List of the prehistoric life of Montana

This list of the prehistoric life of Montana contains the various prehistoric life-forms whose fossilized remains have been reported from within the US state of Montana.

Precambrian
The Paleobiology Database records no known occurrences of Precambrian fossils in Montana.

Selected Paleozoic taxa of Montana

 * †Achistrum
 * Allenypterus montanus (Restoration).jpg †[[Allenypterus]] – type locality for genus
 * †Allenypterus montanus – type locality for species
 * Ammodiscus
 * †Amphiscapha
 * †Amplexus
 * †Aphelaeceras
 * †Athyris
 * †Atrypa
 * †Aulopora
 * †Aviculopecten
 * †Aviculopecten kaibabensis – or unidentified comparable form
 * †Avonia
 * †Bathyuriscus
 * Belantsea montana.JPG †[[Belantsea]] – type locality for genus
 * †Belantsea montana – type locality for species
 * †Bellerophon
 * †Callograptus
 * †Camarotoechia
 * †Camarotoechia contracta
 * †Camarotoechia crenistria
 * †Camarotoechia elegantula
 * †Camarotoechia herrickana – or unidentified related form
 * †Camarotoechia metallica
 * †Camarotoechia mutata
 * †Camarotoechia tuta
 * †Caninia
 * Caridosuctor populosum.jpg †[[Caridosuctor]] – type locality for genus
 * †Carinoclymenia
 * †Cavusgnathus
 * †Cheiloceras
 * †Chonetes
 * †Chonetes geniculatus
 * †Chonetes loganensis
 * †Chonetes logani
 * †Chonetes ornatus
 * †Cladodus
 * †Cleiothyridina
 * †Cleiothyridina atrypoides
 * †Cleiothyridina ciriacksi – type locality for species
 * †Cleiothyridina coloradoensis – or unidentified comparable form
 * †Cleiothyridina devonica
 * †Cleiothyridina hirsuta
 * †Cleiothyridina incrassata – or unidentified related form
 * †Cleiothyridina sublamellosa
 * †Clonograptus
 * Compositafossil.jpg †[[Composita]]
 * †Composita humilis
 * †Composita laevis
 * †Composita lateralis – or unidentified comparable form
 * †Composita madisonensis
 * †Composita ovata
 * †Composita ozarkana
 * †Composita sulcata
 * †Cornulites
 * †Crania
 * †Cyranorhis – type locality for genus
 * †Cyrtospirifer
 * †Cyrtospirifer animaensis
 * †Cyrtospirifer animasensis – or unidentified comparable form
 * †Cyrtospirifer bertrandi – type locality for species
 * †Cyrtospirifer gallatinensis
 * †Cyrtospirifer hornellensis
 * †Cyrtospirifer monticola
 * †Cyrtospirifer perryi – type locality for species
 * †Cyrtospirifer thalattodoxa – tentative report
 * †Cyrtospirifer whitneyi
 * †Cystodictya
 * †Damocles – type locality for genus
 * †Debeerius – type locality for genus
 * Delphyodontos dacriformes cropped.jpg †[[Delphyodontos]] – type locality for genus
 * †Delphyodontos dacriformes – type locality for species
 * †Dendrograptus
 * †Dictyonema
 * †Dikelocephalus
 * †Distomodus
 * †Echinaria
 * †Echinochimaera – type locality for genus
 * †Echinochimaera meltoni – type locality for species
 * †Echinochimaera snyderi – type locality for species
 * †Edmondia
 * †Elrathina
 * Eocaudina
 * †Falcatus
 * †Falcatus falcatus
 * †Favosites
 * †Fenestella
 * †Fenestrella
 * †Geragnostus
 * †Hadronector – type locality for genus
 * Harpagofututor volsellorhinus.jpg †[[Harpagofututor]] – type locality for genus
 * †Harpagofututor volsellorhinus – type locality for species
 * †Helicoprion
 * †Hyolithes
 * †Hypothyris
 * †Hypseloconus
 * †Irvingella
 * †Janassa
 * †Joanellia
 * †Joanellia lundi
 * †Kendallina
 * †Kootenia
 * †Lingula
 * †Lingulella
 * †Lioestheria
 * †Lithostrotion
 * †Lloydia
 * †Lochmocercus – type locality for genus
 * †Maladia
 * †Martinia
 * †Maryvillia
 * †Megalaspidella
 * Trilobites - Megistaspis aliena..JPG †[[Megistaspis]]
