{{Short description|Fossil-bearing geologic formation in Montana, part of the Judith River Group}} {{Infobox rockunit | name = Judith River Formation | image = Judith River Formation exposure-1.jpg | caption = Judith River Formation, Upper Missouri Breaks National Monument | type = Geological formation | age = Campanian, {{Fossil range|79|75.3}}{{period fossil range|Cretaceous|79|75.3}} | period = Campanian | prilithology = Mudstone and sandstone | namedfor = Judith River near the confluence with the Missouri River | namedby = F.V. Hayden, 1871;<ref>Hayden, F.V., 1871. Geology of the Missouri Valley: Preliminary report (4th annual) of the Geol. Surv. of Wyoming and portions of contiguous territories.</ref> F.B. Meek, 1876.<ref>Meek, Fielding Bradford, 1876. A report on the invertebrate Cretaceous and Tertiary fossils of the upper Missouri country, Hayden, F.V., Geologist in Charge; United States Geologic and Geographic Survey of the Territories, vol. 9, page 629</ref> | region = Alberta, Montana, South Dakota, Saskatchewan, Wyoming | country = Canada, United States | unitof = Montana Group | subunits = Parkman Sandstone Member, McClelland Ferry Member, Coal Ridge Member, Woodhawk Member | underlies = Bearpaw Formation | overlies = Claggett Formation, Pakowki Formation | thickness = max {{convert|360|m|ft|sp=us}}<ref name=lexicon>{{Cite web|url=http://cgkn1.cgkn.net/weblex/weblex_litho_detail_e.pl?00053:007256 |title=Judith River Formation|author=Lexicon of Canadian Geologic Units|access-date=2009-02-06}}</ref> }} The '''Judith River Formation''' is a fossil-bearing geologic formation in Montana, and is part of the Montana Group. It dates to the Late Cretaceous, between 79 and 75.3 million years ago,<ref name=":2">{{Cite journal |last1=Ramezani |first1=Jahandar |last2=Beveridge |first2=Tegan L. |last3=Rogers |first3=Raymond R. |last4=Eberth |first4=David A. |last5=Roberts |first5=Eric M. |date=2022-09-26 |title=Calibrating the zenith of dinosaur diversity in the Campanian of the Western Interior Basin by CA-ID-TIMS U–Pb geochronology |journal=Scientific Reports |volume=12 |issue=1 |page=16026 |doi=10.1038/s41598-022-19896-w |issn=2045-2322 |pmc=9512893 |pmid=36163377}}</ref> corresponding to the "Judithian" land vertebrate age. It was laid down during the same time period as portions of the Two Medicine Formation of Montana<ref name=sullivanlucas2006>Sullivan, R.M. and Lucas, S. G. (2006). "The Kirtlandian land-vertebrate "age"–faunal composition, temporal position and biostratigraphic correlation in the nonmarine Upper Cretaceous of western North America." Pp. 7-29 in Lucas, S. G. and Sullivan, R.M. (eds.), ''Late Cretaceous vertebrates from the Western Interior. New Mexico Museum of Natural History and Science Bulletin 35''.</ref> and the Oldman Formation of Alberta.<ref name=eberth1997>{{cite book |last=Eberth |first=David A. |year=1997 |chapter=Judith River Wedge |editor=Currie, Philip J. |editor-link=Phil Currie |editor2=Padian Kevin|title=Encyclopedia of Dinosaurs |url=https://archive.org/details/encyclopediadino00jcur_131 |url-access=limited |publisher= Academic Press |location=San Diego |pages=[https://archive.org/details/encyclopediadino00jcur_131/page/n409 379]–380 |isbn=0-12-226810-5}}</ref> It is an historically important formation, explored by early American paleontologists such as Edward Drinker Cope, who named several dinosaurs from scrappy remains found here on his 1876 expedition (such as ''Monoclonius''). Modern work has found nearly complete skeletons of the hadrosaurid ''Brachylophosaurus''.
==Lithology== The Judith River Formation is composed of mudstone, siltstone and sandstone.<ref name=lexicon/> Coal beds, bentonite and coquinas are also observed. [[File:Judith River Formation Exposure.png|thumb|Surface exposures of the Judith River Formation from the USGS, map courtesy of OpenStreetMap.]] thumb|Judith River Formation, Upper Missouri Breaks National Monument
==Relationship with other units== The Judith River Formation conformably overlies the Claggett Formation and Pakowki Formation. It is overlain by the Bearpaw Formation.<ref name=lexicon/> It is equivalent to the Belly River Formation in the southern Canadian Rockies foothills, the Lea Park Formation in central Alberta and the Wapiti Formation in the northwestern plains.
===Sub-divisions=== thumb|Missouri River carved through the Judith River Formation, Upper Missouri Breaks National Monument The Judith River Formation is divided into four members, the Parkman Sandstone Member, the McClelland Ferry Member, the Coal Ridge member, and the Woodhawk Member.<ref>{{Cite journal|last1=Rogers|first1=Raymond R.|last2=Kidwell|first2=Susan M.|last3=Deino|first3=Alan L.|last4=Mitchell|first4=James P.|last5=Nelson|first5=Kenneth|last6=Thole|first6=Jeffrey T.|date=2016-01-01|title=Age, Correlation, and Lithostratigraphic Revision of the Upper Cretaceous (Campanian) Judith River Formation in Its Type Area (North-Central Montana), with a Comparison of Low- and High-Accommodation Alluvial Records|journal=The Journal of Geology|volume=124|issue=1|pages=99–135|doi=10.1086/684289|bibcode=2016JG....124...99R |s2cid=130555911|issn=0022-1376}}</ref> The McClelland Ferry Member (78.7-76.3 Ma) is believed to be equivalent to the Oldman Formation, with the Coal Ridge Member (76.3-75.3 Ma) equivalent to the Dinosaur Park Formation.<ref name=":2" />
==Fauna== [[Image:Judith River Fauna.jpg|thumb|left|Dinosaurs of Judith River Formation]] Faunal list follows a review published by Ashok Sahni in 1972 unless otherwise noted.<ref name="sahni1972">Sahni, A. (1972). "The vertebrate fauna of the Judith River Formation, Montana." ''Bulletin of the AMNH'', v. '''147''' article 6: 321-415.</ref>
{{paleobiota-key-compact}}
===Amphibians=== There are three potential species of discoglossid frogs. Hip bones, possibly representing a North American member of the European spadefoot toad family are also known from the formation.
