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 Alabama.

Paleozoic

Main article: List of the Paleozoic life of Montana

Selected Paleozoic taxa of Montana

• †Achistrum
• 

  Life restoration of the Carboniferous lobe-finned fish Allenypterus
  †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
• 

  Restoration of the Carboniferous Chimaera relative Belantsea
  †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
• 

  Fossilized skeleton of the Carboniferous coelacanth Caridosuctor
  †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
• 

  Fossilized shell of the Late Devonian-Permian brachiopod Composita
  †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
• 

  Life restoration of the Carboniferous Chimaera relative Delphyodontos
  †Delphyodontos – type locality for genus
  • †Delphyodontos dacriformes – type locality for species
• †Dendrograptus
• †Dictyonema
• †Dikelocephalus
• †Distomodus
• †Echinaria
• †Edmondia
• †Elrathina
• Eocaudina
• †Falcatus
  • †Falcatus falcatus
• †Favosites
• †Fenestella
• †Fenestrella
• †Geragnostus
• †Hadronector – type locality for genus
• 

  Restoration (bottom) of the Carboniferous "antlered" Chimaera relative Harpagofututor
  †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
• 

  Fossil of the Cambrian-Silurian trilobite Megistaspis
  †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
• 

  Fossilized theca of the Carboniferous blastoid echinoderm ("sea bud") Pentremites
  †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
• 

  Fossilized shell of the Late Ordovician-Late Triassic brachiopod Spirifer
  †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
• 

  Life restorations of a male (foreground) and female (background) of the Late Devonian-Carboniferous Chimaera relative Stethacanthus
  †Stethacanthus
  • †Stethacanthus altonensis
• †Syringopora
• †Tornoceras
• †Tylonautilus
• †Westergaardodina
• †Wilkingia
• †Worthenia – tentative report

Mesozoic

Main article: List of the Mesozoic life of Montana

Selected Mesozoic taxa of Montana

• 

  Life restoration of the Late Cretaceous horned dinosaur Achelousaurus
  †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
• 

  Life restoration of the Late Jurassic theropod dinosaur Allosaurus
  †Allosaurus
• †Alphadon
  • †Alphadon attaragos
  • †Alphadon halleyi – type locality for species
  • †Alphadon marshi
  • †Alphadon wilsoni
• †Alzadasaurus – tentative report
• Amia
• †Amphicoelias
• †Anatotitan
  • †Anatotitan copei
• 

  Life restoration of the Late Cretaceous armored dinosaur Ankylosaurus
  †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
• 

  Life restoration of the Late Cretaceous toothed bird Avisaurus perched on a crocodilian
  †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
• 

  Mounted fossilized skeleton of the Cretaceous turtle Basilemys
  †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
• 

  Fossilized natural mummy of the Late Cretaceous duck-billed dinosaur Brachylophosaurus
  †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
• 

  Life restoration of the Late Cretaceous-Eocene choristoderan reptile Champsosaurus
  †Champsosaurus
• †Chasmosaurus – or unidentified comparable form
• Chiloscyllium
• †Chirostenotes
  • †Chirostenotes elegans
• Chlamys
• †Chondroceras
• †Cimexomys
  • †Cimexomys minor
• †Cimolestes
  • †Cimolestes incisus
  • †Cimolestes stirtoni
• †Cimoliasaurus
• †Cimolodon
  • †Cimolodon nitidus
• 

  Life restoration of the face of the Late Cretaceous multituberculate mammal Cimolomys
  †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
• 

  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
• 

  Life restoration of the Early Cretaceous dromaeosaur ("raptor") Deinonychus
  †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
• 

  Life restoration of the Late Jurassic long-necked dinosaur Diplodocus
  †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
  • 

    Life restoration of the Late Cretaceous duck-billed dinosaur Edmontosaurus annectens
    †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
• 

  Restoration of the Late Cretaceous armored dinosaur Euoplocephalus
  †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
• 

  Mounted fossilized skeleton of the Middle Jurassic-Late Cretaceous mammal Gobiconodon
  †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
• 

  Life restoration of the Late Cretaceous toothed bird Hesperornis
  †Hesperornis
• †Hybodus
  • †Hybodus montanensis – type locality for species
• †Hypacrosaurus
  • †Hypacrosaurus stebingeri – type locality for species
• 

  Fossilized shell of the Early Jurassic-Late Cretaceous marine bivalve Inoceramus with a human indicating its size
  †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
• 

  Life restoration of the Late Cretaceous horned dinosaur Judiceratops
  †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
• 

  Life restoration of the Late Cretaceous primitive horned dinosaur Leptoceratops
  †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
• 

  Mounted fossilized skeletons of the Late Cretaceous pterosaur Montanazhdarcho
  †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
• 

  A living Nelumbo lotus
  †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
• 

  A living Odontaspis sand shark
  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
• 

