these efforts were stored at the newly opened [[Texas Memorial Museum]] in Austin. Since the 1940s, collection from the Otis Chalk area has been more limited. One notable find is a pond deposit, the Schaeffer Fish Quarry, discovered in 1967 by [[American Museum of Natural History|AMNH]] paleontologist Bobb Schaeffer.<ref name=":0" />

==Biochronological significance== The Otis Chalk localities that are situated in the Colorado City Formation form the basis of the [[Otischalkian]] [[Land Vertebrate Faunachron]] (LVF), which is defined by the first appearance of ''Parasuchus''.<ref>Lucas, S. G., Hunt, A. P., Heckert, A. B., and Spielmann, J. A., (2007) Global Triassic tetrapod biostratigraphy and biochronology: 2007 status: New Mexico Museum of Natural History and Science Bulletin, v. 41 (The Global Triassic), p. 229- 240.</ref>

==Paleobiota== {{Paleobiota-key-compact}}

=== Reptiles ===

==== Archosaurs ==== Other archosaur fossils include remains of an unnamed [[Silesauridae|silesaurid]]<ref>{{Cite journal |last1=Nesbitt |first1=Sterling J. |last2=Sidor |first2=Christian A. |last3=Irmis |first3=Randall B. |last4=Angielczyk |first4=Kenneth D. |last5=Smith |first5=Roger M. H. |last6=Tsuji |first6=Linda A. |date=2010 |title=Ecologically distinct dinosaurian sister group shows early diversification of Ornithodira |url=https://www.nature.com/articles/nature08718 |journal=Nature |language=en |volume=464 |issue=7285 |pages=95–98 |doi=10.1038/nature08718 |pmid=20203608 |s2cid=4344048 |issn=1476-4687|url-access=subscription }}</ref> and a partial femur of a [[Theropoda|theropod]] or [[herrerasauria]]n [[dinosaur]] referable to the ''[[Chindesaurus]]'' + ''[[Tawa hallae|Tawa]]'' clade.<ref name=":22">{{Cite journal |last1=Marsh |first1=Adam D. |last2=Parker |first2=William G. |last3=Langer |first3=Max C. |last4=Nesbitt |first4=Sterling J. |date=2019-05-04 |title=Redescription of the holotype specimen of Chindesaurus bryansmalli Long and Murry, 1995 (Dinosauria, Theropoda), from Petrified Forest National Park, Arizona |url=http://paleolab.com.br/assets/uploads/files/%28103%29_Marsh_et_al._2019.pdf |journal=Journal of Vertebrate Paleontology |volume=39 |issue=3 |article-number=e1645682 |doi=10.1080/02724634.2019.1645682 |issn=0272-4634 |s2cid=202865005}}</ref> {| class="wikitable" width="100%" align="center" |- ! colspan="7" align="center" |'''Archosaurs of the Colorado City Formation''' |- ! Genus / Taxon !Species ! Material !Location ! Notes ! Images |- | style="background:#fbdddb;" |''"[[Chatterjeea]]"<ref name=":0" />'' | style="background:#fbdddb;" |''C. elegans<ref name=":0" />'' | style="background:#fbdddb;" |Vertebrae, hip bones, and [[Femur|femora]]''<ref name=":0" />'' | style="background:#fbdddb;" | * Quarry 3 (TMM 31100)''<ref name=":0" />'' | style="background:#fbdddb;" |Postcranial bones of an unusual bipedal archosaur related to [[Poposauridae|poposaurids]].''<ref name=":0" />'' Later determined to be synonymous with ''[[Shuvosaurus]]'', a [[Shuvosauridae|shuvosaurid]] [[Poposauroidea|poposauroid]] initially misidentified as a theropod dinosaur.