{| class="wikitable" align="center" width="100%" |- ! colspan="8" align="center" |'''Amphibians of the Judith River Formation''' |- ! Genus ! Species ! Location ! Stratigraphic position ! Abundance ! Notes ! Images |- | ''Habrosaurus'' | ''H. dilatus'' | | | | A siren |- | ''Lisserpeton'' | ''L. bairdi'' | | | | A scapherpetonid salamander |- |''Nezpercius''<ref name=lisanfos>{{cite web |url=http://www.lisanfos.mncn.csic.es/?module=taxon&id=1055&lang=en |title=''Nezpercius'' Blob, Carrano, Rogers, Forster et Espinoza, 2001 |last1=Martín |first1=C. |last2=Sanchiz |first2=B. |year=2014 |work=Lisanfos KMS |version=1.2 |publisher=Museo Nacional de Ciencias Naturales, MNCN-CSIC, Madrid (Spain) |access-date=20 February 2014 |archive-url=https://web.archive.org/web/20140224115111/http://www.lisanfos.mncn.csic.es/?module=taxon&id=1055&lang=en |archive-date=24 February 2014 }}</ref> |''N. dodsoni'' |Clambank Hollow | | |A frog known from a partial illium. |- | ''Opisthotriton'' | ''O. kayi'' | | | | A possible lungless salamander |- | ''Prodesmodon'' | ''P. copei'' | | | | A lungless salamander |- | ''Scapherpeton'' | ''S. tectum'' | | | | A scapherpetonid salamander |- |}
===Fish=== ====Bony fish==== {| class="wikitable" align="center" width="100%" |- ! colspan="8" align="center" |'''Bony fishes of the Judith River Formation''' |- ! Genus ! Species ! Location ! Stratigraphic position ! Abundance ! Notes ! Images |- |''Arotus'' |''A. hieroglyphus'' | | | |A holostean.<ref>{{Cite journal |last=Gardner |first=James D. |last2=Brinkman |first2=Donald B. |last3=Murray |first3=Alison M. |date=2025-06-01 |title=Reidentification of the holotype of ‘Ceratodus’ hieroglyphus Cope from the Upper Cretaceous (Campanian) of Montana, USA, as the scale of a holostean fish |url=https://doi.org/10.1007/s12549-025-00663-4 |journal=Palaeobiodiversity and Palaeoenvironments |language=en |volume=105 |issue=2 |pages=545–572 |doi=10.1007/s12549-025-00663-4 |issn=1867-1608}}</ref> | |- |''Belonostomus'' |''Belonostomus longirostris'' | | | |An aspidorhynchiform. | rowspan="20" |thumb|The holotype of Priscosturion, MOR 1184
|- |''Cyclurus'' |''C. fragosus'' | | | |A bowfin.<ref>{{Cite journal |last=Grande |first=Lance |last2=Bemis |first2=William E. |date=1998-04-10 |title=A Comprehensive Phylogenetic Study of Amiid Fishes (Amiidae) Based on Comparative Skeletal Anatomy. an Empirical Search for Interconnected Patterns of Natural History |url=https://www.tandfonline.com/doi/full/10.1080/02724634.1998.10011114 |journal=Journal of Vertebrate Paleontology |language=en |volume=18 |issue=sup1 |pages=1–696 |doi=10.1080/02724634.1998.10011114 |issn=0272-4634|url-access=subscription }}</ref> |- |''Lepisosteus'' |''L. occidentalis'' | | |Scales<ref name=":3">{{Cite journal |last=Leidy |first=J. |date=1856-12-31 |title=Notice of remains of extinct reptiles and fishes, discovered by Dr. FV Hayden in the Bad Lands of the Judith River, Nebraska Territory. |url=https://zenodo.org/record/1038128 |journal=Proceedings of the Academy of Natural Sciences of Philadelphia |volume=8 |pages=72–73 |doi=10.5281/zenodo.1038128}}</ref> |A gar. |- |?''Paralbula'' |?''P.'' sp. | | | |A bonefish. |- |''Priscosturion'' |''P. longipinnis'' |McClelland Ferry<ref name=":4">{{Cite journal |last1=Grande |first1=Lance |last2=Hilton |first2=Eric J. |date=July 2006 |title=An Exquisitely Preserved Skeleton Representing a Primitive Sturgeon from the Upper Cretaceous Judith River Formation of Montana (Acipenseriformes: Acipenseridae: N. Gen. and Sp.) |url=https://www.cambridge.org/core/journals/journal-of-paleontology/article/abs/an-exquisitely-preserved-skeleton-representing-a-primitive-sturgeon-from-the-upper-cretaceous-judith-river-formation-of-montana-acipenseriformes-acipenseridae-n-gen-and-sp/5F587FC3FB17BBD18E359753BF583E15 |journal=Journal of Paleontology |language=en |volume=80 |issue=S65 |pages=1–39 |doi=10.1666/05032.1 |s2cid=131689748 |issn=0022-3360|url-access=subscription }}</ref> |Upper Campanian<ref name=":4" /> | |A sturgeon. |- | style="background:#E6E6E6;" |''Psammorhynchus'' | style="background:#E6E6E6;" |''P. longipinnis'' | style="background:#E6E6E6;" |McClelland Ferry<ref name=":4" /> | style="background:#E6E6E6;" |Upper Campanian<ref name=":4" /> | style="background:#E6E6E6;" | | style="background:#E6E6E6;" |Preoccupied name, renamed ''Priscosturion''.<ref>{{Cite journal |last1=Grande |first1=Lance |last2=Hilton |first2=Eric J. |date=March 2009 |title=A replacement name for †Psammorhynchus Grande & Hilton, 2006 (Actinopterygii, Acipenseriformes, Acipenseridae) |url=https://www.cambridge.org/core/journals/journal-of-paleontology/article/abs/replacement-name-for-psammorhynchus-grande-hilton-2006-actinopterygii-acipenseriformes-acipenseridae/B426CF08231011559A03771797277003 |journal=Journal of Paleontology |language=en |volume=83 |issue=2 |pages=317–318 |doi=10.1666/08-137.1 |s2cid=85233540 |issn=0022-3360|url-access=subscription }}</ref> |- |Polyodontidae |Indeterminate | | | |A paddlefish. Known remains exceeded size of Chinese paddlefish, total length would exceed {{convert|2|m|ft}}.<ref>{{Cite journal |last=Grande |first=Lance |last2=Bemis |first2=William E. |date=1991 |title=Osteology and Phylogenetic Relationships of Fossil and Recent Paddlefishes (Polyodontidae) with Comments on the Interrelationships of Acipenseriformes |url=https://www.jstor.org/stable/3889328 |journal=Memoir (Society of Vertebrate Paleontology) |volume=1 |pages=ii–121 |doi=10.2307/3889328 |issn=1062-161X|url-access=subscription }}</ref> |- |}
====Cartilaginous fish==== {| class="wikitable" align="center" width="100%" |- ! colspan="8" align="center" |'''Cartilaginous fishes of the Judith River Formation''' |- ! Genus ! Species ! Location ! Stratigraphic position ! Abundance ! Notes ! Images |- | ''Myledaphus'' | ''M. bipartitus'' | | | | A stingray. | rowspan="22" | |- |''Cretalamna'' |''C. sp'' |Montana | | |An Otodontid shark |- |''Carcharias'' |''Carcharias'' sp. | | | |A sand tiger shark |- |''Squalicorax'' |''S.kaupi'' | | | |An Anacoracid shark |}
