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]<ref>{{cite web |last1=Nel |first1=André |title=Maastrichtian representatives of the dragonfly family Aeschnidiidae question the entomofaunal turnover of the early Late Cretaceous |url=https://www.biotaxa.org/pe/article/view/palaeoentomology.4.3.5 |website=Palaeoentomology |access-date=17 Feb 2024 }}</ref> ]<ref>{{cite journal |last1=Nel |first1=André |title=Maastrichtian representatives of the dragonfly family Aeschnidiidae question the entomofaunal turnover of the early Late Cretaceous |url=https://www.biotaxa.org/pe/article/view/palaeoentomology.4.3.5 |journal=Palaeoentomology |date=2021 |volume=4 |issue=3 |doi=10.11646/palaeoentomology.4.3.5 |access-date=17 Feb 2024 }}</ref>
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An isolated tooth. An isolated tooth.
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]<ref>{{cite journal |title=Stratigraphy and paleontology of the Cretaceous Hell Creek Formation, Stumpf site, Morton County, North Dakota |journal=Proceedings of the North Dakota Academy of Sciences |date=1994 |volume=48}}</ref>
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⚫ * North Dakota
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''S. triregnum''<ref name="Woodruff23">{{cite journal |last1=Woodruff |first1=D. Cary |last2=Schott |first2=Ryan K. |last3=Evans |first3=David C. |title=Two new species of small-bodied pachycephalosaurine (Dinosauria, Marginocephalia) from the uppermost Cretaceous of North America suggest hidden diversity in well-sampled formations |journal=Papers in Palaeontology |date=November 2023 |volume=9 |issue=6 |doi=10.1002/spp2.1535 |s2cid=265261709 }}</ref> ''S. triregnum''<ref name="Woodruff23">{{cite journal |last1=Woodruff |first1=D. Cary |last2=Schott |first2=Ryan K. |last3=Evans |first3=David C. |title=Two new species of small-bodied pachycephalosaurine (Dinosauria, Marginocephalia) from the uppermost Cretaceous of North America suggest hidden diversity in well-sampled formations |journal=Papers in Palaeontology |date=November 2023 |volume=9 |issue=6 |doi=10.1002/spp2.1535 |bibcode=2023PPal....9E1535W |s2cid=265261709 }}</ref>
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* Montana<ref name="Woodruff23" /> * Montana<ref name="Woodruff23" />
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==== Ceratopsians ==== ==== Ceratopsians ====
Indeterminate ceratopsid teeth and some identifiable bones from ''Triceratops'' can be extremely common.<ref>{{cite book |last1=Carpenter |first1=Kenneth |title=Horns and Beaks: Ceratopsian and Ornithopod Dinosaurs |date=2006 |publisher=Indiana University Press |id={{Project MUSE|49401|type=book}} |isbn=978-0-253-02795-5 }}{{page needed|date=January 2024}}</ref><ref>{{cite book |last1=Ryan |first1=Michael J. |last2=Chinnery-Allgeier |first2=Brenda J. |last3=Eberth |first3=David A. |title=New Perspectives on Horned Dinosaurs: The Royal Tyrrell Museum Ceratopsian Symposium |date=2010 |publisher=Indiana University Press |isbn=978-0-253-35358-0 |jstor=j.ctt16gzgng }}</ref><ref>{{cite journal |last1=Scannella |first1=John B. |last2=Fowler |first2=Denver W. |title=A stratigraphic survey of Triceratops localities in the Hell Creek Formation, northeastern Montana (2006–2010) |journal=Through the End of the Cretaceous in the Type Locality of the Hell Creek Formation in Montana and Adjacent Areas |date=2014 |doi=10.1130/2014.2503(12) }}</ref><ref>{{cite journal |doi=10.7934/p1099 |title=Evolutionary Trends in Triceratops from the Hell Creek Formation, Montana (Project) |year=2014 |last1=Scannella |first1=B. |last2=Fowler |first2=W. |last3=Goodwin |first3=B. |last4=Horner |first4=R. }}</ref><ref>{{cite journal |last1=Scannella |first1=John |title=A chasmosaurine ceratopsid premaxilla from the basal sandstone of the Hell Creek Formation, Montana |journal=Vertebrate Anatomy Morphology Palaeontology |date=10 November 2020 |volume=8 |pages=154–169 |doi=10.18435/vamp29366 |s2cid=228888356 |doi-access=free }}</ref> 8.31% of all vertebrate remains from the Hell Creek Formation are unassigned ceratopsids.<ref name="parsons4"/> In 2012, a new unidentified species of chasmosaur ceratopsian with noticeable differences from ''Triceratops'' was unearthed in South Dakota by a fossil hunter named John Carter.<ref>{{cite web|last1=Biles|first1=Jan|title=Rare dinosaur skull being prepared for exhibition|url=http://cjonline.com/news-local/2015-09-07/rare-dinosaur-skull-being-prepared-exhibition|website=Topeka Capital-Journal.com|publisher=Topeka Capital-Journal|access-date=7 September 2015}}</ref><ref>{{cite web|title=Super-sized Ceratopsian Skull Might be New Species|url=https://blog.everythingdinosaur.co.uk/blog/_archives/2015/08/29/super-sized-ceratopsian-skull-might-be-new-species.html|website=Everything Dinosaur|date=29 August 2015 |access-date=29 August 2015}}</ref><ref>{{cite web|last1=O' Connell|first1=Max|title=Dinosaur skull found in Buffalo likely a new species|url=http://rapidcityjournal.com/news/local/dinosaur-skull-found-in-buffalo-likely-a-new-species/article_b33d3375-b74c-5941-aa0b-281ad59b430a.html|website=Rapid City Journal|date=27 August 2015 |access-date=27 August 2015}}</ref> Indeterminate ceratopsid teeth and some identifiable bones from ''Triceratops'' can be extremely common.<ref>{{cite book |last1=Carpenter |first1=Kenneth |title=Horns and Beaks: Ceratopsian and Ornithopod Dinosaurs |date=2006 |publisher=Indiana University Press |id={{Project MUSE|49401|type=book}} |isbn=978-0-253-02795-5 }}{{page needed|date=January 2024}}</ref><ref>{{cite book |last1=Ryan |first1=Michael J. |last2=Chinnery-Allgeier |first2=Brenda J. |last3=Eberth |first3=David A. |title=New Perspectives on Horned Dinosaurs: The Royal Tyrrell Museum Ceratopsian Symposium |date=2010 |publisher=Indiana University Press |isbn=978-0-253-35358-0 |jstor=j.ctt16gzgng }}</ref><ref>{{cite journal |last1=Scannella |first1=John B. |last2=Fowler |first2=Denver W. |title=A stratigraphic survey of Triceratops localities in the Hell Creek Formation, northeastern Montana (2006–2010) |journal=Through the End of the Cretaceous in the Type Locality of the Hell Creek Formation in Montana and Adjacent Areas |date=2014 |doi=10.1130/2014.2503(12) }}</ref><ref>{{cite report|doi=10.7934/p1099 |title=Evolutionary Trends in Triceratops from the Hell Creek Formation, Montana (Project) |year=2014 |last1=Scannella |first1=B. |last2=Fowler |first2=W. |last3=Goodwin |first3=B. |last4=Horner |first4=R. }}</ref><ref>{{cite journal |last1=Scannella |first1=John |title=A chasmosaurine ceratopsid premaxilla from the basal sandstone of the Hell Creek Formation, Montana |journal=Vertebrate Anatomy Morphology Palaeontology |date=10 November 2020 |volume=8 |pages=154–169 |doi=10.18435/vamp29366 |s2cid=228888356 |doi-access=free }}</ref> 8.31% of all vertebrate remains from the Hell Creek Formation are unassigned ceratopsids.<ref name="parsons4"/> In 2012, a new unidentified species of chasmosaur ceratopsian with noticeable differences from ''Triceratops'' was unearthed in South Dakota by a fossil hunter named John Carter.<ref>{{cite web|last1=Biles|first1=Jan|title=Rare dinosaur skull being prepared for exhibition|url=http://cjonline.com/news-local/2015-09-07/rare-dinosaur-skull-being-prepared-exhibition|website=Topeka Capital-Journal.com|publisher=Topeka Capital-Journal|access-date=7 September 2015}}</ref><ref>{{cite web|title=Super-sized Ceratopsian Skull Might be New Species|url=https://blog.everythingdinosaur.co.uk/blog/_archives/2015/08/29/super-sized-ceratopsian-skull-might-be-new-species.html|website=Everything Dinosaur|date=29 August 2015 |access-date=29 August 2015}}</ref><ref>{{cite web|last1=O' Connell|first1=Max|title=Dinosaur skull found in Buffalo likely a new species|url=http://rapidcityjournal.com/news/local/dinosaur-skull-found-in-buffalo-likely-a-new-species/article_b33d3375-b74c-5941-aa0b-281ad59b430a.html|website=Rapid City Journal|date=27 August 2015 |access-date=27 August 2015}}</ref>


