List of the Cenozoic life of Wyoming

This list of the Cenozoic life of Wyoming contains the various prehistoric life-forms whose fossilized remains have been reported from within the US state of Wyoming and are between 66 million and 10,000 years of age.

A

 * †Aaptoryctes
 * †Aaptoryctes ivyi
 * †Absarokius
 * †Absarokius abbotti
 * †Absarokius gazini – type locality for species
 * †Absarokius metoecus – type locality for species
 * †Abuta – or unidentified related form
 * †Acacia
 * †Acacia lamarensis
 * †Acacia macrosperma
 * †Acacia wardii
 * †Acarictis
 * †Acarictis ryani – type locality for species
 * Accipiter
 * Northern Goshawk ad M2.jpg [[Accipiter gentilis]]
 * †Accipiter striatus
 * Acer
 * †Acer lesquereuxi
 * †Acer newberryi
 * †Acer silberlingii
 * †Acer vivarium
 * †Aceroryctes – type locality for genus
 * †Aceroryctes dulcis – type locality for species
 * †Achaenodon
 * †Achaenodon insolens – type locality for species
 * †Achaenodon robustus – type locality for species
 * †Acidomomys – type locality for genus
 * †Acidomomys hebeticus – type locality for species
 * †Acmeodon
 * †Acmeodon secans
 * †Acocephalus
 * †Acocephalus adae – type locality for species
 * †Acritoparamys
 * †Acritoparamys atavus
 * †Acritoparamys atwateri
 * †Acritoparamys francesi
 * †Acritoparamys wyomingensis
 * Acros aure 080627 0097 smlu.jpg[[Acrostichum]]
 * †Acrostichum hesperium
 * †Adilophontes – type locality for genus
 * †Adilophontes brachykolos – type locality for species
 * †Adjidaumo
 * †Adjidaumo burkei – tentative report
 * †Adjidaumo craigi – or unidentified comparable form
 * †Adjidaumo minimus
 * Adocidae - Adocus punctatus.jpg†[[Adocus]]
 * †Adunator
 * †Adunator fredericki
 * †Adunator ladae
 * †Adunator martinezi
 * Aegialia
 * †Aegialia rupta – type locality for species
 * Aegolius
 * †Aegolius acadicus
 * Aegolius funereus
 * Aepycamelus Alticamelus hharder.jpg †[[Aepycamelus]]
 * †Aerugoamnis – type locality for genus
 * †Aerugoamnis paulus – type locality for species
 * †Aesculus
 * †Aesculus antiquorum
 * †Aesculus hickeyi
 * †Afairiguana – type locality for genus
 * †Afairiguana avius – type locality for species
 * †Ageina
 * †Ageina tobieni
 * †Ageitodendron
 * †Ageitodendron matthewi
 * Agelaius
 * †Agelaius phoeniceus
 * †Agnotocastor
 * †Agnotocastor galushai – type locality for species
 * Agriochoerus.jpg †[[Agriochoerus]]
 * †Agriochoerus maximus
 * †Agriochoerus minimus – or unidentified comparable form
 * Ailanthus
 * †Ailanthus lesquereuxi
 * †Alagomys
 * †Alagomys russelli – type locality for species
 * †Alastor
 * †Alastor solidescens – type locality for species
 * †Albertanella – or unidentified comparable form
 * †Albertanella minuta
 * Alces
 * †Alces alces
 * †Aletodon
 * †Aletodon conardae – type locality for species
 * †Aletodon gunnelli – type locality for species
 * †Aletodon quadravus
 * The American journal of science (1880) (17965682808).jpg †[[Aletomeryx]]
 * †Aletomeryx gracilis
 * †Aletornis – type locality for genus
 * †Aletornis bellus – type locality for species
 * †Aletornis gracilis – type locality for species
 * †Aletornis nobilis – type locality for species
 * †Aletornis pernix – type locality for species
 * †Aletornis venustus – type locality for species
 * Aleurites
 * †Aleurites glandulosa
 * †Alismaphyllites
 * †Alismaphyllites grandifolius
 * †Allantodiopsis
 * †Allantoidiopsis erosa
 * Allognathosuchus.JPG †[[Allognathosuchus]]
 * †Allognathosuchus heterodon
 * †Allognathosuchus polyodon
 * †Allognathosuchus wartheni – type locality for species
 * †Allomys
 * †Allomys cristabrevis
 * †Allophylus
 * †Allophylus flexifolia
 * Alnus
 * †Alphagaulus
 * †Alphagaulus vetus
 * †Alticonus
 * †Alticonus gazini
 * †Alveojunctus
 * †Alveojunctus minutus
 * †Alveugena
 * †Alveugena carbonensis – type locality for species
 * †Amaramnis
 * †Amaramnis gregoryi – type locality for species
 * †Ambloctonus
 * †Ambloctonus major
 * †Ambloctonus priscus – or unidentified comparable form
 * †Ambloctonus sinosus
 * †Ameiseophis
 * †Ameiseophis robinsoni – type locality for species
 * †Amelotabes – type locality for genus
 * †Amelotabes simpsoni – type locality for species
 * Amentotaxus needles 01.jpg [[Amentotaxus]]
 * †Amentotaxus campbelli
 * Amia
 * †Amia fragosa
 * †Amitabha – type locality for genus
 * †Amitabha urbsinterdictensis – type locality for species
 * †Ampelopsis
 * †Ampelopsis acerifolia
 * †Amphechinus
 * †Amphechinus ellicottae – type locality for species
 * †Amphigyion
 * †Amphigyion straitae
 * †Amphilemur
 * †Amphiplaga
 * Amphiuma
 * †Amphiuma jepseni – type locality for species
 * †Ampliconus
 * †Ampliconus antoni – type locality for species
 * Amyda gregaria.jpg [[Amyda]]
 * †Amyda egregia – type locality for species
 * †Amyda exquisita – type locality for species
 * †Amyda mira – type locality for species
 * †Amynodon
 * †Amynodon advenus
 * †Anacardites
 * †Anacardites schinoloxus
 * Anaclinia – tentative report
 * †Anacodon
 * †Anacodon nexus – type locality for species
 * †Anacodon ursidens
 * Anamirta – or unidentified comparable form
 * †Anamirta milleri
 * †Anaptomorphus
 * †Anaptomorphus aemulus – type locality for species
 * †Anaptomorphus westi – type locality for species
 * Anas
 * †Anas acuta
 * Northern Shoveler by Dan Pancamo.jpg, or northern shoveler]] Anas clypeata''
 * †Anas crecca
 * Anas platyrhynchos
 * †Anas schneideri – type locality for species
 * †Anatella
 * †Anatella tacita – type locality for species
 * †Anconodon
 * †Anconodon cochranensis
 * †Anconodon gidleyi
 * †Anemia
 * †Anemia elongata
 * †Anemorhysis
 * †Anemorhysis natronensis – type locality for species
 * †Anemorhysis pattersoni – type locality for species
 * †Anemorhysis sublettensis – type locality for species
 * †Anemorhysis wortmani – type locality for species
 * †Anilioides
 * †Anilioides nebraskensis
 * †Anisonchus
 * †Anisonchus sectorius
 * †Anisonchus willeyi – type locality for species
 * †Ankylodon
 * †Ankylodon annectens – or unidentified comparable form
 * †Anniealexandria – type locality for genus
 * †Anniealexandria gansi – type locality for species
 * Anobium
 * †Anobium deceptum – type locality for species
 * †Anobium lignitum – type locality for species
 * †Anobium ovale – type locality for species
 * †Anolbanolis – type locality for genus
 * †Anolbanolis banalis – type locality for species
 * †Anolbanolis geminus – type locality for species
 * †Anomoemys
 * †Anomoemys lewisi
 * Anosteira fossil cropped.png †[[Anosteira]]
 * †Anosteira ornata
 * †Anosteira radulina – type locality for species
 * †Anosteira trionychoides
 * †Antherophagus
 * †Antherophagus priscus – type locality for species
 * Anthonomus
 * †Anthonomus revictus – type locality for species
 * †Anthonomus soporus – type locality for species
 * †Antiacodon
 * †Antiacodon pygmaeus – type locality for species
 * †Antiacodon vanvaleni – type locality for species
 * †Antiacodon venustus – type locality for species
 * Antilocapra americana.jpg [[Antilocapra]]
 * †Antilocapra americana
 * Apalone
 * †Apalone extensa – type locality for species
 * †Apalone heteroglypta – type locality for species
 * †Apalone postera – type locality for species
 * †Apatemys
 * †Apatemys bellulus – type locality for species
 * †Apatemys bellus
 * †Apatemys chardini – or unidentified comparable form
 * †Apatemys hendryi – type locality for species
 * †Apatemys rodens
 * †Aphaena
 * †Aphaena rotundipennis – type locality for species
 * †Apheliscus – type locality for genus
 * †Apheliscus chydaeus – type locality for species
 * †Apheliscus insidiosus
 * †Apheliscus nitidus
 * †Apheliscus wapitiensis – type locality for species
 * †Aphelops
 * †Aphelops megalodus
 * †Aphronorus
 * †Aphronorus fraudator
 * †Aphronorus orieli – type locality for species
 * †Aphronorus ratatoski – type locality for species
 * †Apodosauriscus – type locality for genus
 * †Apodosauriscus minutus – type locality for species
 * †Apodosauriscus thermophilus – type locality for species
 * †Apriculus
 * †Apriculus praeteritus – type locality for species
 * †Apternodus
 * †Apternodus brevirostris – type locality for species
 * †Apternodus dasophylakas – type locality for species
 * †Apternodus gregoryi – type locality for species
 * †Apternodus iliffensis
 * †Apternodus major – type locality for species
 * Aquila
 * †Aquila antiqua – type locality for species
 * Golden Eagle in flight - 5.jpg [[Aquila chrysaetos]]
 * Aralia
 * †Aralia notata
 * †Aralia serrulata
 * †Aralia wrightii
 * †Araliophyllum
 * †Araliophyllum quina
 * Araneus
 * †Arapahovius
 * †Arapahovius advena – type locality for species
 * †Arapahovius gazini – type locality for species
 * Araucaria
 * †Araucaria longifolia
 * †Archaeocyon
 * †Archaeocyon falkenbachi
 * †Archaeocyon leptodus
 * †Archaeolagus
 * †Archaeolagus emeraldensis
 * Archaeotherium.jpg †[[Archaeotherium]]
 * †Archaeotherium minimus
 * †Archaeotherium mortoni
 * †Archaeotherium palustris – type locality for species
 * †Archaerhineura – type locality for genus
 * †Archaerhineura mephitis – type locality for species
 * Arcoa
 * †Arcoa lindgreni – type locality for species
 * †Arctocyon
 * †Arctocyon ferox
 * †Arctocyon mumak
 * †Arctodontomys
 * †Arctodontomys nuptus
 * †Arctodontomys simplicidens
 * †Arctodontomys wilsoni – type locality for species
 * ArctodusSimusReconstruct.jpg †[[Arctodus]]
 * †Arctodus simus
 * †Arctostaphylos
 * †Arctostaphylos elliptica
 * †Arctostylops
 * †Arctostylops steini
 * †Arecipites
 * †Arecipites tenuiexinous
 * †Arenahippus
 * †Arenahippus aemulor – type locality for species
 * †Arenahippus pernix – type locality for species
 * †Arfia
 * †Arfia junnei
 * †Arfia opisthotoma
 * †Arfia shoshoniensis
 * †Arfia zele – type locality for species
 * Aristolochia
 * †Aristolochia mortua
 * †Armintodelphys
 * †Armintodelphys blacki
 * †Armintodelphys dawsoni
 * †Armintomys
 * †Armintomys tullbergi
 * †Arpadosaurus – type locality for genus
 * †Arpadosaurus gazinorum – type locality for species
 * †Arpadosaurus sepulchralis – type locality for species
 * †Artimonius
 * †Artimonius nocerai
 * †Artimonius witteri
 * Artocarpus – tentative report
 * †Artocarpus quercoides
 * †Asarkina
 * †Asarkina quadrata – type locality for species
 * †Asiabradypus – or unidentified comparable form
 * Asio
 * †Asio flammeus
 * Asio otus
 * †Asplenium
 * †Asplenium delicatula
 * †Asplenium eoligniticum
 * †Asplenium eolignitum
 * †Asplenium erosum
 * †Asplenium iddingsi
 * †Asplenium remotidens
 * †Astephus
 * †Asterotrygon
 * Stingray prepared by R. Lee Craig (Asterotrygon maloneyi) Fossil Shack.jpg stingray]] †Asterotrygon maloneyi''
 * Astronium
 * †Astronium truncatum
 * †Athyana
 * †Athyana balli
 * †Aulolithomys
 * †Aulolithomys bounites
 * †Aulolithomys vexilliames – type locality for species
 * †Auroralestes
 * †Auroralestes simpsoni
 * †Auxontodon
 * †Averrhoites
 * †Averrhoites affinis
 * †Avunculus
 * †Avunculus didelphodonti – or unidentified comparable form
 * †Axestemys – type locality for genus
 * †Axestemys byssina – type locality for species
 * †Axestemys cerevisia – type locality for species
 * †Axestemys salebrosa – type locality for species
 * †Axestemys uintaensis – type locality for species
 * †Aycrossia
 * †Aycrossia lovei
 * Aythya
 * Aythya collaris
 * Azolla
 * †Azolla cretacea
 * †Azygonyx
 * †Azygonyx ancylion – type locality for species
 * †Azygonyx grangeri
 * †Azygonyx xenicus – type locality for species

