# 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.

## 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 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 with prey †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 multifragum †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