===Plesiosaurs=== {| class="wikitable" align="center" width="100%" |- ! colspan="8" align="center" |'''Plesiosaurs of the Judith River Formation''' |- ! Genus ! Species ! Location ! Stratigraphic position ! Abundance ! Notes ! Images |- | Plesiosauria<ref>{{cite web |title=Cow Creek (Cretaceous to of the United States) |url=https://paleobiodb.org/classic/basicCollectionSearch?collection_no=69153 |website=PBDB.org}}</ref> | Plesiosauria indet. | | | | | rowspan="20" | |- |} ===Pterosaurs=== {| class="wikitable" align="center" width="100%" |- ! colspan="8" align="center" |'''Pterosaurs of the Judith River Formation''' |- ! Genus ! Species ! Location ! Stratigraphic position ! Abundance ! Notes ! Images |- | ?''Quetzalcoatlus''<ref>{{cite journal |last=Fiorillo |first=Anthony R. |date=January 1989 |title=The Vertebrate Fauna from the Judith River Formation (Late Cretaceous) of Wheatland and Golden Valley Counties, Montana |journal=The Mosasaur |volume=4 |pages=127-142 |url=https://www.researchgate.net/publication/272152964_The_vertebrate_fauna_from_the_Judith_River_Formation_Late_Cretaceous_of_Wheatland_and_Golden_Valley_Counties_Montana}}</ref> | | Hidden Valley Quarry | | | | |- |Pterosauria |indet |JDM Quarry |McClelland Ferry<ref>{{Cite journal |last=Prieto-Marquez |first=Albert |date=2005-03-11 |title=New information on the cranium of Brachylophosaurus canadensis (Dinosauria, Hadrosauridae), with a revision of its phylogenetic position |url=https://doi.org/10.1671/0272-4634(2005)025[0144:NIOTCO]2.0.CO;2 |journal=Journal of Vertebrate Paleontology |volume=25 |issue=1 |pages=144–156 |doi=10.1671/0272-4634(2005)025[0144:NIOTCO]2.0.CO;2 |issn=0272-4634}}</ref> | | |center|thumb|A pterosaur metacarpal from the JDM quarry |}
===Choristoderes=== {| class="wikitable" align="center" width="100%" |- ! colspan="8" align="center" |'''Choristoderes of the Judith River Formation''' |- ! Genus ! Species ! Location ! Stratigraphic position ! Abundance ! Notes ! Images |- | ''Champsosaurus'' | ''C.'' sp. | | | | | rowspan="20" | [[File:Champsosaurus BW.jpg|thumb|center|200px|''Champsosaurus'']] |- |}
===Crocodilians=== {| class="wikitable" align="center" width="100%" |- ! colspan="8" align="center" |'''Crocodilians of the Judith River Formation''' |- ! Genus ! Species ! Location ! Stratigraphic position ! Abundance ! Notes ! Images |- | ''Brachychampsa'' | ''B. montana'' | | | | An alligatorid. |[[File:Brachychampsa NT small.jpg|thumb|center|200px|''Brachychampsa'']] |- | ''Leidyosuchus'' | ''L. canadensis'' | | | | An alligatoroid. | |- |''Deinosuchus'' |''D. hatcheri''<ref>{{Cite book|title=King of the Crocodylians: The Paleobiology of Deinosuchus|last=Schwimmer|first=David|publisher=Indiana University Press|year=2002|location=Bloomington, IN|page=200}}</ref> | | |Two giant dorsal vertebrae and a number of osteoderms. |An enormous alligatoroid. |[[File:Deinosuchus hatcheri.png|thumb|center|200px|''Deinosuchus'']] |- |}
===Lizards=== {| class="wikitable" align="center" width="100%" |- ! colspan="8" align="center" |'''Lizards of the Judith River Formation''' |- ! Genus ! Species ! Location ! Stratigraphic position ! Abundance ! Notes ! Images |- | ''Chamops'' | ''C. segnis'' | | | | A whiptail. | rowspan="20" |
|- | ''Exostinus'' | ''E. lancensis'' | | | | A knob-scaled lizard. |- | ''Leptochamops'' | ''L. denticulatus'' | | | | A whiptail. |- | ''Paraderma'' | ''P. bogerti'' | | | | A parasaniwid. |- | ''Parasaniwa'' | ''P. wyomingensis'' | | | | A parasaniwid. |- |}
===Ornithischians=== ==== Ankylosaurs ==== {| class="wikitable" align="center" width="100%" |- ! colspan="8" align="center" |'''Ankylosaurs reported from the Judith River Formation''' |- ! Genus ! Species ! Location ! Member ! Material ! Notes ! Images |- |''Edmontonia'' |''E''. ''longiceps'' | | |Isolated teeth<ref>{{Cite journal |last=Sahni |first=Ashok |date=1972 |title=The vertebrate fauna of the Judith River Formation, Montana |journal=Bulletin of the AMNH |volume=147 |issue=6 |hdl=2246/1099 |url=https://digitallibrary.amnh.org/handle/2246/1099 |language=en-US}}</ref> | A nodosaurid. |[[File:Edmontonia dinosaur.png|thumb|center|''Edmontonia'']] |- |''Zuul'' |''Z. crurivastator'' | |middle Coal Ridge |Cranial and postcranial skeletal remains and soft tissue, type specimen |An ankylosaurid. |[[File:Zuul.jpg|thumb|center|''Zuul'']] |}
==== Hadrosaurs ==== {| class="wikitable" align="center" width="100%" |- ! colspan="8" align="center" |'''Hadrosaurs reported from the Judith River Formation''' |- ! Genus ! Species ! Location ! Member ! Material ! Notes ! Images |- | ''Brachylophosaurus'' | ''B. canadensis'' | |middle McClelland Ferry | | A hadrosaurid which was one of the more common dinosaurs in the area.<ref>{{cite book |last1=Trexler |first1=David |last2=Murphy |first2=Nate |last3=Thompson |first3=Mark |author1-link=David Trexler |editor1-last=Carpenter |editor1-first=Kenneth |title=Horns and Beaks |date=June 2007 |publisher=Indiana University Press |location=Bloomington, IN |pages=117–133 |url=https://www.researchgate.net/publication/325718855 |chapter="Leonardo," a Mummified Brachylophosaurus (Ornithischia: Hadrosauridae) from the Judith River Formation of Montana}}</ref> |[[File:Brachylophosaurus_canadensis.png|thumb|center|''Brachylophosaurus'']] |- |''Corythosaurus'' |''C.'' sp.<ref>{{Cite journal |last1=Takasaki |first1=Ryuji |last2=Chiba |first2=Kentaro |last3=Fiorillo |first3=Anthony R. |last4=Brink |first4=Kirstin S. |last5=Evans |first5=David C. |last6=Fanti |first6=Federico |last7=Saneyoshi |first7=Mototaka |last8=Maltese |first8=Anthony |last9=Ishigaki |first9=Shinobu |date=2022-10-23 |title=Description of the first definitive ''Corythosaurus'' (Dinosauria, Hadrosauridae) specimens from the Judith River Formation in Montana, USA and their paleobiogeographical significance |journal=The Anatomical Record |volume=306 |issue=7 |pages=1918–1938 |doi=10.1002/ar.25097 |pmid=36273398 |s2cid=253081338 |issn=1932-8486}}</ref> | |middle Coal Ridge |two partial skeletons |A lambeosaurine hadrosaurid |[[File:Life_reconstruction_of_Corythosaurus_casuarius.png|center|thumb|''Corythosaurus'']] |- | ''Probrachylophosaurus'' | ''P. bergei'' | |lower McClelland Ferry | | A brachylophosaurin hadrosaur |[[File:Probrachylophosaurus_bergei.png|center|thumb|''Probrachylophosaurus'']] |- |}
