List of the Mesozoic life of Montana

This list of the Mesozoic life of Montana contains the various prehistoric life-forms whose fossilized remains have been reported from within the US state of Montana and are between 252.17 and 66 million years of age.

A

 * †Achelousaurus – type locality for genus
 * †Achelousaurus horneri – type locality for species
 * Acheroraptor NT small.jpg †[[Acheroraptor]] – type locality for genus
 * †Acheroraptor temertyorum – type locality for species
 * Acipenser
 * †Acipenser eruciferus
 * †Acristavus – type locality for genus
 * †Acristavus gagslarsoni – type locality for species
 * †Acrostichopteris
 * †Acrostichopteris longipennis
 * †Adiantites
 * †Adiantites montanensis
 * †Adocus
 * †Albanerpeton
 * †Albanerpeton nexuosus
 * Albertaceratops BW2.jpg †[[Albertaceratops]]
 * †Albertaceratops nesmoi
 * †Albertatherium
 * †Albertatherium primus
 * †Albertosaurus
 * †Allocrioceras
 * †Allocrioceras annulatum
 * Allosaurus Revised.jpg †[[Allosaurus]]
 * †Alostera
 * †Alostera saskatchewanensis
 * †Alphadon
 * †Alphadon attaragos
 * †Alphadon halleyi – type locality for species
 * †Alphadon marshi
 * †Alphadon wilsoni
 * †Altacreodus
 * †Altacreodus magnus
 * †Alzadasaurus – tentative report
 * †Alzadites – type locality for genus
 * †Alzadites alzadensis – type locality for species
 * †Ambilestes
 * †Ambilestes cerberoides – or unidentified comparable form
 * Amia
 * †Amia fragosa
 * †Amia uintaensis
 * †Amphicoelias
 * †Anatotitan
 * †Anatotitan copei
 * †Anchura – tentative report
 * Ankylosaurus magniventris reconstruction.png †[[Ankylosaurus]] – type locality for genus
 * †Ankylosaurus magniventris – type locality for species
 * †Anomozamites
 * †Aquiladelphis
 * †Aquiladelphis incus
 * †Aquiladelphis minor
 * †Aquilapollenites
 * †Aquilapollenites collaris
 * †Aquilapollenites conatus
 * †Aquilapollenites marmarthensis
 * †Aquilapollenites mtchedlishvilii
 * †Aquilapollenites quadrilobus
 * †Aquilapollenites turbidus
 * Aquilops NT small.jpg †[[Aquilops]] – type locality for genus
 * †Aquilops americanus – type locality for species
 * Aralia – or unidentified comparable form
 * †Aralia wellingtonia
 * †Araliaephyllum
 * †Araliaephyllum westonii
 * †Araliopsoides
 * †Araliopsoides cretacea – or unidentified comparable form
 * †Araucarites
 * †Araucarites longifolia
 * †Arcellites
 * †Archaeolamna
 * †Archaeolamna kopingensis
 * †Archaeotriakis – type locality for genus
 * †Archaeotriakis rochelleae – type locality for species
 * Arcticoceras.jpg †[[Arcticoceras]] – tentative report
 * †Arctocephalites
 * †Arctocephalites gracilis – or unidentified comparable form
 * †Arctocephalites maculatus – or unidentified comparable form
 * †Arctocephalites platynotus – or unidentified comparable form
 * †Arctocephalites sawtoothensis
 * †Arctocephalites saypoensis
 * †Argaliatherium – type locality for genus
 * †Argaliatherium robustum – type locality for species
 * †Ariadnaesporites
 * †Ariadnaesporites fluviatilis – type locality for species
 * †Ascarinites – type locality for genus
 * †Ascarinites communis – type locality for species
 * †Aspideretoides
 * †Aspidophyllum – or unidentified comparable form
 * †Aspidophyllum trilobatum
 * †Asplenium
 * Astarte elliptica 2008-09-07-4.jpg bivalve]] Astarte''
 * †Astarte meeki
 * †Astarte morion
 * †Astarte packardi – or unidentified comparable form
 * †Athrotaxites
 * †Athrotaxites berryi – or unidentified comparable form
 * †Aublysodon
 * †Aublysodon mirandus
 * †Austrotindaria
 * †Austrotindaria canalensis
 * †Austrotindaria svalbardensis
 * †Avaceratops – type locality for genus
 * †Avaceratops lammersi – type locality for species
 * Avicula
 * Avisaurus cropped.png †[[Avisaurus]] – type locality for genus
 * †Avisaurus archibaldi – type locality for species
 * †Avisaurus gloriae – type locality for species
 * †Axestemys
 * †Axestemys splendida – type locality for species
 * Azolla
 * †Azolla barbata
 * †Azolla circinata – type locality for species
 * †Azolla distincta
 * †Azolla simplex – type locality for species
 * †Azolla spinata – type locality for species
 * †Azollopsis – type locality for genus
 * †Azollopsis coccoides – type locality for species
 * †Azollopsis tomentosa – type locality for species