{{Paleobiota-key-compact}} {{Paleobiota-key-compact}}
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A ceratopsian that was once proposed to be synonymous with ''Triceratops'',<ref name="scannella&horner2010">{{cite journal | last1 = Scannella | first1 = J. | last2 = Horner | first2 = J.R. | year = 2010 | title = ''Torosaurus'' Marsh, 1891, is ''Triceratops'' Marsh, 1889 (Ceratopsidae: Chasmosaurinae): synonymy through ontogeny | journal = Journal of Vertebrate Paleontology | volume = 30 | issue = 4| pages = 1157–1168 | doi = 10.1080/02724634.2010.483632 | bibcode = 2010JVPal..30.1157S | s2cid = 86767957 }}</ref> but is now regarded as a valid and distinct ceratopsian.<ref>{{cite journal |last1=Mallon |first1=Jordan C |last2=Holmes |first2=Robert B |last3=Bamforth |first3=Emily L |last4=Schumann |first4=Dirk |title=The record of Torosaurus (Ornithischia: Ceratopsidae) in Canada and its taxonomic implications |journal=Zoological Journal of the Linnean Society |date=7 May 2022 |volume=195 |issue=1 |pages=157–171 |doi=10.1093/zoolinnean/zlab120 |doi-access=free }}</ref> A rare ceratopsid.<ref name="parsons3" /> Fossils have been in the ], ], ], ], ], ] and ]. A ceratopsian that was once proposed to be synonymous with ''Triceratops'',<ref name="scannella&horner2010">{{cite journal | last1 = Scannella | first1 = J. | last2 = Horner | first2 = J.R. | year = 2010 | title = ''Torosaurus'' Marsh, 1891, is ''Triceratops'' Marsh, 1889 (Ceratopsidae: Chasmosaurinae): synonymy through ontogeny | journal = Journal of Vertebrate Paleontology | volume = 30 | issue = 4| pages = 1157–1168 | doi = 10.1080/02724634.2010.483632 | bibcode = 2010JVPal..30.1157S | s2cid = 86767957 }}</ref> but is now regarded as a valid and distinct ceratopsian.<ref>{{cite journal |last1=Mallon |first1=Jordan C |last2=Holmes |first2=Robert B |last3=Bamforth |first3=Emily L |last4=Schumann |first4=Dirk |title=The record of Torosaurus (Ornithischia: Ceratopsidae) in Canada and its taxonomic implications |journal=Zoological Journal of the Linnean Society |date=7 May 2022 |volume=195 |issue=1 |pages=157–171 |doi=10.1093/zoolinnean/zlab120 |doi-access=free }}</ref> A rare ceratopsid.<ref name="parsons3" /> Fossils have been in the ], ], ], ], ], ] and ].
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] ]
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'']''<ref name=Fowler2020>{{cite journal |author1=Denver W. Fowler |author2=John P. Wilson |author3=Elizabeth A. Freedman Fowler |author4=Christopher R. Noto |author5=Daniel Anduza |author6=John R. Horner |year=2020 |title=''Trierarchuncus prairiensis'' gen. et sp. nov., the last alvarezsaurid: Hell Creek Formation (uppermost Maastrichtian), Montana |journal=Cretaceous Research |volume=116 |pages=Article 104560 |doi=10.1016/j.cretres.2020.104560 |s2cid=225630913 |doi-access=free |bibcode=2020CrRes.11604560F }}</ref>
'']''<ref name="cretaceous-distribution-montana" />
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''T. prairiensis''<ref name="cretaceous-distribution-montana" /> ''T. prairiensis''<ref name=Fowler2020/>
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A tyrannosaur, known from several specimens including a juvenile nicknamed "]".<ref>{{cite journal |last1=Horner |first1=John R. |last2=Goodwin |first2=Mark B. |last3=Myhrvold |first3=Nathan |title=Dinosaur Census Reveals Abundant Tyrannosaurus and Rare Ontogenetic Stages in the Upper Cretaceous Hell Creek Formation (Maastrichtian), Montana, USA |journal=PLOS ONE |date=9 February 2011 |volume=6 |issue=2 |pages=e16574 |doi=10.1371/journal.pone.0016574 |doi-access=free |bibcode=2011PLoSO...616574H }}</ref> Also found in the ], ], ], ], ], ], ], ], ], ], ], and also found in ]s. Isolated teeth in the Hell Creek are common enough to be dug commercially by collectors, but rare enough that they are often sold for very high prices with fragmentary teeth usually beginning at least in the hundreds of USD, and complete teeth in the thousands of USD. Perhaps the best known iconic dinosaur. A tyrannosaur, known from several specimens including a juvenile nicknamed "]".<ref>{{cite journal |last1=Horner |first1=John R. |last2=Goodwin |first2=Mark B. |last3=Myhrvold |first3=Nathan |title=Dinosaur Census Reveals Abundant Tyrannosaurus and Rare Ontogenetic Stages in the Upper Cretaceous Hell Creek Formation (Maastrichtian), Montana, USA |journal=PLOS ONE |date=9 February 2011 |volume=6 |issue=2 |pages=e16574 |doi=10.1371/journal.pone.0016574 |doi-access=free |pmid=21347420 |pmc=3036655 |bibcode=2011PLoSO...616574H }}</ref> Also found in the ], ], ], ], ], ], ], ], ], ], ], and also found in ]s. Isolated teeth in the Hell Creek are common enough to be dug commercially by collectors, but rare enough that they are often sold for very high prices with fragmentary teeth usually beginning at least in the hundreds of USD, and complete teeth in the thousands of USD. Perhaps the best known iconic dinosaur.
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] ]
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One partial skeleton. One partial skeleton.
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An ]. ''Numem nudum'' An ]; '']''.
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|''E. infernalis'' |''E. infernalis''
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* South Dakota<ref name="Eoneophron">{{Cite journal |last1=Atkins-Weltman |first1=K. L. |last2=Simon |first2=D. J. |last3=Woodward |first3=H. N. |last4=Funston |first4=G. F. |last5=Snively |first5=E. |year=2024 |title=A new oviraptorosaur (Dinosauria: Theropoda) from the end-Maastrichtian Hell Creek Formation of North America |journal=PLOS ONE |volume=19 |issue=1 |at=e0294901 |doi=10.1371/journal.pone.0294901 |doi-access=free|pmid=38266012 |pmc=10807829 }}</ref> * South Dakota<ref name="Eoneophron">{{Cite journal |last1=Atkins-Weltman |first1=K. L. |last2=Simon |first2=D. J. |last3=Woodward |first3=H. N. |last4=Funston |first4=G. F. |last5=Snively |first5=E. |year=2024 |title=A new oviraptorosaur (Dinosauria: Theropoda) from the end-Maastrichtian Hell Creek Formation of North America |journal=PLOS ONE |volume=19 |issue=1 |at=e0294901 |doi=10.1371/journal.pone.0294901 |doi-access=free|pmid=38266012 |pmc=10807829 |bibcode=2024PLoSO..1994901A }}</ref>
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|A partial right hindlimb<ref name="Eoneophron" /> |A partial right hindlimb<ref name="Eoneophron" />
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] ]
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'']''<ref name="parsons"/> '']''<ref name="parsons"/>
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|''A. darwini''<ref name="Magnusavis" />
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* Montana
⚫ ''A.'' sp.<ref name=stidham1999>Stidham, 1999. North American avisaurids (Aves: Enantiornithes): New data on morphology and phylogeny. VII International Symposium on Mesozoic Terrestrial Ecosystems, abstracts.</ref>
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⚫ * Montana<ref name=stidham1999/>
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* DDM 1577.730, a right tarsometatarsus
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⚫ * distal tarsals, metatarsus (juvenile)<ref name=stidham1999/>
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⚫ ''A.'' sp.<ref name="stidham1999">Stidham, 1999. North American avisaurids (Aves: Enantiornithes): New data on morphology and phylogeny. VII International Symposium on Mesozoic Terrestrial Ecosystems, abstracts.</ref>
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⚫ * Montana<ref name="stidham1999" />
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⚫ * distal tarsals, metatarsus (juvenile)<ref name="stidham1999" />
* MOR3070, a partial right tarsometatarsus
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'']''<ref name="DePalma et al.">{{Cite journal|title=The first giant raptor (Theropoda: Dromaeosauridae) from the Hell Creek Formation|first1=Robert T.|last1=Bakker|first2=Peter L.|last2=Larson|first3=Larry D.|last3=Martin|first4=David A.|last4=Burnham|first5=Robert A.|last5=DePalma|date=30 October 2015|doi=10.17161/paleo.1808.18764|journal=Paleontological Contributions|volume= 14: 1–16|doi-access=free}}</ref> '']''<ref name="DePalma et al.">{{Cite journal|title=The first giant raptor (Theropoda: Dromaeosauridae) from the Hell Creek Formation|first1=Robert T.|last1=Bakker|first2=Peter L.|last2=Larson|first3=Larry D.|last3=Martin|first4=David A.|last4=Burnham|first5=Robert A.|last5=DePalma|date=30 October 2015|doi=10.17161/paleo.1808.18764|journal=Paleontological Contributions|volume= 14: 1–16|doi-access=free|hdl=1808/18764|hdl-access=free}}</ref>
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''D. steini ''<ref name="DePalma et al."/> ''D. steini ''<ref name="DePalma et al."/>
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* isolated teeth.<ref name="DePalma et al."/> * isolated teeth.<ref name="DePalma et al."/>
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A ]. Second-largest dromaeosaurid known.<ref name="acheroraptor"/> A large ].<ref name="acheroraptor"/>
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] ]
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|'']''<ref name="Magnusavis">{{Cite journal |last1=Clark |first1=Alexander D. |last2=Atterholt |first2=Jessie |last3=Scannella |first3=John B. |last4=Carroll |first4=Nathan |last5=O'Connor |first5=Jingmai K. |author-link5=Jingmai O'Connor |date=2024-10-09 |editor-last=Pinheiro |editor-first=Felipe Lima |title=New enantiornithine diversity in the Hell Creek Formation and the functional morphology of the avisaurid tarsometatarsus |journal=] |language=en |volume=19 |issue=10 |pages=e0310686 |doi=10.1371/journal.pone.0310686 |issn=1932-6203 |pmid=39383133 |doi-access=free|pmc=11463745 }}</ref>
|''M. ekalakaensis''
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*Montana
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* CCM V2019.5.1, partial right tarsometatarsus and toe bone
|A large enantiornithine closely related to avisaurids.
|
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'']''<ref name="Olshevsky, G. 1991, pp 196">Olshevsky, G., 1991, ''A Revision of the Parainfraclass Archosauria Cope, 1869, Excluding the Advanced Crocodylia. Mesozoic Meanderings 2'' pp 196</ref> '']''<ref name="Olshevsky, G. 1991, pp 196">Olshevsky, G., 1991, ''A Revision of the Parainfraclass Archosauria Cope, 1869, Excluding the Advanced Crocodylia. Mesozoic Meanderings 2'' pp 196</ref>
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''P. caperatus'' <ref name="Olshevsky, G. 1991, pp 196"/> ''P. caperatus''<ref name="Olshevsky, G. 1991, pp 196"/>
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*North Dakota, South Dakota, and Montana. *North Dakota, South Dakota, and Montana.
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'']''<ref name=carpenter1982>{{cite journal|last=Carpenter|first=K.|year=1982|title=Baby dinosaurs from the Late Cretaceous Lance and Hell Creek formations and a description of a new species of theropod|journal=Contributions to Geology, University of Wyoming|volume=20|issue=2|pages=123–134|url=http://doc.rero.ch/record/232469/files/PAL_E4465.pdf}}</ref><ref name="Olshevsky, G. 1991, pp 196"/> '']''<ref name=carpenter1982>{{cite journal|last=Carpenter|first=K.|year=1982|title=Baby dinosaurs from the Late Cretaceous Lance and Hell Creek formations and a description of a new species of theropod|journal=Contributions to Geology, University of Wyoming|volume=20|issue=2|pages=123–134|url=http://doc.rero.ch/record/232469/files/PAL_E4465.pdf}}</ref><ref name="Olshevsky, G. 1991, pp 196"/>
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''P. bakkeri'' <ref name=carpenter1982>{{cite journal|last=Carpenter|first=K.|year=1982|title=Baby dinosaurs from the Late Cretaceous Lance and Hell Creek formations and a description of a new species of theropod|journal=Contributions to Geology, University of Wyoming|volume=20|issue=2|pages=123–134|url=http://doc.rero.ch/record/232469/files/PAL_E4465.pdf}}</ref><ref name="Olshevsky, G. 1991, pp 196"/> ''P. bakkeri''<ref name=carpenter1982>{{cite journal|last=Carpenter|first=K.|year=1982|title=Baby dinosaurs from the Late Cretaceous Lance and Hell Creek formations and a description of a new species of theropod|journal=Contributions to Geology, University of Wyoming|volume=20|issue=2|pages=123–134|url=http://doc.rero.ch/record/232469/files/PAL_E4465.pdf}}</ref><ref name="Olshevsky, G. 1991, pp 196"/>
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*Montana *Montana
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'']'' <ref name="Estes, R. 1964">{{cite book |last1=Estes |first1=Richard |title=Fossil vertebrates from the late Cretaceous Lance formation, eastern Wyoming |date=1964 |publisher=University of California Press |oclc=3753287 }}{{page needed|date=December 2022}}</ref><ref name="Larson & Currie 2013">{{cite journal |last1=Larson |first1=Derek W. |last2=Currie |first2=Philip J. |title=Multivariate Analyses of Small Theropod Dinosaur Teeth and Implications for Paleoecological Turnover through Time |journal=PLOS ONE |date=23 January 2013 |volume=8 |issue=1 |pages=e54329 |doi=10.1371/journal.pone.0054329 |pmid=23372708 |pmc=3553132 |bibcode=2013PLoSO...854329L |doi-access=free }}</ref> '']''<ref name="Estes, R. 1964">{{cite book |last1=Estes |first1=Richard |title=Fossil vertebrates from the late Cretaceous Lance formation, eastern Wyoming |date=1964 |publisher=University of California Press |oclc=3753287 }}{{page needed|date=December 2022}}</ref><ref name="Larson & Currie 2013">{{cite journal |last1=Larson |first1=Derek W. |last2=Currie |first2=Philip J. |title=Multivariate Analyses of Small Theropod Dinosaur Teeth and Implications for Paleoecological Turnover through Time |journal=PLOS ONE |date=23 January 2013 |volume=8 |issue=1 |pages=e54329 |doi=10.1371/journal.pone.0054329 |pmid=23372708 |pmc=3553132 |bibcode=2013PLoSO...854329L |doi-access=free }}</ref>
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''R. sp.'' <ref name="Estes, R. 1964"/><ref name="Larson & Currie 2013"/> ''R. sp.''<ref name="Estes, R. 1964"/><ref name="Larson & Currie 2013"/>
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*Montana. *Montana.
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A coelurosaur that is known from teeth and from two species ''Richardoestesia gilmorei'' and ''Richardestesia isosceles'', which have also been unearthed in the ] in ]. A coelurosaur that is known from teeth and from two species ''Richardoestesia gilmorei'' and ''Richardestesia isosceles'', which have also been unearthed in the ] in ].
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] ]
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|]<ref>{{cite thesis |last1=Stidham |first1=Thomas Allen |title=The origin and ecological diversification of modern birds: Evidence from the extinct wading ducks, Presbyornithidae (Neornithes: Anseriformes) |year=2001 |id={{ProQuest|304684225}} |oclc=892837810 }}</ref> |]<ref>{{cite thesis |last1=Stidham |first1=Thomas Allen |title=The origin and ecological diversification of modern birds: Evidence from the extinct wading ducks, Presbyornithidae (Neornithes: Anseriformes) |year=2001 |id={{ProQuest|304684225}} |oclc=892837810 }}</ref>
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== Pterosaurs == == Pterosaurs ==
Indeterminate ] remains, most likely belong to '']'' or an unidentified genus, have been found in Hell Creek as well as the ] and the ].<ref name="Henderson & Peterson 2006">{{cite journal |last1=Henderson |first1=Michael |last2=Peterson |first2=Joseph |title=An Azhdarchid Pterosaur Cervical Vertebra from the Hell Creek Formation (Maastrichtian) of Southeastern Montana |journal=Journal of Vertebrate Paleontology |date=30 March 2006 |volume=26 |issue=1 |pages=192–195 |doi=10.1671/0272-4634(2006)262.0.CO;2 |jstor=4524549 |s2cid=130751879 |url=http://doc.rero.ch/record/15687/files/PAL_E2073.pdf }}</ref><ref>{{cite journal |last1=Averianov |first1=Alexander |title=Review of taxonomy, geographic distribution, and paleoenvironments of Azhdarchidae (Pterosauria) |journal=ZooKeys |date=11 August 2014 |issue=432 |pages=1–107 |doi=10.3897/zookeys.432.7913 |pmid=25152671 |pmc=4141157 |bibcode=2014ZooK..432....1A |doi-access=free }}</ref> Indeterminate ] remains have also been found here as well.<ref>{{cite journal |last1=Longrich |first1=Nicholas |last2=Martill |first2=David |last3=Andres |first3=Brian |title=Late Maastrichtian pterosaurs from North Africa and mass extinction of Pterosauria at the Cretaceous-Paleogene boundary |journal=PLOS Biology |date=13 March 2018 |volume=16 |issue=3 |page=e2001663 |doi=10.1371/journal.pbio.2001663 |pmid=29534059 |pmc=5849296 |doi-access=free }}</ref><ref>{{cite journal |last1=Longrich |first1=Nicholas |last2=Martill |first2=David |last3=Andres |first3=Brian |title=Correction: Late Maastrichtian pterosaurs from North Africa and mass extinction of Pterosauria at the Cretaceous-Paleogene boundary |journal=PLOS Biology |date=11 April 2018 |volume=16 |issue=4 |page=e1002627 |doi=10.1371/journal.pbio.1002627 |pmid=29641516 |pmc=5894959 |doi-access=free }}</ref> Undescribed pterosaur remains were reported from ].<ref name="Henderson & Peterson 2006"/> A specimen of an ] pterosaur from ] likely belongs to '']'', though it is not diagnostic to the species level.<ref name="Henderson & Peterson 2006">{{cite journal |last1=Henderson |first1=Michael |last2=Peterson |first2=Joseph |title=An Azhdarchid Pterosaur Cervical Vertebra from the Hell Creek Formation (Maastrichtian) of Southeastern Montana |journal=Journal of Vertebrate Paleontology |date=30 March 2006 |volume=26 |issue=1 |pages=192–195 |doi=10.1671/0272-4634(2006)262.0.CO;2 |jstor=4524549 |s2cid=130751879 |url=http://doc.rero.ch/record/15687/files/PAL_E2073.pdf }}</ref>
{| class="wikitable sortable mw-collapsible" {| class="wikitable sortable mw-collapsible"
|- |-
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|- |-
| |
⚫ ] '']''<ref name="Henderson & Peterson 2006"/>
] spp.
| |
Indeterminate Indeterminate
|Montana<ref name="Henderson & Peterson 2006"/>
| |
⚫ * Montana<ref name="Henderson & Peterson 2006"/>
⚫ * North Dakota
| |
|A single ] neck bone which may belong to the genus '']''.<ref name="Henderson & Peterson 2006"/>
⚫ |
⚫ |
Records of ] remains from the Hell Creek Formation are two indeterminate specimens, which have been recorded from ] but not described (Johnson ''et al.'', 2000; Pearson ''et al.'', 2002). A single ] neck bone may belong to the genus '']'', though they are not diagnostic to the generic level.<ref name="Henderson & Peterson 2006"/>
| |
] ]
⚫ |-
⚫ |
] spp.<ref>{{cite web |title=New Hell Creek Pterosaur Species |url=http://trieboldpaleontology.com/hellcreekpterosaur.html |website=TrieboldPaleo.Inc}}</ref>
⚫ |
⚫ Indeterminate
⚫ |
*South Dakota
⚫ |
⚫ |
⚫ |
⚫ |
|- |-
|} |}
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== Squamata == == Squamata ==
{{Paleobiota-key-compact}}
⚫ Indeterminate ] remains have been unearthed in North Dakota; they may belong to a mosasaur measuring {{cvt|11|m|ft}} in length.<ref>{{Cite web|date=2019-03-31|title=Fossils may capture the day the dinosaurs died. Here's what you should know.|url=https://www.nationalgeographic.com/science/article/fossils-found-from-day-dinosaurs-died-chicxulub-tanis-cretaceous-extinction|archive-url=https://web.archive.org/web/20210305093325/https://www.nationalgeographic.com/science/article/fossils-found-from-day-dinosaurs-died-chicxulub-tanis-cretaceous-extinction|url-status=dead|archive-date=March 5, 2021|access-date=2021-08-20|website=Science|language=en}}</ref><ref>{{cite journal |last1=Van Vranken |first1=Nathan E. |last2=Boyd |first2=Clint A. |title=The first in situ collection of a mosasaurine from the marine Breien Member of the Hell Creek Formation in south-central North Dakota, USA |journal=PaleoBios |date=21 August 2021 |volume=38 |issue=1 |doi=10.5070/P938054460 |doi-access=free }}</ref>{{Paleobiota-key-compact}}
{| class="wikitable sortable mw-collapsible" {| class="wikitable sortable mw-collapsible"
|- |-
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| |
] ]
|
|-
|
]
|
⚫ Indeterminate
|
|
|
|
⚫ Indeterminate ] remains have been unearthed in North Dakota; they may belong to a mosasaur measuring {{cvt|11|m|ft}} in length.<ref>{{Cite web|date=2019-03-31|title=Fossils may capture the day the dinosaurs died. Here's what you should know.|url=https://www.nationalgeographic.com/science/article/fossils-found-from-day-dinosaurs-died-chicxulub-tanis-cretaceous-extinction|archive-url=https://web.archive.org/web/20210305093325/https://www.nationalgeographic.com/science/article/fossils-found-from-day-dinosaurs-died-chicxulub-tanis-cretaceous-extinction|url-status=dead|archive-date=March 5, 2021|access-date=2021-08-20|website=Science|language=en}}</ref><ref>{{cite journal |last1=Van Vranken |first1=Nathan E. |last2=Boyd |first2=Clint A. |title=The first in situ collection of a mosasaurine from the marine Breien Member of the Hell Creek Formation in south-central North Dakota, USA |journal=PaleoBios |date=21 August 2021 |volume=38 |issue=1 |doi=10.5070/P938054460 |doi-access=free }}</ref>
|
]
| |
|- |-
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'']''<ref name=JIG362 /> '']''<ref name=JIG362 />
| |
''C. laramiensis''<ref name=JIG362 /> ''C. sp.''<ref name=JIG362 />
| |
* Montana * Montana
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===Paleoflora=== ===Paleoflora===
{{paleobiota-key-compact}} {{paleobiota-key-compact}}

====Liverworts==== ====Liverworts====
{| class="wikitable sortable" style="margin:auto; width:100%;" {| class="wikitable sortable" style="margin:auto; width:100%;"
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| |
| |
A ] wood morphogenus A ]ous wood morphogenus
| |
|- |-
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| |
| |
A ] wood morphogenus A ]ous wood morphogenus
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|- |-
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A ] wood morphogenus A ]ous wood morphogenus
| |
|- |-
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| |
| |
Included in ''] affinis'' by L. Hickey.<br/> Belongs in Rhamnaceae (modern ]s and '']'').{{cn|date=February 2024}} Some other specimens referred to '']''(?) sp.), a real cinnamon bush. Its affinity is questionable. Included in ''] affinis'' by L. Hickey.<br/> Belongs in Rhamnaceae (modern ]s and '']'').{{citation needed|date=February 2024}} Some other specimens referred to '']''(?) sp.), a real cinnamon bush. Its affinity is questionable.
| |
] ]
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| |
Occurs in southern the ] flora,<Br/> Leo Hickey claims it is found further north in ] and the ].{{cn|date=February 2024}} Occurs in southern the ] flora,<Br/> Leo Hickey claims it is found further north in ] and the ].{{citation needed|date=February 2024}}
| |
] ]
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| |
| |
A fossil fruit likely to belonging to ''].'' <ref>{{Cite journal |last1=Crane |first1=Peter R. |last2=Manchester |first2=Steven R. |last3=Dilcher |first3=David L. |date=October 1991 |title=Reproductive and Vegetative Structure of Nordenskioldia (Trochodendraceae), A Vesselless Dicotyledon from the Early Tertiary of the Northern Hemisphere |journal=American Journal of Botany |volume=78 |issue=10 |pages=1311–1334 |doi=10.1002/j.1537-2197.1991.tb12599.x }}</ref> A fossil fruit likely to belonging to ''].''<ref>{{Cite journal |last1=Crane |first1=Peter R. |last2=Manchester |first2=Steven R. |last3=Dilcher |first3=David L. |date=October 1991 |title=Reproductive and Vegetative Structure of Nordenskioldia (Trochodendraceae), A Vesselless Dicotyledon from the Early Tertiary of the Northern Hemisphere |journal=American Journal of Botany |volume=78 |issue=10 |pages=1311–1334 |doi=10.1002/j.1537-2197.1991.tb12599.x }}</ref>
| |
|- |-
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A ] with fruits and seeds visually similar to '']'' though it's dubious.{{cn|date=February 2024}} A ] with fruits and seeds visually similar to '']'' though it's dubious.{{citation needed|date=February 2024}}
| |
] ]
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|A fossil fruit that may belong to ]''.'' |A fossil fruit that may belong to '']''.
| |
|- |-
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=== Bibliography === === Bibliography ===
;General ;General
* {{cite LSA |last1=Broad |first1=William J. |last2=Chang |first2=Kenneth |title=Fossil Site Reveals Day That Meteor Hit Earth and, Maybe, Wiped Out Dinosaurs |url=https://www.nytimes.com/2019/03/29/science/dinosaurs-extinction-asteroid.html |work=The New York Times |date=29 March 2019 }} * {{citation |last1=Broad |first1=William J. |last2=Chang |first2=Kenneth |title=Fossil Site Reveals Day That Meteor Hit Earth and, Maybe, Wiped Out Dinosaurs |url=https://www.nytimes.com/2019/03/29/science/dinosaurs-extinction-asteroid.html |work=The New York Times |date=29 March 2019 }}
* {{cite LSA |first=Douglas |last=Preston |year=2019 |title=The Day the Dinosaurs Died |url=https://newyorker.com/magazine/2019/04/08/the-day-the-dinosaurs-died |work=The New Yorker |pages=1 |access-date=2019-04-01}} * {{citation |first=Douglas |last=Preston |year=2019 |title=The Day the Dinosaurs Died |url=https://newyorker.com/magazine/2019/04/08/the-day-the-dinosaurs-died |magazine=The New Yorker |pages=1 |access-date=2019-04-01}}
* {{cite LSA |last=U.S. National |first=Park Service |year=1966 |title=National Natural Landmarks - National Natural Landmarks (U.S. National Park Service) |url=https://www.nps.gov/subjects/nnlandmarks/site.htm?Site=HECR-MT |publisher=www.nps.gov |pages=1 |access-date=2019-03-22}} * {{citation |last=U.S. National |first=Park Service |year=1966 |title=National Natural Landmarks - National Natural Landmarks (U.S. National Park Service) |url=https://www.nps.gov/subjects/nnlandmarks/site.htm?Site=HECR-MT |publisher=www.nps.gov |pages=1 |access-date=2019-03-22}}


