List of the prehistoric life of Montana facts for kids

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.

Paleozoic

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
• †Echinochimaera – type locality for genus
  • †Echinochimaera meltoni – type locality for species

†Echinochimaera meltoni Lund 1977 from the Mississippian of Bear Gulch

• • †Echinochimaera snyderi – type locality for species
• †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

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

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