B

 * †Babibasiliscus – type locality for genus
 * †Babibasiliscus alxi – type locality for species
 * †Baena
 * †Baena arenosa – type locality for species
 * †Bahndwivici – type locality for genus
 * †Bahndwivici ammoskius – type locality for species
 * †Baioconodon
 * †Baioconodon denverensis – or unidentified comparable form
 * †Baioconodon middletoni – type locality for species
 * †Baioconodon nordicus
 * †Baioconodon wovokae
 * †Baiotomeus
 * †Baiotomeus douglassi
 * †Baiotomeus lamberti
 * †Baltemys – type locality for genus
 * †Baltemys staurogastros – type locality for species
 * †Baptemys
 * †Baptemys wyomingensis – type locality for species
 * †Barbouromeryx – or unidentified comparable form
 * Barylambda-faberi.jpg †[[Barylambda]]
 * †Barylambda churchilli – type locality for species
 * †Barylambda faberi
 * †Bathornis
 * †Bathornis fricki – type locality for species
 * †Bathygenys
 * †Bathygenys alpha
 * †Bathygenys hedlundae
 * †Bathyopsis
 * †Bathyopsis fissidens
 * Batodonoides cropped.png †[[Batodonoides]]
 * †Batodonoides vanhouteni – type locality for species
 * †Batrachosauroides – tentative report
 * Bauhinia
 * †Bauhinia wyomingana
 * †Bauhinia wyomingiana
 * †Beilschmiedia
 * †Beilschmiedia eocenica
 * †Berchemiopsis
 * †Berchemiopsis paucidentata
 * †Beringiaphyllum
 * †Beringiaphyllum cupanioides
 * †Berosus
 * †Berosus sexstriatus – type locality for species
 * †Berosus tenuis – type locality for species
 * †Bessoecetor
 * †Bessoecetor septentrionalis
 * Betula
 * †Betula iddingsi
 * †Betula stevensoni
 * †Betula stevensonii
 * Biomphalaria
 * Bison
 * American bison k5680-1.jpg †[[Bison bison]]
 * †Bisonalveus – type locality for genus
 * †Bisonalveus browni – type locality for species
 * †Bisonalveus holtzmani – type locality for species
 * †Blechnum
 * †Blechnum anceps
 * Bledius
 * †Bledius adamus – type locality for species
 * †Bledius faecorum – type locality for species
 * †Blickomylus
 * †Blickomylus galushai
 * Boavus idelmani.JPG †[[Boavus]] – type locality for genus
 * †Boavus brevis – type locality for species
 * †Boavus idelmani – type locality for species
 * †Boavus occidentalis – type locality for species
 * Boletina
 * †Boletina paludivaga – type locality for species
 * †Boletina umbratica – type locality for species
 * †Bootherium
 * †Bootherium bombifrons
 * †Borealosuchus
 * †Borealosuchus formidabilis
 * †Borealosuchus wilsoni – type locality for species
 * †Botauroides – type locality for genus
 * †Botauroides parvus – type locality for species
 * †Bouromeryx
 * †Boverisuchus
 * †Boverisuchus vorax
 * †Bownomomys – type locality for genus
 * †Bownomomys americanus – type locality for species. Formerly known as Teilhardina americana.
 * †Bownomomys crassidens – type locality for species. Formerly known as Teilhardina crassidens.
 * †Boysia – or unidentified comparable form
 * †Boysia phenacodorum
 * †Brachianodon
 * †Brachianodon westorum – type locality for species
 * Brachycrus.jpg †[[Brachycrus]]
 * †Brachycrus rusticus
 * †Brachycrus sweetwaterensis
 * †Brachycrus vaughani
 * †Brachyerix
 * †Brachyerix macrotis
 * †Brachyhyops
 * †Brachyhyops viensis
 * †Brachyhyops wyomingensis – type locality for species
 * †Brachyrhynchocyon
 * †Brachyrhynchocyon dodgei
 * †Brachyrhynchocyon intermedius
 * †Brachyuranochampsa – type locality for genus
 * †Brachyuranochampsa eversolei – type locality for species
 * Bracon
 * †Bracon laminarum – type locality for species
 * Branta
 * Branta canadensis -near Oceanville, New Jersey, USA -flying-8.jpg †[[Branta canadensis]]
 * †Bridgeremys
 * †Bridgeremys pusilla – type locality for species
 * †Brontops
 * †Browniea
 * †Browniea serrata
 * †Bryophyte – or unidentified related form
 * Bubo
 * †Bubo virginianus
 * †Bunophorus
 * †Bunophorus etsagicus
 * †Bunophorus grangeri
 * †Bunophorus macropternus
 * †Bunophorus robustus
 * †Bunophorus sinclairi – type locality for species
 * †Bunrsera
 * †Bunrsera inaequalateralis
 * Buteo
 * †Buteo jamaicensis
 * †Buteo lagopus
 * †Buteo regalis – or unidentified comparable form
 * Buteogallus fragilis.jpg [[Buteogallus]]

C

 * †Caedocyon
 * †Caedocyon tedfordi – type locality for species
 * †Caenolambda – type locality for genus
 * †Caenolambda jepseni – type locality for species
 * †Caenolambda pattersoni – type locality for species
 * Knight Caenopus.jpg. Charles R. Knight (1890s).]] †Caenopus''
 * †Caenopus yoderensis – type locality for species
 * †Caesalpinia
 * †Caesalpinia flumen-viridensis
 * †Caesalpinia pecorae
 * †Caesalpinites
 * †Caesalpinites falcata – type locality for species
 * †Calamagras
 * †Calamagras angulatus – or unidentified comparable form
 * †Calamagras platyspondyla
 * †Calamagras primus – type locality for species
 * †Calamagras weigeli
 * †Calamospiza
 * †Calamospiza melanocorys
 * †Calandrites
 * †Calandrites cineratius
 * †Calandrites defessus
 * †Calcardea – type locality for genus
 * †Calcardea junnei – type locality for species
 * Calidris
 * Pectoral Sandpiper3.jpg †[[Calidris melanotos]]
 * †Callomyia
 * †Callomyia torporata – type locality for species
 * †Callospilopteron – type locality for genus
 * †Callospilopteron ocellatum – type locality for species
 * †Calycites
 * †Calycites ardtunensis
 * †Calycites hexaphylla
 * †Calycites mikanoides
 * †Calycites polysepala
 * †Calycites RR58 informal
 * †Calycites RR71 informal
 * †Camelops
 * †Camelops hesternus – or unidentified comparable form
 * †Canarium
 * †Canarium californicum
 * †Canavalia
 * †Canavalia diuturna
 * Canis
 * Canis lupus & dirus.jpg, the grey wolf, to scale with a fossilized skeleton of the Pleistocene wolf Canis dirus, or dire wolf]] †Canis dirus''
 * †Canis latrans
 * †Canis lupus
 * †Cantius
 * †Cantius abditus – type locality for species
 * †Cantius frugivorus
 * †Cantius mckennai
 * †Cantius nunienus
 * †Cantius ralstoni
 * †Cantius simonsi – type locality for species
 * †Cantius torresi
 * †Cantius trigonodus – type locality for species
 * †Capacikala
 * †Capacikala parvus – type locality for species
 * Capella
 * †Capella gallinago
 * †Carabites
 * †Carabites kincaidi – type locality for species
 * Caracara
 * Schopfkarakara.jpg †[[Caracara plancus]]
 * †Cardichelyon – type locality for genus
 * †Cardichelyon rogerwoodi – type locality for species
 * †Cardiolophus
 * †Cardiolophus radinskyi – type locality for species
 * †Cardiolophus semihians
 * Cardiospermum
 * [[file:Cardiospermum coloradensis (fossil leaf) (Green River Formation, Eocene; Utah, USA) (44557178634).jpg|thumb|right|upright|A Cardiospermum coloradensis leaf]] †[[Cardiospermum coloradensis]]
 * Carduelis
 * †Carpites
 * †Carpites newberryana
 * †Carpites pedunculatus
 * †Carpites verrucosus
 * †Carpodaptes
 * †Carpodaptes hazelae
 * †Carpodaptes hobackensis
 * †Carpodaptes jepseni
 * †Carpodaptes rosei
 * †Carpodaptes stonleyi
 * †Carpolestes
 * †Carpolestes dubius – type locality for species
 * †Carpolestes nigridens
 * CarpolestesCL.png †[[Carpolestes simpsoni]] – type locality for species
 * †Carpolithes
 * †Carpolithes osseus
 * Carya
 * †Carya antiquorum
 * †Carya veripites
 * †Carya viridifluminipites
 * Castanea
 * †Castanea intermedia
 * †Castanea pulchella
 * Castor
 * †Castor peninsulatus
 * †Catopsalis
 * †Catopsalis alexanderi
 * †Catopsalis calgariensis
 * Cedrela odorata foliage.jpg [[Cedrela]]
 * †Cedrela trainii
 * †Cedrelospermum
 * †Cedrelospermum lineatum
 * †Cedrelospermum nervosum
 * †Cedrobaena – type locality for genus
 * †Cedrobaena putorius
 * †Cedrocherus
 * †Cedrocherus aceratus – type locality for species
 * †Cedrocherus ryani – type locality for species
 * †Cedromus
 * †Cedromus wardi
 * Celastrus scandens.jpg †[[Celastrus]]
 * †Celastrus culveri
 * †Celastrus ellipticus
 * †Celastrus inaequalis
 * †Celastrus winchesteri
 * †Celliforma
 * †Celliforma spirifer
 * Celtis
 * †Celtis aspera
 * †Celtis newberryi
 * †Celtis peracuminata
 * †Celtis phenacodorum
 * †Centetodon
 * †Centetodon bacchanalis
 * †Centetodon bembicophagus
 * †Centetodon chadronensis
 * †Centetodon hendryi
 * †Centetodon magnus
 * †Centetodon marginalis
 * †Centetodon neashami – type locality for species
 * †Centetodon patratus
 * †Centetodon pulcher
 * †Centrinus
 * †Centrinus diruptus – type locality for species
 * †Centrocercus
 * †Centrocercus urophasianus
 * †Cephalogale
 * †Ceratophyllum
 * †Ceratophyllum muricatum
 * Ceratosuchus burdoshi e.jpg †[[Ceratosuchus]]
 * †Ceratosuchus burdoshi
 * Cercidiphyllum
 * †Cercidiphyllum arcticum
 * †Cercidiphyllum articum
 * †Cercidiphyllum BB21 informal
 * †Cercidiphyllum BB34-52 informal
 * †Cercidiphyllum genetrix
 * †Cercidiphyllum tiny winged seeds informal
 * †Cercidiphyllum tiny wingedseeds informal
 * Cercopidae - Cercopis vulnerata.JPG †[[Cercopis]]
 * †Cercopis astricta – type locality for species
 * †Cercopites – type locality for genus
 * †Cercopites calliscens – type locality for species
 * †Cercopites umbratilis – type locality for species
 * †Ceutholestes
 * †Ceutholestes dolosus
 * †Chadrolagus
 * †Chadrolagus emryi
 * †Chaetoptelea
 * †Chaetoptelea microphylla
 * †Chaetoptelea pseudofulva – tentative report
 * †Chalicomomys
 * †Chalicomomys willwoodensis – type locality for species
 * Champsosaurus BW.jpg †[[Champsosaurus]]
 * †Champsosaurus gigas
 * †Chaneya
 * The American Museum journal (c1900-(1918)) (17975178659) Chaneya tenuis.jpg†[[Chaneya tenuis]]
 * Chara
 * Charadrius
 * †Charadrius montanus
 * †Charadrius vociferus
 * Charina
 * †Charina prebottae
 * Cheilosia
 * †Cheilosia ampla – type locality for species
 * †Cheilosia scudderi
 * †Chelomophrynus – type locality for genus
 * †Chelomophrynus bayi – type locality for species
 * †Chilostigma – tentative report
 * †Chilostigma ostracoderma
 * †Chiromyoides
 * †Chiromyoides caesor – type locality for species
 * †Chiromyoides major – type locality for species
 * †Chiromyoides minor – type locality for species
 * †Chiromyoides potior
 * Chironomus
 * †Chironomus septus – type locality for species
 * Chisternon.jpg †[[Chisternon]]
 * †Chisternon hebraicum – type locality for species
 * †Chisternon undatum – type locality for species
 * †Chlororhysis
 * †Chlororhysis incomptus – type locality for species
 * †Chlororhysis knightensis – type locality for species
 * †Choctawius – or unidentified comparable form
 * †Cholula
 * †Cholula triguttata – type locality for species
 * †Choragus
 * †Choragus fictilis – type locality for species
 * †Chordeiles
 * Common Nighthawk (14428313550).jpg †[[Chordeiles minor]]
 * †Chriacus
 * †Chriacus badgleyi
 * †Chriacus baldwini
 * †Chriacus gallinae
 * †Chriacus katrinae
 * †Chriacus oconostotae
 * †Chriacus pelvidens
 * †Chumashius
 * †Cicadula
 * †Cicadula saxosa – type locality for species
 * †Cimolestes
 * †Cinnamomophyllum
 * †Cinnamomophyllum RR19 informal
 * Starr 010419 0038 cinnamomum camphora.jpg [[Cinnamomum]]
 * †Cinnamomum sezannense
 * †Cinnamomum spectabilis
 * Circus
 * †Circus cyaneus
 * †Cissites
 * †Cissites rocklandensis
 * Cissus
 * †Cissus haguei
 * †Cissus marginata
 * †Cissus marginatus
 * †Cixius – tentative report
 * †Cixius hesperidum – type locality for species
 * Cladrastis-kentukea-00.JPG [[Cladrastis]]
 * †Cladrastis GR579 informal
 * †Cladrastis GR580 informal
 * †Claenodon
 * †Claenodon montanensis
 * †Cnemidaria
 * †Cnemidaria magna
 * †Coccothraustes
 * †Coccothraustes vespertinus
 * Cocculus orbiculatus HRM.jpg [[Cocculus]]
 * †Cocculus flabella
 * †Coelidia
 * †Coelidia wyomingensis – type locality for species
 * Colaptes
 * †Colaptes auratus
 * †Colodon
 * †Colodon woodi
 * †Colpocherus
 * †Colpoclaenus
 * †Colpoclaenus keeferi – type locality for species
 * †Colpoclaenus procyonoides – or unidentified comparable form
 * Colymbus
 * †Colymbus nigricollis
 * †Compsemys
 * †Compsemys victa
 * †Conacodon
 * †Conacodon cophater – or unidentified comparable form
 * †Conacodon delphae
 * Coniophis Marsh 1892.png †[[Coniophis]]
 * †Coniophis carinatus – type locality for species
 * †Coniophis platycarinatus – type locality for species
 * †Copecion
 * †Copecion brachypternus
 * †Copecion davisi
 * †Copedelphys
 * †Copedelphys stevensoni
 * †Copelemur
 * †Copelemur australotutus – type locality for species
 * †Copelemur praetutus
 * †Copelemur tutus
 * †Copemys
 * †Copemys longidens
 * †Coriphagus
 * †Coriphagus encinensis – or unidentified comparable form
 * †Coriphagus montanus
 * †Corizus – tentative report
 * †Corizus guttatus – type locality for species
 * Cormocyon leptodus.JPG Cormocyon]] †Cormocyon
 * †Cormocyon haydeni
 * Cornus
 * †Cornus hyperborea
 * †Cornus nebrascensis
 * †Cornus newberryi
 * †Cornus wrightii
 * Corvus
 * †Corvus brachyrhynchos
 * †Corvus corax
 * †Corylites
 * †Corylites FW01 informal
 * †Corylus
 * †Corylus insignis
 * †Corylus macquarryi
 * Corymbites
 * †Corymbites velatus – type locality for species
 * Coryphodon.jpg †[[Coryphodon]]
 * †Coryphodon armatus
 * †Coryphodon eocaenus
 * †Coryphodon lobatus
 * †Coryphodon proterus
 * †Coryphodon radians
 * †Cranea
 * †Cranea wyomingensis
 * Crataegus
 * †Credneria
 * †Credneria daturaefolia – tentative report
 * †Credneria pachyphylla
 * †Cristadjidaumo
 * †Cristadjidaumo skinneri – type locality for species
 * Crocodylus
 * Crocodylus affinis AMNH 6177.jpg]] †Crocodylus affinis'' – type locality for species
 * †Crocodylus ziphodon – type locality for species
 * †Cryptocephalus
 * †Cryptocephalus vetustus – type locality for species
 * Cryptorhynchus
 * †Cryptorhynchus annosus – type locality for species
 * Cryptotis
 * Culex
 * †Culex damnatorum – type locality for species
 * †Cupanieidites
 * †Cupanieidites inaequalis
 * †Cupanieidites inaequatis
 * †Cupidinimus
 * †Cupidinimus whitlocki
 * †Cycadopites
 * †Cycadopites follicularis
 * Cyclocarya
 * †Cyclurus
 * †Cyclurus fragosus
 * †Cylindrodon
 * †Cylindrodon natronensis – type locality for species
 * †Cylindrodon solarborus – type locality for species
 * Cynarctoides fossil cropped.png †[[Cynarctoides]]
 * †Cynarctoides acridens
 * †Cynarctoides harlowi
 * †Cynarctoides luskensis – type locality for species
 * †Cyperacites
 * †Cyperacites angustior
 * †Cyperacites filiferus
 * †Cyperacites giganteus
 * †Cyriacotherium
 * †Cyriacotherium argyreum – type locality for species
 * †Cyriacotherium psamminum – type locality for species
 * †Cyrilavis
 * †Cyrilavis olsoni – type locality for species
 * †Cyrtomenus
 * †Cyrtomenus concinnus – type locality for species