<ref name="nesbitt2007">Nesbitt, S. (2007). "The anatomy of ''Effigia okeeffeae'' (Archosauria, Suchia), theropod-like convergence, and the distribution of related taxa." ''Bulletin of the American Museum of Natural History'', '''302''': 84 pp. http://digitallibrary.amnh.org/dspace/handle/2246/5840</ref> | style="background:#fbdddb;" |[[File:Shuvosaurus_BW.jpg|center|150x150px]] |- |''[[Coahomasuchus]]'' |''C. kahleorum<ref name=":3" />'' |Two skeletons, one of which is nearly complete''<ref name=":3" />'' while the other shows adaptations for a carnivorous diet.<ref name=":4">{{Cite journal |last=Parker |first=William G. |date=2016-01-21 |title=Revised phylogenetic analysis of the Aetosauria (Archosauria: Pseudosuchia); assessing the effects of incongruent morphological character sets |journal=PeerJ |language=en |volume=4 |article-number=e1583 |doi=10.7717/peerj.1583 |pmid=26819845 |pmc=4727975 |issn=2167-8359 |doi-access=free }}</ref> | * [[NMMNH]] locality 3357''<ref name=":3" />'' * Quarry 3 (TMM 31100)?<ref name=":4" /> |An [[Aetosaurinae|aetosaurine]] [[aetosaur]] | |- |[[Crocodylomorpha]]<ref name=":1" /> |indet.<ref name=":1" /> |Isolated [[Ilium (bone)|ilium]]<ref name=":1" /> | * Quarry 3 (TMM 31100)<ref name=":1" /> |An unnamed basal crocodylomorph, one of the oldest from North America.<ref name=":1">{{Cite journal |last1=To |first1=Khanh H. T. |last2=Nesbitt |first2=Sterling |last3=Stocker |first3=Michelle R. |date=2021-10-01 |title=An early-diverging crocodylomorph from the early Norian (Late Triassic) of Texas demonstrates a wide distribution of early members across low-latitude Pangea |url=https://www.researchgate.net/publication/361974452 |journal=Journal of Vertebrate Paleontology |language=en |volume=41 |issue=6 |doi=10.1080/02724634.2021.2075752 |s2cid=250540979 |issn=0272-4634}}</ref> | |- |''[[Desmatosuchus]]?'' |''D. spurensis?'' |[[Osteoderm]]s (scutes) and vertebrae<ref name=":0" /> | * "near Otis Chalk"<ref name=":0" /> * Borden County Site 1 (TMM 31213)<ref name=":0" /> |Most Otis Chalk desmatosuchin aetosaur fossils have been referred to ''Longosuchus'' or ''Lucasuchus'', but a few have been referred to ''Desmatosuchus'' (''Episcoposaurus'') ''haplocerus''.<ref name=":0" /> The modern valid combination for this species is ''Desmatosuchus spurensis''.<ref>{{Cite journal |last=Parker |first=William G. |date=2012 |title=Redescription and taxonomic status of specimens of Episcoposaurus and Typothorax, the earliest known aetosaurs (Archosauria: Suchia) from the Upper Triassic of western North America, and the problem of proxy "holotypes" |url=https://www.researchgate.net/publication/258442730 |journal=Earth and Environmental Science Transactions of the Royal Society of Edinburgh |language=en |volume=103 |issue=3–4 |pages=313–338 |doi=10.1017/S1755691013000212 |s2cid=130822568 |issn=1755-6910}}</ref> |[[File:Desmatosuchus_spurensis_flipped.jpg|center|150x150px]] |- |''[[Dromomeron]]'' |''D. gregorii<ref name="SNetal09">{{cite journal |last=Nesbitt |first=Sterling J. |author2=Irmis, Randall B. |author3=Parker, William G. |author4=Smith, Nathan D. |author5=Turner, Alan H. |author6=Rowe, Timothy |year=2009 |title=Hindlimb osteology and distribution of