;Geology ;Geology
<!--Most recent first--> <!--Most recent first-->
* {{cite LSA |last=DePalma, Smit J, Burnham DA, Kuiper K, Manning PL, Oleinik A, Larson P, Maurrasse FJ, Vellekoop J, Richards MA, Gurche L and Walter Alvarez W |first=R.A |year=2019 |title=A seismically induced onshore surge deposit at the K-Pg boundary, North Dakota |url=https://www.pnas.org/content/116/17/8190 |journal=] |volume=116 |issue=17 |pages=8190–8199 |access-date=2020-03-30}} {{doi|10.1073/pnas.1817407116}} {{PMID|30936306}} {{PMC|6486721}} {{bibcode|2019PNAS..116.8190D}} * {{citation | last=DePalma | first=Robert A. | last2=Smit | first2=Jan | last3=Burnham | first3=David A. | last4=Kuiper | first4=Klaudia | last5=Manning | first5=Phillip L. | last6=Oleinik | first6=Anton | last7=Larson | first7=Peter | last8=Maurrasse | first8=Florentin J. | last9=Vellekoop | first9=Johan | last10=Richards | first10=Mark A. | last11=Gurche | first11=Loren | last12=Alvarez | first12=Walter |year=2019 |title=A seismically induced onshore surge deposit at the K-Pg boundary, North Dakota |journal=] |volume=116 |issue=17 |pages=8190–8199 |doi=10.1073/pnas.1817407116 |doi-access=free |pmid=30936306 |pmc=6486721|bibcode=2019PNAS..116.8190D }} {{bibcode|2019PNAS..116.8190D}}
* {{cite LSA |last=Evans |first=D.C. |last2=Larson |first2=D.W. |last3=Currie |first3=P.J. |year=2013 |title=A new dromaeosaurid (Dinosauria: Theropoda) with Asian affinities from the latest Cretaceous of North America |journal=] |volume=100 |issue=11 |pages=1041–1049}} {{doi|10.1007/s00114-013-1107-5}} {{bibcode|2013NW....100.1041E}} {{PMID|24248432}} * {{citation |last1=Evans |first1=D.C. |last2=Larson |first2=D.W. |last3=Currie |first3=P.J. |year=2013 |title=A new dromaeosaurid (Dinosauria: Theropoda) with Asian affinities from the latest Cretaceous of North America |journal=] |volume=100 |issue=11 |pages=1041–1049 |doi=10.1007/s00114-013-1107-5|pmid=24248432 |bibcode=2013NW....100.1041E }} {{bibcode|2013NW....100.1041E |pmid=24248432}}
* {{cite LSA |last=Husson |first=D. |last2=Galbrun |first2=B. |last3=Laskar |first3=J. |last4=Hinnov |first4=L.A. |last5=Thibault |first5=N. |last6=Gardin |first6=S. |last7=Locklair |first7=R.E. |year=2011 |title=Astronomical calibration of the Maastrichtian (late Cretaceous) |journal=] |volume=305 |issue=3 |pages=328–340}} {{doi|10.1016/j.epsl.2011.03.008}} {{bibcode|2011E&PSL.305..328H}} * {{citation |last1=Husson |first1=D. |last2=Galbrun |first2=B. |last3=Laskar |first3=J. |last4=Hinnov |first4=L.A. |last5=Thibault |first5=N. |last6=Gardin |first6=S. |last7=Locklair |first7=R.E. |year=2011 |title=Astronomical calibration of the Maastrichtian (late Cretaceous) |journal=] |volume=305 |issue=3 |pages=328–340 |doi=10.1016/j.epsl.2011.03.008|bibcode=2011E&PSL.305..328H }} {{bibcode|2011E&PSL.305..328H}}
* {{cite LSA |last=LeCain |first=Rebecca |year=2010 |title=Magnetostratigraphy of the Hell Creek and lower Fort Union formations in northeast Montana |url=https://scholars.unh.edu/thesis/552 |publisher=Master's Theses and Capstones |pages=1 |access-date=2020-03-30}} * {{citation |last=LeCain |first=Rebecca |year=2010 |title=Magnetostratigraphy of the Hell Creek and lower Fort Union formations in northeast Montana |url=https://scholars.unh.edu/thesis/552 |publisher=Master's Theses and Capstones |pages=1 |access-date=2020-03-30}}
* {{cite LSA |last=Johnson |first=K.R. |last2=Nichols |first2=D.J. |last3=Hartman |first3=J.H. |year=2002 |title=Hell Creek Formation: A 2001 synthesis. The Hell Creek Formation and the Cretaceous-Tertiary Boundary in the northern Great Plains |journal=] |volume=361 |pages=503–510}} * {{citation |last1=Johnson |first1=K.R. |last2=Nichols |first2=D.J. |last3=Hartman |first3=J.H. |year=2002 |title=Hell Creek Formation: A 2001 synthesis. The Hell Creek Formation and the Cretaceous-Tertiary Boundary in the northern Great Plains |journal=] |volume=361 |pages=503–510}}


;Paleontology ;Paleontology
<!--Most recent first--> <!--Most recent first-->
* {{cite LSA |last=DePalma |first=Robert |year=2010 |title=Preliminary Notes on the First Recorded Amber Insects from the Hell Creek Formation |url=https://www.researchgate.net/publication/228474031_Preliminary_Notes_on_the_First_Recorded_Amber_Insects_from_the_Hell_Creek_Formation |journal=] |volume=x |pages=x |access-date=2019-02-21}} * {{citation |last=DePalma |first=Robert |year=2010 |title=Preliminary Notes on the First Recorded Amber Insects from the Hell Creek Formation |url=https://www.researchgate.net/publication/228474031 |journal=] |access-date=2019-02-21}}
* {{cite LSA |last=Boyd |first=Clint A. |last2=Brown |first2=Caleb M. |last3=Scheetz |first3=Rodney D. |last4=Clarke |first4=Julia A. |year=2009 |title=Taxonomic revision of the basal neornithischian taxa ''Thescelosaurus'' and ''Bugenasaura'' |journal=] |volume=29 |issue=3 |pages=758–770}} {{doi|10.1671/039.029.0328}} * {{citation |last1=Boyd |first1=Clint A. |last2=Brown |first2=Caleb M. |last3=Scheetz |first3=Rodney D. |last4=Clarke |first4=Julia A. |year=2009 |title=Taxonomic revision of the basal neornithischian taxa ''Thescelosaurus'' and ''Bugenasaura'' |journal=] |volume=29 |issue=3 |pages=758–770 |doi=10.1671/039.029.0328|bibcode=2009JVPal..29..758B }}
* {{cite LSA |last=Longrich |first=N |year=2008 |title=A new, large ornithomimid from the Cretaceous Dinosaur Park Formation of Alberta, Canada: Implications for the study of dissociated dinosaur remains |journal=] |volume=54 |issue=1 |pages=983–996}} {{doi|10.1111/j.1475-4983.2008.00791.x}} * {{citation |last=Longrich |first=N |year=2008 |title=A new, large ornithomimid from the Cretaceous Dinosaur Park Formation of Alberta, Canada: Implications for the study of dissociated dinosaur remains |journal=] |volume=54 |issue=1 |pages=983–996 |doi=10.1111/j.1475-4983.2008.00791.x|bibcode=2008Palgy..51..983L }}
* {{cite LSA |last=Manning |first=P.L. |last2=Ott |first2=C. |last3=Falkingham |first3=P.L. |year=2008 |title=The first tyrannosaurid track from the Hell Creek Formation (Late Cretaceous), Montana, U.S.A |journal=] |volume=23 |issue=10 |pages=645–647}} {{doi|10.2110/palo.2008.p08-030r}} {{bibcode|2008Palai..23..645M}} * {{citation |last1=Manning |first1=P.L. |last2=Ott |first2=C. |last3=Falkingham |first3=P.L. |year=2008 |title=The first tyrannosaurid track from the Hell Creek Formation (Late Cretaceous), Montana, U.S.A |journal=] |volume=23 |issue=10 |pages=645–647 |doi=10.2110/palo.2008.p08-030r|bibcode=2008Palai..23..645M }} {{bibcode|2008Palai..23..645M}}
* {{cite LSA |last=] |first=R.T. |last2=Sullivan |first2=R.M. |last3=Porter |first3=V. |last4=Larson |first4=P. |last5=Saulsbury |first5=S.J. |year=2006 |title=''Dracorex hogwartsia'', n. gen., n. sp., a spiked, flat-headed pachycephalosaurid dinosaur from the Upper Cretaceous Hell Creek Formation of South Dakota in Lucas, S. G. and Sullivan, R. M., eds., Late Cretaceous vertebrates from the Western Interior |url=http://www.childrensmuseum.org/themuseum/dinosphere/draco_rex/dracorex_hogwartsia.pdf |archive-url=https://web.archive.org/web/20110717174743/http://www.childrensmuseum.org/themuseum/dinosphere/draco_rex/dracorex_hogwartsia.pdf |archive-date=2011-07-17 |journal=] |volume=35 |pages=331–354 |access-date=1907-10-31}} * {{citation |last1=Bakker |first1=R.T. |last2=Sullivan |first2=R.M. |last3=Porter |first3=V. |last4=Larson |first4=P. |last5=Saulsbury |first5=S.J. |year=2006 |title=''Dracorex hogwartsia'', n. gen., n. sp., a spiked, flat-headed pachycephalosaurid dinosaur from the Upper Cretaceous Hell Creek Formation of South Dakota in Lucas, S. G. and Sullivan, R. M., eds., Late Cretaceous vertebrates from the Western Interior |url=http://www.childrensmuseum.org/themuseum/dinosphere/draco_rex/dracorex_hogwartsia.pdf |archive-url=https://web.archive.org/web/20110717174743/http://www.childrensmuseum.org/themuseum/dinosphere/draco_rex/dracorex_hogwartsia.pdf |archive-date=2011-07-17 |journal=] |volume=35 |pages=331–354 |author1-link=Robert Bakker }}
* {{cite LSA |last=Henderson |first=M.D. |last2=Peterson |first2=J.E. |year=2006 |title=An azhdarchid pterosaur cervical vertebra from the Hell Creek Formation (Maastrichtian) of southeastern Montana |journal=] |volume=26 |issue=1 |pages=192–195 |doi=10.1671/0272-4634(2006)262.0.CO;2 |jstor=4524549 |s2cid=130751879 }} * {{citation |last1=Henderson |first1=M.D. |last2=Peterson |first2=J.E. |year=2006 |title=An azhdarchid pterosaur cervical vertebra from the Hell Creek Formation (Maastrichtian) of southeastern Montana |journal=] |volume=26 |issue=1 |pages=192–195 |doi=10.1671/0272-4634(2006)262.0.CO;2 |jstor=4524549 |s2cid=130751879 |url=http://doc.rero.ch/record/15687/files/PAL_E2073.pdf }}
* {{cite LSA |last=] |first=David B. |last2=] |first2=Peter |last3=] (eds.) |first3=Halszka |year=2004 |title=The Dinosauria, 2nd edition |url=https://books.google.com/books?id=vtZFDb_iw40C |publisher=Berkeley: University of California Press |pages=1–880 |access-date=2019-02-21}} {{ISBN|0-520-24209-2}} * {{citation |last1=Weishampel |first1=David B. |author2-link=Peter Dodson |last2=Dodson |first2=Peter |author3-link=Halszka Osmólska |last3=Osmólska |first3=Halszka |year=2004 |title=The Dinosauria, 2nd edition |url=https://books.google.com/books?id=vtZFDb_iw40C |publisher=Berkeley: University of California Press |pages=1–880 |access-date=2019-02-21 |isbn=0-520-24209-2 |author1-link=David B. Weishampel }}
* {{cite LSA |last=Pearson |first=D.A. |last2=Schaefer |first2=T. |last3=Johnson |first3=K.R. |last4=Nichols |first4=D.J. |last5=Hunter |first5=J.P. |year=2002 |title=The Hell Creek Formation and the Cretaceous-Tertiary boundary in the northern Great Plains: An integrated continental record of the end of the Cretaceous |url=https://books.google.com/books?id=cHvcIeh2f84C&pg=PA145 |journal=Vertebrate Biostratigraphy of the Hell Creek Formation in Southwestern North Dakota and Northwestern South Dakota, Geological Society of America |volume=Special Paper 361 |pages=145–167 |access-date=2019-03-22}} {{isbn|9780813723617}} * {{citation |last1=Pearson |first1=D.A. |last2=Schaefer |first2=T. |last3=Johnson |first3=K.R. |last4=Nichols |first4=D.J. |last5=Hunter |first5=J.P. |year=2002 |title=The Hell Creek Formation and the Cretaceous-Tertiary boundary in the northern Great Plains: An integrated continental record of the end of the Cretaceous |url=https://books.google.com/books?id=cHvcIeh2f84C&pg=PA145 |journal=Vertebrate Biostratigraphy of the Hell Creek Formation in Southwestern North Dakota and Northwestern South Dakota, Geological Society of America |volume=Special Paper 361 |pages=145–167 |access-date=2019-03-22 |isbn=9780813723617}}
* {{cite LSA |last=Varricchio |first=D.J |year=2001 |title=Late Cretaceous oviraptorosaur (Theropoda) dinosaurs from Montana |publisher=D. H. Tanke and K. Carpenter (eds.), Mesozoic Vertebrate Life. Indiana University Press, Indianapolis, Indiana |pages=42–57}} * {{citation |last=Varricchio |first=D.J |year=2001 |title=Late Cretaceous oviraptorosaur (Theropoda) dinosaurs from Montana |publisher=D. H. Tanke and K. Carpenter (eds.), Mesozoic Vertebrate Life. Indiana University Press, Indianapolis, Indiana |pages=42–57}}
* {{cite LSA |last=Currie |first=P.J. |last2=Padian |first2=K. |year=1997 |title=The Encyclopedia of Dinosaurs |url=https://archive.org/details/encyclopediadino00curr_075 |publisher=Academic Press |pages=1–901 |access-date=2020-03-30}} {{isbn|978-0-122-26810-6}} * {{citation |last1=Currie |first1=P.J. |last2=Padian |first2=K. |year=1997 |title=The Encyclopedia of Dinosaurs |url=https://archive.org/details/encyclopediadino00curr_075 |publisher=Academic Press |pages=1–901 |access-date=2020-03-30 |isbn=978-0-122-26810-6}}
** {{cite book |last=Eberth |first=D.A. |year=1997 |title=Edmonton Group |url=https://archive.org/details/encyclopediadino00curr_075 |url-access=registration |location=San Diego|publisher=Academic Press|pages=–204 |isbn=978-0-122-26810-6}} ** {{cite book |last=Eberth |first=D.A. |year=1997 |title=Edmonton Group |url=https://archive.org/details/encyclopediadino00curr_075 |url-access=registration |location=San Diego|publisher=Academic Press|pages=–204 |isbn=978-0-122-26810-6}}
** {{cite book |last=Lofgren |first=D.F. |year=1997 |title=Hell Creek Formation |url=https://archive.org/details/encyclopediadino00curr_075 |url-access=registration |location=San Diego|publisher=Academic Press|pages=–303 |isbn=978-0-122-26810-6}} ** {{cite book |last=Lofgren |first=D.F. |year=1997 |title=Hell Creek Formation |url=https://archive.org/details/encyclopediadino00curr_075 |url-access=registration |location=San Diego|publisher=Academic Press|pages=–303 |isbn=978-0-122-26810-6}}
** {{cite book |last=Breithaupt |first=B.H |year=1997 |title=Lance Formation |url=https://archive.org/details/encyclopediadino00curr_075 |url-access=registration |location=San Diego|publisher=Academic Press|pages=–395 |isbn=978-0-122-26810-6}} ** {{cite book |last=Breithaupt |first=B.H |year=1997 |title=Lance Formation |url=https://archive.org/details/encyclopediadino00curr_075 |url-access=registration |location=San Diego|publisher=Academic Press|pages=–395 |isbn=978-0-122-26810-6}}
* {{cite LSA |last=Christophel |first=D.C. |year=1976 |title=Fossil floras from the Smoky Tower locality, Alberta, Canada |journal=], Abt. B |volume=157 |pages=x}} * {{citation |last=Christophel |first=D.C. |year=1976 |title=Fossil floras from the Smoky Tower locality, Alberta, Canada |journal=Palaeontographica, Abt. B |volume=157 }}
* {{cite LSA |last=Chandrasekharam |first=A. |year=1974 |title=Megafossil flora from the Genesee locality, Alberta, Canada |journal=], Abt. A |volume=174 |pages=x}} * {{citation |last=Chandrasekharam |first=A. |year=1974 |title=Megafossil flora from the Genesee locality, Alberta, Canada |journal=Palaeontographica, Abt. A |volume=174 }}
* {{cite LSA |last=Estes |first=R. |first2=P. |last2=Berberian |year=1970 |title=Paleoecology of a late Cretaceous vertebrate community from Montana |journal=] |volume=343 |pages=1}} * {{citation |last1=Estes |first1=R. |first2=P. |last2=Berberian |year=1970 |title=Paleoecology of a late Cretaceous vertebrate community from Montana |journal=] |volume=343 |pages=1}}


== External links ==<!-- Geological Society of America Abstracts with Programs, Vol. 38, No. 7, p. 402 --> == External links ==<!-- Geological Society of America Abstracts with Programs, Vol. 38, No. 7, p. 402 -->
* provides a faunal list * provides a faunal list
* *
* *


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Latest revision as of 06:26, 16 December 2024

Fossil flora and fauna of North American site

This is an overview of the fossil flora and fauna of the Maastrichtian-Danian Hell Creek Formation.

Invertebrates

Insects

Insects from the groups Diptera, Zygoptera, and possibly Hemiphlebiidae have been unearthed in Hell Creek in amber. Fossils found in the Hell Creek Formation and the Fort Union Formation of these insects went extinct during the K-T Event.

Color key
Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.
Genus Species Location Stratigraphic position Material Notes Images

Cephaloleichnites

Cephaloleichnites strongi

Possible hispine beetle herbivory on Zingiberopsis attenuta

?Hemiphlebiidae

Indeterminate

Possible Hemiphlebiid damselflies

Brachycera

Indeterminate

Undescribed brachyceran flies

Nematocera

Indeterminate

Undescribed nematoceran flies

Aeschnidiidae

Indeterminate

Indeterminate aeschnidiid dragonflies

Molluscs

Genus Species Location Stratigraphic position Material Notes Images
Plesielliptio

P. postbiplicatus

Freshwater Unionid river mussels

P. gibbosoides

Freshwater Unionid river mussels

P. whitfieldi

Freshwater Unionid river mussels

Rhabdotophorus R. aldrichi Freshwater mussel of family Unionidae.
Pleurobema P. cryptorhynchus Freshwater mussel of family Unionidae.
Plethobasus P. aesopiformis Freshwater mussel of family Unionidae.
P. biesopoides
Quadrula Q. cylindricoides Freshwater mussel of family Unionidae.
Proparreysia P. verrucosiformis Freshwater mussel of family Unionidae.
P. holmesiana
P. barnumi
P. percorrugata
P. pyramidatoides
P. letsoni
P. retusoides
P. corbiculoides
P. paucinodosa
?Obovaria ?O. pyramidella
Corbicula C. cf. subelliptica
C. sp South Dakota From a marine facies ("tongue"). Modern members of the genus live in fresh water
Sphaerium S. beckmani "Pill clam". "Nut clam". "Fingernail clam". "Pea clam". Family Sphaeriidae.
Pleiodon Indeterminate
Campeloma C. sp Freshwater snail
Anomia A. gryphorhyncha Bivalve. Family Anomiidae. From a marine facies ("tongue") in South Dakota.
Crassostrea C. subtrigonalis Oyster. Family Ostreidae. Collected from a marine facies ("tongue") in South Dakota.
Granocardium G. sp Bivalve. Family Cardiidae (cockle). Collected from a marine facies ("tongue") in South Dakota.
?Hiatella ?H. sp Bivalve. Present members of this genus are rock borers. Collected from a marine facies ("tongue") in South Dakota.
Leptosolen indeterminate Bivalve. Family Cultellidae. Collected from a marine facies ("tongue") in South Dakota.
Sphenodiscus S. lenticularis Ammonite. From a marine facies ("tongue") in South Dakota.
Discoscaphites D. rossi Microconch of an ammonite. From a marine facies ("tongue") in South Dakota.
Scaphitidae indeterminate Ammonite. From a marine facies ("tongue") in South Dakota. Other attributes: specimen has hooks on its shell.