 * †Micromitra
 * †Naticopsis
 * †Naticopsis remex – or unidentified comparable form
 * †Neospirifer
 * †Neospirifer praenuntius – type locality for species
 * †Neospirifer striatus
 * †Netsepoye – type locality for genus
 * †Nisusia
 * † Nix – type locality for genus
 * †Obolus
 * †Ogyginus
 * †Orygmaspis
 * †Ozarkodina
 * †Ozarkodina deflecta
 * †Ozarkodina elongata
 * †Ozarkodina macilenta
 * †Ozarkodina modesta
 * †Ozarkodina regularis
 * †Paladin – tentative report
 * †Paleolimulus
 * †Paratarrasius – type locality for genus
 * †Pelagiella
 * Pentremites Glen Dean Fm KY.jpg †[[Pentremites]]
 * †Peronopsis
 * †Pinna
 * †Platyceras
 * †Platyclymenia
 * †Polyosteorhynchus – type locality for genus
 * †Prodentalium
 * †Proetus
 * †Prographularia
 * †Ptychagnostus
 * †Ptychagnostus atavus
 * †Ptychoparia
 * † Ramesses – type locality for genus
 * †Rota
 * †Siksika – type locality for genus
 * †Siksika ottae – type locality for species
 * †Soris – type locality for genus
 * †Spathognathodus
 * Spirifer perlamosus pedunculate valve.jpg †[[Spirifer]]
 * †Spirifer brazerianus – or unidentified related form
 * †Spirifer centronatus
 * †Spirifer greenockensis – or unidentified comparable form
 * †Spirifer grimesi
 * †Spirifer louisianensis – or unidentified related form
 * †Spirifer marionensis – or unidentified comparable form
 * †Spirifer mudulus
 * †Spirifer raymondi
 * †Spirifer shoshonensis
 * †Spirifer welleri – tentative report
 * †Spiriferina
 * Spirorbis
 * Steth pair1 cropped.jpg †[[Stethacanthus]]
 * †Stethacanthus altonensis
 * †Syringopora
 * †Tornoceras
 * †Tylonautilus
 * †Westergaardodina
 * †Wilkingia
 * †Worthenia – tentative report

Selected Mesozoic taxa of Montana

 * Achelousaurus BW.jpg †[[Achelousaurus]] – type locality for genus
 * †Achelousaurus horneri – type locality for species
 * †Acheroraptor – type locality for genus
 * †Acheroraptor temertyorum – type locality for species
 * Acipenser
 * †Acristavus – type locality for genus
 * †Acristavus gagslarsoni – type locality for species
 * †Adocus
 * †Albanerpeton
 * †Albanerpeton nexuosus
 * †Albertaceratops
 * †Albertaceratops nesmoi
 * †Albertosaurus
 * †Allocrioceras
 * Allosaurus Revised.jpg †[[Allosaurus]]
 * †Alphadon
 * †Alphadon attaragos
 * †Alphadon halleyi – type locality for species
 * †Alphadon marshi
 * †Alphadon wilsoni
 * †Alzadasaurus – tentative report
 * Amia
 * †Amphicoelias
 * †Anatotitan
 * †Anatotitan copei
 * Ankylosaurus magniventris reconstruction.png †[[Ankylosaurus]] – type locality for genus
 * †Ankylosaurus magniventris – type locality for species
 * †Aquilops – type locality for genus
 * †Aquilops americanus – type locality for species
 * Aralia – or unidentified comparable form
 * †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
 * †Asplenium
 * Astarte
 * †Aublysodon
 * †Aublysodon mirandus
 * †Avaceratops – type locality for genus
 * †Avaceratops lammersi – type locality for species
 * Avisaurus cropped.png †[[Avisaurus]] – type locality for genus
 * †Avisaurus archibaldi – type locality for species
 * †Avisaurus gloriae – type locality for species
 * Azolla
 * †Baculites
 * †Baculites asper
 * †Baculites codyensis
 * †Baculites compressus
 * †Baculites mariasensis
 * †Baena
 * †Bambiraptor – type locality for genus
 * †Bambiraptor feinbergi – type locality for species
 * Barbourula – or unidentified comparable form
 * Basilemys.jpg †[[Basilemys]]
 * †Belonostomus
 * †Belonostomus longirostris
 * †Bernissartia
 * †Borealosuchus
