{{Short description|Geomorphological formation}} {{Infobox rockunit | name = Hudspeth Formation | image = | caption = | type = Geological formation | age = Albian-Cenomanian<br />~{{fossilrange|107.5|96.6}}<ref>{{cite book|author1=Surpless, K. D.|author2=Gulliver, K. D. H.|year=2018|editor1=Ingersoll, R.V.|editor2=Graham, S.A.|editor3=Lawton, T.F.|chapter=Provenance Analysis of the Ochoco Basin, Central Oregon: A Window Into the Late Cretaceous Paleogeography of the Northern U.S. Cordillera|title=Tectonics, Sedimentary Basins, and Provenance: A Celebration of the Career of William R. Dickinson|publisher=Geological Society of America|doi=10.1130/2018.2540(11)|isbn=9780813725406 |url=https://digitalcommons.trinity.edu/cgi/viewcontent.cgi?article=1037&context=geo_faculty}}</ref> | period = Albian | prilithology = Mudstone, shale | otherlithology = | namedfor = | namedby = | region = Oregon | country = United States | coordinates = {{coord|43.3|N|120.1|W|display=inline,title}} | paleocoordinates = {{coord|42.9|N|74.8|E|display=inline}} | unitof = Mitchell Group | subunits = | underlies = | overlies = | thickness = | extent = | area = Wheeler & Lake Counties, Oregon | map = {{Location map+ | United States#Oregon | relief = 1 | width = 250 | float = center | places = {{Location map~ | United States#Oregon | lat_deg = 44.5 | lon_deg = -120.1 | mark = Green pog.svg | marksize = 12 }} }} | map_caption = }} The '''Hudspeth Formation''' is a Cretaceous sedimentary rock formation, found in Oregon of the United States of America. The formation dates to the Albian age of the Early Cretaceous period. During the Albian much of this formation was submerged beneath shallow seas resulting in the preservation of many marine fossils. Pterosaur, dinosaur and marine fossils have been recovered from the formation. It is intertongued with the Gable Creek Formation.<ref>{{Cite web|date=1971|title=Bedrock geology of the Mitchell Quadrangle, Wheeler County, Oregin |url=https://www.oregongeology.org/pubs/B/B-072.pdf |access-date=2020-07-04}}</ref>

== Fossil content == === Vertebrates === {| class="wikitable sortable" ! colspan="7" align="center" | '''Vertebrates of the Hudspeth Formation''' |- ! Genus !! Species !! Location !! Stratigraphic position !! Material !! Notes !! Images |- | ''Bennettazhia''<ref name=Gilmore1928>Gilmore, 1928</ref> | ''B. oregonensis'' | Oregon | | Humerus and two fused dorsal vertebrae | A Tapejaromorph pterosaur, possible a Caupedactylian<ref name="PteroPhylo">{{cite journal |last1=Thomas |first1=Henry |last2=McDavid |first2=Skye |title=Enter the dragons: the phylogeny of Azhdarchoidea (Pterosauria: Pterodactyloidea) and the evolution of giant size in pterosaurs |journal=Journal of Systematic Palaeontology |date=2025 |volume=23 |issue=1 |doi=10.1080/14772019.2025.2569368}}</ref> | center|200px |- | Dsungaripteromorpha<ref name=PteroPhylo></ref> | Indeterminate | Oregon | | Dentary fragment and two teeth<ref name=guano>{{cite journal|author1=Retallack, G.J.|author2=Carr, G.E.|author3=Broz, A.P.|year=2023|title=Early Cretaceous pterosaur guano deposit from central Oregon, USA|journal=Lethaia|volume=56|issue=1|pages=1–15|doi=10.18261/let.56.1.3|doi-access=free}}</ref> | Originally referred to Bennettazhia, later reinterpreted as an indeterminate dsungaripteromorph<ref name=PteroPhylo></ref> | |- | Ornithopoda (Mitchell ornithopod) | Indeterminate | Oregon | | Toe bone and a vertebra | First dinosaur described from Oregon (not the first discovered), likely a bloated carcass swept out into the ocean from a coastline in what is now Idaho.<ref name=Retallack>Retallack et al., 2018</ref> Further discoveries suggest it may have been deposited by a mudflow<ref name=":0">{{Cite web|last=Strommer|first=Kristin|date=July 14, 2021|title=UO-led team uncovers new pieces of Oregon's dinosaur puzzle|url=https://around.uoregon.edu/content/uo-led-team-uncovers-new-pieces-oregons-dinosaur-puzzle |access-date=July 15, 2021|website=University of Oregon}}</ref> | |- |Ornithopoda |Indeterminate |Oregon | |Vertebra |Likely the same animal as the Mitchell ornithopod.<ref name=":0" /> | |- | Plesiosauroidea | Indeterminate | Oregon | | A partial skull | A short necked Plesiosauroidea<ref name=Fremd2005>Fremd et al., 2005</ref> | |- | Ichthyosauria | Indeterminate | | | Vertebral centra | | |- | ''Scapanorhynchus sp.''<ref name=Welton1972>Welton, 1972</ref> | | | | Teeth |A shark | |- |}