Amphibians

Color key
Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.
Genus Species Location Stratigraphic position Material Notes Images

Anura (frog)

indeterminate

  • North Dakota
  • South Dakota

Middle to upper Hell Creek Formation

3 unassigned specimens

Anura indet. consists of material not currently assigned to any genus of frog.

Barbourula

Indeterminate

  • Montana

Caudata (salamander)

indeterminate

  • North Dakota
  • South Dakota

Lower to uppermost Hell Creek Formation

149 unassigned specimens

Material of Caudata indet. is not currently assigned to any genus.

Eopelobates

Indeterminate

  • Montana

Habrosaurus

H. dilatus

  • Montana
  • North Dakota
  • South Dakota

Middle to upper Hell Creek Formation

6 specimens

Habrosaurus is a sirenid amphibian.

Lisserpeton

L. bairdi

  • Montana

Opisthotriton

O. kayi

  • Montana
  • North Dakota
  • South Dakota

Lower to upper Hell Creek Formation

22 specimens

Opisthotriton is classified as a Batrachosauroididae.

Paranecturus

P. garbanii

  • Montana

A member of Proteidae.

Proamphiuma

P. cretacica

  • Montana

Prodesmodon

P. copei

  • Montana

Scapherpeton

S. tectum

  • Montana
  • North Dakota
  • South Dakota

Lower to upper Hell Creek Formation

144 specimens

Scapherpeton is a scapherpetonid that is very common in the Hell Creek Formation.

Scotiophryne

S. pustulosa

  • Montana

A small frog

Fish

Bony fish

Bony fishes
Genus Species Location Stratigraphic position Material Notes Images
Acipenser A. amnisinferos A sturgeon
A. eruciferus
  • Montana
A. praeparatorum
  • North Dakota (Tanis)
A. cf. A. amnisinferos
  • North Dakota (Tanis)

cf. A. sp.

  • North Dakota
  • South Dakota

Lower to upper Hell Creek Formation

18 specimens are tentatively assigned to Acipenser sp.

Acipenser sp. is tentatively referred to the genus.

Anchiacipencer A. acanthaspis
  • Montana
 A sturgeon, originally considered as indeterminate material
Belonostomus B. longirostris
  • Montana
  • North Dakota
  • South Dakota
 Lower to upper Hell Creek Formation 28 specimens A long-snouted slender fish classified as an aspidorhynchid.
Coriops C. amnicolus
  • Montana

Cyclurus

C. fragosus

  • Montana
  • North Dakota
  • South Dakota

A small amiid fish (ubiquitous). Previously known as Amia fragosa or Kindleia fragosa. 2610 specimens have been assigned to Kindleia, making it an extremely common genus.

Cyclurus kehreri from Messel Pit, species within same genus as C. fragosus
"Lepisosteus" "L. occidentalis"
  • Montana
  • North Dakota
  • South Dakota
 Lower to uppermost Hell Creek Formation 938 specimens are assigned to Lepidosteus A lepidosteid that is very common in the Hell Creek Formation. Nomen dubium.
Melvius M. thomasi
  • North Dakota
  • South Dakota
 Lower to upper Hell Creek Formation 6 specimens are assigned to Melvius A large amiid fish.
Phyllodus P. paulkatoi Fish with columnar teeth
Palaeolabrus P. montanensis
  • Montana
Paleopsephurus P. wilsoni
  • Montana
 A paddlefish
Paralbula P. casei
  • Montana
Parapsephurus P. willybemisi
  • North Dakota (Tanis)
 A paddlefish
Platacodon P. nanus
  • Montana
 Small teleost fish
Protamia Indeterminate
  • Montana
Pachyrhizodontoidei Indeterminate Fish
Polyodontidae Indeterminate
  • Montana
 Paddlefish
Protoscaphirhynchus P. squamosus
  • Montana
 A sturgeon
Pugiopsephurus P. inundatus
  • North Dakota (Tanis)
 A paddlefish

Cartilaginous fish

Chondrichthyes reported from the Hell Creek Formation
Genus Species Location Stratigraphic position Material Notes Images

Chiloscyllium

C. sp.

A member of Hemiscylliidae.

Galagadon

G. nordquistae

  • South Dakota

Isolated teeth

A carpet shark

Lonchidion

L. selachos

  • Montana
  • North Dakota
  • South Dakota

Lower to upper Hell Creek Formation

40 specimens

A genus of prehistoric sharks in the family Hybodontidae. It makes up 0.4% of the remains of the vertebrates of the Hell Creek Formation.

Myledaphus

M. pustulosus

Lower to upper Hell Creek Formation.

1677 specimens previously assigned to M. bipartitus.

Is an anacoracid batoid rajiform related to guitarfishes. Described on the basis of teeth formerly assigned to the species M. bipartitus. The material assigned to Myledaphus bipartitus and makes up 16.5% of the vertebrate remains.

Protoginglymostoma

P. estesi

A member of Ginglymostomatidae. Formerly assigned to the genus Brachaelurus.

Restesia

R. americana

Middle Hell Creek Formation

5 specimens previously assigned to Squatirhina

A wobbegong-like shark. Formerly assigned to Squatirhina. The remains consist of 0.05% of the vertebrates. Also known from the Lance Formation.

Carcharhinidae indet.

Indeterminate

  • South Dakota

An isolated tooth.

Scapanorhynchus

.sp.

  • North Dakota

Dinosaurs

A paleo-population study is one of the most difficult of analyses to conduct in field paleontology. Here is the most recent estimate of the proportions of the eight most common dinosaurian families in the Hell Creek Formation, based on detailed field studies by White, Fastovsky and Sheehan.

  • Ceratopsidae 61%
  • Hadrosauridae 23%
  • Ornithomimidae 5%
  • Tyrannosauridae 4%
  • Hypsilophodontidae 3%
  • Dromaeosauridae 2%
  • Pachycephalosauridae 1%
  • Troodontidae 1% (represented only by teeth)
Pie chart of the time averaged census for large-bodied dinosaurs from the entire Hell Creek Formation in the study area.

Outcrops sampled by the Hell Creek Project were divided into three sections: lower, middle and upper slices. The top and bottom sections were the focus of the PLoS One report, and within each portion many remains of Triceratops, Edmontosaurus, and Tyrannosaurus were found. Triceratops was the most common in each section, but, surprisingly, Tyrannosaurus was just as common, if not slightly more common, than the hadrosaur Edmontosaurus. In the upper Hell Creek section, for example, the census included twenty two Triceratops, five Tyrannosaurus, and five Edmontosaurus.

The dinosaurs Thescelosaurus, Ornithomimus, Pachycephalosaurus and Ankylosaurus were also included in the breakdown, but were relatively rare. Other dinosaurs, such as Sphaerotholus, Denversaurus, Torosaurus, Struthiomimus, Acheroraptor, Dakotaraptor, Pectinodon, Richardoestesia, Paronychodon, Anzu, Leptorhynchos and Troodon (more likely Pectinodon), were reported as being rare and are not included in the breakdown.

The dinosaur collections made over the past decade during the Hell Creek Project yielded new information from an improved genus-level collecting schema and robust data set that revealed relative dinosaur abundances that were unexpected, and ontogenetic age classes previously considered rare. We recognize a much higher percentage of Tyrannosaurus than previous surveys. Tyrannosaurus equals Edmontosaurus in U3 and in L3 comprises a greater percentage of the large dinosaur fauna as the second-most abundant taxon after Triceratops, followed by Edmontosaurus. This is surprisingly consistent in (1) the two major lag deposits (MOR loc. HC-530 and HC-312) in the Apex sandstone and Jen-rex sand where individual bones were counted and (2) in two thirds of the formation reflected in L3 and U3 records of dinosaur skeletons only.

Triceratops is by far the most common dinosaur at 40% (n = 72), Tyrannosaurus is second at 24% (n = 44), Edmontosaurus is third at 20% (n = 36), followed by Thescelosaurus at 8% (n = 15), Ornithomimus at 5% (n = 9), and Pachycephalosaurus and Ankylosaurus both at 1% (n = 2) are relatively rare.

Fossil footprints of dinosaurs from the Hell Creek Formation are very rare. As of 2017, there is only one find of a possible Tyrannosaurus rex footprint, dating from 2007 and described a year later. A trackway made by mid-sized theropod, possibly a small tyrannosaurid individual, was discovered in South Dakota in 1997, and in 2014 these footprints were named Wakinyantanka styxi.

Ornithischians

Ankylosaurs

Indeterminate nodosaur remains have been unearthed in the Hell Creek Formation and other nearby areas.

Ankylosauria reported from the Hell Creek Formation
Genus Species State Stratigraphic position Material Notes Images

Ankylosaurus

A. magniventris

  • Montana
 Upper A partial skull, teeth, cervical vertebrae, dorsal vertebrae, caudal vertebrae, right scapulocoracoid, otic capsule, maxilla fragment, right jugal, left jugal and quadratojugal, sacral centra, additional fragments of the cervical half rings and a partial tail club handle.

An ankylosaur. Also found in the Lance, Frenchman, Ferris and Scollard Formations.

Denversaurus

D. schlessmani

  • Montana
  • South Dakota
 Skull roof, pelvis and osteoderms.

A nodosaurid ankylosaur whose remains have been found in the Lance and Laramie Formation.

Pachycephalosaurs

An undescribed and unnamed pachycephalosaur is present in North Dakota. Pachycephalosaur remains have been unearthed in Montana as in the case of Platytholus and the now invalid genus Stenotholus kohleri, which is now a junior synonym of Pachycephalosaurus.

Pachycephalosaurs reported from the Hell Creek Formation
Genus Species State Stratigraphic position Material Notes Images

Dracorex

D. hogwartsia

  • South Dakota
  • Middle

A pachycephalosaur, possibly synonymous with Pachycephalosaurus.

Pachycephalosaurus

P. wyomingensis

  • Montana
  • South Dakota

A pachycephalosaur. Also found in the Lance Formation.

Platytholus P. clemensi
  • Montana
  • Lower
 A partial skull A medium-sized pachycephalosaurine closely related to Acrotholus and Prenocephale

Sphaerotholus

S. buchholtzae

  • Montana
  • Lower to upper

"Skull material."

A pachycephalosaur whose remains have also been found in the Frenchman Formation. Genus also known from the Kirtland Formation, Dinosaur Park Formation and the Horseshoe Canyon Formation.

S. triregnum

  • Montana
  • Middle

A left squamosal.

A pachycephalosaur distinguished from S. buchholtzae by its more ornamented squamosal.

Stygimoloch

S. spinifer

  • Montana
  • South Dakota
  • North Dakota

A pachycephalosaur, possibly synonymous with Pachycephalosaurus. Also found in the Ferris Formation and the Lance Formation.

Ceratopsians

Indeterminate ceratopsid teeth and some identifiable bones from Triceratops can be extremely common. 8.31% of all vertebrate remains from the Hell Creek Formation are unassigned ceratopsids. In 2012, a new unidentified species of chasmosaur ceratopsian with noticeable differences from Triceratops was unearthed in South Dakota by a fossil hunter named John Carter.

Color key
Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.
Ceratopsians reported from the Hell Creek Formation
Genus Species Synonyms State Stratigraphic position Material Notes Images

Leptoceratops

L. gracilis

  • Montana

A small primitive-looking ceratopsian. Fossils have also been found in the Lance Formation in Wyoming.

Tatankaceratops

T. sacrisonorum

  • South Dakota

A controversial ceratopsian possibly synonymous with Triceratops

Torosaurus

T. latus

  • Montana
  • North Dakota
  • South Dakota

Upper Hell Creek Formation

A ceratopsian that was once proposed to be synonymous with Triceratops, but is now regarded as a valid and distinct ceratopsian. A rare ceratopsid. Fossils have been in the Lance Formation, Javelina Formation, North Horn Formation, Laramie Formation, El Picacho Formation, Frenchman Formation and Scollard Formation.

Triceratops

T. horridus

  • T. serratus
  • Ugrosaurus olsoni
  • Montana
  • North Dakota
  • Wyoming
  • South Dakota

Lowermost to the middle Hell Creek Formation

Four specimens are assigned to Triceratops horridus from the Hell Creek Formation. Isolated, shed ceratopsid teeth are incredibly common in the Hell Creek and Lance Formations, being by most collectors, with some being nothing more than worn down fragments up to superb teeth containing complete, preserved roots. Because the teeth of different ceratopsians are so similar to one another, its hard to differentiate between genera/species, but based on the abundance of identifiable bones belonging to Triceratops in Lancian-aged North American formations, especially the Hell Creek, isolated ceratopsid teeth from the lower and middle Hell Creek Formation have a high likelihood of originating from T. horridus.

A ceratopsian. Also found in the Evanston, Frenchman, Lance, Laramie, and Scollard Formations.

T. prorsus

  • Montana
  • South Dakota
 Upper 1/3 of the Hell Creek Formation

Very common. Because the teeth of different ceratopsians are so similar to one another, its hard to differentiate between genera/species, but based on the abundance of identifiable bones belonging to Triceratops in Lancian-aged North American formations, especially the Hell Creek, isolated ceratopsid teeth from the upper 1/3 of the Hell Creek Formation have a high likelihood of originating from T. prorsus.

Also found in the Frenchman and Lance Formations.

Ornithopods and relatives

Indeterminate hadrosaurid remains are very common in the Hell Creek Formation.

Ornithopods and Thescelosaurs reported from the Hell Creek Formation
Genus Species Synonyms State Stratigraphic position Material Notes Images

Edmontosaurus

E. annectens

  • Anatosaurus annectens
  • Anatotitan copei
  • Montana
  • South Dakota
  • North Dakota(Mummy Fossil)

Very common.

A hadrosaur. Also found in the Denver, Frenchman, Lance, Laramie, and Scollard Formations. Hatchlings have also been unearthed.

Thescelosaurus

T. garbanii

  • Bugenasaura garbanii
  • Montana
  • South Dakota

T. neglectus

  • North Dakota
  • South Dakota

Lower to upper Hell Creek Formation

50 specimens

A small thescelosaurine. Also found in the Frenchman, Lance, Laramie, and Scollard Formations. Two species are known from Hell Creek; T. neglectus and T. garbanii.

Theropods

Theropod tracks have been found in South Dakota. A trackway from South Dakota, named Wakinyantanka, was made by a mid-sized theropod with three slender toes, possibly a small tyrannosaurid. A second footprint that may have been made by a specimen of Tyrannosaurus was first reported in 2007 by British paleontologist Phil Manning, from the Hell Creek Formation of Montana. This second track measures 72 centimeters (28 in) long, shorter than the track described by Lockley and Hunt. Whether or not the track was made by Tyrannosaurus is unclear, though Tyrannosaurus is the only large theropod known to have existed in the Hell Creek Formation, though in past albertosaurine remains have described here but its most likely that they are the remains of Tyrannosaurus rex. Theropod remains are very common in Hell Creek, some of which belong to indeterminate species on maniraptorans.

Alvarezsaurs

Alvarezsaurs reported from the Hell Creek Formation
Genus Species Synonyms State Stratigraphic position Material Notes Images
"Ornithomimus" "O." minutus

Trierarchuncus

T. prairiensis

  • Montana

upper Hell Creek Formation.

An alvarezsaur known from a partial post-cranial skeleton.

Tyrannosaurids

Tyrannosaurids reported from the Hell Creek Formation
Genus Species Synonyms State Stratigraphic position Material Notes Images

Tyrannosaurus

T. rex

  • Montana
  • North Dakota
  • South Dakota

Lower to upper Hell Creek Formation.

A tyrannosaur, known from several specimens including a juvenile nicknamed "Jane". Also found in the Denver, Frenchman, Hill Creek South, Javelina, Lance, Ferris, Livingston, McRae, North Horn, Scollard, Willow Creek Formation, and also found in Lomas Coloradas Formations. Isolated teeth in the Hell Creek are common enough to be dug commercially by collectors, but rare enough that they are often sold for very high prices with fragmentary teeth usually beginning at least in the hundreds of USD, and complete teeth in the thousands of USD. Perhaps the best known iconic dinosaur.

Nanotyrannus?

N.lancensis

  • Stygivenator?
  • Deinodon lancensis
  • Albertosaurus lancensis
  • Tyrannosaurus lancensis?
  • Montana
  • Wyoming

Lower to upper Hell Creek Formation.

A few specimens are known

Invalid genus, now recognised as juvenile T. rex.

Ornithomimosaurs

Ornithomimid remains are not uncommon in the Hell Creek Formation. Fifteen specimens from the Hell Creek Formation are undetermined ornithomimids

Color key
Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.
Ornithomimids reported from the Hell Creek Formation
Genus Species State Stratigraphic position Material Notes Images

"Orcomimus"

unnamed

  • South Dakota

One partial skeleton.

An ornithomimid; nomen nudum.

Struthiomimus

S. sedens

  • Montana
  • AMNH 975, a foot claw
  • UCMP 154569, a partial skeleton

A large ornithomimid similar to Gallimimus in size. Also found in the Lance Formation.

Ornithomimus

O. velox

  • Montana
  • South Dakota
  • North Dakota

Fragmentary specimens

An ornithomimid which was also found in the Denver Formation.

Oviraptorosaurs

Oviraptorosaur fossils have been found at the Hell Creek Formation for many years, most notably from isolated elements until the discovery of Anzu. In the past, oviraptorosaur fossils found were thought to have belonged to Caenagnathus, Chirostenotes, and Elmisaurus. In 2016, an undescribed large-bodied caenagnathid was unearthed in Montana.

Color key
Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.
Oviraptorosaurs reported from the Hell Creek Formation
Genus Species State Stratigraphic position Material Notes Images

Anzu

A. wyliei

  • North Dakota
  • South Dakota

Lower to upper Hell Creek Formation

12 well-preserved specimens

One of the largest known oviraptorosaurs, and the largest known from North America. Material previously assigned to Caenagnathidae indet. is now placed in the genus Anzu.

Caenagnathidae

Indeterminate

  • Montana

Similar to Citipes and Elmisaurus.

Eoneophron E. infernalis
  • South Dakota
 A partial right hindlimb Closely related to Citipes and Elmisaurus.