basal dinosauromorphs from the Late Triassic of North America |journal=Journal of Vertebrate Paleontology |volume=29 |issue=2 |pages=498–516 |doi=10.1671/039.029.0218 |s2cid=34205449}}</ref>'' |Hindlimb bones (femora and tibiae)''<ref name="SNetal09" />'' | * Quarry 3 (TMM 31100)''<ref name="SNetal09" />'' |A [[Lagerpetidae|lagerpetid]] [[avemetatarsalia]]n |[[File:Dromomeron_BW.jpg|center|150x150px]] |- |''[[Lepidus praecisio|Lepidus]]<ref name="NE15">{{cite journal |last1=Nesbitt |first1=Sterling J. |author-link1=Sterling Nesbitt |last2=Ezcurra |first2=Martin D. |date=13 July 2015 |title=The early fossil record of dinosaurs in North America: A new neotheropod from the base of the Upper Triassic Dockum Group of Texas |url=http://www.app.pan.pl/archive/published/app60/app001432014.pdf |journal=[[Acta Palaeontologica Polonica]] |volume=60 |doi=10.4202/app.00143.2014 |doi-access=free}}</ref>'' |''L. praecisio<ref name="NE15" />'' |Partial hindlimb (tibia, fibula, astragalus)<ref name="NE15" /> | * near "site 7" (TMM 41936)<ref name="NE15" /> |A possible [[Coelophysidae|coelophysid]] [[Theropoda|theropod]], potentially the oldest dinosaur from North America.<ref name="NE15" /> |[[File:Lepidus_praecisio.jpg|center|150x150px]] |- |''[[Longosuchus]]'' |''L. meadei'' |Skulls, osteoderms, vertebrae, other postcrania<ref name=":0" /><ref name=":4" /> | * Site 3 (TMM 31098) * Quarry 3 (TMM 31100) * Quarry 3A (TMM 31185) * Borden County Site 1 (TMM 31213) |A common [[Desmatosuchinae|desmatosuchin]] aetosaur previously considered a species of ''[[Typothorax]]''. |[[File:Longosuchus_BW.jpg|center|150x150px]] |- |''[[Lucasuchus]]<ref name=":0" />'' |''L. hunti<ref name=":0" />'' |Osteoderms and other referred fossils (including a possible skull)<ref name=":0" /><ref name=":4" /> | * Quarry 3 (TMM 31100) * Quarry 3A (TMM 31185) |A desmatosuchin aetosaur similar to ''Longosuchus<ref name=":3" />'' but most likely a distinct valid taxon.<ref>{{Cite journal |last1=Parker |first1=William G. |last2=Martz |first2=Jeffrey W. |date=2010-07-14 |title=Using positional homology in aetosaur (Archosauria: Pseudosuchia) osteoderms to evaluate the taxonomic status of Lucasuchus hunti |url=http://www.tandfonline.com/doi/abs/10.1080/02724634.2010.483536 |journal=Journal of Vertebrate Paleontology |language=en |volume=30 |issue=4 |pages=1100–1108 |doi=10.1080/02724634.2010.483536 |s2cid=83713904 |issn=0272-4634|url-access=subscription }}</ref> | |- | rowspan="2" |''[[Poposaurus]]'' |''P. gracilis'' |Hip and ankle bones<ref name=":0" /> | * "Otis Chalk" * Site 3 (TMM 31098) * Quarry 3 (TMM 31100) |A poposaurid poposauroid |[[File:Poposaurus_gracilis_(1)_flipped.jpg|center|150x150px]] |- |''P. langstoni<ref name=":0" />'' |Hip bones and vertebrae<ref name=":0" /> | * Site/Quarry 1 (TMM 31025) * Quarry 3 (TMM 31100) |A poposaurid poposauroid previously given its own genus, ''[[Lythrosuchus]]<ref name=":0" />'' | |- |''[[Postosuchus]]'' |''P. kirkpatricki'' |Vertebrae and hindlimb bones<ref name=":0" /> | * Quarry 3 (TMM 31100) * Borden County Site 1 (TMM 31213) |A [[Rauisuchidae|rausuchid]] [[loricata]]n |[[File:Postosuchus_kirkpatricki_flipped.jpg|center|150x150px]] |}