B

 * †Baculatisporites
 * Baculites grandis shell.JPG †[[Baculites]]
 * †Baculites asper
 * †Baculites codyensis
 * †Baculites compressus
 * †Baculites mariasensis
 * †Baena
 * †Baena callosa – type locality for species
 * †Baioconodon
 * †Baioconodon nordicus – or unidentified comparable form
 * †Bakevellia
 * Bambiraptor feinbergi.jpg †[[Bambiraptor]] – type locality for genus
 * †Bambiraptor feinbergi – type locality for species
 * Barbourula – or unidentified comparable form
 * †Basilemys
 * †Basilemys sinuosa – type locality for species
 * †Batodon
 * †Batodon tenuis
 * †Belfria – type locality for genus
 * †Belfria microphylla – type locality for species
 * Belonostomus fossil cropped.png †[[Belonostomus]]
 * †Belonostomus longirostris
 * †Bernissartia
 * †Biretisporites
 * †Biretisporites deltoideus
 * †Borealosuchus
 * †Borealosuchus sternbergii
 * †Boremys
 * †Boremys pulchra
 * †Borissiakoceras
 * †Borissiakoceras orbiculatum
 * Brachaelurus
 * †Brachaelurus estesi
 * †Brachyceratops – type locality for genus
 * †Brachyceratops montanensis – type locality for species
 * †Brachychampsa – type locality for genus
 * †Brachychampsa montana – type locality for species
 * †Brachychampsa montanus
 * Leonardo mummified brachylophosaurus.jpg †[[Brachylophosaurus]]
 * †Brachylophosaurus canadensis – type locality for species
 * †Buccinammonites – type locality for genus
 * †Buccinammonites minimus – type locality for species

C

 * Camarasaurs1.jpg †[[Camarasaurus]]
 * Campeloma
 * †Camptonectes
 * †Camptonectes platessiformis
 * †Camptonectes stygius
 * Carcharias
 * †Cardiaster
 * †Cardiaster curtus
 * †Carinalestes – type locality for genus
 * †Carinalestes murensis – type locality for species
 * †Cedrobaena
 * †Cedrobaena brinkman
 * †Celastrophyllum – or unidentified comparable form
 * Centrosaurus.png †[[Centrosaurus]]
 * †Cerasinops – type locality for genus
 * †Cerasinops hodgskissi – type locality for species
 * †Ceratodus
 * †Ceratodus frazieri
 * †Ceratodus guentheri – or unidentified comparable form
 * †Ceratops – type locality for genus
 * †Ceratops montanus – type locality for species
 * †Cerberophis – type locality for genus
 * †Cerberophis robustus – type locality for species
 * †Cercomya
 * †Cercomya punctata
 * †Chamops
 * †Chamops segnis
 * †Champsosaurus
 * †Champsosaurus natator
 * Chasmosaurus BW.jpg †[[Chasmosaurus]] – or unidentified comparable form
 * Chiloscyllium
 * †Chiloscyllium missouriensis – type locality for species
 * †Chirostenotes
 * †Chirostenotes elegans
 * Chlamys
 * †Chondroceras
 * †Chondroceras allani – or unidentified comparable form
 * †Chondroceras oblatum
 * †Cimexomys
 * †Cimexomys minor
 * †Cimolestes
 * †Cimolestes incisus
 * †Cimolestes stirtoni
 * †Cimoliasaurus
 * †Cimolodon
 * †Cimolodon nitidus
 * Ptilodus.jpg †[[Cimolomys]]
 * †Cimolomys clarki – type locality for species
 * †Cimolomys gracilis
 * †Cimolopteryx
 * †Cimolopteryx maxima
 * †Cinnamomoides
 * Cladophlebis
 * †Cladophlebis alberta
 * †Cladophlebis constricta
 * †Cladophlebis heterophylla
 * †Cladophlebis inclinata
 * †Cladophlebis oblongifolia
 * †Cladophlebis oerstedi
 * †Cladophlebis virginiensis
 * †Claosaurus
 * †Claraia
 * †Claraia aurita
 * †Claraia clarai
 * †Claraia mulleri
 * †Claraia stachei
 * Clidastes proph1DB.jpg †[[Clidastes]]
 * †Clioscaphites
 * †Clioscaphites vermiformis
 * †Cobbanites
 * †Coelostylina
 * †Colpodontosaurus
 * †Colpodontosaurus cracens
 * †Componocancer
 * †Componocancer roberti
 * †Compsemys
 * †Compsemys victa
 * †Coniophis
 * †Coniophis precedens
 * †Coniopteris
 * †Coniopteris bella – or unidentified comparable form
 * †Coniopteris hymenophylloides
 * †Coniopteris simplex
 * †Continuoolithus
 * †Continuoolithus canadensis
 * †Contogenys – type locality for genus
 * †Contogenys sloani – type locality for species
 * †Coriops
 * †Coriops amnicolus
 * †Corviconodon
 * †Corviconodon montanensis – type locality for species
 * [[File:Corythosaurus casuarius, Dinosaur Provincial Park, Alberta, Canada, Late Cretaceous - Royal Ontario Museum - DSC00023.JPG|upright|thumb|Mounted fossilized skeleton of the Late Cretaceous duck-billed dinosaur Corythosaurus]] †[[Corythosaurus]]
 * †Corythosaurus casuarius
 * Crassatella
 * †Cremnoceramus
 * †Cremnoceramus deformis
 * †Cretolamna
 * †Cretolamna appendiculata
 * †Cretorectolobus – type locality for genus
 * †Cretorectolobus olsoni – type locality for species
 * †Crocodilus
 * †Crocodilus humilis
 * †Cryptometoicoceras
 * †Cryptometoicoceras mite
 * Cucullaea
 * †Cucullaea haguei
 * †Cucullaea rockymontana
 * †Cyathidites
 * †Cyathidites minor
 * †Cycadolepis
 * †Cycadopites
 * †Cycadopites fragilis
 * †Cyclurus
 * †Cyclurus fragosus