D

 * †Dalbergia
 * †Daphoenictis
 * Daphoenus.jpg †[[Daphoenodon]]
 * †Daphoenodon falkenbachi – type locality for species
 * †Daphoenodon niobrarensis
 * †Daphoenodon skinneri – type locality for species
 * †Daphoenodon superbus
 * †Daphoenus
 * †Daphoenus lambei
 * †Dartonius
 * †Dartonius jepseni
 * Common stingray tynemouth.jpg [[Dasyatis]]
 * †Davidia
 * †Davidia antiqua
 * †Dawsonicyon – type locality for genus
 * †Dawsonicyon isami – type locality for species
 * †Dawsonomys
 * †Dawsonomys woodi
 * †Dawsonophis – type locality for genus
 * †Dawsonophis wyomingensis – type locality for species
 * †Debeya
 * †Decatoma
 * †Decatoma antiqua – type locality for species
 * †Delotrochanter
 * †Delotrochanter major – type locality for species
 * Dendragapus
 * Dendragapus obscurus USNPS.jpg †[[Dendragapus obscurus]]
 * †Dendropanax
 * †Dendropanax latens
 * †Dennstaedia
 * †Dennstaedia americana
 * †Dennstaedtia
 * †Dennstaedtia americana
 * †Dennstaedtiopsis
 * †Dennstaedtiopsis aerenchymata
 * †Desmatippus
 * †Desmatippus tyleri
 * †Desmatochoerus
 * †Desmatochoerus hatcheri
 * †Desmatochoerus megalodon
 * †Desmatoclaenus
 * †Desmatoclaenus mearae
 * †Desmatolagus
 * †Desmatolagus schizopetrus
 * †Desmatotherium
 * †Desmatotherium intermedius
 * †Desmocyon
 * †Desmocyon thomsoni
 * †Devallia – tentative report
 * †Devallia montana
 * †Diacocherus
 * †Diacocherus meizon – type locality for species
 * †Diacocherus minutus
 * Diacodexis pakistanensis e.jpg †[[Diacodexis]]
 * †Diacodexis ilicis
 * †Diacodexis kelleyi
 * †Diacodexis kellyi
 * †Diacodexis metsiacus
 * †Diacodexis minutus
 * †Diacodexis primus
 * †Diacodexis secans
 * †Diacodexis woltonensis – type locality for species
 * †Diacodon
 * †Diacodon celatus
 * †Diaplegma
 * †Diaplegma obdormitum – type locality for species
 * †Diatryma – type locality for genus
 * †Diatryma gigantea – type locality for species
 * Subhyracodon tridactylus.jpg Diceratherium. Robert Bruce Horsfall (1913).]] †Diceratherium
 * †Diceratherium annectens
 * †Diceratherium armatum
 * †Diceratherium tridactylum
 * Dicotylophyllum
 * †Dicotylophyllum anomalum
 * †Dicotylophyllum mercerensis
 * Dicranomyia
 * †Dicranomyia primitiva
 * †Dicranomyia rhodolitha – type locality for species
 * Dicrostonyx
 * †Didelphodontine
 * †Didelphodus
 * †Didelphodus absarokae
 * †Didelphodus altidens
 * †Didymictis
 * †Didymictis altidens
 * †Didymictis leptomylus
 * †Didymictis protenus
 * †Didymictis proteus
 * †Didymictis vancleveae – or unidentified comparable form
 * †Dillerlemur
 * †Dillerlemur pagei
 * †Dillerlemur robinettei – type locality for species
 * †Dilophodon
 * †Dilophodon destitutus – type locality for species
 * †Dilophodon minusculus
 * ExtmDinictis1921-029-11.jpg †[[Dinictis]]
 * †Dinictis felina
 * †Dinohyus
 * †Diospyros
 * †Diospyros brachysepala
 * †Diospyros haguei
 * †Diospyros lamarensis
 * †Dipassalus
 * †Dipassalus oryctes
 * †Diplobunops
 * †Diplobunops matthewi
 * †Diplocynodon
 * †Diplolophus
 * †Diplolophus insolens – type locality for species
 * Diplomystus Vienna.jpg †[[Diplomystus]]
 * †Diplomystus dentatus
 * †Dipoides
 * †Dipoides stirtoni
 * †Dipsalidictis
 * †Dipsalidictis aequidens
 * †Dipsalidictis krausei – type locality for species
 * †Dipsalidictis platypus – type locality for species
 * †Dipsalidictis transiens
 * †Dipsalodon
 * †Dipsalodon churchillorum
 * †Dipsalodon matthewi – type locality for species
 * Dipteronia brownii Samara SRIC 01.jpg [[Dipteronia]]
 * †Dipteronia GR551 informal
 * †Dipteronia insignis
 * Discus
 * †Dissacus
 * †Dissacus argenteus – type locality for species
 * †Dissacus longaevus
 * †Dissacus navajovius
 * †Dissacus praenuntius
 * †Distylium
 * †Distylium eocenica
 * †Dithelysia
 * †Dithelysia amorensis
 * Dolichopus urbanus.jpg [[Dolichopus]]
 * †Dombeya
 * †Dombeya novimundi
 * †Domnina
 * †Domnina gradata – or unidentified comparable form
 * †Domninoides
 * †Domninoides valentinensis – or unidentified comparable form
 * †Dorraletes
 * †Dorraletes diminutivus
 * †Douglassciurus
 * †Douglassciurus jeffersoni
 * †Drimys
 * Dryocoetes
 * †Dryocoetes carbonarius – type locality for species
 * †Dryocoetes impressus
 * †Dryomomys – type locality for genus
 * †Dryomomys dulcifer – type locality for species
 * †Dryomomys szalayi – type locality for species
 * Dryopteris filix mas nf.jpg [[Dryopteris]]
 * †Dryopteris lakesi
 * †Dryopteris longipetiolatum
 * †Dryopteris meeteetseana
 * †Dryopteris serrata
 * †Dryopteris weedii
 * †Dryopteris xantholithensis
 * †Dunnophis
 * †Dunnophis microechinis – type locality for species
 * †Dunnophis microechinus
 * †Dysagrion – type locality for genus
 * †Dysagrion fredericii – type locality for species
 * †Dysagrion lakesii – type locality for species
 * †Dysagrion packardii – type locality for species

E

 * Echmatemys stevensoniana AMNH 6084.jpg †[[Echmatemys]]
 * †Echmatemys haydeni
 * †Echmatemys lativertebralis
 * †Echmatemys megaulax
 * †Echmatemys rivalis – type locality for species
 * †Echmatemys septaria
 * †Echmatemys testudinea
 * †Echmatemys wyomingensis
 * †Eclytus
 * †Eclytus lutatus – type locality for species
 * Ectocion Ralstonensis.jpg †[[Ectocion]]
 * †Ectocion cedrus – type locality for species
 * †Ectocion collinus – type locality for species
 * †Ectocion major – or unidentified comparable form
 * †Ectocion mediotuber – type locality for species
 * †Ectocion osbornianus
 * †Ectocion parvus
 * †Ectocion superstes
 * †Ectoconus
 * †Ectoconus cavigellii – type locality for species
 * †Ectoconus ditrigonus
 * †Ectoganus
 * †Ectoganus bighornensis
 * †Ectoganus copei
 * †Ectoganus gliriformes
 * †Ectoganus gliriformis
 * †Ectoganus lobdelli
 * †Ectopistes
 * Ectopistes migratorius (passenger pigeon).jpg †[[Ectopistes migratorius]]
 * †Ectopocynus
 * †Ectopocynus antiquus – type locality for species
 * †Ectopocynus intermedius – type locality for species
 * †Ectypodus
 * †Ectypodus aphronorus
 * †Ectypodus childei – or unidentified comparable form
 * †Ectypodus hazeni – type locality for species
 * †Ectypodus laytoni – type locality for species
 * †Ectypodus lovei
 * †Ectypodus musculus
 * †Ectypodus powelli – type locality for species
 * †Ectypodus simpsoni
 * †Ectypodus szalayi
 * †Ectypodus tardus
 * †Elaeodendron
 * †Elaeodendron polymorphum
 * †Ellipsodon
 * †Ellipsodon lemuroides – or unidentified comparable form
 * †Elphidotarsius
 * †Elphidotarsius florencae – or unidentified comparable form
 * †Elphidotarsius shotgunensis
 * †Elpidophorus
 * †Elpidophorus elegans
 * †Elpidophorus minor – or unidentified comparable form
 * †Elwynella – type locality for genus
 * †Elwynella oreas – type locality for species
 * †Enhydrocyon
 * †Enhydrocyon basilatus
 * †Enhydrocyon crassidens
 * †Enhydrocyon pahinsintewakpa
 * Enochrus
 * †Enochrus primaevus – type locality for species
 * Knight entelodont.jpg †[[Entelodon]]
 * †Entelodon coarctatus – or unidentified comparable form
 * †Entomolestes – type locality for genus
 * †Entomolestes grangeri – type locality for species
 * †Entomolestes westgatei – type locality for species
 * †Entomophontes – type locality for genus
 * †Entomophontes hutchisoni – type locality for species
 * †Entomophontes incrustatus – type locality for species
 * †Entoptychus
 * Eobasileus cropped.png †[[Eobasileus]]
 * †Eobasileus cornutus
 * †Eobucco
 * †Eobucco brodkorbi
 * †Eocalopteryx
 * †Eocalopteryx atavina – type locality for species
 * †Eoceornis – type locality for genus
 * †Eoceornis ardetta – type locality for species
 * †Eoconodon
 * †Eoconodon copanus
 * †Eocrex – type locality for genus
 * †Eocrex primus – type locality for species
 * †Eodiploglossus – type locality for genus
 * †Eodiploglossus borealis – type locality for species
 * †Eoerianthus
 * †Eoerianthus multispinosa
 * †Eoformica
 * †Eoformica pinguis – type locality for species
 * †Eofringillirostrum – type locality for genus
 * †Eofringillirostrum boudreauxi – type locality for species
 * †Eoglyptosaurus
 * †Eoglyptosaurus donohoei – type locality for species
 * Eohiodon
 * Hyracotherium Eohippus hharder cropped.png †[[Eohippus]]
 * †Eohippus cristatus
 * †Eoictops – type locality for genus
 * †Eoictops novaceki – type locality for species
 * †Eoliarus – tentative report
 * †Eoliarus lutensis – type locality for species
 * †Eomoropus
 * †Eomoropus amarorum
 * †Eomoropus anarsius
 * †Eopodagrion – type locality for genus
 * †Eopodagrion abortivum – type locality for species
 * †Eopodagrion scudderi – type locality for species
 * †Eorhinophrynus
 * †Eorhinophrynus septentrionalis – type locality for species
 * †Eoryctes – type locality for genus
 * †Eoryctes melanus – type locality for species
 * †Eostangeria
 * †Eostangeria pseudopteris
 * †Eostrix
 * †Eostrix martinellii – type locality for species
 * Eotitanops borealis.jpg †[[Eotitanops]]
 * †Eotitanops borealis
 * †Eotylopus
 * †Eotylopus reedi – type locality for species
 * †Eozygodactylus – type locality for genus
 * †Eozygodactylus americanus – type locality for species
 * †Epicaerus
 * †Epicaerus dilapsus – type locality for species
 * †Epicaerus effossus – type locality for species
 * †Epicaerus exanimis – type locality for species
 * †Epicaerus fodinarum
 * †Epicaerus saxatilis – type locality for species
 * †Epicaerus subterraneus
 * †Epicaerus terrosus – type locality for species
 * Epihippus sp.jpg †[[Epihippus]]
 * †Epihippus gracilis
 * †Epitriplopus
 * †Epitriplopus uintensis
 * †Epoicotherium
 * †Epoicotherium unicum
 * †Equisetum
 * †Equisetum canaliculatum
 * †Equisetum deciduum
 * †Equisetum FW21 informal
 * †Equisetum haguei
 * Equus
 * †Equus conversidens
 * Eremophila
 * †Eremophila alpestris
 * Erythrina speciosa flower.JPG inflorescences, Brazil]] Erythrina''
 * †Erythrina roanensis – type locality for species
 * Esox
 * †Esox kronneri – type locality for species
 * †Esthonyx
 * †Esthonyx acutidens
 * †Esthonyx bisulcatus
 * †Esthonyx gunnelli
 * †Esthonyx spatularius
 * †Eucastor
 * †Eucommia
 * †Eucommia serrata
 * †Eudaemonema
 * †Eudaemonema cuspidata
 * Eugenia1.jpg [[Eugenia]]
 * †Eugenia americana
 * †Eugnamptus
 * †Eugnamptus decemsatus – type locality for species
 * †Eugnamptus grandaevus
 * †Euhapsis
 * †Euhapsis ellicottae
 * †Eumys
 * †Eumys elegans
 * †Euparius
 * †Euparius elusus – type locality for species
 * †Euparius repertus – type locality for species
 * Euphagus
 * †Euphagus cyanocephalus
 * †Euphagus magnirostris
 * †Euproteaciphyllum
 * †Euproteaciphyllum minutum
 * Eusmilus bidentatus cropped.jpg †[[Eusmilus]]
 * †Eusmilus sicarius
 * Eutamias
 * †Eutypomys
 * †Eutypomys parvus
 * †Exostinus
 * †Exostinus lancensis – or unidentified comparable form

F

 * Fagus
 * †Fagus antipofii
 * †Fagus undulata
 * Falco
 * †Falco columbarius
 * †Falco falconella – type locality for species
 * USGS Prairie Falcon.jpg †[[Falco mexicanus]]
 * †Falco rusticolus
 * †Falco sparverius
 * †Ficarasites – type locality for genus
 * †Ficarasites stigmaticum – type locality for species
 * Ficus
 * †Ficus affinis
 * †Ficus artocarpoides
 * †Ficus asiminaefolia
 * †Ficus deformata
 * †Ficus densifolia
 * †Ficus haguei
 * †Ficus planicostata
 * †Ficus shastensis – tentative report
 * †Ficus subtruncata
 * †Ficus tiliaefolia – tentative report
 * †Ficus ungeri
 * †Firmianites – type locality for genus
 * †Firmianites aterrimus – type locality for species
 * †Florentiamys
 * †Florentiamys kinseyi – type locality for species
 * †Florentiamys loomisi – type locality for species
 * Fluvioviridavis.png †[[Fluvioviridavis]] – type locality for genus
 * †Fluvioviridavis platyrhamphus – type locality for species
 * †Foekenia
 * †Foekenia catenulata
 * †Fortuna
 * †Fortuna marsilioides – or unidentified comparable form
 * †Franimys
 * †Franimys ambos
 * †Franimys amherstensis – type locality for species
 * †Franimys buccatus
 * †Fraxinoipollenis
 * †Fraxinoipollenis variabilis
 * †Fraxinoipollenites
 * †Fraxinoipollenites pachyexinous
 * †Fraxinoipollenites variabilis
 * †Fraxinopollenites
 * †Fraxinopollenites variabilis
 * Koeh-062.jpg †[[Fraxinus]]
 * †Fraxinus eocenica
 * †Fraxinus eocinica
 * †Fraxinus wrightii
 * †Fulgora
 * †Fulgora granulosa – type locality for species
 * †Fulgora populata – type locality for species