 * †Borealosuchus sternbergii
 * Brachaelurus
 * †Brachyceratops – type locality for genus
 * †Brachyceratops montanensis – type locality for species
 * †Brachychampsa – type locality for genus
 * †Brachychampsa montana – type locality for species
 * Leonardo mummified brachylophosaurus.jpg †[[Brachylophosaurus]]
 * †Brachylophosaurus canadensis – type locality for species
 * †Camarasaurus
 * Campeloma
 * Carcharias
 * †Cedrobaena
 * †Centrosaurus
 * †Cerasinops – type locality for genus
 * †Cerasinops hodgskissi – type locality for species
 * †Ceratodus
 * †Ceratops – type locality for genus
 * †Ceratops montanus – type locality for species
 * †Chamops
 * Champsosaurus BW.jpg †[[Champsosaurus]]
 * †Chasmosaurus – or unidentified comparable form
 * Chiloscyllium
 * †Chirostenotes
 * †Chirostenotes elegans
 * Chlamys
 * †Chondroceras
 * †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
 * 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
 * †Componocancer
 * †Componocancer roberti
 * †Compsemys
 * †Coniophis
 * †Continuoolithus
 * †Coriops
 * [[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
 * †Cretolamna
 * †Cretolamna appendiculata
 * †Cretorectolobus – type locality for genus
 * †Cretorectolobus olsoni – type locality for species
 * †Crocodilus
 * Cucullaea
 * †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
 * Dentalium
 * †Derrisemys
 * †Diclonius
 * †Didelphodon
 * †Didymoceras
 * †Didymoceras cheyennense
 * †Didymoceras nebrascense
 * †Didymoceras stevensoni
 * Diplodocus carnegii.jpg †[[Diplodocus]]
 * †Doratodon – or unidentified comparable form
 * †Dromaeosaurus
 * †Dromaeosaurus albertensis
 * †Dyoplosaurus
 * †Dyoplosaurus acutosquameus
 * †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
 * †Emarginachelys – type locality for genus
 * †Emarginachelys cretacea – type locality for species
 * †Eodelphis
 * †Eopelobates – or unidentified comparable form
 * †Equisetum
 * †Essonodon – type locality for genus
 * †Essonodon browni – type locality for species
 * †Eucrossorhinus
 * †Euomphaloceras
 * Euoplocephalus BW.jpg †[[Euoplocephalus]]
 * †Euoplocephalus tutus
 * †Eutrephoceras
 * †Exiteloceras
 * †Exogyra
 * Ficus – or unidentified comparable form
 * †Gervillia
 * †Gilmoremys
 * †Gilmoremys lancensis
 * Ginkgo
 * †Ginkgoites
 * †Glishades – type locality for genus
 * †Glishades ericksoni – type locality for species
 * †Glyptops
 * Glyptostrobus – or unidentified comparable form
 * Gobiconodon ostromi.JPG †[[Gobiconodon]] – type locality for genus
 * †Goniobasis
 * †Gorgosaurus
 * †Gorgosaurus libratus – type locality for species
 * †Gryphaea
 * †Gryphaea impressimarginata
 * †Gryposaurus
 * †Gryposaurus latidens – type locality for species
 * †Gryposaurus notabilis
 * †Habrosaurus
 * †Habrosaurus dilatus
 * †Hadrosaurus
 * †Hadrosaurus breviceps – type locality for species
 * †Hadrosaurus paucidens – type locality for species
 * †Hamites
 * Hesperornis BW.jpg †[[Hesperornis]]
 * †Hybodus
 * †Hybodus montanensis – type locality for species
 * †Hypacrosaurus
 * †Hypacrosaurus stebingeri – 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
 * †Ischyodus
 * †Ischyodus bifurcatus
 * †Ischyrhiza
 * †Ischyrhiza avonicola
 * †Ischyrhiza mira
 * Judiceratops.tif †[[Judiceratops]] – type locality for genus
 * †Judiceratops tigris – type locality for species
 * †Kritosaurus
 * †Krokolithes
 * †Lepidotes
 * †Lepidotes haydeni – type locality for species
 * †Lepidotes occidentalis – type locality for species
 * Lepisosteus
 * †Leptalestes
 * †Leptalestes cooki