D

 * †Daspletosaurus
 * †Daspletosaurus horneri – type locality for species
 * †Deinodon – type locality for genus
 * †Deinodon horridus – type locality for species
 * Deinonychus_ewilloughby.png †[[Deinonychus]] – type locality for genus
 * †Deinonychus antirrhopus – type locality for species
 * †Deinosuchus – type locality for genus
 * †Deinosuchus rugosus – type locality for species
 * †Deltoidospora
 * †Deltoidospora cascadensis – type locality for species
 * †Deltoidospora diaphana
 * †Deltoidospora hallii – type locality for species
 * Dentalium
 * †Derrisemys
 * †Derrisemys sterea
 * †Diclonius
 * †Dictyothykalos
 * Didelphodon Clean.png †[[Didelphodon]]
 * †Didelphodon vorax
 * †Didymoceras
 * †Didymoceras cheyennense
 * †Didymoceras nebrascense
 * †Didymoceras stevensoni
 * †Diettertia
 * †Diettertia montanensis
 * Diplodocus carnegii.jpg †[[Diplodocus]]
 * †Doratodon – or unidentified comparable form
 * †Dromaeosaurus
 * †Dromaeosaurus albertensis
 * †Dryophyllum – report made of unidentified related form or using admittedly obsolete nomenclature
 * †Dryophyllum subfalcatum
 * †Dunveganoceras
 * †Dunveganoceras albertense
 * †Dunveganoceras parvum – type locality for species
 * †Dunveganoceras pondi
 * †Dyadonapites
 * †Dyadonapites reticulatus
 * Ankylosaurus tail terminology.png †[[Dyoplosaurus]]
 * †Dyoplosaurus acutosquameus

E

 * †Echinatisporis
 * †Ectocentrocristus
 * †Ectocentrocristus foxi – type locality for species
 * †Ectoconodon
 * †Ectoconodon montanensis – type locality for species
 * †Edgarosaurus
 * †Edgarosaurus muddi
 * †Edmontonia
 * †Edmontonia longiceps
 * †Edmontonia rugosidens – type locality for species
 * †Edmontosaurus
 * Anatotitan BW.jpg †[[Edmontosaurus annectens]]
 * †Einiosaurus – type locality for genus
 * †Einiosaurus procurvicornis – type locality for species
 * †Elasmodus
 * †Elasmodus greenoughi – or unidentified comparable form
 * †Emarginachelys – type locality for genus
 * †Emarginachelys cretacea – type locality for species
 * †Entolioides
 * †Entolioides utahensis
 * †Eodelphis
 * †Eopelobates – or unidentified comparable form
 * Equisetopsida.jpg †[[Equisetum]]
 * †Equisetum cascadensis – type locality for species
 * †Equisetum laterale
 * †Equisetum montanensis
 * †Erdtmanipollis
 * †Erdtmanipollis procumbentiformis
 * †Essonodon – type locality for genus
 * †Essonodon browni – type locality for species
 * †Eubaena
 * †Eubaena cephalica
 * †Eucrossorhinus
 * †Eucrossorhinus microcuspidatus – type locality for species
 * †Eumorphotis
 * †Eumorphotis amplicostata – type locality for species
 * †Eumorphotis ericius – or unidentified comparable form
 * †Eumorphotis multiformis
 * †Euomphaloceras
 * †Euomphaloceras septemseriatum
 * Euoplocephalus BW.jpg †[[Euoplocephalus]]
 * †Euoplocephalus tutus
 * †Eutrephoceras
 * †Eutrephoceras montanensis – type locality for species
 * †Exiteloceras
 * †Exiteloceras jenneyi
 * †Exogyra
 * †Exogyra columbella
 * †Exostinus
 * †Exostinus lancensis

F

 * †Falepetrus
 * †Falepetrus barwini
 * Ficus – or unidentified comparable form
 * †Ficus ovatifolia
 * †Fletcherithyris – report made of unidentified related form or using admittedly obsolete nomenclature
 * †Fletcherithyris margaritovi
 * †Foraminisporis
 * †Foraminisporis undulates

G

 * †Gastopoda
 * †Gervillia
 * †Gervillia ussurica – or unidentified comparable form
 * †Gilmoremys
 * †Gilmoremys lancensis
 * Ginkgo biloba MacAbee BC.jpg [[Ginkgo]]
 * †Ginkgo pluripartita
 * †Ginkgoites
 * †Ginkgoites cascadensis
 * †Ginkgoites pluripartita
 * †Glasbius
 * †Glasbius twitchelli – type locality for species
 * †Glishades – type locality for genus
 * †Glishades ericksoni – type locality for species
 * †Glyptops
 * †Glyptops pervicax – type locality for species
 * Glyptostrobus – or unidentified comparable form
 * Gobiconodon ostromi.JPG †[[Gobiconodon]] – type locality for genus
 * †Gobiconodon ostromi – type locality for species
 * †Goniobasis
 * †Goniobasis subtortuosa
 * †Gorgosaurus
 * †Gorgosaurus libratus – type locality for species
 * †Grammatodon
 * †Grewipollenites
 * †Grewipollenites radiatus
 * GryphaeidaeCretaceousTexas.jpg †[[Gryphaea]]
 * †Gryphaea – type locality for species – informal
 * †Gryphaea impressimarginata
 * †Gryposaurus
 * †Gryposaurus latidens – type locality for species
 * †Gryposaurus notabilis
 * †Gypsonictops
 * †Gypsonictops hypoconus
 * †Gypsonictops illuminatus
 * †Gypsonictops lewisi – type locality for species
 * Gyrodes
 * †Gyrodes conradi