G

 * †Gagadon
 * †Gagadon minimonstrum
 * †Galbreathia
 * †Galbreathia novellus
 * †Galecyon
 * †Galecyon mordax
 * Galerita
 * †Galerita marshii – type locality for species
 * Gallinuloides wyomingensis.jpg †[[Gallinuloides]] – type locality for genus
 * †Gallinuloides wyomingensis – type locality for species
 * Gastrocopta
 * Gastrodonta
 * †Gaultia – type locality for genus
 * †Gaultia silvaticus – type locality for species
 * †Gazinius
 * †Gazinius amplus
 * †Gazinius bowni – type locality for species
 * †Gazinocyon
 * †Gazinocyon vulpeculus
 * †Gelastops
 * †Gelastops joni – type locality for species
 * †Gelastops parcus
 * †Geranoides – type locality for genus
 * †Geranoides jepseni – type locality for species
 * †Geringophis
 * †Geringophis depressus
 * Gerrhonotus – or unidentified comparable form
 * Ginkgo
 * Ginkgo adiantoides - G. cranii.jpg †[[Ginkgo adiantoides]]
 * †Gleditsia – or unidentified related form
 * †Gleditsia RR29 informal
 * †Gleicheniidites
 * †Glypta
 * †Glypta transversalis – type locality for species
 * †Glyptosaurus – type locality for genus
 * †Glyptosaurus agmodon – type locality for species
 * †Glyptosaurus obtusidens – type locality for species
 * †Glyptosaurus rhodinos – type locality for species
 * †Glyptosaurus sphenodon – type locality for species
 * †Glyptosaurus sylvestris – type locality for species
 * Glyptostrobus
 * Glyptostrobus Foliage 01.JPG †[[Glyptostrobus europaeus]]
 * †Glyptostrobus nordenskioldi
 * †Goinophis – tentative report
 * †Gomphochelys – type locality for genus
 * †Gomphochelys nanus – type locality for species
 * †Goniacodon
 * †Goniacodon levisanus – type locality for species
 * †Goniodontomys
 * †Goniodontomys disjunctus
 * Gopherus
 * †Gopherus laticuneus
 * †Gracilocyon
 * †Gracilocyon rosei
 * †Gracilocyon winkleri
 * †Grangerella
 * †Gregorymys
 * †Gregorymys formosus
 * †Gregorymys riggsi – type locality for species
 * †Grewiopsis – tentative report
 * †Grewiopsis aldersoni
 * †Griphomys
 * Grus
 * †Grus canadensis
 * †Grus marshi – type locality for species
 * Gulo
 * Wolverine 01.jpg †[[Gulo gulo]]
 * †Gymnetron
 * †Gymnetron lecontei – type locality for species
 * †Gymnocladus
 * †Gymnocladus hesperia
 * Gyraulus – or unidentified comparable form

H

 * †Habrosaurus
 * †Habrosaurus dilatus
 * †Hadrianus
 * †Hadrianus allabiatus – type locality for species
 * †Hadrianus quadratus – type locality for species
 * †Hammapteryx – type locality for genus
 * †Hammapteryx reticulata – type locality for species
 * Hapalodectes restoration Stanton Fink.png †[[Hapalodectes]]
 * †Hapalodectes anthracinus
 * †Hapalodectes leptognathus
 * †Hapalorestes
 * †Hapalorestes lovei – type locality for species
 * †Haplaletes
 * †Haplaletes disceptatrix
 * †Haplaletes pelicatus – type locality for species
 * †Haploconus
 * †Haplodontosaurus
 * †Haplodontosaurus excedens
 * †Haplolambda
 * †Haplolambda quinni
 * †Haplomylus
 * †Haplomylus bozemanensis – type locality for species
 * †Haplomylus palustris
 * †Haplomylus scottianus – type locality for species
 * †Haplomylus simpsoni
 * †Haplomylus speirianus
 * †Haplomylus zalmouti
 * Harpagolestes immanis.jpg †[[Harpagolestes]]
 * †Harpagolestes macrocephalus – type locality for species
 * †Harpalodon
 * †Harpalodon sylvestris – or unidentified comparable form
 * †Harrymys
 * †Harrymys irvini
 * †Harrymys woodi
 * †Helaletes – type locality for genus
 * †Helaletes nanus – type locality for species
 * †Heliscomys
 * †Heliscomys hatcheri
 * †Heliscomys mcgrewi
 * †Heliscomys ostranderi
 * †Heliscomys vetus – or unidentified comparable form
 * †Helix
 * †Helix evanstonensis
 * †Helix sinclairi
 * Helodermoides tuberculatus AMNH 11311.jpg †[[Helodermoides]]
 * †Helodermoides tuberculatus
 * †Helohyus
 * †Helohyus lentus
 * †Helohyus milleri – type locality for species
 * †Helohyus plicodon – type locality for species
 * †Hemiacodon
 * †Hemiacodon casamissus – type locality for species
 * †Hemiacodon engardae – type locality for species
 * †Hemiacodon gracilis
 * Fossil maxilla Hemiauchenia Boulle.png relative Hemiauchenia]] †Hemiauchenia
 * †Hemipsalodon
 * †Hemipsalodon grandis
 * Hemitelia
 * †Hemitelia magna
 * †Hemithlaeus
 * †Hemithlaeus harbourae
 * †Hemithlaeus josephi
 * †Hendryomeryx
 * †Hendryomeryx wilsoni
 * †Heptacodon
 * †Heptodon
 * †Heptodon calciculus
 * †Heptodon posticus
 * Herpetotherium.jpg †[[Herpetotherium]]
 * †Herpetotherium innominatum – type locality for species
 * †Herpetotherium knighti
 * †Herpetotherium youngi – or unidentified comparable form
 * †Hesperocyon
 * †Hesperocyon gregarius
 * †Hesperopetes
 * †Hesperopetes thoringtoni – type locality for species
 * †Hesperosorex
 * †Hesperosorex lovei – type locality for species
 * †Heteraletes
 * †Heteraletes leotanus
 * †Hexacodus
 * †Hexacodus pelodes
 * †Hexacodus uintensis
 * †Hicoria
 * †Hicoria antiqua
 * †Hicoria crescentia
 * †Hicoria culveri
 * Hirundo – or unidentified comparable form
 * †Hirundo pyrrhonota
 * †Holospira
 * †Homacodon
 * †Homacodon vagans – type locality for species
 * †Homalota
 * †Homalota recisa – type locality for species
 * †Homogalax
 * †Homogalax protapirinus
 * †Honrovits – type locality for genus
 * †Honrovits tsuwape – type locality for species
 * Hoplophoneus1.jpg †[[Hoplophoneus]]
 * †Hoplophoneus mentalis
 * †Hoplophoneus primaevus
 * †Hovenia
 * †Hovenia oregonensis – or unidentified comparable form
 * †Huerfanodon
 * †Huerfanodon polecatensis – type locality for species
 * †Hummelichelys
 * †Hummelichelys annae – type locality for species
 * †Hummelichelys ellipticus
 * †Hummelichelys grangeri – type locality for species
 * †Hummelichelys guttatus – type locality for species
 * †Hutchemys
 * †Hutchemys rememdium
 * Hyaenodon NT small.jpg †[[Hyaenodon]]
 * †Hyaenodon crucians
 * †Hyaenodon horridus
 * †Hyaenodon megaloides
 * †Hyaenodon montanus
 * †Hyaenodon mustelinus
 * †Hyaenodon venturae
 * †Hyaenodon vetus
 * Hydrangea
 * †Hydrangea antica
 * †Hydrangea GR537 informal
 * Hydrobia – report made of unidentified related form or using admittedly obsolete nomenclature
 * Hydrobius fuscipes.jpg [[Hydrobius]]
 * †Hydrobius confixus – type locality for species
 * †Hydrobius decineratus – type locality for species
 * †Hydrochus
 * †Hydrochus relictus – type locality for species
 * †Hydromystria
 * †Hydromystria expansa
 * †Hylobius
 * †Hylobius packardii – type locality for species
 * †Hylobius provectus – type locality for species
 * Hyopsodus.jpg †[[Hyopsodus]]
 * †Hyopsodus aemulor
 * †Hyopsodus latidens
 * †Hyopsodus lepidus – type locality for species
 * †Hyopsodus loomisi
 * †Hyopsodus lysitensis
 * †Hyopsodus mentalis
 * †Hyopsodus minor
 * †Hyopsodus minusculus – type locality for species
 * †Hyopsodus miticulus
 * †Hyopsodus paulus – type locality for species
 * †Hyopsodus pauxillus – type locality for species
 * †Hyopsodus powellianus
 * †Hyopsodus simplex
 * †Hyopsodus tonksi – type locality for species
 * †Hyopsodus uintensis
 * †Hyopsodus walcottianus
 * †Hyopsodus wortmani
 * †Hypertragulus
 * †Hypertragulus calcaratus
 * †Hypisodus
 * †Hypisodus alacer
 * †Hypisodus minimus
 * Hypohippus.jpg †[[Hypohippus]]
 * †Hypohippus affinis
 * †Hypolagus
 * †Hypolagus parviplicatus – or unidentified comparable form
 * †Hyporhina
 * †Hyporhina tertia
 * †Hypsiops
 * †Hypsiops breviceps
 * †Hyrachyus
 * †Hyrachyus eximius
 * †Hyrachyus modestus – type locality for species
 * Knight Hyracodon cropped.png †[[Hyracodon]]
 * †Hyracodon nebraskensis
 * †Hyracodon petersoni
 * †Hyracodon priscidens
 * †Hyracotherium
 * †Hyracotherium vasacciense

I

 * Icaronycteris index (1).jpg †[[Icaronycteris]] – type locality for genus
 * †Icaronycteris index – type locality for species
 * †Ignacius
 * †Ignacius clarkforkensis – type locality for species
 * †Ignacius fremontensis
 * †Ignacius frugivorus
 * †Ignacius graybullianus
 * †Iguanavus – type locality for genus
 * †Iguanavus exilis – type locality for species
 * †Indusia
 * †Indusia calculosa – type locality for species
 * †Insulapollenites
 * †Insulapollenites leboensis
 * †Insulapollenites rugulatus
 * †Intyrictis
 * †Intyrictis vanvaleni
 * †Iridodon – type locality for genus
 * †Iridodon datzae – type locality for species
 * Ischyromys.jpg†[[Ischyromys]]
 * †Ischyromys typus
 * †Ischyromys veterior
 * †Isectolophus
 * †Isectolophus latidens
 * †Isectolophus radinskyi – type locality for species
 * †Isoetites
 * †Isoetites horridus
 * †Iulus
 * †Iulus telluster – type locality for species

J

 * †Jepsenella
 * †Jepsenella praepropera
 * †Jepsibaena
 * †Jepsibaena minor – type locality for species
 * †Joffrea
 * †Joffrea BB20 informal
 * †Joffrea FW50 informal
 * †Judithemys
 * †Judithemys backmani – or unidentified comparable form
 * †Juglandicarya
 * †Juglandiphyllites
 * †Juglandiphyllites glabra
 * Juglans
 * †Juglans crescentia
 * †Juglans laurifolia
 * †Juglans rugosa
 * †Juglans schimperi
 * Juncitarsus merkeli 1.jpg †[[Juncitarsus]] – type locality for genus
 * †Juncitarsus gracillimus – type locality for species
 * Junco – or unidentified comparable form
 * †Junco hyemalis
 * †Junglandaceae

K

 * †Kalmia
 * †Kalmia elliptica
 * †Kalobatippus
 * †Kalobatippus agatensis
 * †Kalobatippus avus
 * Knightia alta 01.jpg †[[Knightia]]
 * †Knightia eocaena
 * †Knightomys
 * †Knightomys cremneus
 * †Knightomys cuspidatus
 * †Knightomys depressus
 * †Knightomys huerfanensis
 * †Knightomys minor
 * †Knightomys senior
 * Koelreuteria
 * †Koelreuteria viridifluminis
 * †Koniaryctes
 * †Koniaryctes paulus – type locality for species
 * †Kydia – or unidentified related form
 * †Kydia FW61 informal

L

 * †Labidolemur
 * †Labidolemur kayi
 * †Labidolemur major – type locality for species
 * †Labidolemur serus
 * †Labidolemur soricoides
 * Laccobius
 * †Laccobius elongatus – type locality for species
 * †Laevigatosporites
 * Ptarmigan9.jpg †[[Lagopus]]
 * †Lagopus leucurus – or unidentified comparable form
 * †Lambdotherium
 * †Lambdotherium popoagicum
 * †Lambertocyon
 * †Lambertocyon eximius
 * †Lambertocyon gingerichi – type locality for species
 * Lanius
 * †Lanius ludovicianus
 * Larus – or unidentified comparable form
 * †Lastrea
 * †Lastrea goldiana
 * Lathrobium
 * †Lathrobium abscessum – type locality for species
 * †Laurinoxylon
 * †Laurinoxylon pulchellum
 * †Laurophyllum
 * †Laurophyllum caudatum
 * †Laurophyllum perseanum
 * Fanal Madeira 2016 2.jpg [[Laurus]]
 * †Laurus californica
 * †Laurus grandis
 * †Laurus montana
 * †Laurus perdita
 * †Laurus primigenia – tentative report
 * †Laurus princeps
 * †Laurus socialis
 * †Leguminosites
 * †Leguminosites coloradensis
 * †Leguminosites lamarensis
 * †Leguminosites lesquereuxiana
 * †Leguminosites regularis – type locality for species
 * Leiocephalus
 * †Leipsanolestes
 * †Leipsanolestes siegfriedti
 * Longnose gar.png [[Lepisosteus]]
 * †Lepisosteus glaber – or unidentified comparable form
 * †Lepisosteus occidentalis
 * †Leptacodon
 * †Leptacodon donkroni
 * †Leptacodon munusculum
 * †Leptacodon packi – type locality for species
 * †Leptacodon tener
 * †Leptarctus – or unidentified comparable form
 * Leptauchenia by Apokryltaros cropped.png †[[Leptauchenia]]
 * †Leptauchenia decora
 * †Leptauchenia major
 * †Leptictis
 * †Leptictis dakotensis
 * †Leptocyon
 * †Leptocyon gregorii
 * †Leptolambda
 * †Leptolambda schmidti
 * Leptomeryx BW.jpg †[[Leptomeryx]]
 * †Leptomeryx esulcatus
 * †Leptomeryx evansi
 * †Leptomeryx mammifer
 * †Leptomeryx semicinctus
 * †Leptomeryx speciosus
 * †Leptomeryx yoderi – type locality for species
 * †Leptoreodon
 * †Leptotomus
 * †Leptotomus guildayi
 * †Leptotomus parvus – type locality for species
 * †Leptotragulus
 * †Leptotragulus clarki – or unidentified comparable form
 * †Leptotragulus medius
 * †Leptotragulus ultimus
 * Lepus
 * Lepyrus – tentative report
 * †Lepyrus evictus – type locality for species
 * †Lestophis
 * †Lestophis anceps – type locality for species
 * †Lestophis crassus – type locality for species
 * †Leucosticte
 * †Leucosticte arctoa
 * †Limaconyssus – type locality for genus
 * †Limaconyssus habrus – type locality for species
 * †Limalophus
 * †Limalophus compositus
 * †Limalophus contractus – type locality for species
 * Limnocyon ventral.png †[[Limnocyon]]
 * †Limnocyon cuspidens – type locality for species
 * †Limnocyon medius
 * †Limnocyon potens – type locality for species
 * †Limnocyon velox – type locality for species
 * †Limnocyon verus – type locality for species
 * †Limnoecus
 * Limnofregata azygosternon.jpg †[[Limnofregata]] – type locality for genus
 * †Limnofregata azygosternon – type locality for species
 * †Limnofregata hutchisoni – type locality for species
 * Lindera
 * †Lindera obtusata
 * †Lindera varifolia – type locality for species
 * †Lisserpeton
 * †Lisserpeton bairdi
 * †Listronotus
 * †Listronotus muratus – type locality for species
 * †Litaletes
 * †Litaletes disjunctus
 * †Litaletes ondolinde
 * †Lithexorista – type locality for genus
 * †Lithexorista scudderi – type locality for species
 * †Lithohypoderma
 * SR Lithohypoderma ascarides larva 01.jpg †[[Lithohypoderma ascarides]] - type locality for species
 * †Lithophis – type locality for genus
 * †Lithophis sargenti – type locality for species
 * †Lithophysa – type locality for genus
 * †Lithophysa tumulta – type locality for species
 * †Lithopsis – type locality for genus
 * †Lithopsis elongata – type locality for species
 * †Lithopsis fimbriata – type locality for species
 * Lithornis.png †[[Lithornis]]
 * †Lithornis plebius – type locality for species
 * †Lithornis promiscuus – type locality for species
 * †Lithotorus – type locality for genus
 * †Lithotorus cressoni – type locality for species
 * †Litocherus
 * †Litocherus lacunatus – type locality for species
 * †Litocherus notissimus
 * †Litocherus zygeus – type locality for species
 * †Litolagus
 * †Litolagus molidens
 * †Litolestes
 * †Litolestes ignotus – type locality for species
 * †Litomylus
 * †Litomylus dissentaneus – type locality for species
 * †Litomylus ishami – type locality for species
 * †Litomylus scaphicus – type locality for species
 * †Litoyoderimys
 * †Litoyoderimys auogoleus
 * †Lophiotherium
 * †Lophiotherium vasacciensis – type locality for species
 * †Lophiparamys
 * †Lophiparamys debequensis
 * †Lophiparamys murinus
 * †Lophiparamys woodi
 * †Lophocion
 * †Lophocion grangeri – type locality for species
 * †Loveina – type locality for genus
 * †Loveina minuta
 * †Loveina sheai
 * †Loveina wapitiensis
 * †Loveina zephyri – type locality for species
 * †Loxolophus
 * †Loxolophus criswelli
 * †Loxolophus faulkneri – type locality for species
 * †Loxolophus hyattianus – or unidentified comparable form
 * †Loxolophus priscus
 * †Lucashyus – type locality for genus
 * †Lucashyus coombsae – type locality for species
 * †Lyctocoris – tentative report
 * †Lyctocoris terreus – type locality for species
 * Lygodium
 * †Lygodium coloradense
 * †Lygodium kaulfussi
 * Lynx
 * Lynx lynx2.jpg †[[Lynx lynx]] – tentative report
 * †Lystra – tentative report
 * †Lystra leei – type locality for species
 * †Lystra richardsoni – type locality for species