 * †Leptalestes krejcii
 * †Leptalestes prokrejcii
 * †Leptalestes toevsi – type locality for species
 * Leptoceratops BW.jpg †[[Leptoceratops]]
 * †Leptoceratops gracilis
 * †Leptorhynchos – tentative report
 * †Lingula
 * †Lisserpeton – type locality for genus
 * †Lisserpeton atlantes
 * †Lisserpeton bairdi – type locality for species
 * †Lonchidion
 * Lopha
 * † Lucina
 * Lunatia
 * †Magnuviator – type locality for genus
 * †Maiasaura – type locality for genus
 * †Maiasaura peeblesorum – type locality for species
 * †Medusaceratops – type locality for genus
 * †Medusaceratops lokii – type locality for species
 * †Melvius – type locality for genus
 * †Meniscoessus
 * †Meniscoessus major
 * †Meniscoessus robustus – type locality for species
 * †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
 * †Microvenator – type locality for genus
 * †Microvenator celer – type locality for species
 * †Modiolus
 * †Monoclonius – type locality for genus
 * †Monoclonius crassus – type locality for species
 * †Monoclonius recurvicornis – type locality for species
 * †Monoclonius sphenocerus – type locality for species
 * †Montanalestes
 * Montanazdarco cropped.jpg †[[Montanazhdarcho]] – type locality for genus
 * †Montanazhdarcho minor – type locality for species
 * †Montanoceratops
 * †Montanoceratops cerorhynchus – type locality for species
 * †Montanoolithus – type locality for genus
 * †Mosasaurus
 * †Mosasaurus missouriensis
 * †Myledaphus
 * †Myledaphus bipartitus
 * †Mytilus
 * †Nanotyrannus
 * †Nanotyrannus lancensis – type locality for species
 * †Naomichelys – type locality for genus
 * American Lotus (Nelumbo lutea) 01.jpg †[[Nelumbo]]
 * †Neocardioceras
 * †Neocardioceras juddii
 * †Neocardioceras minutum
 * †Neoplagiaulax
 * †Neoplagiaulax burgessi – type locality for species
 * †Nezpercius – type locality for genus
 * †Nidimys – type locality for genus
 * †Normannites – tentative report
 * †Notogoneus
 * Nucula
 * †Obamadon – type locality for genus
 * †Obamadon gracilis – type locality for species
 * †Odaxosaurus
 * †Odaxosaurus piger
 * Odontaspis ferox 3.jpg [[Odontaspis]]
 * †Odontaspis sanguinei – type locality for species
 * †Oklatheridium
 * †Onchosaurus
 * †Oohkotokia – type locality for genus
 * †Oohkotokia horneri – type locality for species
 * †Ophiomorpha
 * †Opisthotriton
 * †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
 * †Oxytoma
 * †Pachycephalosaurus – type locality for genus
 * †Pachycephalosaurus wyomingensis – type locality for species
 * †Pagiophyllum
 * †Palaeobatrachus
 * †Palaeosaniwa
 * †Palaeosaniwa canadensis
 * †Palaeoscincus – type locality for genus
 * †Palaeoscincus costatus – type locality for species
 * †Palatobaena
 * †Paleopsephurus – type locality for genus
 * †Paleopsephurus wilsoni – type locality for species
 * Panoplosaurus.jpg †[[Panoplosaurus]]
 * †Pappotherium
 * †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
 * †Paralbula
 * †Paramacellodus – or unidentified comparable form
 * †Paranecturus – type locality for genus
 * †Paranecturus garbanii – type locality for species
 * Parapuzosia seppenradensis 3.jpg †[[Parapuzosia]]
 * †Parapuzosia bradyi – type locality for species
 * †Paronychodon
 * †Paronychodon lacustris
 * †Pectinodon – or unidentified comparable form
 * Pholadomya
 * †Pholadomya kingi
 * Physa
 * †Piceoerpeton
 * †Piksi – type locality for genus
 * †Piksi barbarulna – type locality for species
 * †Pinna
 * †Pistia
 * †Plesiobaena
 * †Pleuronautilus
 * †Prenoceratops – type locality for genus