H

 * †Habrosaurus
 * †Habrosaurus dilatus
 * †Hadrosaurus
 * †Hadrosaurus breviceps – type locality for species
 * †Hadrosaurus paucidens – type locality for species
 * †Hamites
 * †Hamites cimarronensis
 * †Haptosphenus
 * †Haptosphenus placodon
 * †Hausmannia
 * †Hausmannia fisheri
 * †Hausmannia montanensis
 * †Helopanoplia
 * †Helopanoplia distincta
 * Hesperornis BW.jpg †[[Hesperornis]]
 * †Hesperornis montana – type locality for species
 * †Heteropecten – tentative report
 * †Holocrinus
 * †Hoploscaphites
 * †Hoploscaphites macer – type locality for species
 * †Hummelichelys
 * †Hummelichelys beecheri
 * †Hummelichelys foveatus – type locality for species
 * †Hybodus
 * †Hybodus montanensis – type locality for species
 * †Hybodus storeri – type locality for species
 * †Hypacrosaurus
 * †Hypacrosaurus stebingeri – type locality for species
 * †Hypotodus
 * †Hypotodus grandis – type locality for species

I

 * †Idiohamites
 * †Idiohamites bispinosus – type locality for species
 * †Idiohamites pulchellus – type locality for species
 * Inoceramus steenstrup, world's largest fossil mollusk.jpg †[[Inoceramus]]
 * †Inoceramus arnoldi
 * †Inoceramus canaliculatus
 * †Inoceramus cancellatus
 * †Inoceramus cardissoides - or unidentified loosely related form
 * †Inoceramus cordiformis – or unidentified comparable form
 * †Inoceramus erectus
 * †Inoceramus fragilis – or unidentified related form
 * †Inoceramus frechi – or unidentified comparable form
 * †Inoceramus gibbosus
 * †Inoceramus gilli – type locality for species
 * †Inoceramus glacierensis – type locality for species
 * †Inoceramus koeneni
 * †Inoceramus latisulcatus – or unidentified comparable form
 * †Inoceramus lesginensis
 * †Inoceramus lingua – or unidentified comparable form
 * †Inoceramus lundbreckensis
 * †Inoceramus sokolovi – type locality for species
 * †Inoceramus undabundus
 * †Inoceramus walterdorfensis
 * †Iqualadelphis
 * †Iqualadelphis lactea
 * Ischyodus avitus .jpg †[[Ischyodus]]
 * †Ischyodus bifurcatus
 * †Ischyrhiza
 * †Ischyrhiza avonicola
 * †Ischyrhiza mira
 * †Isocyprina – or unidentified comparable form
 * †Isocyprina iddingsi

J

 * Judiceratops.tif †[[Judiceratops]] – type locality for genus
 * †Judiceratops tigris – type locality for species
 * †Judithemys
 * †Judithemys backmani

K

 * †Kastanoceras – type locality for genus
 * †Kastanoceras spiniger – type locality for species
 * †Klukia
 * †Klukia canadensis
 * Kritosaurus BW.jpg †[[Kritosaurus]]
 * †Kritosaurus breviceps – or unidentified comparable form
 * †Krokolithes

L

 * †Labrodioctes – type locality for genus
 * †Labrodioctes montanensis – type locality for species
 * †Laevigatosporites
 * †Laevigatosporites haardtii
 * Lepidotes elvensis.JPG †[[Lepidotes]]
 * †Lepidotes haydeni – type locality for species
 * †Lepidotes occidentalis – type locality for species
 * †Lepismatina – report made of unidentified related form or using admittedly obsolete nomenclature
 * †Lepismatina mansfieldi
 * Lepisosteus
 * †Lepisosteus occidentalis
 * †Leptalestes
 * †Leptalestes cooki
 * †Leptalestes krejcii
 * †Leptalestes prokrejcii
 * †Leptalestes toevsi – type locality for species
 * Leptoceratops BW.jpg †[[Leptoceratops]]
 * †Leptoceratops gracilis
 * †Leptochamops
 * †Leptochamops denticulatus
 * †Leptochondria
 * †Leptochondria occidanea
 * †Leptopecopites
 * †Leptopecopites pocockii
 * †Leptorhynchos – tentative report
 * †Lesterwardia – type locality for genus
 * †Lesterwardia palustris – type locality for species
 * †Liliacidites
 * †Lingula
 * †Lingularia
 * †Lingularia borealis
 * †Lioplacodes
 * †Lioplacodes judithensis
 * †Lioplacodes williamsi
 * †Liostrea
 * †Liostrea strigilecula
 * †Lisserpeton – type locality for genus
 * †Lisserpeton atlantes
 * †Lisserpeton bairdi – type locality for species
 * †Lonchidion
 * †Lonchidion selachos
 * Bivalvia - Lopha sp.JPG [[Lopha]]
 * †Lucina
 * Lunatia
 * †Lunatia dakotensis – or unidentified comparable form
 * †Lygobius – type locality for genus
 * †Lygobius knowltoni – type locality for species