==== Marginocephalians ==== ===== Ceratopsians ===== {| class="wikitable" align="center" width="100%" |- ! colspan="8" align="center" |'''Ceratopsians reported from the Judith River Formation''' |- ! Genus ! Species ! Location ! Member ! Material ! Notes ! Images |- |style="background:#f3e9f3;"| ''Albertaceratops'' |style="background:#fbdddb;" | ''A. nesmoi''<ref name="ryan&evans2005">Ryan and Evans, 2005</ref> |style="background:#fbdddb;" | |style="background:#fbdddb;" | |style="background:#fbdddb;" | |style="background:#fbdddb;" | Reclassified as ''Medusaceratops lokii'' |style="background:#fbdddb;" | |- | ''Avaceratops'' | ''A. lammersi''<ref name="ryan&evans2005">Ryan and Evans, 2005</ref> | |lower McClelland Ferry | "[Two] partial skulls, skeleton, juvenile,"<ref name="table-23-1-495">"Table 23.1," in Weishampel, et al. (2004). Page 495.</ref> type specimen | A ceratopsid. Possibly dubious.<ref name=":6"/> |[[File:Avaceratops dinosaur.png|thumb|center|''Avaceratops'']] |- |Chasmosaurinae |gen. et sp. nov. | | |A mostly complete skull |MOR 11940, An unnamed Chasmosaur housed at the Museum of the Rockies. |[[File:Unnamed Judith Chasmosaur Lateral.jpg|center|thumb|The skull of the new Chasmosaurine in lateral (side view).]] |- |''Furcatoceratops'' |''F. elucidans'' |Fergus County, Montana<ref name=":6">{{Cite journal |last1=Ishikawa |first1=Hiroki |last2=Tsuihiji |first2=Takanobu |last3=Manabe |first3=Makoto |date=2023-07-20 |title=Furcatoceratops elucidans, a new centrosaurine (Ornithischia: Ceratopsidae) from the upper Campanian Judith River Formation, Montana, USA. |url=https://www.sciencedirect.com/science/article/pii/S019566712300188X |journal=Cretaceous Research |volume=151 |language=en |article-number=105660 |doi=10.1016/j.cretres.2023.105660 |s2cid=260046917 |issn=0195-6671|url-access=subscription }}</ref> |Upper Coal Ridge<ref name=":6" /> |Nearly complete subadult skeleton.<ref name=":6" /> |A ceratopsid |[[File:Furcatoceratops TD.png|thumb|center|''Furcatoceratops'']] |- | ''Judiceratops''<ref name="Nicholas R. Longrich 2013 51–65">{{Cite journal|author=Nicholas R. Longrich |year=2013 |title=''Judiceratops tigris'', a New Horned Dinosaur from the Middle Campanian Judith River Formation of Montana |journal=Bulletin of the Peabody Museum of Natural History |volume=54 |issue=1 |pages=51–65 |doi=10.3374/014.054.0103 |s2cid=129801786 }}</ref> | ''J. tigris''<ref name="Nicholas R. Longrich 2013 51–65"/> | |lower McClelland Ferry | | A ceratopsid |[[File:Judiceratops NT small.jpg|thumb|center|''Judiceratops'']] |- | ''Lokiceratops'' | ''L. rangiformis''<ref name="Lokiceratops">{{Cite journal |last1=Loewen |first1=Mark A. |last2=Sertich |first2=Joseph J. W. |last3=Sampson |first3=Scott |author-link3=Scott D. Sampson |last4=O'Connor |first4=Jingmai K. |author-link4=Jingmai O'Connor |last5=Carpenter |first5=Savhannah |last6=Sisson |first6=Brock |last7=Øhlenschlæger |first7=Anna |last8=Farke |first8=Andrew A. |last9=Makovicky |first9=Peter J. |last10=Longrich |first10=Nick |last11=Evans |first11=David C. |author-link11=David C. Evans (paleontologist) |date=2024-06-20 |title=''Lokiceratops rangiformis'' gen. et sp. nov. (Ceratopsidae: Centrosaurinae) from the Campanian Judith River Formation of Montana reveals rapid regional radiations and extreme endemism within centrosaurine dinosaurs |journal=PeerJ |language=en |volume=12 |article-number=e17224 |doi=10.7717/peerj.17224 |doi-access=free |issn=2167-8359 |pmc=11193970 }}</ref> |Kennedy Coulee |lower McClelland Ferry |Disarticulated, associated skeleton including most of the skull and fragmentary postcrania<ref name="Lokiceratops" /> | A ceratopsid |[[File:Lokiceratops rangiformis.png|thumb|center|''Lokiceratops'']] |- | ''Medusaceratops'' | ''M. lokii''<ref name="Ryan2010">Ryan, Michael J.; Russell, Anthony P., and Hartman, Scott. (2010). "A New Chasmosaurine Ceratopsid from the Judith River Formation, Montana", In: Michael J. Ryan, Brenda J. Chinnery-Allgeier, and David A. Eberth (eds), ''New Perspectives on Horned Dinosaurs: The Royal Tyrrell Museum Ceratopsian Symposium'', Indiana University Press, 656 pp. {{ISBN|0-253-35358-0}}.</ref> | |lower McClelland Ferry | Bonebed<ref name="Ryan2010"/> | A ceratopsid |[[File:Medusaceratops NT.jpg|thumb|center|''Medusaceratops'']] |- | ''Mercuriceratops'' | ''M. gemini''<ref name="Ryan2014">Ryan, Michael J.; Evans, David C.; Currie, Phillip J.; Loewen, Mark A. (2014). "A New chasmosaurine from northern Laramidia expands frill disparity in ceratopsid dinosaurs". Naturwissenschaften. doi:10.1007/s00114-014-1183-1</ref> | |lower Coal Ridge | "one apomorphic squamosal"<ref name="Ryan2014"/> | A ceratopsid |[[File:Mercuriceratops NT small.jpg|thumb|center|''Mercuriceratops'']] |- |''Spiclypeus'' |''S. shipporum'' | |McClelland Ferry<ref name=":1">{{Cite journal |last=Fowler |first=Denver Warwick |date=2017-11-22 |title=Revised geochronology, correlation, and dinosaur stratigraphic ranges of the Santonian-Maastrichtian (Late Cretaceous) formations of the Western Interior of North America |journal=PLOS ONE |volume=12 |issue=11 |article-number=e0188426 |bibcode=2017PLoSO..1288426F |doi=10.1371/journal.pone.0188426 |issn=1932-6203 |pmc=5699823 |pmid=29166406 |doi-access=free}}</ref> |Partial skull, vertebrae, ribs, humerus, ilium, femur, tibia, and fibula. |A ceratopsid |[[File:Spiclypeus NT small.jpg|thumb|center|''Spiclypeus'']] |- |}