Eumaniraptorans

Historically, numerous teeth have been attributed to various dromaeosaurid and troodontid taxa with known body fossils from only older formations, including Saurornithoides, Zapsalis, Dromaeosaurus, Saurornitholestes, and Troodon. However, in a 2013 study, Evans et al. concluded that there is little evidence for more than a single dromaeosaurid taxon, Acheroraptor, in the Hell Creek-Lance assemblages, which would render these taxa invalid for this formation. This was disproved in a 2015 study, DePalma et al., when they described the new genus Dakotaraptor, a large species of dromaeosaur. Fossilized teeth of various troodontids and coelurosaurs are common throughout the Hell Creek Formation; the best known examples include Paronychodon, Pectinodon and Richardoestesia, respectively. Teeth belonging to possible intermediate species of Dromaeosaurus and Saurornitholestes have been unearthed at the Hell Creek Formation and the nearby Lance Formation.

Eumaniraptorans reported from the Hell Creek Formation
Genus Species State Stratigraphic position Material Notes Images

Acheroraptor

A. temertyorum

  • Montana
  • North Dakota?
  • South Dakota?

Lower? to upper Hell Creek Formation

  • ROM 63777, a maxilla and tooth
  • ROM 63778, a partial dentary
  • isolated teeth

A velociraptorine dromaeosaurid. Teeth previously referred to various Campanian dromaeosaurids Saurornitholestes and Dromaeosaurus, frequently found throughout the formation, probably belong to this one species. Evans et al. conclude that there is little evidence for the former two taxa being present in the Hell Creek-Lance assemblages.

Avisaurus

A. archibaldi

  • Montana

Middle Hell Creek Formation

  • UCMP 117600, holotype, a tarsometatarsus
  • PU 17324, a tarsometatarsus

An avisaurid.

cf. A. archibaldi

  • Montana

Uppermost Hell Creek Formation

  • YPM 57235, a coracoid

An avisaurid tentatively referred to A. archibaldi based on its size.

A. darwini
  • Montana
  • DDM 1577.730, a right tarsometatarsus

A. sp.

  • Montana
  • distal tarsals, metatarsus (juvenile)
  • MOR3070, a partial right tarsometatarsus

Brodavis

B. baileyi

  • South Dakota
  • UNSM 50665, a left tarsometatarsus missing proximal end, trochleae II and III.

A primitive hesperornithiform.

Dakotaraptor

D. steini

  • South Dakota

Upper Hell Creek Formation

  • PBMNH.P.10.113.T, a partial skeleton.
  • PBMNH.P.10.115.T, a tibia.
  • PBMNH.P.10.118.T, an astragalocalcaneum.
  • isolated teeth.

A large dromaeosaurid.

Magnusavis M. ekalakaensis
  • Montana
  • CCM V2019.5.1, partial right tarsometatarsus and toe bone
 A large enantiornithine closely related to avisaurids.

Paronychodon

P. caperatus

  • North Dakota, South Dakota, and Montana.
  • YPM 10624, a fossilized tooth. Teeth of this genus have been found too.

A troodontid theropod who is known from fossil teeth. Fossils have also been found in the Lance Formation in Wyoming.

Pectinodon

P. bakkeri

  • Montana
  • UCM 38445, a fossilized tooth. Teeth of this genus have been found too.
  • A troodontid theropod who is known from fossil teeth. Fossils have also been found in the Lance Formation in Wyoming.

Potamornis

P. skutchi

  • Montana
  • UCMP 117605, a tarsometatarsus

A hesperornithiform also found in the Lance Formation.

Richardoestesia

R. sp.

  • Montana.
  • Teeth.

A coelurosaur that is known from teeth and from two species Richardoestesia gilmorei and Richardestesia isosceles, which have also been unearthed in the Lance Formation in Wyoming.

"Styginetta" "S. lofgreni."
  • Montana.
 A Presbyornithid, it is notable for being one of the few birds known to have survived the Cretaceous–Paleogene extinction event.

"Unnamed enantiornithine B"

Unnamed

  • Montana
  • YPM 57823, a partial coracoid

An unnamed enantiornithean.

"Unnamed hesperornithiform A"

Unnamed

  • Montana
  • UCMP 13355, a tarsometatarsus

A primitive hesperornithiform. The Hell Creek specimen was referred to the same unnamed taxon as RSM P 2315.1 from the Canadian Frenchman Formation. RSM P 2315.1 was later made the holotype of Brodavis americanus. May be a synonym of Potamornis.

"Unnamed ornithurine B"

Unnamed

  • Montana
  • UCMP 129143, a partial coracoid

An ornithurine possibly similar to Cimolopteryx

"Unnamed ornithurine C"

Unnamed

  • Montana
  • South Dakota
  • SDSM 64281A, a partial coracoid
  • SDSM 64281B, a partial coracoid
  • UCMP 175251, a partial coracoid
  • MOR 2918, a partial coracoid

An ornithurine, also present in the Lance Formation and Fort Union Formation, one of the few individual bird species known to have survived the Cretaceous–Paleogene extinction

"Unnamed ornithurine D"

Unnamed

  • Montana
  • UCMP 187207, a partial coracoid

An ichthyornithean also present in the Frenchman Formation

Pterosaurs

Undescribed pterosaur remains were reported from North Dakota. A specimen of an azhdarchid pterosaur from Montana likely belongs to Quetzalcoatlus, though it is not diagnostic to the species level.

Pterosaurs of the Hell Creek Formation
Taxa Species State Stratigraphic location Material Notes Images

cf. Quetzalcoatlus

Indeterminate

Montana A single azhdarchid neck bone which may belong to the genus Quetzalcoatlus.

Crocodylomorphs

Color key
Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.
Crocodylomorphs reported from the Hell Creek Formation
Genus Species State Stratigraphic position Material Notes Images

Borealosuchus

  • B. sternbergii
  • Montana
  • North Dakota
  • South Dakota

Extinct genus of crocodylians that lived from the Late Cretaceous to the Eocene in North America.

Brachychampsa

  • B. montana
  • Montana
  • South Dakota
  • North Dakota

Extinct genus of alligatoroid.

Thoracosaurus

  • T. neocesariensis
  • Montana

Extinct genus of gavialoid crocodilian which existed during the Late Cretaceous and early Paleocene.

Turtles

Color key
Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.
Turtles reported from the Hell Creek Formation
Genus Species State Stratigraphic position Material Notes Images

Adocus

Indeterminate

  • Montana

Extinct genus of aquatic turtles belonging to the family Adocidae.

Axestemys

A. infernalis

  • Montana
  • North Dakota
  • South Dakota
  • Wyoming

A turtle belonging to the family Trionychidae. Its fossils from the Hell Creek Formation were formerly assigned to the late Campanian species Axestemys splendidus.

Compsemys

C. victa

  • Montana

A relative of Dermatemydidae.

Peckemys

P. brinkman

  • Montana
  • North Dakota

A relative of Baenidae.

Emarginachelys

E. cretacea

  • Montana

A relative of chelydrids.

Eubaena

E. cephalica

  • Montana

Baenid turtle

Gamerabaena

G. sonsalla

  • North Dakota

Extinct genus of baenid turtle.

Palatobaena

P. cohen

  • North Dakota

A relative of extinct family of cryptodiran turtles.

Cedrobaena

C. putorius

  • South Dakota
  • North Dakota

A relative of Baenidae.

Gilmoremys

G. lancensis

  • Montana
  • North Dakota

Trionychidae related to the softshell turtle.

Hoplochelys

H. clark

  • North Dakota

A kinosternoid related to the Central American river turtle.

Hutchemys H. walkerorum
  • North Dakota
 A shell A Plastomeninae related to the softshell turtle.

Plastomenus

P. sp

Trionychidae turtle.

Basilemys

B. sinuosa

Largest dermatemydid land tortoise.

Trionyx

Indeterminate

  • Montana

A genus of softshell turtles belonging to the family Trionychidae.

Aspideretoides

A. foveatus

Trionychidae turtle.

Helopanoplia

H. distincta

Trionychidae turtle.

Judithemys

J. backmani

Thin-shelled macrobaenid turtle.

Plesiobaena

P. antiqua

Baenid turtle.

Stygiochelys

S. estesi

Baenid turtle.

Neurankylus

N. eximius

Largest baenid turtle in Hell Creek Formation.

Saxochelys

S. gilberti

  • North Dakota
  • A population of over 30 individual skeletons

A member of the family Baenidae.

Thescelus

T. insiliens

Baenid turtle.

Chelydridae

Indeterminate

Chelydrids-like turtle.

Squamata

Color key
Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.
Squamates reported from the Hell Creek Formation
Genus Species State Stratigraphic position Material Notes Images

Cemeterius

C. monstrosus

  • Montana

A platynotan lizard of uncertain phylogenetic placement, also known from the Lance Formation.

Cerberophis

C. robustus

  • Montana

An alethinophidian snake of uncertain phylogenetic placement.

Obamadon

O. gracilis

  • Montana

A polyglyphanodontian lizard of uncertain phylogenetic placement. Also known from the Lance Formation.

Peneteius

P. aquilonius

  • Montana

A chamopsiid polyglyphanodontian lizard.

Haptosphenus

H. placodon

Teiidae lizard.

Leptochamops

L. denticulatus

Small Teiidae lizard.

Chamops

C. segnis

Largest Teiidae lizard in Hell Creek Formation

Contogenys

C. sloani

Scincidae? lizard.

Exostinus

E. lancensis

xenosaurid lizard.

Proxestops

P. jepseni

Anguidae lizard.

Parasaniwa

P. wyomingensis

Necrosaurid lizard.

Paraderma

P. bogerti

Helodermatidae? lizard.

Palaeosaniwa

P. canadensis

A large Monstersauria lizard, closely related to today's varanid lizards. It was the largest lizard in the Hell Creek formation.

Boidae

Indeterminate

Snake. Earliest-known boid.

Mosasauridae

Indeterminate

Indeterminate mosasaur remains have been unearthed in North Dakota; they may belong to a mosasaur measuring 11 m (36 ft) in length.

Choristoderans

Color key
Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.
Choristoderans reported from the Hell Creek Formation
Genus Species State Stratigraphic position Material Notes Images

Champsosaurus

C. sp.

  • Montana

A champsosaur.


Mammals

Multituberculates

Color key
Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.
Multituberculates reported from the Hell Creek Formation
Genus Species State Stratigraphic position Material Notes Images

Cimexomys

C. minor

  • Montana

A multituberculate of uncertain phylogenetic placement.

Cimolodon

C. nitidus

  • Montana
  • North Dakota

A cimolodontid multituberculate.

C. cf. nitidus

  • South Dakota

A cimolodontid multituberculate.

C. sp.

  • North Dakota

A cimolodontid multituberculate.

Cimolomys

C. gracilis

  • Montana

A cimolomyid multituberculate.

  • C. cf. gracilis
  • South Dakota

A cimolomyid multituberculate.

Essonodon

E. browni

  • Montana

A cimolomyid multituberculate.

Meniscoessus

M. conquistus

  • South Dakota

A cimolomyid multituberculate.

M. robustus

  • Montana
  • North Dakota
  • South Dakota

A cimolomyid multituberculate.

M. cf. robustus

  • South Dakota

A cimolomyid multituberculate.

M. sp.

  • North Dakota

A cimolomyid multituberculate.

?M. sp.

  • North Dakota

A cimolomyid multituberculate.

Mesodma

M. formosa

  • Montana
  • South Dakota

A neoplagiaulacid multituberculate.

M. cf. formosa

  • Montana

A neoplagiaulacid multituberculate.

M. hensleighi

  • Montana
  • South Dakota

A neoplagiaulacid multituberculate.

M. cf. hensleighi

  • South Dakota

A neoplagiaulacid multituberculate.

M. thompsoni

  • Montana
  • North Dakota
  • South Dakota

A neoplagiaulacid multituberculate.

M. cf. thompsoni

  • Montana

A neoplagiaulacid multituberculate.

M sp.

  • Montana

A neoplagiaulacid multituberculate.

?M sp.

  • Montana

A neoplagiaulacid multituberculate.

?Neoplagiaulax

?N. burgessi

  • Montana

A neoplagiaulacid multituberculate.

Paracimexomys

P. priscus

  • Montana

A multituberculate of uncertain phylogenetic placement.

Paressonodon

P. nelsoni

A cimolomyid multituberculate.

Stygimys

S. kuszmauli

  • Montana

It was a member of the extinct order Multituberculata.

Metatherians

Color key
Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.
Metatherians reported from the Hell Creek Formation
Genus Species State Stratigraphic position Material Notes Images

Alphadon

A. marshi

  • Montana
  • North Dakota

An alphadontid. genus of small, primitive mammal that was a member of the Metatheria, a group of mammals that includes modern-day marsupials.

A. cf. marshi

  • Montana
  • South Dakota

An alphadontid.

A. wilsoni

  • Montana

An alphadontid.

A. cf. wilsoni

  • Montana

An alphadontid.

A. sp.

  • North Dakota
  • South Dakota

An alphadontid.

Didelphodon

D. padanicus

  • South Dakota

A stagodontid.

D. vorax

  • Montana
  • North Dakota

A stagodontid. genus of Stagodontidae marsupials from the Late Cretaceous of North America.


D. cf. vorax

  • South Dakota

A stagodontid.

D. sp.

  • North Dakota

A stagodontid.

cf. D. sp.

  • North Dakota
  • South Dakota

A stagodontid.

Glasbius

G. twitchelli

  • Montana

A glasbiid.

G. cf. twitchelli

  • Montana

A glasbiid.

Leptalestes

L. cooki

  • Montana

A pediomyid.

L. krejcii

  • Montana
  • South Dakota

A pediomyid.

Nanocuris

N. improvida

A deltatheridiid.

Nortedelphys

N. jasoni (= N. intermedius)

  • Montana
  • South Dakota

A herpetotheriid.

Pediomys

P. elegans

  • Montana
  • South Dakota

A pediomyid.

Protalphadon

P. foxi

  • Montana

An alphadontid.

P. lulli

  • Montana

An alphadontid.

Protolambda

P. florencae

  • Montana
  • North Dakota
  • South Dakota

A pediomyid.

P. hatcheri
  • Montana
  • South Dakota

A pediomyid.

P. mcgilli
  • Montana

A pediomyid.

Turgidodon

T. rhaister

  • Montana

An alphadontid.

Eutherians

Color key
Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.
Eutherians reported from the Hell Creek Formation
Genus Species State Stratigraphic position Material Notes Images

Altacreodus

A. magnus

  • Montana
  • North Dakota

a possible creodont, formerly a species of Cimolestes

Alostera

A. saskatchewanensis

  • Montana

A eutherian of uncertain phylogenetic placement.

Ambilestes

A. cerberoides

  • Montana

A eutherian of uncertain classification, formally a species of Cimolestes

Batodon

B. tenuis

  • Montana

A cimolestid eutherian.

Cimolestes

C. incisus

  • Montana

A cimolestid eutherian.

C. stirtoni

  • Montana

A cimolestid eutherian.

Gypsonictops

G. hypoconus

  • Montana
  • South Dakota

A gypsonictopsid eutherian.

G. illuminatus

  • Montana
  • North Dakota

A gypsonictopsid eutherian.

G. cf. illuminatus

  • Montana

A gypsonictopsid eutherian.

G. sp.

  • Montana

A gypsonictopsid eutherian.

cf. Paranyctoides

cf. Paranyctoides sp.

  • Montana

A nyctitheriid eutherian.

Protungulatum

P. coombsi

  • Montana

A stem-placental.

Purgatorius

P. ceratops

  • Montana

A genus with four species believed to be either stem-placentals or stem-primates.

Scollardius

S. propalaeoryctes

  • Montana

A eutherian of uncertain classification, formally a species of Cimolestes

Flora

Detail of Hell Creek diorama at Milwaukee Public Museum is represented by angiosperm-dominated riparian forest.

The Hell Creek Formation was a low floodplain at the time before the sea retreated, and in the wet ground of the dense woodland, the diversity of angiosperms and conifers were present. An endless diversity of herbaceous flowering plants, ferns and moss grew in the forest understory. On the exposed point bars of large river systems, there were shrubs and vines. The evidence of the forested environment is overwhelmingly supported by petrified wood, rooted gley paleosols, and ubiquitous tree leaves. The presence of the simple and lobed leaves, combined with an extremely high dicot diversity, extinct cycadeoid Nilssoniocladus, Ginkgo, many types of monocots, and several types of conifers is different from any modern plant community. There are numerous types of leaves, seeds, flowers and other structures from Angiosperms, or flowering plants. The Hell Creek Formation of this layer contains over 300 tablets, of which angiosperms are by far the most diverse and dominant flora of the entire population, about 90 percent, followed by about 5% of conifers, 4% of ferns, and others. Compared to today Hell Creek's flora which is prairie, then Hell Creek's flora was hardwood forest mixed with deciduous and evergreen forest. In sharp contrast to the Great Plains today, the presence of many thermophilous taxa such as palm trees and gingers meant the climate was warmer and wetter then.

Fossil fruits from the Hell Creek Formation of Spinifructus antiquus of the palm family (Arecaceae), closely related to the genus Astrocaryum.

The plants of the Hell Creek Formation generally represent angiosperm-dominated riparian forests of variable diversity, depending on stratigraphic position and sedimentary environment. There appears to be floral transitions visible on a stratigraphic range from the lower to the upper Hell Creek Formation. For this reason, Kirk Johnson and Leo Hickey divided it into five zones and described them as HCIa, HCIb, HCIIa, HCIIb, and HCIII as a reflection of floral change through time. For example, the HCIa zone is dominated by "Dryophyllum" subfalcatum, Leepierceia preartocarpoides, "Vitis" stantonii, and "Celastrus" taurenensis, and is located 55 to 105 meters below the K-Pg boundary layer. Although the HCIb zone is a very thin layer, about 5 meters of rock, it bears unusually high diversity of herbaceous and shrubby plants, including Urticaceae, Ranunculaceae, Rosaceae, and Cannabaceae.

Bisonia niemii is one of the common fossil leaf species in the HCIII zone.

There is evidence of transitional floras in the middle of the Hell Creek Formation as shown by HCII and HCIII zones. The HCII flora represents a transitional period where taxa from the lower Hell Creek are replaced by the HCIII flora. The diversity of the HCIII zone is very high, and its composition is more uniform than that of HCII, many of which were rare or absent from the zones below, and some others that used to be common below became rarer in the HCIII zone. These forms include Elatides longifolia, "Dryophyllum" tennessensis, Liriodendrites bradacii, and many members of the Laurales including Bisonia niemii, "Ficus" planicostata, and Marmarthia trivialis, while "Celastrus" taurenensis, Leepierceia preartocarpoides, and many cupressaceous conifers became rarer. This phenomenon suggests that the global temperature was warming during the last 300,000-500,000 years of the Cretaceous period.