M

 * †Magadiceramus
 * †Magadiceramus soukupi
 * †Magnuviator – type locality for genus
 * †Magnuviator ovimonsensis – type locality for species
 * †Maiasaura – type locality for genus
 * †Maiasaura peeblesorum – type locality for species
 * †Marchantiolites
 * †Marchantiolites blairmorensis
 * †Marmarthia
 * †Marmarthia trivialis
 * †Medusaceratops – type locality for genus
 * †Medusaceratops lokii – type locality for species
 * †Meleagrinella
 * †Meleagrinella curta
 * †Melvius – type locality for genus
 * †Melvius thomasi – type locality for species
 * †Meniscoessus
 * †Meniscoessus major
 * †Meniscoessus robustus – type locality for species
 * †Meniscognathus
 * †Meniscognathus altmani
 * Mercuriceratops NT small.jpg †[[Mercuriceratops]] – type locality for genus
 * †Mercuriceratops gemini – type locality for species
 * †Mesodma
 * †Mesodma formosa
 * †Mesodma hensleighi
 * †Mesodma primaeva
 * †Mesodma thompsoni
 * †Metoicoceras
 * †Metoicoceras geslinianum
 * †Metoicoceras mosbyense – type locality for species
 * †Metoicoceras muelleri
 * †Metzgeriites
 * †Metzgeriites montanensis – type locality for species
 * †Micrabacia
 * †Micrabacia radiata
 * †Microsulcatoceras – type locality for genus
 * †Microsulcatoceras puzosiiforme – type locality for species
 * Microvenator.jpg †[[Microvenator]] – type locality for genus
 * †Microvenator celer – type locality for species
 * †Minerisporites
 * †Minerisporites pseudorichardsonii
 * †Miocidaris
 * †Modiolus
 * †Modiolus rosii
 * †Monoclonius – type locality for genus
 * †Monoclonius crassus – type locality for species
 * †Monoclonius recurvicornis – type locality for species
 * †Monoclonius sphenocerus – type locality for species
 * †Monosulcites
 * †Monosulcites riparius
 * †Montanalestes
 * †Montanalestes keeblerorum
 * Montanazdarco cropped.jpg †[[Montanazhdarcho]] – type locality for genus
 * †Montanazhdarcho minor – type locality for species
 * †Montania – type locality for genus
 * †Montania glandulosa – type locality for species
 * †Montanoceratops
 * †Montanoceratops cerorhynchus – type locality for species
 * †Montanoolithus – type locality for genus
 * †Montanoolithus strongorum – type locality for species
 * †Moremanoceras
 * †Moremanoceras costatum
 * †Moremanoceras montanaense – type locality for species
 * †Moremanoceras straini
 * †Mosasaurus
 * †Mosasaurus missouriensis
 * †Myalina
 * †Myalina postcarbonica
 * †Myledaphus
 * †Myledaphus bipartitus
 * Miesmuscheln Mytilus 1.jpg †[[Mytilus (genus)|Mytilus]]

N

 * †Nannometoicoceras
 * †Nannometoicoceras nanos – type locality for species
 * Nanotyrannus lancensis skull.jpg †[[Nanotyrannus]]
 * †Nanotyrannus lancensis – type locality for species
 * †Naomichelys – type locality for genus
 * †Naomichelys speciosa – type locality for species
 * †Necrocarcinus
 * †Nelumbo
 * †Nelumbo peltata – type locality for species
 * †Neocardioceras
 * †Neocardioceras juddii
 * †Neocardioceras minutum
 * †Neogastroplites
 * †Neogastroplites haasi
 * †Neoplagiaulax
 * †Neoplagiaulax burgessi – type locality for species
 * †Neoschizodus
 * †Neurankylus – type locality for genus
 * †Neurankylus eximius – type locality for species
 * †Nezpercius – type locality for genus
 * †Nezpercius dodsoni – type locality for species
 * †Nidimys – type locality for genus
 * †Nidimys occultus – type locality for species
 * †Nilsonia
 * †Nilsonia compta – or unidentified comparable form
 * †Normannites – tentative report
 * †Normannites crickmayi – or unidentified comparable form
 * †Nortedelphys – type locality for genus
 * †Nortedelphys jasoni – type locality for species
 * †Nortedelphys minimus – type locality for species
 * Utah Museum of Natural History - IMG 1773.JPG †[[Notogoneus]]
 * †Notogoneus montananesis – type locality for species
 * †Notogoneus montenensis – type locality for species
 * Nucula
 * †Nymphaeites

O

 * †Obamadon – type locality for genus
 * †Obamadon gracilis – type locality for species
 * †Odaxosaurus
 * †Odaxosaurus piger
 * Odontaspis
 * †Odontaspis sanguinei – type locality for species
 * †Oklatheridium
 * †Oklatheridium wiblei – type locality for species
 * †Onchosaurus
 * †Onchosaurus avonicolus
 * Oohkotokia.jpg †[[Oohkotokia]] – type locality for genus
 * †Oohkotokia horneri – type locality for species
 * †Ophioglypha
 * †Ophioglypha bridgerensis
 * †Ophiomorpha
 * †Opisthotriton
 * †Opisthotriton kayi
 * †Orbicoelia
 * †Ornithomimus
 * †Ornithomimus grandis – type locality for species
 * †Ornithomimus tenuis – type locality for species
 * †Orodromeus – type locality for genus
 * †Orodromeus makelai – type locality for species
 * Oryctodromeus.jpg †[[Oryctodromeus]] – type locality for genus
 * †Oryctodromeus cubicularis – type locality for species
 * Ostrea
 * †Oxybeloceras
 * †Oxybeloceras crassum
 * †Oxytoma
 * †Oxytoma mclearni