==== Phytosaurs ==== {| class="wikitable" width="100%" align="center" ! colspan="7" align="center" |'''[[Phytosaur]]s of the Colorado City Formation''' |- !Genus / Taxon !Species !Material !Location !Notes !Images |- | rowspan="2" |''[[Angistorhinus]]'' |style="background:#E6E6E6;"|''A. alticephalus'' |style="background:#E6E6E6;"|Partial skeleton with skull<ref name=":0" /> |style="background:#E6E6E6;"| * Roy Lamb Ranch<ref name=":0" /> |style="background:#E6E6E6;"|Probable junior synonym of ''A. grandis.'' |style="background:#E6E6E6;"| |- |''A. grandis'' |Several complete skulls and associated cranial and postcranial fragments<ref name=":10" /><ref name=":0" /><ref name="Lucas02">{{cite journal |author=S. G. Lucas |author2=A. B. Heckert |author3=R. Kahle |name-list-style=amp |year=2002 |editor2=S. G. Lucas |title=Postcranial anatomy of ''Angistorhinus'', a Late Triassic phytosaur from West Texas |url=https://books.google.com/books?id=imIfCgAAQBAJ&pg=PA157 |journal=Upper Triassic Stratigraphy and Paleontology, New Mexico Museum of Natural History and Science Bulletin |volume=21 |pages=157–164 |editor=A. B. Heckert}}</ref> | * Site 3 (TMM 31098)<ref name=":0" /> * Quarry 3 (TMM 31100)<ref name=":0" /> * TMM 42060<ref name=":0" /> * "locality 9"<ref name="Lucas02" /> |A common [[Mystriosuchinae|mystriosuchine]] phytosaur. Some sources refer all Otis Chalk ''Angistorhinus'' material to ''"Angistorhinus megalodon"'',<ref name=":0" /> while most other sources support affinities with the type species ''Angistorhinus grandis'' from Wyoming.<ref name="Lucas02" /> |[[File:Angistorhinus NMMNH P-33527.jpg|center|150x150px]] |- |''[[Brachysuchus]]'' |''B. megalodon'' |Two nearly complete skulls and postcranial fragments | * "near Otis Chalk"<ref name=":0" /> |A mystriosuchine phytosaur closely related to ''Angistorhinus'', and sometimes regarded as a species within that genus.<ref name=":0" /> |[[File:Phytosaurus Exhibit Museum of Natural History.JPG|center|150x150px]] |- | rowspan="2" |''[[Paleorhinus]]'' |''"P." sawini<ref name=":0" />'' |A skull<ref name=":0" /> | * Borden County Site 1 (TMM 31213)<ref name=":0" /> |A basal (non-mystriosuchine) phytosaur from Borden County. Probably does not form a clade with other species referred to ''Paleorhinus'' or ''Parasuchus.'' | |- |''P. bransoni'' |Several skulls<ref name=":0" /> | * Site/Quarry 1 (TMM 31025) * Quarry 3 (TMM 31100) * Quarry 3A (TMM 31185) |A common basal (non-mystriosuchine) phytosaur, sometimes considered a species of ''[[Parasuchus]]''. |[[File:Paleorhinus Warsaw.jpg|center|150x150px]] |}

==== Other reptiles ==== {| class="wikitable" width="100%" align="center" ! colspan="7" align="center" |'''Other reptiles of the Colorado City Formation''' |- !Genus !Species !Material !Location !Notes !Images |- |''[[Ankylosuchus]]<ref name="LSH13">{{cite book |last=Lucas |first=S.G. |url=https://books.google.com/books?id=0_spCgAAQBAJ |title=The Triassic System |author2=Spielmann, J.A. |author3=Hunt, A.P. |year=2013 |editor=Tanner, L.H. |series=New Mexico Museum of Natural History and Science Bulletin |volume=61 |pages=382–388 |chapter=A new