Johnson claims that there are no grasses, oaks, maples, beeches, figs, or willows in the Hell Creek Formation. There is no evidence of fern prairie either. However, there was an extremely high angiosperm diversity — common plane trees, "Dryophyllum" subfalcatum, Leepierceia preartocarpoides, and palm trees — along with extinct cycadeoid Nilssoniocladus, Ginkgo, araucariaceous, podocarpaceous, and cupressaceous conifers. This represents the mixed deciduous and evergreen broad-leaved forest as the Hell Creek landscape. The nature of these forests is uncertain because Johnson found that the majority of the angiosperm and conifer genera are now extinct. He also believes that, very roughly 80% of the terrestrial plant taxa died out in what is now Great Plains at the K-Pg boundary. On other hand, there is a great increase in the abundance of fossil fern spores in the two centimeters of rock that directly overlies the impact fallout layer (the famous K-Pg boundary layer). This increase in fern spore abundance is commonly referred as "the fern spike" (meaning that if the abundance of spores as a function of stratigraphic position were plotted out, the graph would show a spike just above the impact fallout layer).

Many of the modern plant affinities in the Hell Creek Formation (e.g., those with the prefix "aff." or with quotes around the genus name) may not in reality belong to these genera; instead they could be entirely different plants that resemble modern genera. Therefore, there is some question regarding whether the modern Ficus or Juglans, as two examples, actually lived in the Late Cretaceous.

Compared to the rich Hell Creek Formation fossil plant localities of the Dakotas, relatively few plant specimens have been collected from Montana. A few taxa were collected at Brownie Butte Montana by Shoemaker, but most plants were collected from North Dakota (Slope County) and from South Dakota. Among the localities, the Mud Buttes, located in Bowman County, North Dakota, is probably the richest megaflora assemblage known and the most diverse leaf quarry from the Hell Creek Formation. "TYPE" after the binomial means that it is represented by a type specimen found in the Yale-Peabody Museum collections. "YPM" is the prefix for the Yale-Peabody Museum specimen number; "DMNH" is for the Denver Museum of Nature & Science; "USNM" is for Smithsonian National Museum of Natural History; and so on. The majority of Hell Creek megafloral specimens are collected at the Denver Museum of Nature & Science.

Overview (from Johnson, 2002)

302 plant morphotypes based on leaf only, including:

  • 1 bryophyte (mosses and liverworts)
  • 11 ferns
  • 1 sphenopsid
  • 10 conifers
  • 1 ginkgo (uncommon)
  • 278 angiosperms (roughly 92% of all taxa found)

Paleoflora

Color key
Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

Liverworts

Genus Species Location Stratigraphic position Abundance Notes Images

Marchantia

M. pealii

Only known liverwort in Hell Creek.

Ferns

Genus Species Location Stratigraphic position Abundance Notes Images

Equisetum

E. sp

Rare in the Hell Creek Formation.

Polypodiaceae?

indeterminate

Salvinia

S. sp

Floating aquatic plant.

Cycadophytes

Genus Species Location Stratigraphic position Abundance Notes Images
Nilssoniocladus

N. comtula

Unlike N. yukonensis, its leaves are pinnatisect pinnules. Common.

N. yukonensis

The only Hell Creek Formation cycadophyte. A simple leaf. Common.

Ginkgoales

Genus Species Location Stratigraphic position Abundance Notes Images

Ginkgo

G. adiantoides

The only ginkgoalean in the Hell Creek Formation; uncommon

Conifers

Genus Species Location Stratigraphic position Abundance Notes Images

Araucaria?

indeterminate

Casts of Monkey-puzzle leaves.

Cupressinocladus

C. interruptus

Casts of cupressaceae foliage. Uncommon

Dammarites

D. sp

A conifer seed cone. It's likely to belong to Elatides longifolia.

Ditaxocladus

D. catenulata

A cupressaceous conifer closely related to Cupressinocladus. Common.

Elatocladus

Elatocladus sp,

A taxodioid leaf morphogenus

Elatides

E. longifolia

Araucaria-like or Cunninghamia-like conifer.
Less common in the lower 2/3 but more common in the upper 1/3 of the Hell Creek Formation.

Glyptostrobus

G. europaeus

Uncommon conifer.

Metasequoia

M. occidentalis

M. occidentalis seed cones are known from the Hell Creek.

Platyspiroxylon

Platyspiroxylon sp.

A cupressaceaeous wood morphogenus

Podocarpoxylon

Podocarpoxylon sp.

A possibly podocarpaceous wood morphogenus

Sequoiaxylon

Sequoiaxylon sp.

A cupressaceaeous wood morphogenus

Taxodioxylon

Taxodioxylon sp.

A cupressaceaeous wood morphogenus

Taxodium

T. olrikii

Related to today's bald cypress.

Unidentified

Unidentified

Unspecified cheirolepidiacous fossils

Angiosperms

Genus Species Location Stratigraphic position Abundance Notes Images

"Artocarpus"

"A." lessigiana

Abundant at Brownie Butte, Montana.

Annona?

A?. robusta

Abundant at Brownie Butte, Montana.

Araliaephyllum

A. polevoi

A lobed leaf. Closely relating to Bisonia. Fairly common.
Averrhoites cf. A. affinis An uncommon taxon with compound leaves.
Bisonia

B. niemi

A broad leaf, probably in the Laurales.
A common taxon. Type specimen was found in South Dakota.

Browniea B. serrata In the Nyssaceae, closely relating to extant Camptotheca. Less common.
Cannabaceae?

indeterminate

Incertae sedis. It's not likely in the Cannabaceae.

Carpites C. ulmiformis Though this fossil fruit is abundant in the Early Paleocene, it's also found in Hell Creek. It may belong to Apiaceae.

"Celastrus"

"C." taurenensis

Incertae sedis. It's common in the lowermost to the middle Hell Creek Formation, but less common in the upper 1/3 Hell Creek Formation.

"Cinnamomum"

"C." lineafolia

Included in Ficus affinis by L. Hickey.
Belongs in Rhamnaceae (modern buckthorns and Ceanothus). Some other specimens referred to Cinnamomum sezanensis(?) sp.), a real cinnamon bush. Its affinity is questionable.

Cissites cf. C. acerifolia This morphotype was first described from the Cenomanian Dakota Group.

C. insignis

This form represents of the group of Cenomanian leaves from Dakota Formation.

C. lobata

A lobed leaf with half-naked basal lateral veins. Common in the upper 1/3 of the Hell Creek Formation.

C. puilasokensis

A palmately lobed leaf with 5 primary veins. Common in the upper 1/3 of the Hell Creek Formation.

Cobbania

C. corrugata

A prehistoric species of water lettuce, previously assigned to the genus Pistia.

C. hickeyi Another Cobbania species from pond sediments known as "Licking Leaves."
Cornophyllum C. newberryi The majority of leaves are entire-margined but some may develop a few teeth.
"Cypercites" "C." sp A reed-type plant.
Dryophyllum

D. subfalcatum

This taxon is extremely common in the Hell Creek Formation, but is rare in Paleocene sediments.
It is believed to be in Sabiaceae, closely related to the living Meliosma.

aff. "Dryophyllum" subfalcatum

see above.

"D." tenneseensis

This taxon is similar to D. subfalcatum]] but with extremely high L/W ratio and craspedodromous venation.
Erlingdorfia

E. montana

Johnson, 1996. In the Platanaceae (related to today's Sycamore). A very common taxon.

"Ficus"

"F." planicostata

Despite the genus name, it's in Lauraceae.

Grewiopsis

G. saportana

Another generic Platanaceae.

Harmsia

H. hydrocotyloidea

Incertae sedis. May be related to lotus. An uncommon taxon.

Humulus?

aff. Humulus sp.

May be related to the extant genus Humulus.

Hydropteris

H. pinnata

Floating aquatic fern

Limnobiophyllum

L. scutatum

Floating aquatic monocot, closely related to Pistia.

Liriodendrites

L. bradacii

Johnson, 1996. In the Magnoliidae: a common taxon.

"Liriodendron"

"L." laramiense

Unlobed leaf. May be related to today's tulip tree (yellow poplar). An uncommon taxon.

Liriodendron

L. sp

Four-lobed leaf. May be related to today's tulip tree (yellow poplar). An uncommon taxon.

Leepierceia

L. preartocarpoides

Incertae sedis but possibly in Proteales. Johnson, 1996.

Laurophyllum

L. wardiana

Large leaves. Closely related to "Dryophyllum" subfalcatum.
"Magnolia"

M. pulchra

Occurs in southern the Wyoming flora,
Leo Hickey claims it is found further north in Montana and the Dakotas.

Marmarthia

M. johnsonii

A new Marmarthia species described in Peppe et al. 2007.

M. pearsonii

Johnson, 1996. In the Lauraceae: a very common taxon.

M. trivialis

Johnson, 1996. In the Lauraceae: a very common taxon.

"Myrica"

"Myrica" torreyi

Incertae sedis. Not actually a bayberry.

Nelumbo

N. sp

One of the most common aquatic plants in Hell Creek.
Nelumbium

N. montanum

An aquatic angiosperm, closely related to lotus. Uncommon.
Nordenskioldia

N. borealis

A fossil fruit likely to belonging to Zizyphoides flabella.

Paranymphaea

P. hastata

Despite the name, it's not related to extant genus Nymphaea.
Palaeoaster

P. porosia

A papaveraceous with fruits and seeds visually similar to Romneya though it's dubious.

Penosphyllum

P. cordatum

May be related to Sterculioideae. A common taxon.

Platanites

P. marginata

Johnson, 1996. In the Platanaceae. A common taxon.

P. raynoldsii

An uncommon taxon.

Porosia

P. verrucosa

A fossil fruit that may belong to Rutaceae.

Rhamnica

R. cleburnii

Incertae sedis. A Tetracera look-alike leaf.

Sabalites

S. sp

Coryphoid palm tree. Very common.

Spinifructus

S. antiquus

A fruit seed that may belong to the palm family (Arecaceae), closely related to the genus Astrocaryum.

Trapago

T. angulata

A water caltrop look-alike.

Trochodendroides

T. arctica

A fossil fruit that may belong to Trochodendroides nebrascensis.
T. ellipticum A katsura look-alike. An uncommon taxon.
T. genetrix A katsura look-alike. A common taxon.

T. nebrascensis

A very common taxon.

"Vitis"

"V." stantonii

Possibly a member of the Platanaceae rather than Vitaceae

"Ziziphus"

"Z." fibrillosus

A common taxon.

Zingiberopsis

Z. attenuata

Related to today's ginger plant. Its closest living relative is the Asian genus Alpinia.
Some Hell Creek Formation specimens show damage from hispine beetles ("leaf beetles" (Wilf et al., 2000)).

Z. magnifolia Another Zinigberopsis species, previously assigned to Canna? magnifolia.

Zizyphoides

Z. flabella

An uncommon taxon.

Palynology

Genus Species Location Stratigraphic position Abundance Notes Images
Abietineaepollenites

Abietineaepollenites foveoreticulatus

Montana

A conifer palynomorph

Abietineaepollenites microalatus

Montana

A conifer palynomorph

Abietineaepollenites varius

Montana

A conifer palynomorph

Acanthotriletes

Acanthotriletes levidensis

Montana

Alnipollenites

Alnipollenites verus

Montana

Appendicisporites

Appendicisporites tricornitatus

Montana

Aquilapollenites

Aquilapollenites amplus

Montana

Aquilapollenites attenuatus

Aquilapollenites collaris

Aquilapollenites conatus

Montana

Aquilapollenites delicatus

Montana

Aquilapollenites marmarthensis

Aquilapollenites polaris

Montana

Aquilapollenites pulvinus

Montana

Aquilapollenites pyriformis

Montana

Aquilapollenites quadricretaeus

Aquilapollenites quadrilobus

Aquilapollenites reductus

Montana

Aquilapollenites reticulatus

Montana

Aquilapollenites senonicus

Aquilapollenites turbidus

Aquilapollenites striatus

Azolla

Azolla cretacea

Montana

A mosquito fern palynomorph

Balmeisporites

Balmeisporites sp.

Calamospora

Calamospora mesozoica

Montana

Camarozonosporites

Camarozonosporites heskemensis

Montana

Cicatricosisporites

Cicatricosisporites carlylensis

Montana

Cicatricosisporites dorogensis

Montana

Cingulatisporites

Cingulatisporites dakotaensis

Montana

Cingulatisporites scabratus

Montana

Clavatricolpites

Clavatricolpites prolatus

Montana

Concavisporites

Concavisporites rugulatus

Montana

Concavisporites rugulatus

Montana

Converrucosisporites

Converrucosisporites sp.

Montana

Corylus

Corylus granilabratus

Montana

A hazelnut palynomorph

Cupanieidites

Cupanieidites major

Montana

Cyathidites

Cyathidites foveolatus

Montana

Cyathidites minor

Montana

Cycadopites

Cycadopites scabratus

Montana

Deltoidospora

Deltoidospora diaphana

Montana

Dicotetradites

Dicotetradites granulatus

Montana

Ephedripites

Ephedripites ovatus

Montana

Ephedripites undulatus

Montana

Erdtmanipollis

Erdtmanipollis cretaceus

Montana
South Dakota

Gleicheniidites

Gleicheniidites excelsus

Montana

Gleicheniidites senonicus

Montana

Gnetaceaepollenites

Gnetaceaepollenites eocenipites

Montana

Haloragacidites

Haloragacidites quadratus

Montana

Hamulatisporis

Hamulatisporis hamulatis

Montana

Hymenophyllumsporites

Hymenophyllumsporites parvus

Montana

A fern spore palynomorph

Hymenophyllumsporites pseudomaximus

Montana

A fern spore palynomorph

Ilexpollenites

Ilexpollenites compactus

Inaperturopollenites

Inaperturopollenites rugulatus

Montana

Interpollis

Interpollis cf. I. supplingensis

Kurtzipites

Kurtzipites trispissatus

Montana

Kurtzipites trispissatus

Montana

Laevigatosporites

Laevigatosporites anomalus

Montana

Laevigatosporites discordatus

Montana

Laevigatosporites gracilis

Montana

Laevigatosporites ovatus

Montana

Liliacidites

Liliacidites variegatus

Montana

Liliacidites sp.

Montana

Lycopodiumsporites

Lycopodiumsporites austroclavatidites

Montana

Momipites

Momipites circularis

Montana

Momipites parvus

Montana

Monosulcites

Monosulcites carpentieri

Montana

Monosulcites crescentus

Montana

Monosulcites latus

Montana

Monosulcites tectatus

Montana

Monosulcites sp.