P

 * Pachycephalosaurus head butting.png †[[Pachycephalosaurus]] – type locality for genus
 * †Pachycephalosaurus wyomingensis – type locality for species
 * †Pagiophyllum
 * †Palaeobatrachus
 * †Palaeobatrachus occidentalis
 * †Palaeolabrus
 * †Palaeolabrus montanensis
 * †Palaeosaniwa
 * †Palaeosaniwa canadensis
 * †Palaeoscincus – type locality for genus
 * †Palaeoscincus costatus – type locality for species
 * †Palatobaena
 * †Palatobaena bairdi
 * †Paleopsephurus – type locality for genus
 * †Paleopsephurus wilsoni – type locality for species
 * †Paleoungulatum – type locality for genus
 * †Paleoungulatum hooleyi – type locality for species
 * Panoplosaurus.jpg †[[Panoplosaurus]]
 * †Pappotherium
 * †Pappotherium pattersoni
 * †Parachondroceras
 * †Parachondroceras andrewsi
 * †Parachondroceras filicostatum
 * †Paracimexomys
 * †Paracimexomys judithae – type locality for species
 * †Paracimexomys magnus – type locality for species
 * †Paracimexomys priscus
 * †Paracimexomys propriscus – type locality for species
 * †Paracimexomys robisoni – or unidentified comparable form
 * †Paraderma
 * †Paraderma bogerti
 * †Paralbula
 * †Paralbula casei
 * †Paramacellodus – or unidentified comparable form
 * †Paramacellodus keebleri – type locality for species
 * †Paranecturus – type locality for genus
 * †Paranecturus garbanii – type locality for species
 * †Paranyctoides
 * †Paranyctoides maleficus
 * Parapuzosia seppenradensis 3.jpg †[[Parapuzosia]]
 * †Parapuzosia bradyi – type locality for species
 * †Parasaniwa
 * †Parasaniwa wyomingensis
 * †Parataxodium
 * †Parazolla – type locality for genus
 * †Parazolla heterotricha – type locality for species
 * †Parazollopsis – type locality for genus
 * †Parazollopsis cascadensis – type locality for species
 * †Paronychodon
 * †Paronychodon lacustris
 * Pectinodon.png †[[Pectinodon]] – or unidentified comparable form
 * †Pediomys
 * †Pediomys elegans
 * †Peneteius – type locality for genus
 * †Peneteius aquilonius – type locality for species
 * †Penetetrapites
 * †Penetetrapites inconspicuous
 * †Pentacrinus
 * †Pentacrinus asteriscus
 * †Permophorus
 * †Permophorus triassicus
 * †Phelopteria
 * Pholadomya
 * †Pholadomya inaequiplicatus
 * †Pholadomya kingi
 * Physa fontinalis.jpg [[Physa]]
 * †Physa copei – or unidentified comparable form
 * †Piceoerpeton
 * †Piceoerpeton naylori – type locality for species
 * †Piksi – type locality for genus
 * †Piksi barbarulna – type locality for species
 * †Pinna
 * †Pinna kingi
 * †Pistia
 * †Pistia corrugata
 * †Pityocladus
 * †Pityophyllum
 * †Pityophyllum lindstromi
 * †Pityosporites
 * †Pityosporites constrictus
 * †Placunopsis
 * †Plastomenus
 * †Plastomenus costatus
 * †Platacodon
 * †Platacodon nanus
 * †Platanophyllum
 * †Plesiacanthoceras
 * †Plesiacanthoceras wyomingense
 * †Plesiacanthoceratoides
 * †Plesiacanthoceratoides alzadense
 * †Plesiobaena
 * †Plesiobaena antiqua
 * †Pleuromya
 * †Pleuromya oblongata – or unidentified comparable form
 * †Pleuromya subcompressa
 * †Pleuronautilus
 * †Pleuronectites – tentative report
 * †Plicatolamna
 * †Plicatolamna arcuata
 * †Podozamites
 * †Podozamites lanceolatus
 * †Polycingulatisporites
 * †Polycingulatisporites reduncus
 * The Childrens Museum of Indianapolis - Prenoceratops pieganensis -1.jpg †[[Prenoceratops]] – type locality for genus
 * †Prenoceratops pieganensis – type locality for species
 * †Prismatoolithus
 * †Prismatoolithus hirschi – type locality for species
 * †Prismatoolithus levis
 * †Pristinuspollenites
 * †Pristinuspollenites microsaccus
 * †Proamphiuma
 * †Proamphiuma cretacea
 * †Procerberus
 * †Prodesmodon
 * †Prodesmodon copei
 * †Promyalina
 * †Promyalina spathi – type locality for species
 * Prosaurolophus maximus1.JPG †[[Prosaurolophus]]
 * †Prosaurolophus blackfeetensis – type locality for species
 * †Protalphadon
 * †Protalphadon foxi – type locality for species
 * †Protalphadon lulli
 * †Protexanites
 * †Protocaiman
 * †Protocardia
 * †Protocardia schucherti
 * †Protolambda
 * †Protolambda mcgilli – type locality for species
 * †?Protolambda clemensi – type locality for species
 * †Protolambda florencae
 * †Protolambda hatcheri
 * †Protolamna
 * †Protolamna sokolovi
 * †Protophyllocladus
 * †Protophyllocladus subintegrifolius
 * †Protophyllum – or unidentified comparable form
 * †Protoplatyrhina – type locality for genus
 * †Protoplatyrhina renae – type locality for species
 * †Protoscaphirhynchus – type locality for genus
 * †Protoscaphirhynchus squamosus – type locality for species
 * Protungulatum donnae cropped.jpg †[[Protungulatum]]
 * †Protungulatum coombsi – type locality for species
 * †Protungulatum gorgun
 * †Psammorhynchus
 * †Psammorhynchus longipinnis – type locality for species
 * †Pseudocycas
 * †Pseudocycas douglasii – type locality for species
 * †Pseudohypolophus
 * †Pseudomelania
 * †Pseudomelania hendricksoni
 * †Pteria – tentative report
 * †Pteria ussurica – or unidentified comparable form
 * †Pteropelyx – type locality for genus
 * †Pteropelyx grallipes – type locality for species
 * †Ptychotrygon
 * †Ptychotrygon blainensis – type locality for species
 * †Ptychotrygon hooveri
 * †Ptychotrygon triangularis
 * Pycnodonte pulaskiensis Clayton.jpg [[Pycnodonte]]