doswelliid archosauromorph from the Upper Triassic of West Texas |editor2=Spielmann, J.A. |editor3=Lucas, S.G. |chapter-url=https://books.google.com/books?id=0_spCgAAQBAJ&pg=PA382}}</ref>'' |''A. chinlegroupensis<ref name="LSH13" />'' |Partial skeleton with cranial and pelvic fragments, osteoderms, vertebrae, and an indeterminate limb bone''<ref name="LSH13" />'' | * NMMNH locality 3101''<ref name="LSH13" />'' |A [[Doswelliidae|doswelliid]] [[Archosauriformes|archosauriform]]. | |- |''[[Doswellia]]'' |''D. kaltenbachi'' |Vertebrae and osteoderms<ref name=":0" /> | * Site/Quarry 1 (TMM 31025) * Site 3 (TMM 31098) |A doswelliid archosauriform.<ref name=":0" /> |[[File:Doswellia_kaltenbachi_life_restoration.png|center|150x150px]] |- |''[[Malerisaurus]]'' |''M. langstoni''<ref name=":5">{{Cite journal |last=Chatterjee |first=Sankar |date=1986-12-24 |title=Malerisaurus langstoni, a new diapsid reptile from the Triassic of Texas |url=http://www.tandfonline.com/doi/abs/10.1080/02724634.1986.10011627 |journal=Journal of Vertebrate Paleontology |language=en |volume=6 |issue=4 |pages=297–312 |doi=10.1080/02724634.1986.10011627 |issn=0272-4634|url-access=subscription }}</ref> |Disarticulated skeleton<ref name=":5" /><ref name=":6">{{Cite journal |last1=Nesbitt |first1=Sterling J. |last2=Stocker |first2=Michelle R. |last3=Ezcurra |first3=Martín D. |last4=Fraser |first4=Nicholas C. |last5=Heckert |first5=Andrew B. |last6=Parker |first6=William G. |last7=Mueller |first7=Bill |last8=Sengupta |first8=Saradee |last9=Bandyopadhyay |first9=Saswati |last10=Pritchard |first10=Adam C. |last11=Marsh |first11=Adam D. |date=2022 |editor-last=Field |editor-first=Daniel |title=Widespread azendohsaurids (Archosauromorpha, Allokotosauria) from the Late Triassic of western USA and India |journal=Papers in Palaeontology |language=en |volume=8 |issue=1 |doi=10.1002/spp2.1413 |s2cid=245049571 |issn=2056-2799|doi-access=free }}</ref> | * Quarry 2 (TMM 31099)<ref name=":5" /> |A carnivorous [[Azendohsauridae|azendohsaurid]] [[allokotosauria]]n in the subfamily [[Malerisaurinae]]. Regarded as a [[Chimera (paleontology)|chimera]] by Spielmann ''et al.'' (2006),<ref>{{Cite journal |last1=Spielmann |first1=Justin A. |last2=Lucas |first2=Spencer G. |last3=Hunt |first3=Adrian P. |last4=Heckert |first4=Andrew B. |date=2006 |title=Reinterpretation of the holotype of ''Malerisaurus langstoni'', a diapsid reptile from the Upper Triassic Chinle Group of West Texas |url=https://www.researchgate.net/publication/267398643 |journal=New Mexico Museum of Natural History and Science Bulletin |volume=37 |pages=543–547}}</ref> but treated as valid by other sources.<ref name=":5" /><ref name=":6" /> Numerous disarticulated ''Malerisaurus''-like fossils are also known from Quarry 1 (TMM 31025).<ref name=":6" /> |[[File:Malerisaurus_BW.jpg|center|150x150px]] |- |style="background:#E6E6E6;"|''[[Otischalkia]]'' |style="background:#E6E6E6;"|''O. elderae'' |style="background:#E6E6E6;"|Humeri, femora<ref name=":0" /> |style="background:#E6E6E6;"| * Site/Quarry 1 (TMM 31025) * Quarry 3A (TMM 31185) |style="background:#E6E6E6;"|A dubious putative [[rhynchosaur]], likely synonymous with ''Malerisaurus langstoni''.''