 * †Prenoceratops pieganensis – type locality for species
 * †Prismatoolithus
 * †Proamphiuma
 * †Prodesmodon
 * Prosaurolophus maximus1.JPG †[[Prosaurolophus]]
 * †Prosaurolophus blackfeetensis – type locality for species
 * †Protocardia
 * †Protoscaphirhynchus – type locality for genus
 * †Protungulatum
 * †Pseudomelania
 * †Pteria – tentative report
 * †Pteropelyx – type locality for genus
 * †Pteropelyx grallipes – type locality for species
 * †Ptychotrygon
 * †Ptychotrygon blainensis – type locality for species
 * †Ptychotrygon triangularis
 * Pycnodonte
 * Quercus – report made of unidentified related form or using admittedly obsolete nomenclature
 * [[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
 * †Rhamnus – report made of unidentified related form or using admittedly obsolete nomenclature
 * †Richardoestesia
 * †Richardoestesia gilmorei
 * †Richardoestesia isosceles
 * †Rubeosaurus
 * †Rubeosaurus ovatus – type locality for species
 * †Rugocaudia – type locality for genus
 * †Rugocaudia cooneyi – type locality for species
 * †Sagenopteris
 * †Sagenopteris elliptica
 * †Sagenopteris mclearni
 * †Sagenopteris williamsii
 * Sauropelta reconstruction.png †[[Sauropelta]] – type locality for genus
 * †Sauropelta edwardsorum – type locality for species
 * †Saurornitholestes
 * †Saurornitholestes langstoni
 * †Scapherpeton
 * †Scaphites
 * †Scaphites impendicostatus
 * †Scaphites preventricosus
 * †Scaphites ventricosus
 * †Scolosaurus
 * †Scolosaurus cutleri
 * †Scotiophryne – type locality for genus
 * Del Norte Titan 230 cropped.jpg †[[Sequoia (genus)|Sequoia]]
 * Sphaerium
 * †Sphaerotholus
 * †Sphaerotholus buchholtzae – type locality for species
 * †Sphenopteris
 * †Sphenopteris brulensis
 * †Sphenopteris geopperti
 * †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
 * Squalicorax
 * †Squalicorax kaupi
 * †Squalicorax pristodontus
 * †Squatirhina
 * †Squatirhina americana
 * †Stegoceras
 * †Stegoceras validum
 * †Stegosaurus
 * †Suuwassea – type locality for genus
 * †Suuwassea emilieae – type locality for species
 * †Tatankacephalus – type locality for genus
 * †Tatankacephalus cooneyorum – type locality for species
 * Tenontosaurus BW.jpg †[[Tenontosaurus]] – type locality for genus
 * †Tenontosaurus tilletti – type locality for species
 * †Terminonaris – type locality for genus
 * †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
 * †Toxolophosaurus – type locality for genus
 * †Trachodon – type locality for genus
 * †Trachodon altidens
 * †Trachodon marginatus
 * †Trachodon mirabilis – type locality for species
 * LA-Triceratops mount-2.jpg †[[Triceratops]]
 * †Triceratops horridus
 * †Triceratops maximus – type locality for species
 * †Triceratops prorsus
 * †Trigonia
 * †Trigonia montanaensis
 * Trionyx
 * †Triprismatoolithus – type locality for genus
 * †Troodon – type locality for genus
 * †Troodon formosus – type locality for species
 * †Tubercuoolithus – type locality for genus
 * Turritella
 * †Tylosaurus
 * †Tylosaurus proriger
 * Tyrannosaurus Rex Holotype.jpg †[[Tyrannosaurus]] – type locality for genus
 * †Tyrannosaurus rex – type locality for species
 * †Ugrosaurus – type locality for genus
 * †Ugrosaurus olsoni – type locality for species
 * Unio
 * †Valenopsalis
 * Valvata – tentative report
 * Vitis – report made of unidentified related form or using admittedly obsolete nomenclature
 * Viviparus
 * †Volviceramus
 * †Woodwardia – report made of unidentified related form or using admittedly obsolete nomenclature