===== Pachycephalosaurs ===== {| class="wikitable" align="center" width="100%" |- ! colspan="8" align="center" |'''Pachycephalosaurs reported from the Judith River Formation''' |- ! Genus ! Species ! Location ! Member ! Material ! Notes ! Images |- |''Colepiocephale'' |''C. lambei''<ref>{{Cite journal |last=Schott |first=Ryan K. |last2=Evans |first2=David C. |last3=Williamson |first3=Thomas E. |last4=Carr |first4=Thomas D. |last5=Goodwin |first5=Mark B. |date=2009-09-12 |title=The anatomy and systematics of ''Colepiocephale lambei'' (Dinosauria: Pachycephalosauridae) |journal=Journal of Vertebrate Paleontology |language=en |volume=29 |issue=3 |pages=771–786 |doi=10.1671/039.029.0329 |issn=0272-4634}}</ref> |Kennedy Coulee |lower McClelland Ferry |"nearly complete frontoparietal dome" |A pachycephalosaurid closely related to ''Stegoceras.'' |[[File:Colepiocephale updating version.JPG|thumb|center|''Colepiocephale'']] |- |''Hanssuesia'' |''H''. ''sternbergi'' | | | |A pachycephalosaurid. Also present in the Dinosaur Park and Oldman Formations. Possible synonym of ''Stegoceras''. | rowspan = 100| [[File:Hanssuesia sternbergi.jpg|thumb|center|''Hanssuesia'']] |}
===Theropods=== ==== Dromaeosaurs ==== {| class="wikitable" align="center" width="100%" |- ! colspan="8" align="center" |'''Dromeosaurs reported from the Judith River Formation''' |- ! Genus ! Species ! Location ! Stratigraphic position ! Material ! Notes ! Images |- | ''Dromaeosaurus'' | ''D. albertensis'' |Ox Hill Quarry, Careless Creek Quarry, Hidden Valley Quarry & Blackbird Ridge Quarry.<ref name=":5">{{Cite journal |last1=Fiorillo |first1=Anthony R. |last2=Currie |first2=Philip J. |date=1994-03-31 |title=Theropod teeth from the Judith River Formation (Upper Cretaceous) of south-central Montana |url=https://www.researchgate.net/publication/40662369 |journal=Journal of Vertebrate Paleontology |language=en |volume=14 |issue=1 |pages=74–80 |doi=10.1080/02724634.1994.10011539 |issn=0272-4634}}</ref> |lower McClelland Ferry | Teeth<ref name=":5" /> | A dromaeosaurid, also found in the Dinosaur Park Formation |[[File:Dromaeosaurus Restoration.png|thumb|center|''Dromaeosaurus'']] |- |''Saurornitholestes'' |''S. langstoni'' |Careless Creek, Emily's Ankle, Top Cat, Hidden Valley & Blackbird Ridge quarries.<ref name=":5" /> |Lower McClelland Ferry |Numerous teeth<ref name=":5" /> |A dromaeosaurid |[[File:Saurornitholestes digging Burrows wahweap.jpg|thumb|center|''Saurornitholestes'']] |- |}
==== Troodonts ==== {| class="wikitable" align="center" width="100%" |- ! colspan="8" align="center" |'''Troodonts reported from the Judith River Formation''' |- ! Genus ! Species ! Location ! Stratigraphic position ! Material ! Notes ! Images |- |Troodon |''T. Formorous''
|Antelope Head, Careless Creek, Emily's Ankle, Top Cat, Hidden Valley, Blackbird Ridge & Jensen Ranch quarries.<ref name=":5" /> | |28 teeth<ref name=":5" /> |Teeth of a Small theropod distinct from those of tyrannosaurids | |
|}
==== Tyrannosaurs ==== {| class="wikitable" align="center" width="100%" |- ! colspan="8" align="center" |'''Tyrannosaurs reported from the Judith River Formation''' |- ! Genus ! Species ! Location ! Stratigraphic position ! Material ! Notes ! Images |- | rowspan="3" |''Daspletosaurus'' |''D. torosus'' | |Coal Ridge |Maxilla<ref name=":0">{{Cite journal|last=Carr|first=Thomas D.|date=2018|title=Significant geographic range extension for the sympatric tyrannosaurids ''Albertosaurus libratus'' and ''Daspletosaurus torosus'' from the Judith River Formation (Late Campanian) of northern Montana|url=https://vertpaleo.org/wp-content/uploads/2021/03/SVP-2018-program-book-V4-FINAL-with-covers-9-24-18.pdf|journal=Journal of Vertebrate Paleontology|volume=38|issue=Supplement 1|page=102}}</ref> |A large tyrannosaurid. |rowspan="3"|[[File:Daspletosaurus wilsoni profile.png|thumb|center|''Daspletosaurus'']] |- |''D. wilsoni''<ref name=D.wilsoni>{{Cite journal |last1=Warshaw |first1=Elías A.|last2=Fowler |first2=Denver W. |year=2022 |title=A transitional species of ''Daspletosaurus'' Russell, 1970 from the Judith River Formation of eastern Montana |journal=PeerJ |volume=10 |at=e14461 |doi=10.7717/peerj.14461 |pmid=36452080 |pmc=9703990 |doi-access=free}}</ref> |Jack's B2 |lower Coal Ridge<ref name=":7">{{Cite journal |last=Warshaw |first=Elías A. |last2=Guevara |first2=Daniela Barrera |last3=Fowler |first3=Denver W. |date=November 2024 |title=Anagenesis and the tyrant pedigree: A response to "Re-analysis of a dataset refutes claims of anagenesis within ''Tyrannosaurus''-line tyrannosaurines (Theropoda, Tyrannosauridae)" |journal=Cretaceous Research |volume=163 |article-number=105957 |doi=10.1016/j.cretres.2024.105957 |issn=0195-6671|doi-access=free }}</ref> |Partial skull, cervical, sacral, and caudal vertebrae, and a rib, chevron, and first metatarsal |Originally considered to be a transitional species between ''D. torosus'' and ''D. horneri'', though the validity of this claim has been questioned <ref name=SV23>{{Cite journal |last1=Scherer |first1=Charlie Roger |last2=Voiculescu-Holvad |first2=Christian |date=November 28, 2023 |title=Re-analysis of a dataset refutes claims of anagenesis within ''Tyrannosaurus''-line tyrannosaurines (Theropoda, Tyrannosauridae) |url=https://www.sciencedirect.com/science/article/pii/S0195667123003087 |journal=Cretaceous Research |issue=In press |article-number=105780 |doi=10.1016/j.cretres.2023.105780 |issn=0195-6671|doi-access=free }}</ref><ref name=Warner2025>{{Cite journal |last1=Warner-Cowgill |first1=E. |last2=Storrs |first2=G. W. |last3=Rogers |first3=R. R. |last4=Maltese |first4=A. E. |title=Cranial anatomy and stratigraphy of a new specimen of the tyrannosaurine dinosaur ''Daspletosaurus'' from the Judith River Formation of Central Montana, USA |year=2025 |journal=Acta Palaeontologica Polonica |volume=70 |issue=1 |pages=159–174 |doi=10.4202/app.01143.2024 |doi-access=free }}</ref><ref name="Khankhuuluu">{{Cite journal |last1=Voris |first1=Jared T. |last2=Zelenitsky |first2=Darla K. |author2-link=Darla Zelenitsky |last3=Kobayashi |first3=Yoshitsugu |author3-link=Yoshitsugu Kobayashi |last4=Modesto |first4=Sean P. |last5=Therrien |first5=François |last6=Tsutsumi |first6=Hiroki |last7=Chinzorig |first7=Tsogtbaatar |last8=Tsogtbaatar |first8=Khishigjav |date=June 11, 2025 |title=A new Mongolian tyrannosauroid and the evolution of Eutyrannosauria |journal=Nature |volume=642 |issue=8069 |pages=973–979 |doi=10.1038/s41586-025-08964-6 |pmid=40500434 |bibcode=2025Natur.642..973V |language=en |issn=0028-0836}}</ref> |- |''D.'' sp. | |Coal Ridge<ref>Maltese, Anthony E. "DIFFICULT EXCAVATION AND PREPARATION OF A LARGE DASPLETOSAURUS SPECIMEN." Methods in Preparation: 63.