Q

 * †Quenstedtia – tentative report
 * Quercus – report made of unidentified related form or using admittedly obsolete nomenclature
 * †Quercus stantoni
 * [[File:Life restoration of a group of giant azhdarchids, Quetzalcoatlus northropi, foraging on a Cretaceous fern prairie.png|thumb|upright|Life restoration of a flock of the Late Cretaceous pterosaur Quetzalcoatlus feeding on the ground]] †[[Quetzalcoatlus]] – or unidentified comparable form

R

 * †Retinovena – type locality for genus
 * †Retinovena fluvialis – type locality for species
 * †Retitricolpites
 * †Retitricolpites microreticulatus
 * Rhabdocolpus
 * †Rhaeboceras
 * †Rhaeboceras burkholderi – type locality for species
 * †Rhaeboceras cedarense – type locality for species
 * †Rhaeboceras coloradoense
 * †Rhaeboceras halli
 * †Rhaeboceras subglobosum
 * †Rhamnus – report made of unidentified related form or using admittedly obsolete nomenclature
 * †Rhamnus cleburni
 * †Richardoestesia
 * †Richardoestesia gilmorei
 * †Richardoestesia isosceles
 * †Rostellites – tentative report
 * Rubeosaurus NT.jpg †[[Rubeosaurus]]
 * †Rubeosaurus ovatus – type locality for species
 * †Rugocaudia – type locality for genus
 * †Rugocaudia cooneyi – type locality for species

S

 * †Sagenopteris
 * †Sagenopteris elliptica
 * †Sagenopteris mclearni
 * †Sagenopteris williamsii
 * Sauropelta reconstruction.png †[[Sauropelta]] – type locality for genus
 * †Sauropelta edwardsorum – type locality for species
 * †Saurornitholestes
 * †Saurornitholestes langstoni
 * †Scabrastephanocolpites
 * †Scabrastephanocolpites lepidus
 * †Scapherpeton
 * †Scapherpeton tectum
 * †Scaphites
 * †Scaphites impendicostatus
 * †Scaphites mariasensis
 * †Scaphites preventricosus
 * †Scaphites ventricosus
 * †Scaphotrigonia
 * †Scaphotrigonia naviformis
 * †Schizolepis
 * †Schizosporis
 * †Schizosporis laevigatus
 * †Sciponoceras
 * †Sciponoceras gracile
 * †Scollardius
 * †Scollardius propalaeoryctes
 * Scolosaurus.tif †[[Scolosaurus]]
 * †Scolosaurus cutleri
 * †Scotiophryne – type locality for genus
 * †Scotiophryne pustulosa – type locality for species
 * †Sequoia
 * †Siberiapollis
 * †Siberiapollis montanensis
 * †Sohlites
 * †Sohlites spinosus
 * †Solenoceras
 * †Solenoceras bearpawense
 * †Spalacotheridium
 * †Spalacotheridium mckennai
 * Sphaerium
 * †Sphaerium planum
 * †Sphaerotholus
 * †Sphaerotholus buchholtzae – type locality for species
 * †Sphenopteris
 * †Sphenopteris brulensis
 * †Sphenopteris geopperti
 * †Sphenopteris goepperti
 * †Sphenopteris latiloba
 * †Sphenopteris mclearni
 * †Spheroolithus
 * †Spheroolithus albertensis
 * †Spheroolithus choteauensis – type locality for species
 * †Spheroolithus maiasauroides
 * Spiclypeus NT small.jpg †[[Spiclypeus]] – type locality for genus
 * †Spiclypeus shipporum – type locality for species
 * †Spiriferina – report made of unidentified related form or using admittedly obsolete nomenclature
 * †Sporonites
 * †Sporonites montanensis – type locality for species
 * Squalicorax
 * †Squalicorax kaupi
 * †Squalicorax pristodontus
 * †Squatirhina
 * †Squatirhina americana
 * †Stantoniella – type locality for genus
 * †Stantoniella cretacea – type locality for species
 * †Stegoceras
 * †Stegoceras validum
 * Stegosaurus stenops sophie wiki martyniuk.png †[[Stegosaurus]]
 * †Stemmatoceras
 * †Stemmatoceras albertense – or unidentified related form
 * †Stemmatoceras arcicostum
 * †Stemmatoceras palliseri – or unidentified related form
 * †Stygiochelys – type locality for genus
 * †Stygiochelys estesi – type locality for species
 * †Sumitomoceras
 * †Suuwassea – type locality for genus
 * †Suuwassea emilieae – type locality for species
 * †Symmetrodontoides
 * †Symmetrodontoides canadensis
 * †Synechodus
 * †Synechodus andersoni – type locality for species
 * †Synechodus striatus – type locality for species