 * †Xenocephalites – tentative report
 * Xenophora
 * †Yezoites
 * Zamites mariposana.jpg †[[Zamites]]
 * †Zamites arcticus
 * †Zapsalis – or unidentified comparable form
 * †Zephyrosaurus – type locality for genus
 * †Zephyrosaurus schaffi – type locality for species

Selected Cenozoic taxa of Montana

 * Abies
 * Abies
 * Acer
 * †Acheronodon
 * †Acheronodon garbani – type locality for species
 * Acipenser
 * Acritohippus isonesus.jpg †[[Acritohippus]]
 * †Acritohippus isonesus
 * †Aelurodon
 * †Aepycamelus
 * †Aepycamelus stocki
 * †Agnotocastor
 * †Agriochoerus
 * †Agrostis
 * †Ailanthus
 * Alangium
 * Alnus
 * Amebelodon fricki.jpg †[[Amebelodon]]
 * Amelanchier
 * †Amentotaxus
 * Amia
 * †Ampelopsis
 * †Amphechinus
 * †Amphicyon
 * †Amyzon
 * Anas
 * †Anas platyrhynchos – or unidentified comparable form
 * †Anconodon
 * †Anemia
 * †Angustidens
 * Antilocapra – or unidentified comparable form
 * †Antilocapra americana
 * †Aphelops
 * †Araucaria
 * †Archaeocyon
 * †Archaeohippus
 * †Arctocyon
 * †Arctodus
 * †Arctodus simus
 * †Arctostaphylos
 * Arundo
 * Arvicola
 * †aspera
 * †Astronium
 * †Athyana
 * †Avunculus
 * Azolla caroliniana0.jpg [[Azolla]]
 * †Baiotomeus
 * †Baiotomeus douglassi
 * †Baiotomeus lamberti – type locality for species
 * †Bathygenys
 * †Berberis
 * Berchemia
 * Betula
 * Bibio – or unidentified related form
 * Bison
 * †Bison bison
 * Bison latifrons fossil buffalo (Pleistocene; North America) 1 (15257877377).jpg †[[Bison latifrons]] – or unidentified comparable form
 * †Bisonalveus
 * †Bisonalveus browni
 * †Blastomeryx
 * †Blastomeryx gemmifer
 * †Bootherium
 * †Borealosuchus
 * †Borealosuchus sternbergii
 * †Brachychampsa
 * †Brachycrus
 * †Brachyrhynchocyon
 * †Camelops
 * †Camelops minidokae
 * †Canavalia
 * Canis
 * †Canis latrans
 * †Canis lupus
 * †Canna
 * †Cardiospermum
 * Carpinus
 * CarpolestesCL.png †[[Carpolestes]]
 * Carya
 * †Cassia
 * Castanea
 * Castor
 * †Castor californicus
 * †Castor canadensis
 * †Catalpa
 * †Catopsalis
 * †Catopsalis alexanderi
 * †Catopsalis waddleae
 * Ceanothus
 * Cedrela
 * †Celastrus
 * Celtis
 * Cercidiphyllum
 * Cercis
 * †Cercocarpus
 * †Chamaecyparis
 * †Chamops
 * Champsosaurus BW.jpg †[[Champsosaurus]]
 * †Chisternon
 * †Chriacus
 * †Chriacus calenancus
 * †Chthonophis – type locality for genus
 * †Chthonophis subterraneus – type locality for species
 * †Cimexomys
 * †Cimexomys minor – type locality for species
 * †Cimolestes
 * †Cimolestes incisus
 * Starr 010419 0038 cinnamomum camphora.jpg [[Cinnamomum]]
 * Cissus
 * Clematis
 * Cocculus
 * †Colodon
 * †Colubrina
 * †Colubrina asiatica – or unidentified comparable form
 * †Compsemys
 * †Coniophis – or unidentified comparable form
 * †Conzattia
 * Cornus
 * †Corylus
 * †Coryphodon
 * †Cosoryx – tentative report
 * Crataegus
 * Credneria triacuminata.jpg †[[Credneria]]
 * Crematogaster
 * Culiseta
 * †Cynodesmus
 * Cynomys
 * †Cynomys ludovicianus
 * †Dalbergia
 * †Dalbergia retusa
 * †Daphoenictis – or unidentified comparable form
 * †Davidia
 * †Derrisemys – type locality for genus
 * †Desmatochoerus
 * †Diceratherium
 * †Didymictis
 * ExtmDinictis1921-029-11.jpg †[[Dinictis]]
 * †Dinohippus
 * †Dioctria – tentative report
 * †Diospyros
 * †Diphysa
 * Dipteronia
 * †Dissacus
 * Dolichoderus
 * †Domnina
 * Dromomeryx borealis.jpeg †[[Dromomeryx]]
 * †Dromomeryx borealis
 * Dryopteris
 * †Ectocion
 * †Elomeryx – tentative report
 * †Eoconodon
 * †Eoconodon nidhoggi
 * †Eotitanops
 * †Epicyon
 * †Epicyon haydeni
 * †Epihippus
 * †Equisetum
 * Equus