</ref> |Partial skeleton<ref>Maltese, Anthony E. "DIFFICULT EXCAVATION AND PREPARATION OF A LARGE DASPLETOSAURUS SPECIMEN." Methods in Preparation: 63.</ref><ref name=Warner2025>{{Cite journal |last1=Warner-Cowgill |first1=E. |last2=Storrs |first2=G. W. |last3=Rogers |first3=R. R. |last4=Maltese |first4=A. E. |title=Cranial anatomy and stratigraphy of a new specimen of the tyrannosaurine dinosaur ''Daspletosaurus'' from the Judith River Formation of Central Montana, USA |year=2025 |journal=Acta Palaeontologica Polonica |volume=70 |issue=1 |pages=159–174 |doi=10.4202/app.01143.2024 |doi-access=free }}</ref> |While initially referred to ''D. torosus'' <ref>Maltese, Anthony E. "DIFFICULT EXCAVATION AND PREPARATION OF A LARGE DASPLETOSAURUS SPECIMEN." Methods in Preparation: 63.</ref><ref name=SV23>{{Cite journal |last1=Scherer |first1=Charlie Roger |last2=Voiculescu-Holvad |first2=Christian |date=November 28, 2023 |title=Re-analysis of a dataset refutes claims of anagenesis within ''Tyrannosaurus''-line tyrannosaurines (Theropoda, Tyrannosauridae) |url=https://www.sciencedirect.com/science/article/pii/S0195667123003087 |journal=Cretaceous Research |issue=In press |article-number=105780 |doi=10.1016/j.cretres.2023.105780 |issn=0195-6671|doi-access=free }}</ref>, it is more recently classified as ''Daspletosaurus sp.'' as it contains some characters in common with other named species of the genus as well as its own unique features. Furthermore, most of the skull is not preserved and is therefore missing many crucial features required for a specific classification <ref name=":7" /><ref name=Warner2025>{{Cite journal |last1=Warner-Cowgill |first1=E. |last2=Storrs |first2=G. W. |last3=Rogers |first3=R. R. |last4=Maltese |first4=A. E. |title=Cranial anatomy and stratigraphy of a new specimen of the tyrannosaurine dinosaur ''Daspletosaurus'' from the Judith River Formation of Central Montana, USA |year=2025 |journal=Acta Palaeontologica Polonica |volume=70 |issue=1 |pages=159–174 |doi=10.4202/app.01143.2024 |doi-access=free }}</ref> |- |''Gorgosaurus'' |''G. libratus'' | | |Postorbital<ref name=":0" /> |A large tyrannosaurid, also found in the Dinosaur Park Formation and possibly the Two Medicine Formation. |[[File:Gorgosaurus flipped.png|thumb|center|''Gorgosaurus'']] |- |<small>?''Tyrannosaurus''</small> |T. sp. |Fergus County | |A Lacrimal |Found alongside a specimen of ''Deinosuchus,<ref>{{Cite journal |last1=Urban |first1=Michael A. |last2=Lamanna |first2=Matthew C. |date=December 2006 |title=Evidence of a Giant Tyrannosaurid (Dinosauria: Theropoda) from the Upper Cretaceous (?Campanian) of Montana |url=http://www.bioone.org/doi/abs/10.2992/0097-4463%282006%2975%5B231%3AEOAGTD%5D2.0.CO%3B2 |journal=Annals of Carnegie Museum |language=en |volume=75 |issue=4 |pages=231–235 |doi=10.2992/0097-4463(2006)75[231:EOAGTD]2.0.CO;2 |issn=0097-4463|url-access=subscription }}</ref>'' but may not be from the Judith River Formation<ref>{{Cite journal |last=Dalman |first=Sebastian G. |last2=Lucas |first2=Spencer G. |last3=Malinzak |first3=D. Edward |date=2018 |title=Tyrannosaurid teeth from the upper Cretaceous (Campanian) Two Medicine Formation of Montana |url=https://www.researchgate.net/publication/328676947 |journal=New Mexico Museum of Natural History and Science Bulletin |volume=79 |issue= |pages=125–139}}</ref> | |- |}
==== Other theropods ====
{| class="wikitable" align="center" width="100%" |- ! colspan="8" align="center" |'''Theropods reported from the Judith River Formation''' |- ! Genus ! Species ! Location ! Stratigraphic position ! Material ! Notes ! Images |- | ''Hesperornis'' | ''H. altus'' | | | Partial tibiotarsus | One of the only known freshwater occurrences of a hesperornithid.<ref name=fox1974>Fox, R.C. (1974). "A middle Campanian, nonmarine occurrence of the Cretaceous toothed bird ''Hesperornis'' Marsh." ''Canadian Journal of Earth Sciences'', '''11''': 1335-1338.</ref> | [[File:Hesperornis BW (white background).jpg|thumb|center|''Hesperornis'']] |- |Ornithomimosauria indet.<ref name="Chinzorig2025">{{Cite journal|last1=Chinzorig|first1=Tsogtbaatar|last2=Takasaki|first2=Ryuji|last3=Chiba|first3=Kentaro|last4=Fiorillo|first4=Anthony R.|last5=Kobayashi|first5=Yoshitsugu|last6=Saneyoshi|first6=Mototaka|last7=Ishigaki|first7=Shinobu|date=2025-09-10|title=A potential deinocheirid ornithomimosaur from the Judith River Formation (Upper Cretaceous: Montana, U.S.A.) and its paleobiogeographic implications|journal=Journal of Vertebrate Paleontology|language=en|volume=e2536844|pages=(13 pages)|doi=10.1080/02724634.2025.2536844|doi-access=}}</ref> |Indeterminate | |Coal Ridge Member |A left and right dentary |A large ornithomimosaur with potential affinities to the Deinocheiridae |thumb|center|Skull reconstruction of the possible Judith River deinocheirid |- |''Richardoestesia'' |''R. gilmorei'' |Careless Creek, Emily's Ankle, Hidden Valley & Blackbird Ridge quarries.<ref name=":5" /> | |12 teeth<ref name=":5" /> |A coelurosaur | |}
===Dubious Taxa=== Many early American dinosaur discoveries were made in the Judith River Formation, and most of the early taxa are considered ''nomina dubia'' today.