T

 * †Tancredia
 * †Tancredia inornata – or unidentified comparable form
 * †Tarrantoceras
 * †Tarrantoceras cuspidum
 * †Tatankacephalus – type locality for genus
 * †Tatankacephalus cooneyorum – type locality for species
 * †Taxodiaceaepollenites
 * †Taxodiaceaepollenites hiatus
 * Tenontosaurus BW.jpg †[[Tenontosaurus]] – type locality for genus
 * †Tenontosaurus tilletti – type locality for species
 * †Terminonaris – type locality for genus
 * †Terminonaris browni – type locality for species
 * †Terminonaris robusta – type locality for species
 * †Thalassomedon – type locality for genus
 * †Thalassomedon hanningtoni – type locality for species
 * †Thescelosaurus
 * †Thescelosaurus garbanii – type locality for species
 * †Thescelosaurus neglectus
 * †Thescelus
 * †Thescelus insiliens
 * †Thlaeodon – tentative report
 * †Todisporites
 * †Todisporites dubius – or unidentified comparable form
 * †Toxolophosaurus – type locality for genus
 * †Toxolophosaurus cloudi – type locality for species
 * †Trachodon – type locality for genus
 * †Trachodon altidens
 * †Trachodon marginatus
 * †Trachodon mirabilis – type locality for species
 * †Trachytriton
 * †Trachytriton – type locality for species – informal
 * LA-Triceratops mount-2.jpg †[[Triceratops]]
 * †Triceratops horridus
 * †Triceratops maximus – type locality for species
 * †Triceratops prorsus
 * †Trigonia
 * †Trigonia conradi – or unidentified comparable form
 * †Trigonia montanaensis
 * †Trigonia trafalgarensis – or unidentified comparable form
 * †Trigonocallista
 * †Trigonocallista orbiculata
 * Trionyx
 * †Triprismatoolithus – type locality for genus
 * †Triprismatoolithus stephensi – type locality for species
 * †Trochicola
 * †Trochicola scollardiana
 * †Trochodendroides
 * Troodon formosus.jpg †[[Troodon]] – type locality for genus
 * †Troodon formosus – type locality for species
 * †Tubercuoolithus – type locality for genus
 * †Tubercuoolithus tetonensis – type locality for species
 * †Tubulifloridites
 * †Tubulifloridites aedicula
 * †Tullochelys
 * †Tullochelys montana
 * †Turgidodon
 * †Turgidodon praesagus
 * †Turgidodon rhaister
 * †Turgidodon russelli
 * Turritella
 * †Tylosaurus
 * †Tylosaurus proriger
 * Tyrannosaurus Rex Holotype.jpg †[[Tyrannosaurus]] – type locality for genus
 * †Tyrannosaurus rex – type locality for species

U

 * †Ugrosaurus – type locality for genus
 * †Ugrosaurus olsoni – type locality for species
 * Unio
 * †Unionites
 * †Unionites fassaensis

V

 * †Valenopsalis
 * †Valenopsalis joyneri
 * Valvata – tentative report
 * †Valvata montanensis
 * †Varalphadon
 * †Varalphadon wahweapensis
 * †Veniella
 * Vitis – report made of unidentified related form or using admittedly obsolete nomenclature
 * †Vitis stantoni
 * Viviparus
 * †Viviparus couesii
 * Volviceramus Durania Pseudoperna.jpg †[[Volviceramus]]
 * †Volviceramus exogyroides
 * †Volviceramus involutus

W

 * †Weediaphyllum – type locality for genus
 * †Weediaphyllum parkensis – type locality for species
 * †Weltrichia
 * †Wodehousia
 * †Wodehousia spinata
 * †Woodwardia – report made of unidentified related form or using admittedly obsolete nomenclature
 * †Woodwardia crenata

X

 * †Xenocephalites – tentative report
 * Xenophoridae - Xenophora infundibulum.jpg of Xenophora infundibulum]] Xenophora

Y

 * †Yezoites
 * †Yezoites delicatulus

Z

 * Zamites mariposana.jpg †[[Zamites]]
 * †Zamites arcticus
 * †Zapsalis – or unidentified comparable form
 * †Zephyrosaurus – type locality for genus
 * †Zephyrosaurus schaffi – type locality for species
 * †Zlivisporis
 * †Zlivisporis cenomanianus
 * †Zygastrocarcinus
 * †Zygastrocarcinus waagei