M

 * †Maceopolipollenites
 * †Maceopolipollenites amplus
 * †Maceopolipollenites leboensis
 * †Maceopolipollenites rotundus
 * †Maceopolipollenites tenuipolus
 * †Maceopolipollenites triorbicularis
 * †Macginitiea
 * †Macginitiea gracilis
 * †Macginitiea wyomingensis
 * †Machaeroides
 * †Machaeroides eothen
 * †Machaeroides simpsoni – type locality for species
 * †Machaerosaurus
 * †Machaerosaurus torrejonensis
 * Macrocranion
 * †Macrocranion junnei – type locality for species
 * †Macrocranion nitens
 * †Macrocranion robinsoni
 * †Macrotarsius
 * †Macrotarsius siegerti – type locality for species
 * Sweetbay Magnolia Magnolia virginiana Flower Closeup 2146px.jpg [[Magnolia]]
 * †Magnolia borealis
 * †Magnolia californica
 * †Magnolia culveri
 * †Magnolia magnifica
 * †Magnolia magnifolia
 * †Magnolia microphylla
 * †Magnolia pollardi
 * †Magnolia spectabilis
 * †Maiorana
 * †Maiorana ferrisensis – type locality for species
 * †Maiorana noctiluca
 * †Malapoenna
 * †Malapoenna cuneata
 * †Malapoenna lamarensis
 * †Malaquiferus
 * †Malaquiferus tourteloti – type locality for species
 * †Malfelis – type locality for genus
 * †Malfelis badwaterensis – type locality for species
 * †Mammacyon
 * †Mammacyon ferocior – type locality for species
 * †Mammuthus
 * Columbian mammoth cropped.png †[[Mammuthus columbi]]
 * Marmota
 * †Marsholestes
 * †Marsholestes dasypelix – type locality for species
 * †Mattimys
 * †Mattimys kalicola
 * †Megacerops
 * †Megacerops osborni – type locality for species
 * †Megadelphus
 * †Megadelphus lundeliusi
 * †Megalagus
 * †Megalagus brachyodon
 * †Megalagus primitivus
 * †Megalagus turgidus
 * †Megalesthonyx
 * †Megalesthonyx hopsoni
 * Megalictis (cropped).PNG †[[Megalictis]]
 * †Megalictis ferox
 * †Megalictis petersoni
 * †Melanosaurus – type locality for genus
 * †Melanosaurus maximus – type locality for species
 * †Melastomites
 * †Melastomites montanensis
 * †Meliakrouniomys
 * †Meliakrouniomys skinneri
 * †Meliosma
 * †Meliosma flexuosa
 * †Meliosma longifolia
 * Meniscotherium restoration cropped.jpg †[[Meniscotherium]]
 * †Meniscotherium chamense
 * †Meniscotherium priscum
 * †Meniscotherium tapiacetum
 * †Meniscotherium tapiacitum
 * †Menisperimites
 * †Menisperimites parvareolatus
 * †Menispermites
 * †Menispermites limacioides – type locality for species
 * †Menispermites parvareolatus
 * Menoceras NT small.jpg †[[Menoceras]]
 * †Menoceras arikarense
 * †Menoceras barbouri
 * †Menops
 * †Menops heloceras
 * †Menops marshi – or unidentified comparable form
 * †Mentoclaenodon
 * †Mentoclaenodon acrogenius – type locality for species
 * Mergus
 * †Mergus merganser
 * Merychippus insignis life restoration.jpg †[[Merychippus]]
 * †Merychippus coloradense
 * †Merychippus insignis – or unidentified comparable form
 * †Merychippus primus
 * †Merychyus
 * †Merychyus arenarum
 * †Merychyus crabilli
 * †Merychyus elegans – or unidentified comparable form
 * †Merychyus minimus
 * †Merycobunodon – tentative report
 * †Merycobunodon walshi – type locality for species
 * †Merycochoerus
 * †Merycochoerus chelydra
 * †Merycochoerus magnus
 * †Merycochoerus matthewi
 * Merycodus cf. nectatus - National Museum of Natural History - IMG 2024.JPG †[[Merycodus]]
 * †Merycodus sabulonis – or unidentified comparable form
 * †Merycodus warreni – or unidentified comparable form
 * †Merycoides
 * †Merycoides longiceps
 * †Merycoides pariogonus
 * †Merycoidodon
 * †Merycoidodon culbertsoni – type locality for species
 * †Merycoidodon major
 * †Merycoidodon presidioensis – or unidentified comparable form
 * †Mesatirhinus
 * †Mesatirhinus megarhinus
 * †Mesocyon – report made of unidentified related form or using admittedly obsolete nomenclature
 * †Mesocyon temnodon
 * †Mesodma
 * †Mesodma ambigua – type locality for species
 * †Mesodma formosa
 * †Mesodma garfieldensis – or unidentified comparable form
 * †Mesodma hensleighi
 * †Mesodma pygmaea
 * Mesohippus.jpg †[[Mesohippus]]
 * †Mesohippus bairdi
 * †Mesohippus westoni – or unidentified comparable form
 * †Mesomeryx – or unidentified comparable form
 * †Mesomeryx grangeri
 * †Mesonyx
 * †Mesonyx obtusidens – type locality for species
 * †Mesoreodon
 * †Mesoreodon chelonyx
 * †Mesoreodon minor – type locality for species
 * †Mesoscalops
 * †Mesoscalops scopelotemos
 * Metacheiromys DB152.jpg †[[Metacheiromys]]
 * †Metacheiromys dasypus – type locality for species
 * †Metacheiromys marshi – type locality for species
 * †Metadjidaumo
 * †Metadjidaumo hendryi – type locality for species
 * †Metamynodon
 * †Metamynodon planifrons – or unidentified comparable form
 * †Metanoiamys
 * †Metanoiamys paradoxus
 * †Metarhinus
 * Metasequoia
 * †Metasequoia occidentalis
 * †Metatomarctus
 * †Metatomarctus canavus
 * Miacis cropped.png †[[Miacis]]
 * †Miacis deutschi
 * †Miacis exiguus
 * †Miacis latidens
 * †Miacis medius
 * †Miacis parvivorus – type locality for species
 * †Miacis petilus
 * †Miacis vorax
 * †Michenia
 * Micrasema – tentative report
 * †Micrasema tessellatum – type locality for species
 * †Microclaenodon
 * †Microclaenodon assurgens
 * †Microcosmodon
 * †Microcosmodon conus – type locality for species
 * †Microcosmodon rosei – type locality for species
 * †Micromomys
 * †Micromomys antelucanus
 * †Micromomys silvercouleei – type locality for species
 * †Microparamys
 * †Microparamys cheradius
 * †Microparamys dubius
 * †Microparamys hunterae
 * †Microparamys minutus
 * Microphysula cookei shell.jpg [[Microphysula]] – or unidentified comparable form
 * †Micropternodus
 * †Micropternodus borealis
 * †Microsus
 * †Microsus cuspidatus – type locality for species
 * †Microsyops
 * †Microsyops angustidens – type locality for species
 * †Microsyops annectens
 * †Microsyops cardiorestes
 * †Microsyops elegans – type locality for species
 * †Microsyops knightensis
 * †Microsyops latidens
 * †Microsyops scottianus
 * Microtus
 * Meadvole.jpg †[[Microtus pennsylvanicus]]
 * Mictomys
 * †Mictomys vetus
 * †Mimatuta
 * †Mimatuta makpialutae
 * †Mimatuta minuial – type locality for species
 * †Mimetodon
 * †Mimetodon churchilli – type locality for species
 * †Mimetodon silberlingi
 * †Mimoperadectes
 * †Mimoperadectes houdei – type locality for species
 * †Mimoperadectes labrus – type locality for species
 * †Mimosites
 * †Mimosites coloradensis
 * †Mimotricentes
 * †Mimotricentes fremontensis – type locality for species
 * Miniochoerus.jpg †[[Miniochoerus]]
 * †Miniochoerus affinis – type locality for species
 * †Miniochoerus chadronensis – type locality for species
 * †Miniochoerus forsythae
 * †Miniochoerus gracilis
 * †Minippus
 * †Minippus index
 * †Mioclaenus
 * †Mioclaenus opisthacus – or unidentified comparable form
 * †Mioclaenus turgidus
 * †Miocyon
 * †Miocyon major – or unidentified comparable form
 * †Mioheteromys
 * †Mioheteromys amplissimus
 * †Miohippus
 * †Miohippus obliquidens
 * †Miolabis
 * †Miolabis fissidens
 * †Miomustela
 * Mioplossus Labracoides.jpg †[[Mioplosus]]
 * †Miospermophilus
 * †Miospermophilus wyomingensis
 * †Miotapirus
 * †Miotapirus harrisonensis – type locality for species
 * †Miotylopus
 * †Miotylopus gibbi
 * †Miotylopus leonardi
 * †Miotylopus taylori – type locality for species
 * Miracinonyx inexpectatus.jpg †[[Miracinonyx]]
 * †Miracinonyx studeri
 * †Mithrandir
 * †Mithrandir gillianus
 * †Mitostylus
 * †Mitostylus seculorum – type locality for species
 * †Mixodectes
 * †Mixodectes malaris
 * Mnemosyne
 * †Mnemosyne terrentula – type locality for species
 * †Mojavemys
 * †Mojavemys magnumarcus
 * †Monosaulax
 * †Monosaulax curtus – or unidentified comparable form
 * †Moropus
 * †Moropus hollandi
 * Morus
 * †Morus montanensis
 * †Musophyllum
 * †Musophyllum complicatum
 * Mustela
 * †Mustela americana
 * †Mustela nigripes
 * Mycetobia – tentative report
 * †Mycetobia terricola – type locality for species
 * †Mylanodon – type locality for genus
 * †Mylanodon rosei – type locality for species
 * Myrica faya fruit.jpg [[Myrica]]
 * †Myrica lamarensis
 * †Myrica scottii
 * †Myrica wardii
 * †Myrmecoboides
 * †Myrmecoboides montanensis
 * Myrmica
 * †Myrtophyllum
 * †Myrtophyllum torreyi
 * †Mysops
 * †Mysops fraternus
 * †Mysops minimus – type locality for species
 * †Mysops parvus – type locality for species
 * †Mytonolagus
 * †Mytonolagus petersoni
 * †Mytonolagus wyomingensis – type locality for species
 * †Mytonomys
 * †Mytonomys coloradensis
 * †Mytonomys wortmani

N

 * †Namatomys
 * †Namatomys erythrus – type locality for species
 * †Namatomys lloydi
 * †Nannodectes
 * †Nannodectes gazini – type locality for species
 * †Nannodectes gidleyi
 * †Nannodectes intermedius – type locality for species
 * †Nannodectes simpsoni – type locality for species
 * †Nanodelphys
 * †Nanodelphys hunti
 * †Nanomomys
 * †Nanomomys thermophilus
 * †Nanotragulus
 * †Nanotragulus loomisi – type locality for species
 * †Nanotragulus ordinatus
 * †Naocephalus – type locality for genus
 * †Naocephalus porrectus – type locality for species
 * †Navajovius
 * †Navajovius kohlhaasae
 * †Neanis
 * †Neanis schucherti
 * †Necrocydnus
 * †Necrocydnus gosiutensis – type locality for species
 * †Necygonus – type locality for genus
 * †Necygonus rotundatus – type locality for species
 * †Nelumbago
 * †Nelumbago montanum
 * Nelumno nucifera open flower - botanic garden adelaide2.jpg †[[Nelumbo]]
 * †Neocathartes
 * †Neocathartes grallator
 * †Neodiacodexis
 * †Neodiacodexis emryi
 * †Neoliotomus
 * †Neoliotomus conventus
 * †Neoliotomus ultimus
 * Neophrontops americanus fossil cropped.jpg [[Neophrontops]]
 * †Neophrontops americana
 * †Neophrontops americanus
 * †Neoplagiaulax
 * †Neoplagiaulax grangeri – tentative report
 * †Neoplagiaulax hunteri
 * †Neoplagiaulax jepi – type locality for species
 * †Neoplagiaulax mckennai – type locality for species
 * †Neoplagiaulax nelsoni
 * †Neothanes
 * †Neothanes testeus – type locality for species
 * Neotoma
 * †Neovulpavus
 * †Neovulpavus washakius
 * †Nexuotapirus
 * †Nexuotapirus marslandensis
 * †Niglarodon
 * †Niptomomys
 * †Niptomomys doreenae
 * †Niptomomys favorum – type locality for species
 * †Niptomomys thelmae
 * †Nonomys
 * †Nonomys simplicidens
 * †Nordenskioldia
 * †Nordenskioldia borealis
 * †Nosodendron
 * †Nosodendron tritavum – type locality for species
 * †Notharctus
 * †Notharctus robinsoni – type locality for species
 * †Notharctus robustior
 * Notharctus tenebrosus paris.JPG †[[Notharctus tenebrosus]] – type locality for species
 * †Notharctus venticolus
 * †Notogoneus
 * †Notomorpha – type locality for genus
 * †Notomorpha garmanii – type locality for species
 * †Notomorpha gravis – type locality for species
 * †Notomorpha testudinea – type locality for species
 * †Notoparamys – tentative report
 * †Notoparamys blochi – type locality for species
 * †Nototamias – or unidentified comparable form
 * †Nucifraga
 * †Nucifraga columbiana
 * Numenius
 * †Numenius americanus
 * Numenius borealis ULaval 1.jpg †[[Numenius borealis]]
 * †Nyctea
 * †Nyctea scandiaca
 * †Nyctitherium
 * †Nyctitherium christopheri
 * †Nyctitherium gunnelli – type locality for species
 * †Nyctitherium serotinum – type locality for species
 * †Nyctitherium velox
 * †Nyssa
 * †Nyssa alata
 * †Nyssa borealis

