{{Short description|Geologic formation in the United States}} {{Infobox rockunit | name = Popo Agie Formation | image = | caption = | type = [[Geological formation]] | age = [[Late Triassic]]<br/>{{fossilrange/linked|Carnian}} | period = Carnian | prilithology = | otherlithology = | namedfor = | namedby = | region = North America | country = United States | coordinates = | unitof = [[Chugwater Group]] | subunits = | underlies = | overlies = [[Gartra Formation]] | thickness = | extent = | area = | map = | map_caption = }}
The '''Popo Agie Formation''' ({{IPAc-en|p|oʊ|ˈ|p|oʊ|ʒ|ə}} {{respell|poh|POH|zhə}})<ref>Locally "po-PO-zha" according to Don Pitcher, 2006, ''Moon Handbooks Wyoming,'' p. 269 [https://books.google.com/books?id=nMG0xC1Y_eoC&pg=PA269&vq=Popo+Agie&source=gbs_search_r&cad=0_1]</ref><ref name="Popo">More ambiguous transcription of "po-po-zsha" at {{cite web |url=http://www.wilderness.net/index.cfm?fuse=NWPS&sec=wildView&WID=470 |title=Popo Agie Wilderness |work=The National Wilderness Preservation System |publisher=Wilderness.net |access-date=2008-03-08}}</ref> is a [[Triassic]] geologic [[Formation (geology)|formation]] that [[outcrop|crops out]] in western [[Wyoming]], western [[Colorado]], and [[Utah]]. It was deposited during the [[Late Triassic]] in [[fluvial]] (river) and [[lake|lacustrine]] (lake) environments that existed across much of what is now the American southwest.<ref name=HHCP69>{{cite book|last=High|first=L.R.|title=Geologic Guidebook of the Uinta Mountains: Utah's Maverick Range|year=1969|publisher=Utah Geological Association|pages=181–192|edition=Sixteenth Annual Field Conference|author2=Hepp, D.M. |author3=Clark, T. |author4= Picard, M.D. |chapter=Stratigraphy of Popo Agie Formation (Late Triassic), Uinta Mountain Area, Utah and Colorado}}</ref> The earliest known [[dinosaur]] of the [[Laurasia]]n continent, ''[[Ahvaytum]]'', is discovered from the Popo Agie Formation. Dinosaurian trace fossils and fragmentary fossils of prehistoric reptiles and amphibians, including [[pseudosuchian]] reptiles and [[temnospondyl]] amphibians, have also been reported from this formation.<ref name="Ahvaytum"/>
==Paleobiota== {{paleobiota-key-compact}}
===Amphibians===
{| class="wikitable sortable" align="center" width="100%" |- ! Taxon ! Species ! Member ! class="unsortable" | Material ! class="unsortable" | Notes ! class="unsortable" | Images |- | ''[[Apachesaurus]]'' | ''A. sp.'' | | Complete skull | A [[metoposaurid]] temnospondyl, originally described as ''Anaschisma'' sp. and later ''Eupelor browni''<ref name=ST02>{{cite journal|last=Sulej|first=T.|title=Species discrimination of the Late Triassic temnospondyl amphibian Metoposaurus diagnosticus|journal=Acta Palaeontologica Polonica|year=2002|volume=47|issue=3|pages=535–546|url=https://www.app.pan.pl/archive/published/app47/app47-535.pdf}}</ref> | [[File:Apachesaurus1DB.jpg|150px]] |- |''[[Anaschisma]]'' | ''A. browni'' | | Complete skull | A [[metoposaurid]] temnospondyl<ref>{{Cite journal|last1=Gee |first1=B. M. |last2=Jasinski |first2=S. E. |year=2021 |title=Description of the metoposaurid ''Anaschisma browni'' from the New Oxford Formation of Pennsylvania |journal=Journal of Paleontology |volume=95 |issue=5 |pages=1061–1078 |doi=10.1017/jpa.2021.30 |bibcode=2021JPal...95.1061G |s2cid=235546289 }}</ref> | [[File:Koskinonodon perfectus.jpg|150px]] |- | [[Metoposauridae]] | Indeterminate | | Complete skull | Originally described as ''Anaschisma browni''<ref name=ST02/> | |- |}