Montana

Myrtipites

Myrtipites granulatus

Montana

Myrtipites scabratus

Montana

Nyssapollenites

Nyssapollenites analepticus

Montana

Nyssapollenites pseudocruciatus

Montana

Osmundacidites

Osmundacidites wellmanii

Montana

Pachysandra

Pachysandra cretaceae

Montana
South Dakota

Palmidites

Palmidites maximus

Montana

Peromonolites

Peromonolites granulatus

Montana

Phyllocladidites

Phyllocladidites mawsonii

Montana

Phyllocladidites ruei

Montana

Podocarpidites

Podocarpidites otagoensis

Montana

Polyadopollenites

Polyadopollenites psilatus

Montana

Polycolpites

Polycolpites granulatus

Montana

Polypodiidites

Polypodiidites inangahuensis

Montana

Proteacidites

Proteacidites retusus

Montana

Proteacidites retusus

Montana

Proteacidites thalmannii

Montana

Psilatricolporites

Psilatricolporites prolatus

Montana

Pterocaryapollenites

Pterocaryapollenites stellatus

Montana

Reticuloidosporites

Reticuloidosporites dentatus

Montana

Schizosporis

Schizosporis complexus

Montana

Schizosporis parvus

Montana

Spheripollenites

Spheripollenites subgranulatus

Montana

Spinamonoporites

Spinamonoporites typicus

Montana

Stereisporites

Stereisporites antiquasporites

Montana

Stereisporites psilatus

Montana

Striainaperturites

Striainaperturites ovatus

Montana

Styx

Styx major

Montana

Styx minor

Montana

Taxodiaceaepollenites

Taxodiaceaepollenites hiatus

Montana

Triatriopollenites

Triatriopollenites granilabratus

Montana

Tricolpites

Tricolpites bacustriatus

Montana

Tricolpites delicatulus

Montana

Tricolpites foveolatus

Montana

Tricolpites interangulus

Tricolpites parvistriatus

Montana

Tricolpites psilascabratus

Montana

Tricolpites reticulatus

Montana

Tricolpites striatus

Montana

Tricolpopollenites

Tricolpopollenites clavireticulatus

Montana

Tricolpopollenites megaexactus

Montana

Tricolpopollenites microreticulatus

Montana

Tricolpopollenites microscabratus

Montana

Tricolpopollenites sp1, sp2

Montana

Tricolporopollenites

Tricolporopollenites elongatus

Montana

Tricolporopollenites foveotectatus

Montana

Tricolporopollenites granustriatus

Montana

Tricolporopollenites megaexactus

Montana

Tricolporopollenites prolatus

Montana

Tricolporopollenites striatus

Montana

Triplanosporites

Triplanosporites sinuosus

Montana

Triporopollenites

Triporopollenites rugatus

Montana

Ulmipollenites

Ulmipollenites undulosus

Montana

Ulmipollenites verrucatus

Montana

Ulmoideipites

Ulmoideipites tricostatus

Montana

Wodehouseia

Wodehouseia spinata

Montana

Zlivisporis

Zlivisporis blanensis

Montana

See also

References

  1. ^ DePalma, Robert; Cichocki, Frederich; Dierick, Manuel; Feeney, Robert (2010). "Preliminary Notes on the First Recorded Amber Insects from the Hell Creek Formation" (PDF). The Journal of Paleontological Sciences. 10: 1–7. Retrieved 16 November 2020.
  2. ^ Nel, André; DePalma, Robert A.; Engel, Michael S. (2010). "A possible hemiphlebiid damselfly in Late Cretaceous amber from South Dakota (Odonata: Zygoptera)". Transactions of the Kansas Academy of Science. 113 (3/4): 231–234. doi:10.1660/062.113.0312. JSTOR 41309615. S2CID 84827761.
  3. Messer, A'ndrea Eluse. "Leaf-mining insects destroyed with the dinosaurs, others quickly appeared". Penn State News. Pennsylvania State University. Retrieved 20 August 2014.
  4. "North Dakota site shows wreckage from same object that killed the dinosaurs". UW News. University of Washington. Retrieved 29 March 2019.
  5. Peterson, Douglas. "The Day the Dinosaurs Died". The New Yorker.
  6. Nel, André (2021). "Maastrichtian representatives of the dragonfly family Aeschnidiidae question the entomofaunal turnover of the early Late Cretaceous". Palaeoentomology. 4 (3). doi:10.11646/palaeoentomology.4.3.5. Retrieved 17 Feb 2024.
  7. ^ Graf, Dan; Cummings, Kevin. "The Mussel Project". UWSP Mussel Project. The University of Wisconsin-Stevens Point. Retrieved 7 June 2021.
  8. ^ Pearson et al. (2002) p. 154
  9. ^ Pearson et al. (2002) pp. 145–167
  10. ^ Pearson et al. (2002) p. 155
  11. ^ Pearson et al. (2002) pp. 156
  12. Listed as "cf. Barbourula sp." in "Class Amphibia," Estes and Berberian, (1970). Page 4.
  13. ^ "Class Amphibia," in Estes and Berberian, (1970). Page 4.
  14. ^ "Class Amphibia," in Estes and Berberian, (1970). Page 4. All taxa listed occur in Montana, see page 1.
  15. Listed as "Eopelobates? sp." in "Class Amphibia," Estes and Berberian, (1970). Page 4.
  16. ^ David G. Demar Jr. (2013). "A new fossil salamander (Caudata, Proteidae) from the Upper Cretaceous (Maastrichtian) Hell Creek Formation, Montana, U.S.A". Journal of Vertebrate Paleontology. 33 (3): 588–598. Bibcode:2013JVPal..33..588D. doi:10.1080/02724634.2013.734887. S2CID 128532897.
  17. ^ "Class Osteichthyes," in Estes and Berberian, (1970). Page 3.
  18. ^ Hilton, Eric J.; Grande, Lance (2022-10-03). "Late Cretaceous sturgeons (Acipenseridae) from North America, with two new species from the Tanis site in the Hell Creek Formation of North Dakota". Journal of Paleontology. 97 (1): 189–217. doi:10.1017/jpa.2022.81. S2CID 252702937.
  19. ^ "Class Osteichthyes," in Estes and Berberian, (1970). Page 3. All taxa listed occur in Montana, see page 1.
  20. ^ Sato, Hiroki; Murray, Alison M.; Vernygora, Oksana; Currie, Philip J. (4 July 2018). "A rare, articulated sturgeon (Chondrostei: Acipenseriformes) from the Upper Cretaceous of Dinosaur Provincial Park, Alberta, Canada". Journal of Vertebrate Paleontology. 38 (4): (1)-(15). doi:10.1080/02724634.2018.1488137. S2CID 92574712.
  21. ^ "Class Osteichthyes," in Estes and Berberian, (1970). Page 4.
  22. ^ "Class Osteichthyes," in Estes and Berberian, (1970). Page 4. All taxa listed occur in Montana, see page 1.
  23. Grande, Lance; Bemis, William E. (10 April 1998). "A Comprehensive Phylogenetic Study of Amiid Fishes (Amiidae) Based on Comparative Skeletal Anatomy. an Empirical Search for Interconnected Patterns of Natural History". Journal of Vertebrate Paleontology. 18 (sup1): 1–696. Bibcode:1998JVPal..18S...1G. doi:10.1080/02724634.1998.10011114.
  24. Grande, Lance (2010). "An Empirical Synthetic Pattern Study of Gars (lepisosteiformes) and Closely Related Species, Based Mostly on Skeletal Anatomy. the Resurrection of Holostei". Copeia. 2010 (2A): iii–871. JSTOR 20787269.
  25. ^ Listed as "cf. Paralbula casei" in "Class Osteichthyes," Estes and Berberian, (1970). Page 4.
  26. ^ Hilton, Eric J.; During, Melanie A.D.; Grande, Lance; Ahlberg, Per E. (May 2023). "New paddlefishes (Acipenseriformes, Polyodontidae) from the Late Cretaceous Tanis Site of the Hell Creek Formation in North Dakota, USA". Journal of Paleontology. 97 (3): 675–692. Bibcode:2023JPal...97..675H. doi:10.1017/jpa.2023.19. S2CID 258095684.
  27. ^ Grande, Lance; Bemis, William E. (1991). "Osteology and Phylogenetic Relationships of Fossil and Recent Paddlefishes (Polyodontidae) with Comments on the Interrelationships of Acipenseriformes". Memoir. 1. Society of Vertebrate Paleontology: ii–121. doi:10.2307/3889328. JSTOR 3889328.
  28. ^ Todd D. Cook; Michael G. Newbrey; Donald B. Brinkman; James I. Kirkland (2014). "Euselachians from the freshwater deposits of the Hell Creek Formation of Montana". Through the End of the Cretaceous in the Type Locality of the Hell Creek Formation in Montana and Adjacent Areas. Geological Society of America Special Papers. Vol. 503. pp. 229–246. doi:10.1130/2014.2503(08). ISBN 978-0-8137-2503-1.
  29. ^ Terry A. Gates; Eric Gorscak; Peter J. Makovicky (2019). "New sharks and other chondrichthyans from the latest Maastrichtian (Late Cretaceous) of North America". Journal of Paleontology. 93 (3): 512–530. Bibcode:2019JPal...93..512G. doi:10.1017/jpa.2018.92.
  30. ^ "Class Chondrichthyes," in Estes and Berberian, (1970). Page 3.
  31. "Class Chondrichthyes," in Estes and Berberian, (1970). Page 3. All taxa listed occur in Montana, see page 1.
  32. "Stratigraphy and paleontology of the Cretaceous Hell Creek Formation, Stumpf site, Morton County, North Dakota". Proceedings of the North Dakota Academy of Sciences. 48. 1994.
  33. White, Paul; Fastovsky, David; Sheehan, Peter (1998). "Taphonomy and suggested structure of the dinosaurian assemblage of the Hell Creek Formation (Maastrichtian), eastern Montana and western North Dakota". PALAIOS. 13 (1): 41. Bibcode:1998Palai..13...41W. doi:10.2307/3515280. JSTOR 3515280.
  34. Manning, P. L.; Ott, C.; Falkingham, P. L. (2008). "The first tyrannosaurid track from the Hell Creek Formation (Late Cretaceous), Montana, U.S.A". PALAIOS. 23 (10): 645–647. Bibcode:2008Palai..23..645M. doi:10.2110/palo.2008.p08-030r. S2CID 129985735.
  35. ^ Lockley, M.; Triebold, M.; Janke, P. R. (2014). "Dinosaur Tracks from the Hell Creek Formation (Upper Cretaceous, Maastrichtian), South Dakota". Fossil Footprints of Western North America: New Mexico Museum of Natural History and Science, Bulletin. 62: 459–468.
  36. ^ Carpenter, Kenneth; Breithaupt, Brent (2 September 1986). "Latest Cretaceous occurrence of nodosaurid ankylosaurs (Dinosauria, Ornithischia) in Western North America and the gradual extinction of the dinosaurs". Journal of Vertebrate Paleontology. 6 (3): 251–257. Bibcode:1986JVPal...6..251C. doi:10.1080/02724634.1986.10011619.
  37. Carpenter, K. (November 2002). "Late Cretaceous dinosaurs from the Denver Basin, Colorado" (PDF). Rocky Mountain Geology. 37 (2): 237–254. Bibcode:2002RMGeo..37..237C. doi:10.2113/11.
  38. ^ "Dinosaur distribution (Late Cretaceous; North America; Montana)." Weishampel, et al. (2004). Page 584.
  39. ^ "Dinosaur distribution (Late Cretaceous; North America; South Dakota)." Weishampel, et al. (2004). Page 586.
  40. ^ "Dinosaur distribution (Late Cretaceous; North America; North Dakota)." Weishampel, et al. (2004). Page 585.
  41. Giffin, Emily B.; Gabriel, Diane L.; Johnson, Rolf E. (22 January 1988). "A New Pachycephalosaurid Hell Creek Formation of Montana". Journal of Vertebrate Paleontology. 7 (4): 398–407. doi:10.1080/02724634.1988.10011672. JSTOR 4523163.
  42. ^ Bakker et al. (2006)
  43. ^ Horner, John R.; Goodwin, Mark B.; Evans, David C. (28 October 2022). "A new pachycephalosaurid from the Hell Creek Formation, Garfield County, Montana, U.S.A.". Journal of Vertebrate Paleontology. 42 (4). Bibcode:2022JVPal..42E0369H. doi:10.1080/02724634.2023.2190369. S2CID 258154892.
  44. Williamson, Thomas E.; Carr, Thomas D. (2003). "A new genus of derived pachycephalosaurian from western North America". Journal of Vertebrate Paleontology. 22 (4): 779–801. doi:10.1671/0272-4634(2002)022[0779:ANGODP]2.0.CO;2. S2CID 86112901.
  45. ^ Woodruff, D. Cary; Schott, Ryan K.; Evans, David C. (November 2023). "Two new species of small-bodied pachycephalosaurine (Dinosauria, Marginocephalia) from the uppermost Cretaceous of North America suggest hidden diversity in well-sampled formations". Papers in Palaeontology. 9 (6). Bibcode:2023PPal....9E1535W. doi:10.1002/spp2.1535. S2CID 265261709.
  46. "Table 21.1," in Weishampel, et al. (2004). Page 465.
  47. Carpenter, Kenneth (2006). Horns and Beaks: Ceratopsian and Ornithopod Dinosaurs. Indiana University Press. ISBN 978-0-253-02795-5. Project MUSE book 49401.
  48. Ryan, Michael J.; Chinnery-Allgeier, Brenda J.; Eberth, David A. (2010). New Perspectives on Horned Dinosaurs: The Royal Tyrrell Museum Ceratopsian Symposium. Indiana University Press. ISBN 978-0-253-35358-0. JSTOR j.ctt16gzgng.
  49. Scannella, John B.; Fowler, Denver W. (2014). "A stratigraphic survey of Triceratops localities in the Hell Creek Formation, northeastern Montana (2006–2010)". Through the End of the Cretaceous in the Type Locality of the Hell Creek Formation in Montana and Adjacent Areas. doi:10.1130/2014.2503(12).
  50. Scannella, B.; Fowler, W.; Goodwin, B.; Horner, R. (2014). Evolutionary Trends in Triceratops from the Hell Creek Formation, Montana (Project) (Report). doi:10.7934/p1099.
  51. Scannella, John (10 November 2020). "A chasmosaurine ceratopsid premaxilla from the basal sandstone of the Hell Creek Formation, Montana". Vertebrate Anatomy Morphology Palaeontology. 8: 154–169. doi:10.18435/vamp29366. S2CID 228888356.
  52. Biles, Jan. "Rare dinosaur skull being prepared for exhibition". Topeka Capital-Journal.com. Topeka Capital-Journal. Retrieved 7 September 2015.
  53. "Super-sized Ceratopsian Skull Might be New Species". Everything Dinosaur. 29 August 2015. Retrieved 29 August 2015.
  54. O' Connell, Max (27 August 2015). "Dinosaur skull found in Buffalo likely a new species". Rapid City Journal. Retrieved 27 August 2015.
  55. Ostrom, John H. (May 1978). "Leptoceratops gracilis from the 'Lance' Formation of Wyoming". Journal of Paleontology. 52 (3): 697–704. JSTOR 1303974.
  56. ^ Christopher J. Ott and Peter L. Larson, 2010, "A New, Small Ceratopsian Dinosaur from the Latest Cretaceous Hell Creek Formation, Northwest South Dakota, United States: A Preliminary Description", In: Ryan, M.J., Chinnery-Allgeier, B.J., and Eberth, D.A. (eds.) New Perspectives on Horned Dinosaurs: The Royal Tyrrell Museum Ceratopsian Symposium, Bloomington, Indiana University Press, 656 pp.
  57. Nicholas R. Longrich (2011). "Titanoceratops ouranous, a giant horned dinosaur from the Late Campanian of New Mexico". Cretaceous Research. 32 (3): 264–276. Bibcode:2011CrRes..32..264L. doi:10.1016/j.cretres.2010.12.007.
  58. Scannella, J.; Horner, J.R. (2010). "Torosaurus Marsh, 1891, is Triceratops Marsh, 1889 (Ceratopsidae: Chasmosaurinae): synonymy through ontogeny". Journal of Vertebrate Paleontology. 30 (4): 1157–1168. Bibcode:2010JVPal..30.1157S. doi:10.1080/02724634.2010.483632. S2CID 86767957.
  59. Mallon, Jordan C; Holmes, Robert B; Bamforth, Emily L; Schumann, Dirk (7 May 2022). "The record of Torosaurus (Ornithischia: Ceratopsidae) in Canada and its taxonomic implications". Zoological Journal of the Linnean Society. 195 (1): 157–171. doi:10.1093/zoolinnean/zlab120.
  60. Forster, Catherine A. (March 1993). "Taxomomic validity of the ceratopsid dinosaur Ugrosaurus olsoni (Cobabe and Fastovsky)". Journal of Paleontology. 67 (2): 316–318. Bibcode:1993JPal...67..316F. doi:10.1017/S0022336000032273. S2CID 133184183.
  61. ^ Scannella, John B.; Fowler, Denver W.; Goodwin, Mark B.; Horner, John R. (15 July 2014). "Evolutionary trends in Triceratops from the Hell Creek Formation, Montana". Proceedings of the National Academy of Sciences. 111 (28): 10245–10250. Bibcode:2014PNAS..11110245S. doi:10.1073/pnas.1313334111. PMC 4104892. PMID 24982159.
  62. ^ Campione, N.E.; Evans, D.C. (2011). "Cranial Growth and Variation in Edmontosaurs (Dinosauria: Hadrosauridae): Implications for Latest Cretaceous Megaherbivore Diversity in North America". PLOS ONE. 6 (9): e25186. Bibcode:2011PLoSO...625186C. doi:10.1371/journal.pone.0025186. PMC 3182183. PMID 21969872.
  63. Manning, Phillip L.; Morris, Peter M.; McMahon, Adam; Jones, Emrys; Gize, Andy; Macquaker, Joe H. S.; Wolff, George; Thompson, Anu; Marshall, Jim; Taylor, Kevin G.; Lyson, Tyler; Gaskell, Simon; Reamtong, Onrapak; Sellers, William I.; van Dongen, Bart E.; Buckley, Mike; Wogelius, Roy A. (7 October 2009). "Mineralized Soft-Tissue Structure and Chemistry in a Mummified Hadrosaur from the Hell Creek Formation, North Dakota (USA)". Proceedings: Biological Sciences. 276 (1672): 3429–3437. doi:10.1098/rspb.2009.0812. JSTOR 30244137. PMC 2817188. PMID 19570788.
  64. Vajda, Vivi; Lyson, Tyler R.; Bercovici, Antonie; Doman, Jessman H.; Pearson, Dean A. (November 2013). "A snapshot into the terrestrial ecosystem of an exceptionally well-preserved dinosaur (Hadrosauridae) from the Upper Cretaceous of North Dakota, USA". Cretaceous Research. 46: 114–122. Bibcode:2013CrRes..46..114V. doi:10.1016/j.cretres.2013.08.010.
  65. Rohrer, W. L.; Konizeski, R. (May 1960). "On the Occurrence of Edmontosaurus in the Hell Creek Formation of Montana". 34. 34 (3): 464–466. JSTOR 1300943.
  66. ^ Wosik, Mateusz; Goodwin, Mark B.; Evans, David C. (2 November 2017). "A nestling-sized skeleton of Edmontosaurus (Ornithischia, Hadrosauridae) from the Hell Creek Formation of northeastern Montana, U.S.A., with an analysis of ontogenetic limb allometry". Journal of Vertebrate Paleontology. 37 (6): e1398168. Bibcode:2017JVPal..37E8168W. doi:10.1080/02724634.2017.1398168. S2CID 90735967.
  67. ^ Listed as "?Thescelosaurus garbanii" in "Dinosaur distribution (Late Cretaceous; North America; Montana)." Weishampel, et al. (2004). Page 584.
  68. ^ Boyd, Clint A.; Brown, Caleb Marshal; Scheetz, Rodney D.; Clarke, Julia A. (12 September 2009). "Taxonomic Revision of the Basal Neornithischian Taxa Thescelosaurus and Bugenasaura". Journal of Vertebrate Paleontology. 29 (3): 758–770. Bibcode:2009JVPal..29..758B. doi:10.1671/039.029.0328. JSTOR 20627088. S2CID 84273584.
  69. Noted as being present, although misspelled as "Thescelosaurus garbani, in " "Dinosaur distribution (Late Cretaceous; North America; South Dakota)." Weishampel, et al. (2004). Page 586.
  70. Boyd, Brown, et al. (2009)
  71. Galton, Peter M. (September 1974). "Notes on Thescelosaurus, a Conservative Ornithopod Dinosaur from the Upper Cretaceous of North America, with Comments on Ornithopod Classification". Journal of Paleontology. 48 (5): 1048–1067. JSTOR 1303302.
  72. Manning, Phillip L.; Ott, Christopher; Falkingham, Peter L. (September–October 2008). "A Probable Tyrannosaurid Track from the Hell Creek Formation (Upper Cretaceous), Montana, United States". PALAIOS. 23 (9/10): 645–647. Bibcode:2008Palai..23..645M. doi:10.2110/palo.2008.p08-030r. JSTOR 27670550. S2CID 129985735.