 * †Equus conversidens – or unidentified comparable form
 * †Eucastor
 * †Eucommia
 * Eucommia montana Klondike Mtn Fmt 01.jpg †[[Eucommia montana]]
 * †Euonymus
 * †Euoplocyon
 * Exbucklandia
 * Ficus
 * Fokienia
 * Formica
 * †Fraxinus
 * Geochelone
 * Gerrhonotus – or unidentified comparable form
 * Ginkgo
 * †Ginkgo adiantoides
 * Gleichenia
 * Glyptostrobus
 * †Goniacodon
 * †Habrosaurus
 * †Habrosaurus dilatus
 * †Helaletes
 * Helius
 * Helodermoides tuberculatus AMNH 11311.jpg †[[Helodermoides]] – type locality for genus
 * †Helodermoides tuberculatus – type locality for species
 * †Herpetotherium
 * †Herpetotherium fugax
 * †Herpetotherium knighti – or unidentified comparable form
 * †Hesperocyon
 * †Heteraletes
 * †Hiodon
 * Holmskioldia
 * †Holopogon
 * Homo
 * †Homo sapiens
 * Homotherium serum.jpg †[[Homotherium]]
 * †Homotherium serum
 * †Hutchemys – type locality for genus
 * †Hyaenodon
 * †Hyaenodon crucians
 * Hydrangea
 * †Hydromystria
 * †Hyopsodus
 * †Hypertragulus
 * †Hypisodus
 * Hypohippus.jpg †[[Hypohippus]]
 * †Hypolagus
 * †Hypsiops
 * †Hyrachyus
 * †Hyracodon
 * †Ictidopappus
 * †Intyrictis
 * †Ischyrhiza – or unidentified comparable form
 * †Ischyrhiza avonicola
 * †Ischyromys
 * Isoetes
 * Juglans
 * †Juglans regia – or unidentified comparable form
 * Juniperus
 * †Kerria
 * †Kimbetohia
 * Koelreuteria
 * Lasius
 * Laurus
 * Lemmiscus
 * †Lemmiscus curtatus
 * Lepisosteus
 * Leptauchenia by Apokryltaros cropped.png †[[Leptauchenia]]
 * †Leptictis
 * †Leptocyon
 * †Leptomeryx
 * †Leptoreodon
 * †Leucaena
 * †Limnenetes
 * Lindera
 * †Lisserpeton
 * †Lisserpeton bairdi
 * †Lithornis
 * †Lithornis celetius – type locality for species
 * Lynx
 * Calero Creek Trail Bobcat.jpg †[[Lynx rufus]]
 * Magnolia
 * Mahonia
 * †Mammut
 * †Mammut americanum
 * †Mammuthus
 * †Mammuthus columbi
 * †Mammuthus primigenius
 * Marchantia
 * Marmota
 * Martes
 * Titanotherium cropped.png †[[Megacerops]]
 * †Megahippus
 * †Megalonyx
 * †Megalonyx jeffersonii
 * †Megantereon
 * †Megatylopus
 * †Menodus
 * †Merriamoceros
 * †Merychippus
 * †Merychippus sejunctus
 * †Merychyus
 * Merycochoerus proprius.jpg †[[Merycochoerus]]
 * †Merycodus
 * †Merycoides
 * †Merycoidodon
 * †Mesodma
 * †Mesodma formosa
 * †Mesodma garfieldensis – type locality for species
 * †Mesodma pygmaea – type locality for species
 * †Mesodma thompsoni
 * †Mesohippus
 * †Mesoreodon
 * Metasequoia
 * †Metasequoia occidentalis
 * †Metopium
 * Miacis cropped.png †[[Miacis]] – report made of unidentified related form or using admittedly obsolete nomenclature
 * †Microcosmodon
 * †Microcosmodon harleyi – type locality for species
 * Microtus
 * †Microtus pennsylvanicus – or unidentified comparable form
 * †Mimetodon
 * †Miniochoerus – tentative report
 * †Miohippus – type locality for genus
 * †Miohippus grandis
 * †Monosaulax
 * Morus
 * Mustela
 * †Mustela frenata
 * Myrica
 * †Nanotragulus
 * †Nelumbo
 * Neohipparion cropped.png †[[Neohipparion]]
 * †Neoplagiaulax
 * †Neoplagiaulax donaldorum – type locality for species
 * †Neoplagiaulax grangeri – type locality for species
 * †Neoplagiaulax hunteri – type locality for species
 * †Neoplagiaulax kremnus
 * †Neoplagiaulax mckennai
 * †Neoplagiaulax nelsoni – type locality for species
 * †Niglarodon
 * †Nuphar
 * †Nyssa
 * †Odaxosaurus
 * †Odaxosaurus piger
 * White-tailed deer.jpg [[Odocoileus]] – or unidentified comparable form
 * Olar
 * Ondatra
 * †Ondatra zibethicus
 * †Onoclea
 * †Opisthotriton
 * Oreohelix
 * †Oreonetes
 * †Osmanthus
 * †Osmunda