<ref name=":6" />'' Supposed [[premaxilla]] fossils have been reinterpreted as metoposaurid cleithra.''<ref name=":6" />'' Femora and humeri previously referred to this species likely belong to ''Trilophosaurus''<ref name=":0" /> or ''Malerisaurus<ref name=":6" />'' instead. |style="background:#E6E6E6;"| |- |''[[Protecovasaurus]]<ref name=":8">{{Cite journal |last=Heckert |first=Andrew B. |date=2004 |title=Late Triassic microvertebrates from the lower Chinle Group (Otischalkian-Adamanian: Carnian), southwestern U.S.A. |url=https://books.google.com/books?id=T2cfCgAAQBAJ&pg=PP1 |journal=New Mexico Museum of Natural History and Science Bulletin |volume=27 |pages=1–170}}</ref>'' |''P. lucasi<ref name=":8" />'' |Teeth<ref name=":8" /> | * Quarry 1 (NMMNH 860)<ref name=":8" /> |A reptile of uncertain affinities known from serrated teeth similar to [[ornithischia]]n dinosaurs.<ref name=":8" /> | |- |''[[Trilophosaurus]]'' |''T. buettneri'' |Numerous skulls, braincases, and postcranial material<ref name=":0" /><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 |url=http://libres.uncg.edu/ir/asu/f/Heckert_Andrew_2006_Revision_of_the_Archosauromorph_orig.pdf.X.pdf |journal=Palaeontology |volume=49 |issue=3 |pages=621–640 |doi=10.1111/j.1475-4983.2006.00556.x |doi-access=free}}</ref> | * Site/Quarry 1 (TMM 31025) * Quarry 2 (TMM 31099)<ref name="Hetal06" /> * Quarry 3 (TMM 31100) * Quarry 3A (TMM 31185)<ref name="Hetal06" /> * Borden County Site 1 (TMM 31213) |A common [[Trilophosauridae|trilophosaurid]] allokotosaurian.<ref name="Hetal06" /> |[[File:Trilophosaurus_buettneri_(flipped).jpg|center|150x150px]] |- |''[[Triopticus]]<ref name="stockeretal2016">{{cite journal |last1=Stocker |first1=M.R. |last2=Nesbitt |first2=S.J. |last3=Criswell |first3=K.E. |last4=Parker |first4=W.G. |last5=Witmer |first5=L.M. |last6=Rowe |first6=T.B. |last7=Ridgely |first7=R. |last8=Brown |first8=M.A. |date=2016 |title=A Dome-Headed Stem Archosaur Exemplifies Convergence among Dinosaurs and Their Distant Relatives |journal=Current Biology |volume=26 |issue=19 |pages=2674–2680 |doi=10.1016/j.cub.2016.07.066 |pmid=27666971 |doi-access=free}}</ref>'' |''T. primus<ref name="stockeretal2016" />'' |Partial skull''<ref name="stockeretal2016" />'' | * Quarry 3 (TMM 31100)''<ref name="stockeretal2016" />'' |A [[protopyknosia]]n archosauriform with a reinforced skull similar to [[Pachycephalosauria|pachycephalosaurid]] dinosaurs.''<ref name="stockeretal2016" />'' | |}

=== Amphibians === {| class="wikitable" width="100%" align="center" |- ! colspan="7" align="center" |'''Amphibians of the Colorado City Formation''' |- ! Genus !Species ! Material !Location ! Notes ! Images |- |''[[Anaschisma]]'' |''A. browni'' |Numerous skulls, [[interclavicle]]s, [[clavicle]]s, vertebrae, and other postcranial bones<ref name=":0" /> | * Site/Quarry 1 (TMM 31025) * Site 3 (TMM 31098) * Quarry 2 (TMM 31099) * Quarry 3 (TMM 31100) * Quarry 3A (TMM 31185) * Borden County Site 3 (TMM 41921) |A common [[Metoposauridae|metoposaurid]] [[Temnospondyli|temnospondyl]], previously named under the genus ''Koskinonodon'' or ''Buettneria<ref