O

 * Ochotona
 * Ochotona princeps rockies.JPG †[[Ochotona princeps]]
 * Ocotea
 * †Ocotea coloradensis
 * †Ocotea FW03 informal
 * †Odaxosaurus
 * †Odaxosaurus jepseni – or unidentified comparable form
 * †Odaxosaurus piger
 * †Ogmophis
 * †Ogmophis microcompactus – or unidentified comparable form
 * †Ogmophis voorhiesi
 * †Oligodontosaurus – type locality for genus
 * †Oligodontosaurus wyomingensis – type locality for species
 * †Oligoryctes
 * †Oligoryctes altitalonidus
 * †Oligoryctes cameronensis
 * †Oligoscalops – tentative report
 * †Oligospermophilus
 * †Oligotheriomys
 * †Oligotheriomys senrudi
 * †Oliveremys
 * †Oliveremys uintaensis – type locality for species
 * †Omalodiscus
 * †Omomys
 * †Omomys carteri
 * †Omomys lloydi
 * Ondatra
 * †Ondatra meadensis
 * †Onoclea
 * †Onoclea hesperia
 * Onychonycteris NT small.jpg †[[Onychonycteris]] – type locality for genus
 * †Onychonycteris finneyi – type locality for species
 * †Oodectes
 * †Oodectes herpestoides – type locality for species
 * †Oodectes jepseni
 * Ophryastes
 * †Ophryastes compactus – type locality for species
 * †Opisthotriton
 * †Opisthotriton kayi
 * Mountain Goat USFWS.jpg [[Oreamnos]]
 * †Oreoconus
 * †Oreodontoides
 * †Oreodontoides oregonensis
 * Oreohelix
 * †Oreohelix megarche
 * †Oreolagus
 * †Oreolagus colteri
 * †Oreolagus nebrascensis
 * †Oreopanax
 * †Oreopanax elongatum
 * †Ormiscus
 * †Ormiscus partitus – type locality for species
 * Orohippus pumilus - AMNH - DSC06339.JPG †[[Orohippus]]
 * †Orohippus major – type locality for species
 * †Orohippus proteros
 * †Orohippus pumilus – type locality for species
 * †Orohippus sylvaticus
 * †Orthogenysuchus – type locality for genus
 * †Orthogenysuchus olseni – type locality for species
 * †Osbornodon
 * †Osbornodon brachypus – type locality for species
 * †Osmanthus
 * †Osmanthus praemissa
 * OsmundaRegalis.jpg †[[Osmunda]]
 * †Osmunda affinis
 * †Osmundacidites
 * †Otarocyon
 * †Otarocyon cooki
 * †Otiorhynchites
 * †Otiorhynchites fossilis – type locality for species
 * †Otiorhynchites tysoni
 * †Otiorhynchus
 * †Otiorhynchus dubius – type locality for species
 * †Otiorhynchus perditus – type locality for species
 * †Ototriton – type locality for genus
 * †Ototriton solidus – type locality for species
 * †Ourayia
 * †Ourayia hopsoni
 * †Ourayia uintensis
 * Ovis
 * New Mexico Bighorn Sheep.JPG †[[Ovis canadensis]]
 * †Oxyacodon
 * †Oxyacodon agapetillus
 * †Oxyacodon apiculatus
 * †Oxyacodon priscilla
 * †Oxyaena
 * †Oxyaena forcipata
 * †Oxyaena gulo
 * †Oxyaena intermedia
 * †Oxyaena lupina
 * †Oxyclaenus
 * †Oxyclaenus cuspidatus
 * Oxydactylus longipes.jpg †[[Oxydactylus]]
 * †Oxydactylus longipes – or unidentified comparable form
 * †Oxydactylus lulli – type locality for species
 * †Oxydactylus wyomingensis
 * †Oxyprimus
 * †Oxyprimus galadrielae – type locality for species
 * †Oxyprimus putorius