{| class="wikitable" align="center" width="100%" |- ! colspan="8" align="center" |'''Turtles of the Judith River Formation''' |- ! Genus ! Species ! Location ! Stratigraphic position ! Abundance ! Notes ! Images |- | rowspan="2" style="background:#E6E6E6;"| ''Aublysodon'' |style="background:#E6E6E6;"| ''A. lateralis'' |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| "Isolated teeth,"<ref name="table-4-1-78">"Table 4.1," in Weishampel, et al. (2004). Page 78.</ref><ref name="table-5-1-114">"Table 5.1," in Weishampel, et al. (2004). Page 114.</ref> type specimen |style="background:#E6E6E6;"| Junior synonym of ''Deinodon horridus''<ref name=sahni1972/> | rowspan="2" style="background:#E6E6E6;"| |- |style="background:#E6E6E6;"| ''A. mirandus'' |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| Teeth, type specimen |style="background:#E6E6E6;"| Possible junior synonym of ''Deinodon horridus''<ref name=sahni1972/> |- |style="background:#E6E6E6;"| ''Ceratops'' |style="background:#E6E6E6;"| ''C. montanus'' |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| "occipital condyle, paired horn cores,"<ref name="table-23-1-496">"Table 23.1," in Weishampel, et al. (2004). Page 496.</ref> type specimen |style="background:#E6E6E6;"| A dubious ceratopsid |style="background:#E6E6E6;"| |- |rowspan=5 style="background:#E6E6E6;"| ''Deinodon'' |style="background:#E6E6E6;"| ''D. falculus'' |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| Teeth |style="background:#E6E6E6;"| Isolated tyrannosaur teeth classified in the dubious genus ''Deinodon'' |rowspan=5 style="background:#E6E6E6;"| |- |style="background:#E6E6E6;"| ''D. hazenianus'' |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| Teeth |style="background:#E6E6E6;"| Junior synonym of ''Deinodon horridus''<ref name=sahni1972/> |- |style="background:#E6E6E6;"| ''D. horridus'' |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| "Teeth,"<ref name=":3" /> type specimen |style="background:#E6E6E6;"| Isolated tyrannosaur teeth that formed the basis of the dubious genus ''Deinodon'' |- |style="background:#E6E6E6;"| ''D. incrassatus'' |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| Teeth |style="background:#E6E6E6;"| Junior synonym of ''Deinodon horridus''<ref name=sahni1972/> |- |style="background:#fbdddb;" | ''D. lateralis'' |style="background:#fbdddb;" | |style="background:#fbdddb;" | |style="background:#fbdddb;" | |style="background:#fbdddb;" | Junior synonym of ''Deinodon horridus''<ref name=sahni1972/> |- | rowspan="3" style="background:#E6E6E6;"| ''Diclonius'' |style="background:#E6E6E6;"| ''D. calamarius'' |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| "Teeth."<ref name="table-20-1-442">"Table 20.1," in Weishampel, et al. (2004). Page 442.</ref> |style="background:#E6E6E6;"| ''Nomen dubium'' | rowspan="3" style="background:#E6E6E6;"| |- |style="background:#E6E6E6;"| ''D. pentagonius'' |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| "Fragmentary dentary with teeth,"<ref name="table-20-1-442"/> type specimen |style="background:#E6E6E6;"| A dubious hadrosaurid |- |style="background:#E6E6E6;"| ''D. perengulatus'' |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| "Teeth."<ref name="table-20-1-442"/> |style="background:#E6E6E6;"| ''Nomen dubium'' |- style="background:#f3e9f3;" |rowspan=2| ''Dromaeosaurus'' |style="background:#E6E6E6;"| ''D. explanatus'' |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| "Tooth."<ref name="table-9-1-186">"Table 9.1," in Weishampel, et al. (2004). Page 186.</ref> |style="background:#E6E6E6;"| Possible relative of ''Saurornitholestes'' |rowspan="2"|[[File:Dromaeosaurus Restoration.png|thumb|center|''Dromaeosaurus'']] |- |style="background:#E6E6E6;"| ''D. laevifrons'' |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| "Tooth."<ref name="table-9-1-186"/> |style="background:#E6E6E6;"| Possible relative of ''Saurornitholestes'' |- | rowspan="4" style="background:#E6E6E6;"| ''Dysganus'' |style="background:#E6E6E6;"| ''D. bicarinatus'' |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| "Isolated teeth."<ref name="table-23-1-496"/> |style="background:#E6E6E6;"| ''Nomen dubium'' |rowspan="4" style="background:#E6E6E6;"| |- |style="background:#E6E6E6;"| ''D. encaustus'' |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| "Single tooth and [five] tooth fragments."<ref name="table-20-1-442"/> "Isolated teeth."<ref name="table-23-1-496"/> |style="background:#E6E6E6;"| ''Nomen dubium'' |- |style="background:#E6E6E6;"| ''D. haydenianus'' |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| "Isolated teeth."<ref name="table-23-1-496"/> |style="background:#E6E6E6;"| ''Nomen dubium'' |- |style="background:#E6E6E6;"| ''D. peiganus'' |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| "Tooth."<ref name="table-23-1-496"/> |style="background:#E6E6E6;"| ''Nomen dubium'' |- |style="background:#E6E6E6;"| <s>''Hadrosaurus''</s> |style="background:#E6E6E6;"| ''H. paucidens'' |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| A dubious hadrosaur, sometimes known as ''Lambeosaurus paucidens'' |style="background:#E6E6E6;"| |- |style="background:#E6E6E6;"| ?"''Kritosaurus''" |style="background:#E6E6E6;"| ?"K." ''breviceps'' |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| A dubious hadrosaurid |style="background:#E6E6E6;"| |- |style="background:#E6E6E6;"| ''Monoclonius'' |style="background:#E6E6E6;"| ''M. crassus''<ref name="ryan&evans2005">Ryan and Evans, 2005</ref> |style="background:#E6E6E6;"| |style="background:#E6E6E6;"|lower Coal Ridge |style="background:#E6E6E6;"| "[Five] skulls, [one] complete."<ref name="table-23-1-495"/> Type specimen |style="background:#E6E6E6;"| A dubious ceratopsid |style="background:#E6E6E6;"| |- |style="background:#f3e9f3;"| <small>''Ornithomimus''</small> |style="background:#E6E6E6;"| ''O. tenuis'' |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| "Fragmentary metatarsal."<ref name="table-6-1-139">"Table 6.1," in Weishampel, et al. (2004). Page 139.</ref> |style="background:#E6E6E6;"| A possible troodontid or juvenile tyrannosaurid |style="background:#E6E6E6;"| |- |style="background:#E6E6E6;"| ''Paleoscincus'' |style="background:#E6E6E6;"| ''P. costatus'' |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| "Tooth,"<ref name=":3" /> type specimen |style="background:#E6E6E6;"| A dubious ankylosaur |style="background:#E6E6E6;"| |- |style="background:#E6E6E6;"| ''Paronychodon'' |style="background:#E6E6E6;"| ''P. lacustris'' |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| Teeth, type specimen |style="background:#E6E6E6;"| An indeterminate maniraptoran, also found in the Dinosaur Park, Milk River, and Kirtland Formations |style="background:#E6E6E6;"| |- |style="background:#E6E6E6;"| ''Pteropelyx'' |style="background:#E6E6E6;"| ''P. grallipes'' |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| "Skeleton lacking skull."