  73. Dalman, S.G.; Lucas, S.G. "A new large Tyrannosaurid Alamotyrannus brinkmani, n. gen., n. sp. (Theropoda: Tyrannosauridae), from the Upper Cretaceous Ojo Alamo Formation (Naashoibito Member), San Juan Basin, New Mexico". New Mexico Museum of Natural History and Science Bulletin.
  74. Molnar, R.E. (January 1980). "An Albertosaur from the Hell Creek Formation of Montana". Journal of Paleontology. 54 (1): 102–108. JSTOR 1304167.
  75. Molnar, R. E. (January 1978). "A New Theropod Dinosaur from the Upper Cretaceous of Central Montana". Journal of Paleontology. 52 (1): 73–82. JSTOR 1303791.
  76. ^ Denver W. Fowler; John P. Wilson; Elizabeth A. Freedman Fowler; Christopher R. Noto; Daniel Anduza; John R. Horner (2020). "Trierarchuncus prairiensis gen. et sp. nov., the last alvarezsaurid: Hell Creek Formation (uppermost Maastrichtian), Montana". Cretaceous Research. 116: Article 104560. Bibcode:2020CrRes.11604560F. doi:10.1016/j.cretres.2020.104560. S2CID 225630913.
  77. Hutchinson and Chiappe, 1998. The first known alvarezsaurid (Theropoda: Aves) from North America. Journal of Vertebrate Paleontology. 18(3), 447–450.
  78. Horner, John R.; Goodwin, Mark B.; Myhrvold, Nathan (9 February 2011). "Dinosaur Census Reveals Abundant Tyrannosaurus and Rare Ontogenetic Stages in the Upper Cretaceous Hell Creek Formation (Maastrichtian), Montana, USA". PLOS ONE. 6 (2): e16574. Bibcode:2011PLoSO...616574H. doi:10.1371/journal.pone.0016574. PMC 3036655. PMID 21347420.
  79. Triebold, 1997. The Sandy Site: Small Dinosaurs from the Hell Creek Formation of South Dakota. in Wolberg, Stump and Rosenberg (eds). Dinofest International: Proceedings of a Symposium sponsored by Arizona
  80. ^ Longrich (2008), pages 983–996.
  81. ^ Lamanna, M. C.; Sues, H. D.; Schachner, E. R.; Lyson, T. R. (2014). "A New Large-Bodied Oviraptorosaurian Theropod Dinosaur from the Latest Cretaceous of Western North America". PLOS ONE. 9 (3): e92022. Bibcode:2014PLoSO...992022L. doi:10.1371/journal.pone.0092022. PMC 3960162. PMID 24647078.
  82. Stein, Walter W. (2019). "TAKING COUNT: A Census of Dinosaur Fossils Recovered From the Hell Creek and Lance Formations (Maastrichtian)" (PDF). The Journal of Paleontological Sciences. 8: 1–42.
  83. Schachner, Emma; Larson, Tyler; Hanks, Harold. A preliminary report of a new specimen of Chirostenotes (Oviraptorosauria: Theropoda) from the Hell Creek Formation of North Dakota (Report). in "Abstracts of Papers". Journal of Vertebrate Paleontology. 26: 1–152. 2006. Bibcode:2006JVPal..26S...1.. doi:10.1080/02724634.2006.10010069.
  84. Russel, Dale A.; Manabe, Makoto (2002). "Synopsis of the Hell Creek (uppermost Cretaceous) dinosaur assemblage". Geological Society of America Special Papers. 361: 169–176. ISBN 9780813723617. Retrieved 18 October 2020.
  85. Benner, Elizabeth K. C.; Cullen, T. M.; Evans, D. C. (May 18–21, 2016). "MORPHOLOGICAL AND HISTOLOGICAL ANALYSIS OF A NEW LARGE-BODIED 10 CAENAGNATHID SPECIMEN (THEROPODA: OVIRAPTOROSAURIA) FROM THE HELL CREEK FORMATION (MONTANA)" (PDF). Canadian Society of Vertebrate Paleontology: 17–18. Retrieved 17 November 2020.
  86. ^ Atkins-Weltman, K. L.; Simon, D. J.; Woodward, H. N.; Funston, G. F.; Snively, E. (2024). "A new oviraptorosaur (Dinosauria: Theropoda) from the end-Maastrichtian Hell Creek Formation of North America". PLOS ONE. 19 (1). e0294901. Bibcode:2024PLoSO..1994901A. doi:10.1371/journal.pone.0294901. PMC 10807829. PMID 38266012.
  87. ^ Evans, D. C.; Larson, D. W.; Currie, P. J. (2013). "A new dromaeosaurid (Dinosauria: Theropoda) with Asian affinities from the latest Cretaceous of North America". Naturwissenschaften. 100 (11): 1041–9. Bibcode:2013NW....100.1041E. doi:10.1007/s00114-013-1107-5. PMID 24248432. S2CID 14978813.
  88. Russel, Dale A.; Manabe, Makoto (2002). "Synopsis of the Hell Creek (uppermost Cretaceous) dinosaur assemblage". Geological Society of America Special Papers. 361: 169–176. ISBN 9780813723617. Retrieved 23 October 2020.
  89. Dinosaur distribution (Late Cretaceous; North America; North Dakota). Weishampel, et al. (2004). Page 585
  90. ^ Longrich, N.R.; Tokaryk, T.; Field, D.J. (2011). "Mass extinction of birds at the Cretaceous–Paleogene (K–Pg) boundary". Proceedings of the National Academy of Sciences. 108 (37): 15253–15257. Bibcode:2011PNAS..10815253L. doi:10.1073/pnas.1110395108. PMC 3174646. PMID 21914849.
  91. ^ Clark, Alexander D.; Atterholt, Jessie; Scannella, John B.; Carroll, Nathan; O'Connor, Jingmai K. (2024-10-09). Pinheiro, Felipe Lima (ed.). "New enantiornithine diversity in the Hell Creek Formation and the functional morphology of the avisaurid tarsometatarsus". PLOS One. 19 (10): e0310686. doi:10.1371/journal.pone.0310686. ISSN 1932-6203. PMC 11463745. PMID 39383133.
  92. ^ Stidham, 1999. North American avisaurids (Aves: Enantiornithes): New data on morphology and phylogeny. VII International Symposium on Mesozoic Terrestrial Ecosystems, abstracts.
  93. ^ Larry D. Martin; Evgeny N. Kurochkin; Tim T. Tokaryk (2012). "A new evolutionary lineage of diving birds from the Late Cretaceous of North America and Asia". Palaeoworld. 21: 59–63. doi:10.1016/j.palwor.2012.02.005.
  94. ^ Bakker, Robert T.; Larson, Peter L.; Martin, Larry D.; Burnham, David A.; DePalma, Robert A. (30 October 2015). "The first giant raptor (Theropoda: Dromaeosauridae) from the Hell Creek Formation". Paleontological Contributions. 14: 1–16. doi:10.17161/paleo.1808.18764. hdl:1808/18764.
  95. ^ Olshevsky, G., 1991, A Revision of the Parainfraclass Archosauria Cope, 1869, Excluding the Advanced Crocodylia. Mesozoic Meanderings 2 pp 196
  96. ^ Carpenter, K. (1982). "Baby dinosaurs from the Late Cretaceous Lance and Hell Creek formations and a description of a new species of theropod" (PDF). Contributions to Geology, University of Wyoming. 20 (2): 123–134.
  97. ^ Elzanowski, A.; Paul, G.S.; Stidham, T.A. (2001). "An avian quadrate from the Late Cretaceous Lance Formation of Wyoming". Journal of Vertebrate Paleontology. 20 (4): 712–719. doi:10.1671/0272-4634(2000)020[0712:aaqftl]2.0.co;2. S2CID 86292770.
  98. ^ Estes, Richard (1964). Fossil vertebrates from the late Cretaceous Lance formation, eastern Wyoming. University of California Press. OCLC 3753287.
  99. ^ Larson, Derek W.; Currie, Philip J. (23 January 2013). "Multivariate Analyses of Small Theropod Dinosaur Teeth and Implications for Paleoecological Turnover through Time". PLOS ONE. 8 (1): e54329. Bibcode:2013PLoSO...854329L. doi:10.1371/journal.pone.0054329. PMC 3553132. PMID 23372708.
  100. Stidham, Thomas Allen (2001). The origin and ecological diversification of modern birds: Evidence from the extinct wading ducks, Presbyornithidae (Neornithes: Anseriformes) (Thesis). OCLC 892837810. ProQuest 304684225.
  101. ^ "Class Aves," in Estes and Berberian, (1970). Page 7.
  102. "Class Aves," in Estes and Berberian, (1970). Page 7. All taxa listed occur in Montana, see page 1.
  103. ^ Henderson, Michael; Peterson, Joseph (30 March 2006). "An Azhdarchid Pterosaur Cervical Vertebra from the Hell Creek Formation (Maastrichtian) of Southeastern Montana" (PDF). Journal of Vertebrate Paleontology. 26 (1): 192–195. doi:10.1671/0272-4634(2006)26[192:AAPCVF]2.0.CO;2. JSTOR 4524549. S2CID 130751879.
  104. ^ R. Matsumoto; S. E. Evans (2010). "Choristoderes and the freshwater assemblages of Laurasia". Journal of Iberian Geology. 36 (2): 253–274. Bibcode:2010JIbG...36..253M. doi:10.5209/rev_jige.2010.v36.n2.11.
  105. ^ "Order Testudinata," in Estes and Berberian, (1970). Page 5.
  106. ^ "Order Testudinata," in Estes and Berberian, (1970). Page 5. All taxa listed occur in Montana, see page 1.
  107. ^ Walter G. Joyce; Donald B. Brinkman; Tyler R. Lyson (2019). "A new species of trionychid turtle, Axestemys infernalis sp. nov., from the Late Cretaceous (Maastrichtian) Hell Creek and Lance formations of the Northern Great Plains, USA". Palaeontologia Electronica. 22 (3): Article number 22.3.72. doi:10.26879/949.
  108. Arbour, Victoria M.; Zanno, Lindsay E.; Larson, Derek W.; Evans, David C.; Sues, Hans-Dieter (9 February 2016). "The furculae of the dromaeosaurid dinosaur Dakotaraptor steini are trionychid turtle entoplastra". PeerJ. 4: e1691. doi:10.7717/peerj.1691. PMC 4756751. PMID 26893972.
  109. ^ Georgia E. Knauss; Walter G. Joyce; Tyler R. Lyson; Dean Pearson (2011). "A new kinosternoid from the Late Cretaceous Hell Creek Formation of North Dakota and Montana and the origin of the Dermatemys mawii lineage". Paläontologische Zeitschrift. 85 (2): 124–142. Bibcode:2011PalZ...85..125K. doi:10.1007/s12542-010-0081-x. S2CID 129123961.
  110. ^ "Cretaceous-Period Softshell Turtle Lived alongside Giant Dinosaurs | Sci-News.com". Breaking Science News | Sci-News.com. 14 March 2022. Retrieved 2022-03-15.
  111. Tyler R. Lyson; Jacob L. Sayler; Walter G. Joyce (2019). "A new baenid turtle, Saxochelys gilberti, gen. et sp. nov., from the uppermost Cretaceous (Maastrichtian) Hell Creek Formation: sexual dimorphism and spatial niche partitioning within the most speciose group of Late Cretaceous turtles". Journal of Vertebrate Paleontology. 39 (4): e1662428. Bibcode:2019JVPal..39E2428L. doi:10.1080/02724634.2019.1662428. S2CID 208587902.
  112. ^ Nicholas R. Longrich; Bhart-Anjan S. Bhullar; Jacques A. Gauthier (2012). "Mass extinction of lizards and snakes at the Cretaceous–Paleogene boundary". Proceedings of the National Academy of Sciences of the United States of America. 109 (52): 21396–21401. Bibcode:2012PNAS..10921396L. doi:10.1073/pnas.1211526110. PMC 3535637. PMID 23236177.
  113. ^ Nicholas R. Longrich; Bhart-Anjan S. Bhullar; Jacques A. Gauthier (2013). "Correction for "Mass extinction of lizards and snakes at the Cretaceous–Paleogene boundary," by Nicholas R. Longrich, Bhart-Anjan S. Bhullar, and Jacques A. Gauthier, which appeared in issue 52, December 26, 2012, of Proc Natl Acad Sci USA (109:21396–21401; first published December 10, 2012; 10.1073/pnas.1211526110)". Proceedings of the National Academy of Sciences of the United States of America. 110 (16): 6608. Bibcode:2013PNAS..110Q6608.. doi:10.1073/pnas.1303907110. PMC 3631639.
  114. "Fossils may capture the day the dinosaurs died. Here's what you should know". Science. 2019-03-31. Archived from the original on March 5, 2021. Retrieved 2021-08-20.
  115. Van Vranken, Nathan E.; Boyd, Clint A. (21 August 2021). "The first in situ collection of a mosasaurine from the marine Breien Member of the Hell Creek Formation in south-central North Dakota, USA". PaleoBios. 38 (1). doi:10.5070/P938054460.
  116. ^ Zofia Kielan-Jaworowska, Richard L. Cifelli, and Zhe-Xi Luo, Mammals from the Age of Dinosaurs: Origins, Evolution, and Structure, Columbia University Press, New York, 2004 ISBN 0-231-11918-6, p. 98-99
  117. ^ Gregory P. Wilson (2013). "Mammals across the K/Pg boundary in northeastern Montana, U.S.A.: dental morphology and body-size patterns reveal extinction selectivity and immigrant-fueled ecospace filling". Paleobiology. 39 (3): 429–469. Bibcode:2013Pbio...39..429W. doi:10.1666/12041. S2CID 36025237.
  118. ^ J. David Archibald; Yue Zhang; Tony Harper; Richard L. Cifelli (2011). "Protungulatum, confirmed Cretaceous occurrence of an otherwise Paleocene eutherian (placental?) mammal". Journal of Mammalian Evolution. 18 (3): 153–161. doi:10.1007/s10914-011-9162-1. S2CID 16724836.
  119. Thomas E. Williamson; Stephen L. Brusatte; Thomas D. Carr; Anne Weil; Barbara R. Standhardt (2012). "The phylogeny and evolution of Cretaceous–Palaeogene metatherians: cladistic analysis and description of new early Palaeocene specimens from the Nacimiento Formation, New Mexico". Journal of Systematic Palaeontology. 10 (4): 625–651. Bibcode:2012JSPal..10..625W. doi:10.1080/14772019.2011.631592. S2CID 83996185.
  120. ^ Davis, B. M. (2007). "A revision of 'pediomyid' marsupials from the Late Cretaceous of North America" (PDF). Acta Palaeontologica Polonica. 52 (2): 217–256.
  121. ^ Kelly, T.S. (2014). "Preliminary report on the mammals from Lane's Little Jaw Site Quarry: a latest Cretaceous (earliest Puercan?) local fauna, Hell Creek Formation, southeastern Montana" (PDF). Paludicola. 10 (1): 50–91.
  122. Fox, Richard C. (December 2015). "A revision of the Late Cretaceous–Paleocene eutherian mammal Cimolestes Marsh, 1889". Canadian Journal of Earth Sciences. 52 (12): 1137–1149. Bibcode:2015CaJES..52.1137F. doi:10.1139/cjes-2015-0113.
  123. Fastovsky, David E.; McSWEENEY, Kevin (1987). "Paleosols spanning the Cretaceous-Paleogene transition, eastern Montana and western North Dakota". Geological Society of America Bulletin. 99 (1): 66. Bibcode:1987GSAB...99...66F. doi:10.1130/0016-7606(1987)99<66:PSTCTE>2.0.CO;2.
  124. Johnson, Kirk R.; Hickey, Leo J. (1990). "Megafloral change across the Cretaceous/Tertiary boundary in the northern Great Plains and Rocky Mountains, U.S.A.". Global Catastrophes in Earth History; an Interdisciplinary Conference on Impacts, Volcanism, and Mass Mortality. Geological Society of America Special Papers. Vol. 247. pp. 433–444. doi:10.1130/SPE247-p433. ISBN 0-8137-2247-0.
  125. ^ Johnson, Kirk Richard (1989). A high-resolution megafloral biostratigraphy spanning the Cretaceous-Tertiary boundary in the northern Great Plains (Thesis).
  126. ^ Johnson, Kirk R. (2002). "Megaflora of the Hell Creek and lower Fort Union Formations in the western Dakotas: Vegetational response to climate change, the Cretaceous-Tertiary boundary event, and rapid marine transgression". The Hell Creek Formation and the Cretaceous-Tertiary boundary in the northern Great Plains: An Integrated continental record of the end of the Cretaceous. doi:10.1130/0-8137-2361-2.329. ISBN 978-0-8137-2361-7.
  127. Johnson, Kirk R.; Nichols, Douglas J.; Attrep, Moses; Orth, Charles J. (August 1989). "High-resolution leaf-fossil record spanning the Cretaceous/Tertiary boundary". Nature. 340 (6236): 708–711. Bibcode:1989Natur.340..708J. doi:10.1038/340708a0. S2CID 4302433.
  128. Barnet, James S.K.; Littler, Kate; Kroon, Dick; Leng, Melanie J.; Westerhold, Thomas; Röhl, Ursula; Zachos, James C. (1 February 2018). "A new high-resolution chronology for the late Maastrichtian warming event: Establishing robust temporal links with the onset of Deccan volcanism". Geology. 46 (2): 147–150. Bibcode:2018Geo....46..147B. doi:10.1130/G39771.1. hdl:10871/30937.
  129. Retallack, Gregory J. (November 1994). "A pedotype approach to latest Cretaceous and earliest Tertiary paleosols in eastern Montana". Geological Society of America Bulletin. 106 (11): 1377–1397. Bibcode:1994GSAB..106.1377R. doi:10.1130/0016-7606(1994)106<1377:APATLC>2.3.CO;2.
  130. "Cruisin' the fossil freeway : an epoch tale of a scientist and an artist on the ultimate 5,000-mile paleo road trip | WorldCat.org". search.worldcat.org. Retrieved 2024-01-27.
  131. Manchester, Steven R.; O'Leary, Elizabeth L. (2010). "Phylogenetic Distribution and Identification of Fin-winged Fruits". Botanical Review. 76 (1): 1–82. Bibcode:2010BotRv..76....1M. doi:10.1007/s12229-010-9041-0. JSTOR 40792810. S2CID 8207808.
  132. Stockey, Ruth A.; Rothwell, Gar W.; Johnson, Kirk R. (October 2016). "Evaluating Relationships among Floating Aquatic Monocots: A New Species of Cobbania (Araceae) from the Upper Maastrichtian of South Dakota". International Journal of Plant Sciences. 177 (8): 706–725. doi:10.1086/688285. S2CID 89477112.
  133. Peppe, Daniel J.; Hickey, Leo J. (October 2014). "Fort Union Formation Fossil Leaves (Paleocene, Williston Basin, North Dakota, USA) Indicate Evolutionary Relationships Between Paleocene and Eocene Plant Species". Bulletin of the Peabody Museum of Natural History. 55 (2): 171–189. doi:10.3374/014.055.0209. S2CID 129724520.
  134. Peppe, Daniel J.; Erickson, J. Mark; Hickey, Leo J. (May 2007). "Fossil leaf species from the Fox Hills Formation (Upper Cretaceous: North Dakota, USA) and their paleogeographic significance". Journal of Paleontology. 81 (3): 550–567. Bibcode:2007JPal...81..550P. doi:10.1666/05067.1. S2CID 129967389.
  135. Crane, Peter R.; Manchester, Steven R.; Dilcher, David L. (October 1991). "Reproductive and Vegetative Structure of Nordenskioldia (Trochodendraceae), A Vesselless Dicotyledon from the Early Tertiary of the Northern Hemisphere". American Journal of Botany. 78 (10): 1311–1334. doi:10.1002/j.1537-2197.1991.tb12599.x.
  136. Manchester, Steven R.; Kodrul, Tatyana M. (June 2014). "Morphology, affinities and phytogeographic history of Porosia Hickey in the Cretaceous and Paleocene of North America and Asia". Acta Palaeobotanica. 54 (1): 77–99. doi:10.2478/acpa-2014-0002.
  137. McIver, Elisabeth E (February 2002). "The paleoenvironment of Tyrannosaurus rex from southwestern Saskatchewan, Canada". Canadian Journal of Earth Sciences. 39 (2): 207–221. Bibcode:2002CaJES..39..207M. doi:10.1139/e01-073.
  138. Arens, Nan Crystal; Allen, Sarah E. (1 January 2014). "A florule from the base of the Hell Creek Formation in the type area of eastern Montana: Implications for vegetation and climate". Through the End of the Cretaceous in the Type Locality of the Hell Creek Formation in Montana and Adjacent Areas. doi:10.1130/2014.2503(06). ISBN 9780813725031.
  139. ^ Norton, N.J.; Hall, J.H. (1969). "Palynology of the Upper Cretaceous and Lower Tertiary in the type locality of the Hell Creek Formation, Montana, USA". Palaeontographica Abteilung B. 125: 1–64.

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