P

 * Pachyaena gigantea cropped.jpg †[[Pachyaena]]
 * †Pachyaena gigantea
 * †Pachyaena gracilis
 * †Pachyaena ossifraga
 * Pachycondyla
 * †Pachycondyla labandeirai – type locality for species
 * †Pachylobius
 * †Pachylobius compressus
 * †Palaeanodon
 * †Palaeanodon ignavus
 * †Palaeanodon Ignavus
 * †Palaeanodon nievelti
 * †Palaeanodon parvulus – tentative report
 * †Palaearctonyx
 * †Palaearctonyx meadi – type locality for species
 * †Palaechthon
 * †Palaechthon alticuspis – or unidentified comparable form
 * †Palaechthon woodi
 * †Palaeictops
 * †Palaeictops bicuspis
 * †Palaeictops bridgeri
 * †Palaeictops multicuspis
 * †Palaeocarpinus
 * †Palaeocarpinus aspinosa
 * †Palaeocarya
 * †Palaeocarya clarnensis
 * †Palaeogale
 * †Palaeogale sanguinarius
 * †Palaeogale sectoria
 * Palaeolagus NT small.jpg relative Palaeolagus]] †Palaeolagus
 * †Palaeolagus burkei
 * †Palaeolagus haydeni
 * †Palaeolagus hypsodus – type locality for species
 * †Palaeolagus intermedius
 * †Palaeolagus philoi
 * †Palaeolagus primus – type locality for species
 * †Palaeolagus temnodon
 * †Palaeonictis
 * †Palaeonictis occidentalis
 * †Palaeonictis peloria – type locality for species
 * †Palaeonictis wingi – type locality for species
 * †Palaeophasianus – type locality for genus
 * †Palaeophasianus meleagroides – type locality for species
 * †Palaeorallus – type locality for genus
 * †Palaeorallus troxelli – type locality for species
 * †Palaeoryctes
 * †Palaeoryctes cruoris – type locality for species
 * †Palaeoryctes puercensis
 * †Palaeoryctes punctatus
 * †Palaeosinomenium – or unidentified comparable form
 * †Palaeosinomenium venablesii
 * †Palaeosinopa
 * †Palaeosinopa didelphoides
 * †Palaeosinopa dorri – type locality for species
 * †Palaeosinopa incerta – type locality for species
 * †Palaeosinopa lacus – type locality for species
 * †Palaeosinopa lutreola
 * †Palaeosinopa veterrima
 * Palaeosyops leidyi.JPG †[[Palaeosyops]]
 * †Palaeosyops fontinalis
 * †Palaeosyops paludosus – type locality for species
 * †Palaeosyops robustus – type locality for species
 * †Palaeotheca
 * †Palaeotheca terrestris – type locality for species
 * †Palaeoxantusia – type locality for genus
 * †Palaeoxantusia amara – type locality for species
 * †Palaeoxantusia fera – type locality for species
 * †Palatobaena – type locality for genus
 * †Palatobaena bairdi – type locality for species
 * †Palatobaena gaffneyi – type locality for species
 * †Palecphora
 * †Palecphora patefacta – type locality for species
 * †Palenochtha
 * †Palenochtha minor
 * †Palenochtha weissae – type locality for species
 * †Paleoamphiuma – type locality for genus
 * †Paleoamphiuma tetradactylum – type locality for species
 * †Paleomyrtinaea
 * †Paleomyrtinaea FW66 informal
 * †Paleonelumbo
 * †Paleonelumbo macroloba
 * †Paleonuphar
 * †Paleonuphar hesperium
 * †Paleotomus
 * †Paleotomus carbonensis – type locality for species
 * †Paleotomus milleri – type locality for species
 * †Paleotomus radagasti
 * †Palepidophyma – type locality for genus
 * †Palepidophyma lilliputiana – type locality for species
 * †Palepidophyma paradisa – type locality for species
 * Paliurus
 * †Paliurus colombi
 * †Palmocarpon
 * †Palmocarpon subcylindricum
 * †Pandaniidites
 * †Pandaniidites radicus
 * Panthera
 * Lion (Panthera leo) (30941994012) cropped.jpg †[[Panthera leo]]
 * †Pantolambda
 * †Pantolambda cavirictus
 * †Pantolambda intermedius – or unidentified comparable form
 * †Pantolestes
 * †Pantolestes longieundus – type locality for species
 * †Pantolestes natans – or unidentified comparable form
 * †Paracathartes
 * †Paracathartes howardae
 * †Paracosoryx
 * †Paracosoryx wilsoni
 * †Paracynarctus
 * †Paracynarctus kelloggi
 * †Paradjidaumo
 * †Paradjidaumo hypsodus
 * †Paradjidaumo trilophus
 * †Paraenhydrocyon
 * †Paraenhydrocyon josephi
 * †Paraenhydrocyon robustus
 * †Paraenhydrocyon wallovianus
 * †Paraepicrates
 * †Paraepicrates brevispondylus – type locality for species
 * †Paraglyptosaurus
 * †Paraglyptosaurus princeps – type locality for species
 * †Parahippus
 * †Parahippus pawniensis
 * †Parahippus pristinus – tentative report
 * †Parahippus wyomingensis – type locality for species
 * †Paralatindia
 * †Paralatindia saussurei – type locality for species
 * †Paramerychyus
 * †Paramerychyus harrisonensis
 * †Paramerychyus relictus
 * †Paramys
 * †Paramys adamus – type locality for species
 * †Paramys compressidens
 * †Paramys copei
 * †Paramys delicatior
 * †Paramys delicatus
 * †Paramys excavatus
 * †Paramys leptodus
 * †Paramys pycnus
 * †Paramys relictus
 * †Paramys taurus
 * †Parandrita
 * †Parandrita vestita – type locality for species
 * †Paranolis – type locality for genus
 * †Paranolis delicatus – type locality for species
 * †Paranymphaea
 * †Paranymphaea crassifolia
 * †Paranymphea
 * †Paranymphea crassifolia
 * †Parapliosaccomys
 * †Parapliosaccomys transversus
 * †Paraprionosaurus – type locality for genus
 * †Paraprionosaurus wyomingensis – type locality for species
 * †Parapternodus
 * †Parapternodus antiquus – type locality for species
 * †Pararyctes
 * †Pararyctes pattersoni – type locality for species
 * †Parasauromalus – type locality for genus
 * †Parasauromalus olseni – type locality for species
 * †Paraternstroemia
 * †Paraternstroemia hyphovenosa
 * †Paratomarctus
 * †Paratomarctus temerarius
 * Kimberly Mural - Roger Witter cropped.png †[[Paratylopus]]
 * †Paratylopus labiatus
 * †Paratylopus primaevus
 * †Parectypodus
 * †Parectypodus clemensi
 * †Parectypodus lunatus
 * †Parectypodus sinclairi
 * †Parectypodus sylviae
 * †Pareumys
 * †Pareumys grangeri
 * †Parictis
 * †Parictis dakotensis
 * †Parictis gilpini
 * †Parictis parvus
 * †Parictis personi
 * †Paromomys
 * †Paromomys depressidens
 * †Paromomys maturus
 * †Parophisaurus
 * †Parophisaurus pawneensis
 * †Parvericius
 * †Parvericius montanus
 * †Parvileguminophyllum
 * †Parvileguminophyllum coloradensis
 * †Parvitragulus
 * †Parvitragulus priscus
 * Knight Patriofelis.jpg †[[Patriofelis]]
 * †Patriofelis ferox – type locality for species
 * †Patriofelis ulta
 * †Patriomanis
 * †Patriomanis americanus
 * †Pauromys
 * †Pauromys schaubi – type locality for species
 * †Peltosaurus
 * †Pelycodus
 * †Pelycomys
 * †Pelycomys placidus
 * †Penetrigonias
 * †Penetrigonias dakotensis
 * †Penosphyllum
 * †Penosphyllum cordatum
 * †Pentacemylus – tentative report
 * †Pentacodon
 * †Pentacosmodon
 * †Pentacosmodon pronus – type locality for species
 * †Peradectes
 * †Peradectes californicus
 * †Peradectes chesteri
 * †Peradectes elegans – type locality for species
 * †Peradectes protinnaminatus
 * †Peradectes protinnominatus
 * Peratherium cropped.png †[[Peratherium]]
 * †Peratherium comstocki
 * †Peratherium edwardi
 * †Peratherium marsupium
 * †Perchoerus
 * †Perchoerus minor
 * †Periptychus
 * †Periptychus carinidens
 * †Periptychus coarctatus
 * Perognathus
 * †Perognathus furlongi
 * DiGangi-Deermouse.jpg [[Peromyscus]]
 * Persea
 * †Persea brossiana
 * †Persea coriacea – type locality for species
 * †Persea pseudocarolinensis
 * †Perseoxylon
 * †Perseoxylon aromaticum
 * †Persites
 * †Persites argutus
 * †Petauristodon
 * †Phalaenoptilus
 * †Phalaenoptilus nuttallii
 * †Phareodus
 * †Phareodus encaustus
 * †Phareodus testis
 * †Phenacocoelus
 * †Phenacocoelus typus
 * †Phenacodaptes
 * †Phenacodaptes sabulosus – type locality for species
 * †Phenacodontid
 * Knight Phenacodus.jpg †[[Phenacodus]]
 * †Phenacodus bisonensis – type locality for species
 * †Phenacodus grangeri
 * †Phenacodus intermedius
 * †Phenacodus magnus
 * †Phenacodus matthewi
 * †Phenacodus trilobatus
 * †Phenacodus vortmani
 * †Phenacolemur
 * †Phenacolemur fortior – type locality for species
 * †Phenacolemur mcgrewi – type locality for species
 * †Phenacolemur praecox
 * †Phenacolemur shifrae
 * †Phenacolemur simonsi
 * Phenacomys
 * †Phenacomys longicaudus
 * †Phenolia
 * †Phenolia incapax – type locality for species
 * Philhydrus
 * †Philodendron – or unidentified related form
 * †Philodendron RR61 informal
 * †Philotrox
 * †Philotrox condoni
 * Phlaocyon.png †[[Phlaocyon]]
 * †Phlaocyon annectens
 * †Phlaocyon leucosteus
 * †Phlaocyon minor
 * †Phlaocyon multicuspus
 * †Phoebe
 * Phragmites – tentative report
 * †Phragmites latissima
 * †Phyllites
 * †Phyllites crassifolia
 * †Phyllites demoresi
 * Phyllobius copulation.jpg [[Phyllobius]]
 * †Phyllobius avus
 * Physa
 * Phytocrene
 * †Phytocrene sordida
 * Pica
 * †Pica pica
 * †Piceoerpeton – type locality for genus
 * †Piceoerpeton willwoodense – type locality for species
 * †Picrodus
 * †Picrodus calgariensis
 * †Picrodus canpacius
 * †Picrodus silberlingi
 * †Picromomys
 * †Picromomys petersonorum – type locality for species
 * Pinus densiflora Kumgangsan.jpg [[Pinus]]
 * †Pinus balli
 * †Pinus florissanti
 * †Pinus GR542 informal
 * †Pinus gracilistrobus
 * †Pinus iddingsi
 * †Pinus Lesquereux
 * †Pinus macrolepis
 * †Pinus premurrayana
 * †Pinus wardii
 * †Pipestoneomys
 * †Pipestoneomys bisulcatus – or unidentified comparable form
 * Pipilo
 * Green-tailed Towhee.jpg †[[Pipilo chlorurus]]
 * †Plagioctenodon
 * †Plagioctenodon krausae
 * †Plagioctenodon rosei
 * †Plagioctenodon savagei
 * †Plagioctenodon thewisseni – type locality for species
 * †Plagioctenoides
 * †Plagioctenoides microlestes
 * †Plagioctenoides tombowni
 * †Plagiomene
 * †Plagiomene accola
 * †Plagiomene multicuspis
 * †Planatus
 * †Planatus raynoldsi
 * NAS-130y Planera aquatica.png †[[Planera]]
 * †Planera longifolia
 * †Planetetherium
 * †Planetetherium mirabile
 * †Planetochelys
 * †Planetochelys dithyros
 * †Planorbina
 * †Planorbina pseudoammonius
 * †Plastomenoides
 * †Plastomenoides lamberti
 * †Plastomenus
 * †Plastomenus molopinus
 * †Plastomenus oedemius – type locality for species
 * †Plastomenus tantillus – type locality for species
 * †Plastomenus thomasi
 * †Plastomenus visendus – type locality for species
 * †Plataninium
 * †Plataninium haydeni
 * †Platanophyllum
 * †Platanophyllum whitneyi
 * Plataan bladeren.jpg [[Platanus]]
 * †Platanus brownii
 * †Platanus GR552 informal
 * †Platanus gracilis
 * †Platanus guillelmae
 * †Platanus montana
 * †Platanus raynoldsi
 * †Platanus raynoldsii
 * †Platanus wyomingensis
 * Platycarya
 * †Platycarya americana
 * †Platycarya BB09 informal
 * †Platycarya castaneopis
 * †Platycarya castaneopsis
 * Platynus
 * †Platynus caesus – type locality for species
 * †Platynus senex – type locality for species
 * Plecia
 * †Plecia dejecta – type locality for species
 * †Plecia pealei – type locality for species
 * Plesiadapis NT.jpg †[[Plesiadapis]]
 * †Plesiadapis anceps – type locality for species
 * †Plesiadapis churchilli
 * †Plesiadapis cookei
 * †Plesiadapis dubius
 * †Plesiadapis fodinatus – type locality for species
 * †Plesiadapis gingerichi
 * †Plesiadapis praecursor
 * †Plesiadapis rex
 * †Plesiadapis simonsi – type locality for species
 * †Plesiolestes
 * †Plesiolestes problematicus – type locality for species
 * †Pliophenacomys
 * †Pliophenacomys meadensis
 * †Pliophenacomys primaevus
 * †Poabromylus
 * †Poabromylus golzi
 * †Poebrodon
 * Poebrotherium.jpg †[[Poebrotherium]]
 * †Poebrotherium eximium
 * †Poebrotherium wilsoni
 * †Poliomyia – type locality for genus
 * †Poliomyia recta – type locality for species
 * †Pollyosbornia
 * †Pollyosbornia altidens – or unidentified comparable form
 * Polygyra
 * †Pontifactor
 * †Pontifactor bestiola – type locality for species
 * Four Poplars in four seasons.JPG [[Populus]]
 * †Populus balsamoides
 * †Populus cinnamomoides
 * †Populus daphnogenoides
 * †Populus FW60 informal
 * †Populus glandulifera
 * †Populus meigsii
 * †Populus nebraskana
 * †Populus speciosa
 * †Populus vivaria
 * †Populus wilmattae
 * †Populus wyomingiana
 * †Populus xantholithensis
 * Porzana
 * †Porzana carolina
 * †Potamogeton
 * †Premnoides
 * †Premnoides douglassi
 * Presbyornis Enhancement.jpg †[[Presbyornis]]
 * †Primobucco
 * †Primobucco kistneri
 * †Primobucco mcgrewi
 * †Princetonia
 * †Princetonia yalensis
 * †Priscacara
 * †Priscachara
 * †Pristichampsus
 * †Probathyopsis
 * †Probathyopsis harrisorum
 * †Probathyopsis lysitensis
 * †Probathyopsis praecursor
 * †Problastomeryx
 * †Problastomeryx primus – type locality for species
 * †Procaimanoidea
 * †Procaimanoidea kayi – type locality for species
 * †Procamelus
 * †Procamelus grandis
 * †Procerberus
 * †Procerberus formicarum – or unidentified comparable form
 * †Procerberus grandis – or unidentified comparable form
 * †Prochetodon
 * †Prochetodon cavus – type locality for species
 * †Prochetodon foxi
 * †Prochetodon taxus – type locality for species
 * †Procydnus – tentative report
 * †Procydnus mamillanus – type locality for species
 * †Procynodictis
 * †Procynodictis vulpiceps
 * †Prodiacodon
 * †Prodiacodon concordiarcensis – type locality for species
 * †Prodiacodon furor – or unidentified comparable form
 * †Prodiacodon puercensis – or unidentified comparable form
 * †Prodiacodon tauricinerei
 * †Proharrymys
 * †Proharrymys schlaikjeri
 * †Prolimnocyon
 * †Prolimnocyon antiguus
 * †Prolimnocyon antiquus
 * †Prolimnocyon atavus
 * †Prolimnocyon eerius
 * †Prolimnocyon haematus – type locality for species
 * †Promartes
 * †Promartes lepidus
 * †Promartes olcotti
 * †Promartes vantasselensis
 * Promerycochoerus cropped.png-like oreodont Promerycochoerus both onshore and in the water. Robert Bruce Horsfall (1913).]] †Promerycochoerus
 * †Promerycochoerus carrikeri
 * †Promerycochoerus superbus
 * †Promioclaenus
 * †Promioclaenus acolytus
 * †Promioclaenus pipiringosi – type locality for species
 * †Pronemobius
 * †Pronemobius induratus – type locality for species
 * †Pronemobius tertiarius – type locality for species
 * †Pronothodectes
 * †Pronothodectes jepi – type locality for species
 * †Propalaeanodon – type locality for genus
 * †Propalaeanodon schaffi – type locality for species
 * †Proscalops
 * †Proscalops miocaenus
 * †Proscalops secundus – or unidentified comparable form
 * †Prosciurus
 * †Prosciurus vetustus
 * †Protadjidaumo – tentative report
 * †Protadjidaumo typus
 * †Protagras – type locality for genus
 * †Protagras lacustris – type locality for species
 * †Protamphipteryx – type locality for genus
 * †Protamphipteryx basalis – type locality for species
 * †Prothryptacodon
 * †Prothryptacodon furens
 * †Prothryptacodon hilli – type locality for species
 * †Protictis
 * †Protictis agastor – type locality for species
 * †Protictis aprophatos
 * †Protictis haydenianus
 * †Protictis microlestes
 * †Protictis paralus
 * †Protoboysia
 * †Protoboysia complicata
 * Knight Protoceras.jpg †[[Protoceras]]
 * †Protoceras neatodelpha – type locality for species
 * †Protochelydra
 * †Protochelydra zangerli – or unidentified comparable form
 * †Protochriacus
 * †Protochriacus simplex – or unidentified comparable form
 * †Protohippus
 * †Protohippus perditus – or unidentified comparable form
 * †Protolabis
 * †Protolabis heterodontus – or unidentified comparable form
 * †Protomarctus
 * †Protomarctus optatus
 * †Protopsalis
 * †Protoptychus
 * †Protoptychus hatcheri
 * †Protoreodon
 * †Protoreodon parvus – or unidentified comparable form
 * †Protoreodon petersoni – or unidentified comparable form
 * †Protoreodon pumilus
 * F John Series 2 Protorohippus card 5 cropped.jpg †[[Protorohippus]]
 * †Protorohippus montanum
 * †Protorohippus venticolum
 * †Protoselene – tentative report
 * †Protoselene novissimus – type locality for species
 * †Protospermophilus
 * †Protospermophilus kelloggi
 * †Protostrix
 * †Protostrix leptosteus
 * †Protostrix saurodosis – type locality for species
 * †Prototomus
 * †Prototomus deimos – type locality for species
 * †Prototomus martis – type locality for species
 * †Prototomus phobos
 * †Prototomus robustus
 * †Prototomus secundarius
 * †Protungulatum
 * †Protungulatum donnae
 * †Protungulatum gorgun
 * †Protungulatum sloani
 * Protylopus petersoni skull.jpg †[[Protylopus]]
 * †Protylopus petersoni
 * †Provaranosaurus – type locality for genus
 * †Provaranosaurus acutus – type locality for species
 * †Provaranosaurus fatuus – type locality for species
 * †Proviverroides
 * †Proviverroides piercei
 * †Proxestops
 * †Proxestops silberlingii – type locality for species
 * Prunus
 * †Prunus corrugis
 * †Prunus stewarti
 * Pseudaelurus cropped.png †[[Pseudaelurus]]
 * †Pseudaelurus intrepidus
 * †Pseudhipparion
 * †Pseudhipparion retrusum
 * †Pseudoblastomeryx
 * †Pseudoblastomeryx advena
 * †Pseudocemophora
 * †Pseudocemophora antiqua – or unidentified comparable form
 * †Pseudocrypturus – type locality for genus
 * †Pseudocrypturus cercanaxius – type locality for species
 * †Pseudocylindrodon
 * †Pseudocylindrodon medius
 * †Pseudocylindrodon tobeyi
 * †Pseudodesmatochoerus – type locality for genus
 * †Pseudodesmatochoerus hoffmani – type locality for species
 * †Pseudolabis
 * †Pseudolabis dakotensis
 * †Pseudopalaeocastor
 * †Pseudopalaeocastor osmagnus
 * Pseudoprotoceras fossil.jpg †[[Pseudoprotoceras]]
 * †Pseudoprotoceras longinaris
 * †Pseudoprotoceras minor – type locality for species
 * †Pseudoprotoceras taylori
 * †Pseudotetonius
 * †Pseudotetonius ambiguus
 * †Pseudotheridomys
 * †Pseudotheridomys pagei – or unidentified comparable form
 * †Pseudotomus
 * †Pseudotomus hians – type locality for species
 * †Pseudotomus horribilis – type locality for species
 * †Pseudotomus robustus – type locality for species
 * †Psilosemys – type locality for genus
 * †Psilosemys wyomingensis – type locality for species
 * †Psilota
 * †Psilota tabidosa – type locality for species
 * Psittacotherium multifragumDB24.jpg]] †Psittacotherium''
 * †Psittacotherium multifragum
 * Ptelea
 * †Ptelea cassioides
 * Pteris – or unidentified related form
 * †Pteris silvicola
 * Pterocarya
 * †Pterocarya glabra
 * †Pterocarya hispida
 * †Pterocarya macginitii
 * †Pteromogoplistes
 * †Pteromogoplistes smithii – type locality for species
 * †Pterospermites
 * †Pterospermites haguei
 * Ptilodus skull BW cropped.jpg †[[Ptilodus]]
 * †Ptilodus fractus
 * †Ptilodus gnomus
 * †Ptilodus kummae
 * †Ptilodus mediaevus
 * †Ptilodus montanus – or unidentified comparable form
 * †Ptilodus tsosiensis – or unidentified comparable form
 * †Ptilodus wyomingensis – type locality for species
 * †Pulverflumen
 * †Pulverflumen magnificum – type locality for species
 * Puma
 * †Puma concolor
 * Pupilla – or unidentified comparable form
 * †Pyramidula
 * †Pyramidula ralstonensis
 * †Pyrocyon
 * †Pyrocyon dioctetus

Q

 * †Quadratomus
 * †Quadratomus grandis
 * †Quadratomus grossus
 * †Quadratomus sundelli
 * †Quercinium
 * †Quercinium knowltoni
 * †Quercinium lamarense
 * Eiche bei Schönderling, 2.jpg [[Quercus]]
 * †Quercus consimilis – tentative report
 * †Quercus culveri
 * †Quercus cuneatus – type locality for species
 * †Quercus drymeja
 * †Quercus furcinervis
 * †Quercus GR522 informal
 * †Quercus GR575 informal
 * †Quercus greenlandica
 * †Quercus grosidentata
 * †Quercus hesperia
 * †Quercus magnifolia
 * †Quercus olafseni
 * †Quercus petros – type locality for species
 * †Quercus sullyi
 * †Quercus weedii
 * †Quercus yanceyi
 * †Quereuxia
 * †Quereuxia angulata
 * GrackleInFlight.jpg [[Quiscalus]] – or unidentified comparable form

R

 * Merycodus osborni cropped.png †[[Ramoceros]]
 * †Rapamys
 * †Rapamys wilsoni
 * †Raphictis
 * †Raphictis gausion – type locality for species
 * †Reithroparamyine
 * †Reithroparamys
 * †Reithroparamys delicatissimus – type locality for species
 * †Reithroparamys huerfanensis
 * †Restes – type locality for genus
 * †Restes rugosus – type locality for species
 * †Reticuloidosporites
 * †Reticuloidosporites pseudomurii
 * †Rhamnacinium
 * †Rhamnacinium radiatum
 * †Rhamnus
 * †Rhamnus cleburni
 * †Rhamnus hirsuta
 * †Rhamnus rectinervis
 * Rhineura – type locality for genus
 * †Rhineura hatcherii – type locality for species
 * Rhinoclemmys – report made of unidentified related form or using admittedly obsolete nomenclature
 * †Rhinoclemmys terrestris
 * Rhus
 * †Rhus mixta – tentative report
 * [[file:Rhus nigricans (fossil leaf) (Green River Formation, Eocene; Utah, USA) 1 (43464239600).jpg|thumb|right|upright|A Rhus nigricans leaf]] †[[Rhus nigricans]]
 * †Rhyssa
 * †Rhyssa juvenis – type locality for species
 * Robina9146.JPG †[[Robinia]]
 * †Robinia wardi
 * Rosa
 * †Rosa hilliae
 * †Rymosia
 * †Rymosia strangulata – type locality for species