name=":0" />'' |[[File:Buettneria.jpg|center|150x150px]] |- |''[[Latiscopus]]''<ref name=":7">{{Cite journal |last=Wilson |first=John Andrew |date=1948 |title=A Small Amphibian from the Triassic of Howard County, Texas |journal=Journal of Paleontology |volume=22 |issue=3 |pages=359–361 |jstor=1299405}}</ref> |''L. disjunctus<ref name=":7" />'' |A skull<ref name=":7" /> | * Site/Quarry 1 (TMM 31025)<ref name=":7" /> |A [[Latiscopidae|latiscopid]] temnospondyl<ref name=":7" /> | |}

=== Fish === Fish fossils from Quarry 1 (NMMNH 860 / TMM 31025) include [[lungfish]] teeth (''[[Arganodus]]''?<ref name=":10" />), [[coelacanth]] scales, "[[Palaeoniscidae|palaeoniscid]]" scales (aff. ''[[Turseodus]]<ref name=":10" />''), and [[Hybodontiformes|hybodont]] shark teeth and spines (''[[Lissodus]]''?<ref name=":10" /> or ''[[Lonchidion]]''?).<ref name=":8" /> {| class="wikitable" width="100%" align="center" ! colspan="7" align="center" |'''Fish of the Colorado City Formation''' |- !Genus / Taxon !Species !Material !Location !Notes !Images |- |''[[Cionichthys]]'' |''C. greeni<ref name=":9">{{Cite journal |last=Schaeffer |first=Bobb |date=1967 |title=Late Triassic fishes from the Western United States |url=https://digitallibrary.amnh.org/items/8404895d-0c38-4d35-995e-aa2a7a9126ff |journal=Bulletin of the American Museum of Natural History |volume=135 |issue=6 |pages=285–342}}</ref>'' |Articulated skulls and postcrania<ref name=":9" /> | * Schaeffer Fish Quarry<ref name=":9" /> |A [[Redfieldiiformes|redfieldiiform]] [[Actinopterygii|actinopterygian]] (ray-finned fish) | |- | rowspan="2" |''[[Lasalichthys]]'' |''L. hillsi'' |Skull, scale, and postcranial fragments<ref name=":9" /><ref name=":2" /> | * Schaeffer Fish Quarry<ref name=":9" /><ref name=":2" /> |A redfieldiiform actinopterygian | |- |''L. otischalkensis<ref name=":2" />'' |Numerous articulated skulls and postcrania<ref name=":2" /> | * Schaeffer Fish Quarry<ref name=":2" /> |A redfieldiiform actinopterygian.<ref name=":2">{{Cite journal |last=Gibson |first=Sarah Z. |date=2018-09-03 |title=A new species of Lasalichthys (Actinopterygii, Redfieldiiformes) from the Upper Triassic Dockum Group of Howard County, Texas, with revisions to the genera Lasalichthys and Synorichthys |url=https://www.tandfonline.com/doi/full/10.1080/02724634.2018.1513009 |journal=Journal of Vertebrate Paleontology |language=en |volume=38 |issue=5 |article-number=e1513009 |doi=10.1080/02724634.2018.1513009 |s2cid=92328870 |issn=0272-4634|url-access=subscription }}</ref> Some specimens were previously referred to ''Lasalichthys (= Synorichthys) stewarti''.<ref name=":2" /> | |}

==See also== {{Portal|Earth sciences|Texas|Paleontology}} * [[List of fossiliferous stratigraphic units in Texas]] * [[Paleontology in Texas]]

==References== {{reflist}} * {{cite web|title= Fossilworks: Gateway to the Paleobiology Database|author= ((Various Contributors to the Paleobiology Database))|url= https://www.fossilworks.org|access-date= 17 December 2021}}

[[Category:Triassic geology of Texas]] [[Category:Sandstone formations of the United States]] [[Category:Siltstone formations of the United States]]