===Reptiles===
{| class="wikitable sortable" align="center" width="100%" |- ! Taxon ! Species ! Member ! class="unsortable" | Material ! class="unsortable" | Notes ! class="unsortable" | Images |- | ''[[Ahvaytum]]''<ref name="Ahvaytum">{{Cite journal |last1=Lovelace |first1=David M |last2=Kufner |first2=Aaron M |last3=Fitch |first3=Adam J |last4=Curry Rogers |first4=Kristina |last5=Schmitz |first5=Mark |last6=Schwartz |first6=Darin M |last7=LeClair-Diaz |first7=Amanda |last8=St.Clair |first8=Lynette |last9=Mann |first9=Joshua |last10=Teran |first10=Reba |date=2025-01-01 |title=Rethinking dinosaur origins: oldest known equatorial dinosaur-bearing assemblage (mid-late Carnian Popo Agie FM, Wyoming, USA) |journal=Zoological Journal of the Linnean Society |volume=203 |issue=1 |article-number=zlae153 |doi=10.1093/zoolinnean/zlae153 |issn=0024-4082}}</ref> | ''A. bahndooiveche'' | | UWGM 1975, a left astragalus, and UWGM 7549, a partial left femur | A probable [[sauropodomorph]] dinosaur and the oldest known Laurasian dinosaur | [[File:Ahvaytum bahndooiveche.png|Center|200px]] |- | ''[[Heptasuchus]]'' | ''H. clarki'' | | UW 11562, a partial skull and postcranial skeleton; UW 11563 through UW 11565, partial postcranial remains; both from Big Horn Mountains, Wyoming<ref name=DZC79>{{cite journal|last=Dawley|first=R.M.|author2=Zawiskie, J.M. |author3= Cosgriff, J.W. |title=A rauisuchid thecodont from the Upper Triassic Popo Agie Formation of Wyoming|journal=Journal of Paleontology|year=1979|volume=53|issue=6|pages=1428–1431}}</ref> | A [[rauisuchia]]n | [[File:Beesiiwo cooowuse Life Reconstruction Gabriel Ugueto.jpg|150px]] <br />(in background) |- | ''[[Beesiiwo]]'' | ''B. cooowuse'' | | USNM 494329, a left [[maxilla]] and left [[dentary]] from Hole in the Wall, Wyoming; TxVP 46037.1, UWGM 7027 and UWGM 7028, maxillary fragments from Cottonwood Creek, Wyoming<ref name="Fitch2023">{{cite journal |last1=Fitch |first1=A. J. |last2=Haas |first2=M. |last3=C'Hair |first3=W. |last4=Ridgley |first4=E. |last5=Ridgley |first5=B. |last6=Oldman |first6=D. |last7=Reynolds |first7=C. |last8=Lovelace |first8=D. M. |title=A New Rhynchosaur Taxon from the Popo Agie Formation, WY: Implications for a Northern Pangean Early-Late Triassic (Carnian) Fauna |journal=Diversity |date=2023 |volume=15 |issue=4 |page=544 |doi=10.3390/d15040544|hdl=10919/114487 |hdl-access=free |doi-access=free }}</ref> | A [[rhynchosaur]], previously assigned to ''[[cf.]] [[Hyperodapedon|Hyperodapedon sanjuanensis]]'' | [[File:Beesiiwo cooowuse Life Reconstruction Gabriel Ugueto.jpg|150px]] <br />(in foreground) |- | ''[[Poposaurus]]'' | ''P. gracilis'' | | UR 358, a partial [[Ilium (bone)|ilium]] from Lander, Wyoming;<ref name=LJH07>{{cite journal |last=Lees |first=J.H. |year=1907 |title=The skull of ''Paleorhinus'', a Wyoming phytosaur |journal=The Journal of Geology |volume=15 |issue=2 |pages=121–151 |jstor=30056366 |doi=10.1086/621382 |bibcode=1907JG.....15..121L|s2cid=129850970 |url=https://zenodo.org/record/1431447 }}</ref> UR 357, a partial skeleton including vertebrae, hips, and limb bones<ref name=MMG15>{{cite journal |last=Mehl |first=M.G. |year=1915 |title=''Poposaurus gracilis'', a new reptile from the Triassic of Wyoming |journal=The Journal of Geology |volume=23 |issue=6 |pages=516–522 |jstor= 30067173 |doi=10.1086/622268 |bibcode=1915JG.....23..516M|url=https://zenodo.org/record/1431461 |doi-access=free }}</ref> | A [[bipedal]] [[poposauroid]] first described from the Popo Agie Formation and known from more complete specimens from the [[Chinle Formation]]<ref name=Getal11>{{cite journal |last=Gauthier |first=J.A. |author2=Nesbitt, S.J. |author3=Schachner, E.R. |author4=Bever, G.S. |author5=Joyce, W.G. |year=2011 |title=The bipedal stem crocodilian ''Poposaurus gracilis'': inferring function in fossils and innovation in archosaur locomotion |journal=Bulletin of the Peabody Museum of Natural History |volume=52 |issue=1 |pages=107–126 |url=http://www.geo.uni-tuebingen.de/fileadmin/website/arbeitsbereich/palaeo/biogeologie/Images/Joyce_Publications/32__Gauthier_et_al.__Poposaurus__2011.pdf |doi=10.3374/014.052.0102 |s2cid=86687464 |archive-url=https://web.archive.org/web/20150924021606/http://www.geo.uni-tuebingen.de/fileadmin/website/arbeitsbereich/palaeo/biogeologie/Images/Joyce_Publications/32__Gauthier_et_al.__Poposaurus__2011.pdf |archive-date=2015-09-24 }}</ref> | [[File:Poposaurus gracilis (1).jpg|150px]] |- | [[Sulcimentisauria]] indet.<ref name="Ahvaytum" /> | Indeterminate | | A partial left humerus and right femur | A '[[silesaurid]]' | |}
===Synapsids===
{| class="wikitable sortable" align="center" width="100%" |- ! Taxon ! Species ! Member ! class="unsortable" | Material ! class="unsortable" | Notes ! class="unsortable" | Images |- | ''[[Eubrachiosaurus]]'' | ''E. browni'' | | FMNH UC 633, a partial left scapula, left humerus, and left pelvis from Lander, Wyoming | A [[dicynodont]]<ref name=KFA13>{{Cite journal | last1 = Kammerer | first1 = C. F. | last2 = Fröbisch | first2 = J. R. | last3 = Angielczyk | first3 = K. D. | editor1-last = Farke | editor1-first = Andrew A | title = On the Validity and Phylogenetic Position of Eubrachiosaurus browni, a Kannemeyeriiform Dicynodont (Anomodontia) from Triassic North America | doi = 10.1371/journal.pone.0064203 | journal = PLOS ONE | volume = 8 | issue = 5 | article-number = e64203 | year = 2013 | pmid = 23741307| pmc = 3669350| bibcode = 2013PLoSO...864203K | doi-access = free }}</ref> | [[Image:Eubrachiosaurus.png|150px]] |- |}
==See also== {{Portal|Earth sciences|Paleontology|Dinosaurs||}} * [[List of dinosaur-bearing rock formations]] ** [[List of stratigraphic units with indeterminate dinosaur fossils]]
==Footnotes== {{Reflist}}
==References== * Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. 861 pp. {{ISBN|0-520-24209-2}}.
[[Category:Carnian Stage]] [[Category:Triassic geology of Wyoming]]
{{US-geologic-formation-stub}}