  Life restoration of the Late Cretaceous herbivorous dinosaur Oryctodromeus in a burrow
  †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
• 

  Illustration of a fossilized skull of the Late Cretaceous armored dinosaur Panoplosaurus
  †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
• 

  Fossilized shell of the Late Cretaceous ammonoid cephalopod Parapuzosia with a human indicating its size
  †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
• 

  Mounted fossilized skeleton of the Late Cretaceous duck-billed dinosaur Prosaurolophus
  †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
• 

  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
• 

  Life restoration of the Early Cretaceous armored dinosaurs Sauropelta
  †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
• 

  Base of the trunk of a living Sequoia tree with a human to scale
  †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
• 

  Restoration of the Late Cretaceous horned dinosaur Spiclypeus
  †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
• 

  Life restoration of the Early Cretaceous Iguanodon relative Tenontosaurus
  †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
• 

  Mounted fossilized skeleton of the Late Cretaceous horned dinosaur Triceratops
  †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
• 

  Fossilized skeleton of the Late Cretaceous tyrannosaur Tyrannosaurus
  †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
• 

  Fossil of the Early Triassic-Eocene cycad-like frond Zamites
  †Zamites
  • †Zamites arcticus
• †Zapsalis – or unidentified comparable form
• †Zephyrosaurus – type locality for genus
  • †Zephyrosaurus schaffi – type locality for species

Cenozoic

Main article: List of the Cenozoic life of Montana

Selected Cenozoic taxa of Montana

• Abies
• Abies
• Acer
• †Acheronodon
  • †Acheronodon garbani – type locality for species
• Acipenser
• 

  Mounted fossilized skeleton of the Miocene horse Acritohippus
  †Acritohippus
  • †Acritohippus isonesus
• †Aelurodon
• †Aepycamelus
  • †Aepycamelus stocki
• †Agnotocastor
• †Agriochoerus
• †Agrostis
• †Ailanthus
• Alangium
• Alnus
• 

  Life restoration of the Miocene elephant relative Amebelodon. Margret Flinsch (1932).
  †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
• 

  Living Azolla water ferns
  Azolla
• †Baiotomeus
  • †Baiotomeus douglassi
  • †Baiotomeus lamberti – type locality for species
• †Bathygenys
• †Berberis
• Berchemia
• Betula
• Bibio – or unidentified related form
• Bison
  • †Bison bison
  • 

    Mounted fossilized skeleton of the Pleistocene Bison latifrons, also known as the giant bison or long-horned bison
    †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
• 

  Life restoration of the Paleocene primate relative Carpolestes
  †Carpolestes
• Carya
• †Cassia
• Castanea
• Castor
  • †Castor californicus
  • †Castor canadensis
• †Catalpa
• †Catopsalis
  • †Catopsalis alexanderi
  • †Catopsalis waddleae
• Ceanothus
• Cedrela
• †Celastrus
• Celtis
• Cercidiphyllum
• Cercis
• †Cercocarpus
• †Chamaecyparis
• †Chamops
• 

  Life restoration of the Late Cretaceous-Eocene choristoderan reptile Champsosaurus
  †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
• 

  A living Cinnamomum, or cinnamon tree
  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
• 

  Fossilized leaf from a Credneria tree
  †Credneria
• Crematogaster
• Culiseta
• †Cynodesmus
• Cynomys
  • †Cynomys ludovicianus
• †Dalbergia
  • †Dalbergia retusa
• †Daphoenictis – or unidentified comparable form
• †Davidia
• †Derrisemys – type locality for genus
• †Desmatochoerus
• †Diceratherium
• †Didymictis
• 

  Life restoration of the Eocene-Miocene false saber-toothed cat Dinictis. Robert Bruce Horsfall (1913).
  †Dinictis
• †Dinohippus
• †Dioctria – tentative report
• †Diospyros
• †Diphysa
• Dipteronia
• †Dissacus
• Dolichoderus
• †Domnina
• 

  Fossilized horns, jaws, and limb bones of the Miocene deer relative Dromomeryx
  †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
  • 

    Fossilized fruit of the Eocene Eucommia montana plant
    †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
• 

  Fossilized skull of the Oligocene lizard Helodermoides
  †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
• 

  Restoration of Pliocene-Pleistocene Homotherium, or scimitar cat
  †Homotherium
  • †Homotherium serum
• †Hutchemys – type locality for genus
• †Hyaenodon
  • †Hyaenodon crucians
• Hydrangea
• †Hydromystria
• †Hyopsodus
• †Hypertragulus
• †Hypisodus
• 

  Life restoration of the Miocene horse Hypohippus. Heinrich Harder (1920).
  †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
• 