<ref name="table-20-1-443">"Table 20.1," in Weishampel, et al. (2004). Page 443.</ref> |style="background:#E6E6E6;"| A dubious hadrosaurid |style="background:#E6E6E6;"| |- |style="background:#E6E6E6;"| ''Trachodon'' |style="background:#E6E6E6;"| ''T. mirabilis'' |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| Isolated teeth, type specimen<ref name=":3" /> |style="background:#E6E6E6;"| A dubious hadrosaurid |style="background:#E6E6E6;"| |- | style="background:#E6E6E6;" | ''Troodon'' | style="background:#E6E6E6;" | ''T. formosus'' | style="background:#E6E6E6;" |Antelope Head, Careless Creek, Emily's Ankle, Top Cat & Hidden Valley quarries.<ref name=":5" /> | style="background:#E6E6E6;" | | style="background:#E6E6E6;" | Teeth (type specimen),<ref name=":3" /><ref name=":5" /> egg | style="background:#E6E6E6;" | A troodontid, possibly dubious. A neotype from the Two Medicine Formation has been proposed. | style="background:#E6E6E6;" |[[File:Troodon formosus (feathers).JPG|thumb|center|''Troodon'']] |- |style="background:#E6E6E6;"| ''Zapsalis''<ref>Larson, D. W.; Currie, P. J. (2013). "Multivariate Analyses of Small Theropod Dinosaur Teeth and Implications for Paleoecological Turnover through Time". In Evans, Alistair Robert. PLoS ONE 8: e54329. doi:10.1371/journal.pone.0054329. edit</ref> |style="background:#E6E6E6;"| ''Z. abradens'' |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| |style="background:#E6E6E6;"| "Teeth,"<ref name="table-9-1-186"/> type specimen |style="background:#E6E6E6;"| A dromaeosaurid |style="background:#E6E6E6;"| |}
===Turtles=== {| class="wikitable" align="center" width="100%" |- ! colspan="8" align="center" |'''Turtles of the Judith River Formation''' |- ! Genus ! Species ! Location ! Stratigraphic position ! Abundance ! Notes ! Images |- |''Adocus''<ref name=":8">{{Cite journal |last=Smith |first=Heather F. |last2=Berg |first2=Madison |last3=Adrian |first3=Brent |date=2023 |title=A well-preserved cranium from the Judith River Formation (Montana, USA) reveals the inner ear and neuroanatomy of a Campanian baenid turtle |url=https://onlinelibrary.wiley.com/doi/abs/10.1002/ar.25185 |journal=The Anatomical Record |language=en |volume=306 |issue=6 |pages=1431–1451 |doi=10.1002/ar.25185 |issn=1932-8494}}</ref> |''A.'' sp. | | | | | |- |''Aspideretoides''<ref name=":8" /> |''A. sp'' | | | | | |- |''Aspideretoides''<ref name=":8" /> |''A. foveatus'' | | | | | |- |''Axestemys''<ref name=":8" /> |''A. spledidus'' | | | | | |- |''Basilemys''<ref name=":8" /> |''B.'' sp. | | | | A Mesoamerican river turtle. | |- |''Boremys''<ref name=":8" /> |''B. sp'' | | | | | |- |''Boremys''<ref name=":8" /> |''B. pulchra'' | | | | | |- |Chelydridae<ref name=":8" /> |indet. | | | | | |- |''Neuankylus''<ref name=":8" /> |''N. sp.'' | | | | |- |''Neuankylus''<ref name=":8" /> |''N. eximius'' | | | | | |- |''Plesiobaena''<ref name=":8" /> |''P. antiqua'' | | | | | |}
== Flora == All the flora stated below is pulled from the PBDB.<ref>{{cite web |title=JWHall #223, Phillips Co., MT (Cretaceous to of the United States) |url=https://paleobiodb.org/classic/basicCollectionSearch?collection_no=32404 |website=PBDB.org}}</ref><ref>{{cite web |title=Leo Site, Malta (Cretaceous of the United States) |url=https://paleobiodb.org/classic/basicCollectionSearch?collection_no=73891 |website=PBDB.org}}</ref><ref>{{cite web |title=West end of the Fort Peck reservoir at the Robinson Bridge (Cretaceous to of the United States) |url=https://paleobiodb.org/classic/basicCollectionSearch?collection_no=34016 |website=PBDB.org}}</ref><ref>{{cite web |title=Loki Quarry, Kennedy Coulee (Cretaceous of the United States) |url=https://paleobiodb.org/classic/basicCollectionSearch?collection_no=235325 |website=PBDB.org}}</ref> === Ferns === {| class="wikitable" align="center" width="100%" |- ! colspan="8" align="center" |'''Ferns of the Judith River Formation''' |- ! Genus ! Species ! Location ! Stratigraphic position ! Abundance ! Notes ! Images |- |''Azollopsis'' |''A. coccoides'' |Montana | | | | |- | ''Azolla'' | ''A. simplex'' |Montana | | | | rowspan="26" | |- |''Biretisporites'' |''B. deltoideus'' |Montana | | | |- |''Baculatisporites'' |''B.'' sp |Montana | | | |- |''Cyathidites'' |''C.'' sp |Montana | | | |- |''Deltoidospora'' |''D. diaphana'' |Montana | | | |- |''Echinatisporis'' |''E.'' sp |Montana | | | |- |''Laevigatosporites'' |''L. haardtii'' |Montana | | | |- |Todisporites |''T. dubius'' |Montana | | | |}
=== Gymnosperms ===
==== Cycadophyta ==== {| class="wikitable" align="center" width="100%" |- ! colspan="8" align="center" |'''Ferns of the Judith River Formation''' |- ! Genus ! Species ! Location ! Stratigraphic position ! Abundance ! Notes ! Images |- |''Cycadopites'' |''C. fragilis'' |Montana | | | | |}
==== Conifers ==== {| class="wikitable" align="center" width="100%" |- ! colspan="8" align="center" |'''Ferns of the Judith River Formation''' |- ! Genus ! Species ! Location ! Stratigraphic position ! Abundance ! Notes ! Images |- |Araucariales |Indeterminate |Montana | | | | |- | ''Pityosporites'' | ''P. constrictus'' |Montana | | | | rowspan="20" | |- |''Taxodiaceaepollenites'' |''T. hiatus'' |Montana | | | |} === Angiosperms === {| class="wikitable" align="center" width="100%" |- ! colspan="8" align="center" |'''Ferns of the Judith River Formation''' |- ! Genus ! Species ! Location ! Stratigraphic position ! Abundance ! Notes ! Images |- |''Scabrastephanocolpites'' |''S. lepidus'' |Montana | | | | |- | ''Monosulcites'' | ''M. riparius'' |Montana | | | | rowspan="22" | |- |''Tubulifloridites'' |''T. aedicula'' |Montana | | | |- |''Erdtmanipollis'' |''E. procumbentiformis'' |Montana | | | |- |''Liliacidites'' |''L.'' sp. |Montana | | | |}
==See also== * List of dinosaur-bearing rock formations
==References== {{Reflist}}
{{Western Canadian Sedimentary Basin|Central_Plains=yes}}
Category:Campanian Stage Category:Cretaceous Montana Category:Geologic formations of Montana Category:Cretaceous geology of South Dakota Category:Geologic formations of South Dakota Category:Cretaceous Wyoming Category:Geologic formations of Wyoming Category:Cretaceous Alberta Category:Geologic formations of Alberta Category:Cretaceous Saskatchewan Category:Geologic formations of Saskatchewan Category:Mudstone formations of the United States Category:Sandstone formations of the United States Category:Mudstone formations of Canada Category:Sandstone formations of Canada