 * †Osmunda greenlandica
 * Ostrya
 * †Otarocyon
 * †Oxyacodon
 * Oxydactylus longipes.jpg †[[Oxydactylus]]
 * †Palaeogale
 * †Palaeolagus
 * †Palaeoryctes
 * †Palaeosinopa
 * †Palaeosyops
 * †Palatobaena
 * †Paleopsephurus – or unidentified comparable form
 * Paliurus
 * †Pandemonium
 * †Pantolambda
 * †Pantomimus – type locality for genus
 * San Diego Paramylodon.jpg Paramylodon]] †Paramylodon
 * †Paramylodon harlani
 * †Paramys
 * †Paratomarctus
 * †Parectypodus
 * †Parectypodus sinclairi – type locality for species
 * †Parectypodus sylviae
 * †Parictis
 * †Parthenocissus
 * †Paulownia
 * †Peltosaurus
 * Penthetria
 * †Peraceras
 * Perognathus
 * Peromyscus
 * †Peromyscus maniculatus – or unidentified comparable form
 * Persea
 * Knight Phenacodus.jpg †[[Phenacodus]]
 * Phragmites
 * Picea
 * †Piceoerpeton
 * Pinus
 * †Pithecolobium
 * †Planetetherium
 * †Planetetherium mirabile – type locality for species
 * †Plastomenoides – type locality for genus
 * Platanus
 * Plecia
 * †Plesiadapis
 * †Pliohippus
 * †Plithocyon
 * †Poebrotherium
 * Pogonodon platycopis.jpg †[[Pogonodon]]
 * Populus
 * †Potentilla
 * †Prochetodon
 * †Prochetodon foxi – type locality for species
 * †Prodesmodon
 * †Proiridomyrmex
 * †Promerycochoerus
 * †Proscalops
 * †Prosphyracephala
 * Bmnhp27347 p 1 high.jpg †[[Protazteca]]
 * †Protohippus
 * †Protolabis
 * †Protungulatum
 * †Protungulatum donnae
 * Prunus
 * †Pseudhipparion
 * †Pseudolarix
 * †Pseudomesoreodon – type locality for genus
 * Pseudomyrmex
 * †Pseudotsuga
 * Psittacotherium multifragumDB24.jpg]] †Psittacotherium''
 * Ptelea
 * Pteris
 * Pterocarya
 * †Ptilodus
 * †Ptilodus kummae
 * †Ptilodus montanus – type locality for species
 * †Ptilodus tsosiensis
 * Purgatorius BW.jpg †[[Purgatorius]]
 * †Purgatorius janisae – type locality for species
 * †Purgatorius titusi – type locality for species
 * †Purgatorius unio – type locality for species
 * †Pyracantha
 * Quercus
 * †Rana – or unidentified comparable form
 * Rangifer
 * †Rangifer tarandus
 * †Rhamnus
 * †Rhamnus crocea
 * Rhus
 * †Robinia
 * Rosa
 * Sabal
 * †Saccoloma
 * Salix
 * †Sambucus
 * †Sapindus
 * Sassafras
 * Sassafras hesperia 01.jpg †[[Sassafras hesperia]]
 * †Scapherpeton
 * †Scaphohippus
 * †Scotiophryne – or unidentified comparable form
 * †Selaginella
 * Sequoia
 * †Sequoia affinis
 * †Simoedosaurus
 * †Simpson
 * †Smilax
 * †Sophora
 * †Sorbus
 * †Sparganium
 * Spea
 * Spermophilus
 * †Spermophilus richardsonii
 * †Spiraea
 * †Stelocyon
 * †Steneofiber
 * Stenomylus.jpg †[[Stenomylus]]
 * †Stenomylus hitchcocki – or unidentified comparable form
 * Sterculia
 * †Stygimys
 * †Stygimys camptorhiza – or unidentified comparable form
 * †Stygimys jepseni – type locality for species
 * †Stygimys kuszmauli – type locality for species
 * †Subdromomeryx
 * †Subdromomeryx antilopinus
 * †Subhyracodon
 * †Submerycochoerus
 * †Sylvicola fenestralis
 * Sylvilagus
 * †Sylvilagus nuttallii
 * †Symplocarpus
 * †Taeniolabis
 * †Taeniolabis lamberti – type locality for species
 * Tapocyon robustus.jpg †[[Tapocyon]]
 * Taricha
 * Taxodium
 * †Teleoceras
 * †Tetraclaenodon
 * Thomomys
 * †Thomomys talpoides
 * †Thrinax
 * †Thuja
 * †Ticholeptus
 * Tilia
 * †Tinuviel
 * Tipula
 * Titanoides primaevus.jpg †[[Titanoides]]
 * †Titanoides gidleyi
 * †Trapa
 * †Trigenicus
 * †Trigonias
 * †Tropidia
 * †Tylocephalonyx
 * Typha
 * Ulmus
 * Ursus
 * †Vaccinium
 * †Valenopsalis
 * †Vauquelinia
 * †Viburnum
 * †Viguiera
 * Vitis
 * †Viverravus – tentative report
 * †Woodwardia
 * †Xyronomys
 * Zelkova