=== Ammonites === {| class="wikitable sortable" ! colspan="7" align="center" | '''Ammonites of the Hudspeth Formation''' |- ! Genus !! Species !! Location !! Stratigraphic position !! Material !! Notes !! Images |- | rowspan="2" | ''Brewericeras'' | ''B. hulenensis'' | Oregon | | Shell in siderite nodules | | |- | ''B. breweri'' | Oregon | | | | |- | ''Leconteites'' | ''L. lecontei'' | Oregon | | Shell | | |- | ''Desmoceras'' | ''D. alamoense'' | Oregon | | Siderite nodule and shells<ref>{{Cite web|title=Condon Collection's Searchable Database|url=http://paleo.uoregon.edu/condon/|access-date=July 4, 2020|website=University of Oregon|archive-date=July 5, 2020|archive-url=https://web.archive.org/web/20200705164559/http://paleo.uoregon.edu/condon/|url-status=dead}}</ref> |Desmoceras is one of the most common Ammonite genera to be found in the Hudspeth Formation | center|200px |- | rowspan="2" | ''Anisoceras'' | Indeterminate | Oregon | | | | |- | ''A. merriami'' | Oregon | | Coiled shell | | |- | ''Mariella'' | ''M. oregonensis'' | Oregon | | Siderite nodule | | |- | ''Anagaudryceras'' | Indeterminate | Oregon | | Siderite nodule | | |- | ''Pseudohelicoceras'' | ''P. petersoni'' | Oregon | | | | |- | rowspan="2" | ''Mortoniceras'' | ''M. inflatum'' | Oregon | | | | center|200px |- | ''M. fallax'' | Oregon | | | | |- |}

=== Other invertebrates === {| class="wikitable sortable" ! colspan="7" align="center" | '''Other invertebrates of the Hudspeth Formation''' |- ! Genus !! Species !! Location !! Stratigraphic position !! Material !! Notes !! Images |- | ''Pleuromya'' | ''P. russelli'' | Oregon | | | | |- | ''Buchia'' | Indeterminate | Oregon | | | | |- | ''Epiaster'' | ''E. californicus'' | Oregon | | | | |- | ''Trigonarca'' | ''T. jacksonensis'' | Oregon | | | | |- | ''Goniomya'' | ''G. vespera'' | Oregon | | | | |- | ''Sogdianella'' | ''S. oregonensis'' | Oregon | | | | |- | ''Euspira'' | ''E. conradiana'' | Oregon | | | ''Euspira'' is still extant though ''E. conradiana'' is extinct | thumb|center|200px|An extant ''Euspira catena'' |- | ''Eucorystes'' | ''E. platys'' | Oregon | | | A type of small crab, also present in Europe | |- |}

== See also == * List of pterosaur-bearing stratigraphic units * Paleontology in Oregon

== References == {{Reflist|3}}

=== Bibliography === <!--most recent first--> * {{cite journal |last1=Retallack |first1=Gregory J. |last2=Theodor |first2=Jessica M. |last3=Davis |first3=Edward B. |last4=Hopkins |first4=Samantha S. |last5=Barrett |first5=Paul Z. |year=2018 |title=First Oregon dinosaur (Ornithopoda) from Early Cretaceous (Albian) of Oregon, U.S.A. |journal=Journal of Vertebrate Paleontology|doi=10.1080/02724634.2018.1486847 |s2cid=91379584 |url=https://figshare.com/articles/journal_contribution/7206707 |url-access=subscription }} * {{cite web |last1=Fremd |first1=Ted |last2=Retallack |first2=Gregory |last3=Springer |first3=Dale |last4=Scotchmoor |first4=Judy |year=2005 |title=Oregon, U.S. |url=http://paleoportal.org/index.php?globalnav=time_space&sectionnav=state&name=Oregon |access-date=2020-07-04 |website=The Paleontology Portal}} * {{cite journal |last=Welton |first=B.J |year=1972 |title=Fossil sharks in Oregon |journal=The Ore Bin |volume=34 |pages=161–170}} * {{cite journal |last=Gilmore |first=C.W |year=1928 |title=A new pterosaurian reptile from the marine Cretaceous of Oregon |journal=Proceedings of the United States National Museum |volume=73|issue=2745 |pages=1–5 |doi=10.5479/si.00963801.73-2745.1 }}

Category:Geologic formations of Oregon Category:Cretaceous geology of Oregon Category:Lower Cretaceous Series of North America Category:Albian Stage Category:Mudstone formations of the United States Category:Shale formations of the United States Category:Shallow marine deposits Category:Paleontology in Oregon Formations Formations