  Restoration of the Oligocene-Miocene oreodont mammal Leptauchenia
  †Leptauchenia
• †Leptictis
• †Leptocyon
• †Leptomeryx
• †Leptoreodon
• †Leucaena
• †Limnenetes
• Lindera
• †Lisserpeton
  • †Lisserpeton bairdi
• †Lithornis
  • †Lithornis celetius – type locality for species
• Lynx
  • 

    A living Lynx rufus, or bobcat
    †Lynx rufus
• Magnolia
• Mahonia
• †Mammut
  • †Mammut americanum
• †Mammuthus
  • †Mammuthus columbi
  • †Mammuthus primigenius
• Marchantia
• Marmota
• Martes
• 

  Life restoration of battling males of the Eocene brontothere mammal Megacerops
  †Megacerops
• †Megahippus
• †Megalonyx
  • †Megalonyx jeffersonii
• †Megantereon
• †Megatylopus
• †Menodus
• †Merriamoceros
• †Merychippus
  • †Merychippus sejunctus
• †Merychyus
• 

  Restorative portrait of the Oligocene-Miocene oreodont mammal Merycochoerus
  †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
• 

  Life restoration of the Paleocene-Eocene mammal Miacis
  †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
• 

  Life restoration of a herd of Neohipparion. Robert Bruce Horsfall (1913).
  †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
• 

  A living Odocoileus deer
  Odocoileus – or unidentified comparable form
• Olar
• Ondatra
  • †Ondatra zibethicus
• †Onoclea
• †Opisthotriton
• Oreohelix
• †Oreonetes
• †Osmanthus
• †Osmunda
  • †Osmunda greenlandica
• Ostrya
• †Otarocyon
• †Oxyacodon
• 

  Life restoration of a pair of the Oligocene-Miocene camel Oxydactylus. Robert Bruce Horsfall (1913).
  †Oxydactylus
• †Palaeogale
• †Palaeolagus
• †Palaeoryctes
• †Palaeosinopa
• †Palaeosyops
• †Palatobaena
• †Paleopsephurus – or unidentified comparable form
• Paliurus
• †Pandemonium
• †Pantolambda
• †Pantomimus – type locality for genus
• 

  Fossilized skeleton of the Pliocene-Pleistocene ground sloth 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
• 

  Life restoration of the Paleocene-Eocene ungulate Phenacodus. Charles R. Knight (1898).
  †Phenacodus
• Phragmites
• Picea
• †Piceoerpeton
• Pinus
• †Pithecolobium
• †Planetetherium
  • †Planetetherium mirabile – type locality for species
• †Plastomenoides – type locality for genus
• Platanus
• Plecia
• †Plesiadapis
• †Pliohippus
• †Plithocyon
• †Poebrotherium
• 

  Illustration of a fossilized skull of the Oligocene false faber-toothed cat Pogonodon
  †Pogonodon
• Populus
• †Potentilla
• †Prochetodon
  • †Prochetodon foxi – type locality for species
• †Prodesmodon
• †Proiridomyrmex
• †Promerycochoerus
• †Proscalops
• †Prosphyracephala
• 

  Fossil of the Oligocene ant Protazteca
  †Protazteca
• †Protohippus
• †Protolabis
• †Protungulatum
  • †Protungulatum donnae
• Prunus
• †Pseudhipparion
• †Pseudolarix
• †Pseudomesoreodon – type locality for genus
• Pseudomyrmex
• †Pseudotsuga
• 

  Restoration of the Paleocene taeniodont mammal Psittacotherium
  †Psittacotherium
• Ptelea
• Pteris
• Pterocarya
• †Ptilodus
  • †Ptilodus kummae
  • †Ptilodus montanus – type locality for species
  • †Ptilodus tsosiensis
• 

  Life restoration of the Late Cretaceous-Paleocene primate relative Purgatorius
  †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
  • 

    Fossilized leaf of the Eocene sassafras Sassafras hesperia
    †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
• 

  Life restoration of the Oligocene-Miocene camel Stenomylus
  †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
• 

  Life restoration of the Eocene carnivoran relative Tapocyon
  †Tapocyon
• Taricha
• Taxodium
• †Teleoceras
• †Tetraclaenodon
• Thomomys
  • †Thomomys talpoides
• †Thrinax
• †Thuja
• †Ticholeptus
• Tilia
• †Tinuviel
• Tipula
• 

  Life restoration of the Paleocene pantodonts mammal Titanoides
  †Titanoides
  • †Titanoides gidleyi
• †Trapa
• †Trigenicus
• †Trigonias
• †Tropidia
• †Tylocephalonyx
• Typha
• Ulmus
• Ursus
• †Vaccinium
• †Valenopsalis
• †Vauquelinia
• †Viburnum
• †Viguiera
• Vitis
• †Viverravus – tentative report
• †Woodwardia
• †Xyronomys
• Zelkova

References

• Various Contributors to the Paleobiology Database. "Fossilworks: Gateway to the Paleobiology Database". Retrieved 7 August 2017.