S

 * SabalPalm.jpg [[Sabal]]
 * †Sabal grayana
 * †Sabal powelli
 * †Sabalitesamesoneuron
 * †Sabalitesamesoneuron RR34 informal
 * †Saccoloma
 * †Saccoloma gardneri
 * †Sackenia
 * †Sackenia gibbosa – type locality for species
 * †Salilx
 * †Salilx longiacuminata
 * Salix alba Morton.jpg [[Salix]]
 * †Salix angusta
 * †Salix aquilina
 * †Salix cockerelli
 * †Salix elongata – tentative report
 * †Salix lavateri
 * †Salix varians
 * †Salpinctes – or unidentified comparable form
 * †Salpinctes obsoletus
 * †Salvinia
 * †Salvinia preauriculata
 * †Sanctimus
 * †Sanctimus simonisi – type locality for species
 * †Sanctimus stouti – type locality for species
 * †Sanctimus stuartae
 * Saniwa ensidens.jpg †[[Saniwa]] – type locality for genus
 * †Saniwa ensidens – type locality for species
 * †Saniwa major – type locality for species
 * †Saniwa stenodon
 * †Sapindaceous
 * †Sapindus
 * †Sapindus alatus
 * †Sapindus grandifolioloides
 * †Sapindus grandifoliolus
 * †Sapindus wardii
 * Sassafras
 * †Sassafras thermale
 * †Scalopoides
 * †Scapherpeton
 * †Scapherpeton tectum
 * †Scenopagus
 * †Scenopagus curtidens
 * †Scenopagus edenensis
 * †Scenopagus hewettensis – type locality for species
 * †Scenopagus priscus
 * †Schaubeumys
 * †Schaubeumys sabrae
 * †Schizodontomys
 * †Schizodontomys harkseni
 * †Schizodontomys sulcidens
 * Schoepfia arenaria.jpg †[[Schoepfia]]
 * †Schoepfia republicensis
 * Sciara
 * †Sciara scopuli – type locality for species
 * †Scincoideus
 * †Scincoideus grassator – type locality for species
 * Sciomyza – tentative report
 * †Sciomyza disjecta – type locality for species
 * †Sciomyza manca – type locality for species
 * †Sciophila
 * †Sciophila hyatti – type locality for species
 * †Sciuravus
 * †Sciuravus bridgeri – type locality for species
 * †Sciuravus nitidus – type locality for species
 * †Sciuravus popi – or unidentified comparable form
 * †Sciuravus wilsoni
 * †Scottimus
 * †Scottimus ambiguus – or unidentified comparable form
 * †Scottimus kellamorum – type locality for species
 * †Scottimus viduus
 * †Selenaletes
 * †Selenaletes scopaeus
 * Sequoia
 * †Sequoia couttsiae
 * †Sequoia langsdorfii
 * †Sequoia magnifica
 * Sespia ultima californica cropped.png †[[Sespia]]
 * †Sespia nitida
 * †Shoshonius
 * †Shoshonius bowni
 * †Shoshonius cooperi
 * †Sialia
 * †Sifrhippus
 * †Sifrhippus grangeri
 * †Sifrhippus sandrae
 * †Sigynorum – type locality for genus
 * †Sigynorum magnadivisus – type locality for species
 * †Simoedosaurus
 * †Simpsonictis
 * †Simpsonictis jaynanneae – type locality for species
 * †Simpsonictis pegus – type locality for species
 * †Simpsonictis tenuis
 * †Simpsonlemur
 * †Simpsonlemur citatus
 * †Simpsonlemur jepseni – or unidentified comparable form
 * †Sinclairella
 * †Sinomenium – or unidentified related form
 * †Sinomenium RR08 informal
 * Sinopa rapax 1.jpg †[[Sinopa]]
 * †Sinopa agilis – type locality for species
 * †Sinopa major – type locality for species
 * †Sinopa minor
 * †Sinopa rapax – type locality for species
 * †Sinopa viverrinus
 * †Siphonophoroides
 * †Siphonophoroides antiqua – tentative report
 * Siren
 * †Siren dunni – type locality for species
 * Sitona
 * †Sitona grandaevus – type locality for species
 * †Sitona paginarum
 * Sloanea – or unidentified related form
 * †Sloanea RR18 informal
 * †Smilax
 * †Smilax GR550 informal
 * †Smilax lamarensis
 * DMNS65L PrimateSkeleton.jpg †[[Smilodectes]]
 * †Smilodectes gibossus – type locality for species
 * †Smilodectes gracilis – type locality for species
 * †Smilodectes mcgrewi – type locality for species
 * †Smilodectes sororis – type locality for species
 * Sorex
 * †Sorex hoyi
 * †Sparganium
 * †Sparganium stygium
 * †Spathorhynchus – type locality for genus
 * †Spathorhynchus fossorium – type locality for species
 * †Spathorhynchus natronicus
 * Spermophilus
 * †Spermophilus primitivus
 * †Spermophilus variegatus
 * †Sphacorhysis
 * †Sphacorhysis burntforkensis – type locality for species
 * Mesatirhinus cropped.jpg †[[Sphenocoelus]]
 * †Sphenocoelus hyognathus
 * †Sphenocoelus uintensis
 * Spirodela
 * †Spirodela magna
 * †Spiza
 * †Spiza americana
 * †Spurimus
 * †Spurimus scotti
 * †Spurimus selbyi
 * Stagnicola
 * †Staphylinites
 * †Staphylinites obsoletum – type locality for species
 * †Stegobium
 * †Stegobium defunctus – type locality for species
 * †Steinius
 * †Steinius annectens – type locality for species
 * †Steinius vespertinus
 * †Steneofiber
 * †Steneofiber fossor
 * †Steneofiber gradatus
 * †Stenocinclis – type locality for genus
 * †Stenocinclis anomala – type locality for species
 * †Stenogomphus
 * †Stenogomphus scudderi – type locality for species
 * Stenomylus.jpg †[[Stenomylus]]
 * †Stenomylus gracilis
 * †Stenomylus hitchcocki
 * †Stenomylus keelinensis
 * †Stenopelta
 * †Stenopelta punctulata – type locality for species
 * Sterculia
 * †Sterculia coloradensis
 * †Stibarus
 * †Stibarus quadricuspis
 * †Stibarus yoderensis
 * †Stillingia
 * †Stillingia casca
 * †Straitopollis
 * †Straitopollis tectatus
 * †Strigorhysis – type locality for genus
 * †Strigorhysis bridgerensis – type locality for species
 * †Strigorhysis rugosus
 * Sturnella
 * †Sturnella neglecta
 * †Stygimys
 * †Stygimys gratus
 * †Stygimys kuszmauli
 * Stylemys (1).jpg †[[Stylemys]]
 * †Stylemys nebrascensis
 * †Stylinodon
 * †Stylinodon mirus – type locality for species
 * †Styrax
 * †Styrax transversa
 * †Subhyracodon
 * †Subhyracodon mitis
 * †Subhyracodon occidentalis
 * Surnia
 * †Surnia ulula
 * †Suzanniwana – type locality for genus
 * †Suzanniwana patriciana – type locality for species
 * †Suzanniwana revenanta – type locality for species
 * †Swaindelphys
 * †Swaindelphys cifellii – type locality for species
 * †Swainiguanoides – type locality for genus
 * †Swainiguanoides milleri – type locality for species
 * †Swartzia
 * †Swartzia wardelii – type locality for species
 * Sylvicola – type locality for genus
 * †Sylvicola cadaver – type locality for species
 * Sylvilagus
 * Symplocos
 * †Symplocos exilis
 * Synaptomys
 * †Syncolporites
 * †Syncolporites minimus
 * Syndyoceras BW.jpg †[[Syndyoceras]]
 * †Syndyoceras cooki
 * †Syntomostylus
 * †Syntomostylus fortis – type locality for species
 * Syrphus
 * †Systemodon
 * †Systemodon tapirinus
 * †Syzygioides
 * †Syzygioides americana

T

 * Tachycineta – or unidentified comparable form
 * †Tachycineta bicolor
 * Taeniolabis NT small.jpg †[[Taeniolabis]]
 * †Taeniolabis taoensis
 * †Talpavoides
 * †Talpavoides dartoni – type locality for species
 * †Talpavus
 * †Talpavus duplus
 * †Talpavus nitidus
 * †Talpavus sullivani – type locality for species
 * Tamias
 * †Tamias ateles – or unidentified comparable form
 * †Tanymykter
 * †Tanymykter brachyodontus
 * Tapocyon robustus.jpg †[[Tapocyon]]
 * †Tapocyon robustus – or unidentified comparable form
 * †Tarka
 * †Tarka stylifera
 * †Tatmanius – type locality for genus
 * †Tatmanius szalayi – type locality for species
 * Taxidea
 * †Taxidea taxus
 * †Taxites
 * †Taxites olriki
 * Taxodium
 * †Taxodium olriki
 * †Taxodium olrikii
 * †Taxonus
 * †Taxonus nortoni – type locality for species
 * †Taxymys
 * †Taxymys lucaris
 * Teilhardina fossil cropped.png †[[Teilhardina]]
 * †Teilhardina americana – type locality for species. Late reclassified in the new genus Bownomomys as the species B. americanus.
 * †Teilhardina brandti – type locality for species
 * †Teilhardina crassidens – type locality for species. Later reclassified as Bownomomys crassidens.
 * †Teilhardina demissa – type locality for species
 * †Teilhardina gingerichi
 * †Teilhardina mathewi
 * †Teilhardina tenuicula
 * †Teleoceras
 * †Telmatherium
 * †Telmatherium validum – or unidentified comparable form
 * †Telmatherium validus – type locality for species
 * †Telmatrechus
 * †Telmatrechus parallelus – type locality for species
 * †Temnocyon
 * †Temnocyon macrogenys – type locality for species
 * †Temnotrionyx – type locality for genus
 * †Temnotrionyx manducans – type locality for species
 * †Teretrum
 * †Teretrum quiescitum – type locality for species
 * †Ternstroemites
 * †Ternstroemites aureavallis
 * †Tetigonia
 * †Tetigonia priscomarginata – type locality for species
 * †Tetigonia priscovariegata – type locality for species
 * †Tetonius
 * †Tetonius matthewi – type locality for species
 * †Tetonoides
 * †Tetonoides pearcei
 * †Tetraclaenodon
 * †Tetraclaenodon puercensis
 * †Tetrapassalus
 * †Tetrapassalus proius – type locality for species
 * †Thamnotettix
 * †Thamnotettix gannetti – type locality for species
 * †Thamnotettix mutilata – type locality for species
 * Thelypteris acuminata hosida001.jpg [[Thelypteris]]
 * †Thelypteris iddingsi
 * †Thelypteris iddingsii
 * †Thinocyon
 * †Thisbemys
 * †Thisbemys brevicrista
 * †Thisbemys corrugatus – type locality for species
 * †Thisbemys perditus
 * †Thouinia
 * †Thouinia eocenica
 * †Thryptacodon
 * †Thryptacodon antiquus
 * †Thryptacodon australis
 * †Thryptacodon barae
 * †Thryptacodon orthogonius – type locality for species
 * †Thryptacodon pseudarctos
 * †Thuites
 * †Thuites interruptus
 * †Thuja
 * †Thuja interrupta
 * †Thuja interruptus
 * †Thylacaelurus
 * †Thylacaelurus montanus – or unidentified comparable form
 * †Thylacodon
 * †Thylacodon pusillus
 * Tilia tomentosa.jpg [[Tilia]]
 * †Tilia populifolia
 * †Tillodon
 * †Tillodon fodiens – type locality for species
 * †Tillomys
 * †Tillomys parvidens – type locality for species
 * †Tillomys senex
 * †Tinimomys
 * †Tinimomys graybulliensis
 * †Tinimomys loomisi
 * †Tinimomys tribos – type locality for species
 * Tinosaurus – type locality for genus
 * †Tinosaurus pristinus – type locality for species
 * †Tinosaurus stenodon – type locality for species
 * Tipula
 * †Tipula sepulchri – type locality for species
 * †Tipula spoliata – type locality for species
 * Titanoides2010.jpg †[[Titanoides]]
 * †Titanoides gidleyi – type locality for species
 * †Titanoides major
 * †Titanoides nanus – type locality for species
 * †Titanoides primaevus
 * †Titanomyrma
 * Titanomyrma lubei 02.jpg †[[Titanomyrma lubei]] – type locality for species
 * †Torrejonia
 * †Torrejonia sirokyi – type locality for species
 * †Toxotherium
 * †Toxotherium hunteri
 * Trapa
 * †Trapa angulata
 * †Trapa paulula
 * †Tremanotus
 * †Tremanotus angustata
 * †Triatriopollenites
 * †Triatriopollenites granulatus
 * †Triatriopollenites granulus
 * †Tricalpites
 * †Tricalpites parvus
 * †Tricentes
 * †Tricentes subtrigonus
 * †Tricolpites
 * †Tricolpites anguloluminosus + bathyreticulatus
 * †Tricolpites anguloluminosus + bothyreticulatus
 * †Tricolpites angulolumonosus + bathyreticulatus
 * †Tricolpites mutabilis
 * †Tricolpites parvus
 * †Trigenicus
 * †Trigenicus profectus
 * †Trigonias
 * †Trigonias osborni
 * †Trigonorhinus
 * †Trigonorhinus pristinus – type locality for species
 * Trionyx
 * †Trionyx concentricus – type locality for species
 * †Trionyx thomasii – type locality for species
 * †Triplopus
 * †Triplopus cubitalis – type locality for species
 * †Triplopus implicatus – type locality for species
 * †Triplopus obliquidens – or unidentified comparable form
 * Tritemnodon agilis cropped.jpg †[[Tritemnodon]]
 * †Tritemnodon strenuus
 * †Tritoma
 * †Tritoma binotata – type locality for species
 * †Triumfetta
 * †Triumfetta ovata
 * †Trochodendroides
 * †Trochodendroides flabella
 * †Trogolemur
 * †Trogolemur amplior – type locality for species
 * †Trogolemur fragilis – type locality for species
 * †Trogolemur myodes – type locality for species
 * †Trogosus
 * †Trogosus castoridens – type locality for species
 * †Trogosus gazini – type locality for species
 * †Trogosus latidens
 * †Tropideres
 * †Tropideres remotus – type locality for species
 * †Tropisternus
 * †Tropisternus saxialis – type locality for species
 * †Tropisternus sculptilis – type locality for species
 * †Trypodendron
 * †Trypodendron impressus – type locality for species
 * †Tsoabichi – type locality for genus
 * †Tsoabichi greenriverensis – type locality for species
 * †Tubulodon
 * †Tubulodon atopum
 * †Tubulodon pearcei
 * †Tubulodon taylori
 * †Tubulodon woodi
 * Turdus – or unidentified comparable form
 * †Turdus migratorius
 * †Tuscahomys
 * †Tuscahomys ctenodactylops – type locality for species
 * †Tuscahomys major – or unidentified comparable form
 * †Tuscahomys walshi – type locality for species
 * †Tuscahomys worlandensis
 * †Tylocephalonyx
 * †Tylocephalonyx skinneri
 * Tympanuchus
 * Sharp-Tailed Grouse (26089894256) (cropped) cropped.jpg †[[Tympanuchus phasianellus]]
 * Typha – or unidentified related form
 * †Tytthaena
 * †Tytthaena lichna
 * †Tytthaena parrisi – type locality for species

U

 * †Uintaceras
 * †Uintaceras radinskyi
 * †Uintacyon
 * †Uintacyon asodes
 * †Uintacyon gingerichi
 * †Uintacyon jugulans – type locality for species
 * †Uintacyon massetericus
 * †Uintacyon rudis
 * †Uintanius
 * †Uintanius ameghini
 * †Uintanius rutherfurdi
 * †Uintasorex
 * †Uintasorex parvulus – type locality for species
 * Uinttather DB.jpg †[[Uintatherium]] – type locality for genus
 * †Uintatherium anceps – type locality for species
 * †Uintornis – type locality for genus
 * †Uintornis lucaris – type locality for species
 * †Uintornis marionae – type locality for species
 * Ulmus
 * †Ulmus microphylla
 * †Ulmus minima – tentative report
 * †Ulmus rhamnifolia
 * Unio
 * †Unuchinia
 * †Unuchinia diaphanes – type locality for species
 * †Unuchinia dysmathes
 * Ursus
 * 2010-kodiak-bear-1.jpg †[[Ursus arctos]]
 * †Ustatochoerus
 * †Ustatochoerus medius
 * †Utahia
 * †Utahia carina – type locality for species
 * †Utemylus
 * †Utemylus serior – type locality for species

V

 * †Valenia
 * †Valenia wilsoni
 * †Valenopsalis
 * †Valenopsalis joyneri
 * †Vassacyon
 * †Vassacyon bowni – type locality for species
 * †Vassacyon promicrodon
 * †Vauquelinia
 * †Vauquelinia comptonifolia
 * †Viburnum
 * †Viburnum antiquorum
 * †Viburnum antiquum
 * †Viburnum asperum
 * †Vinea – or unidentified comparable form
 * †Vinea pugetensis
 * Vitis californica with grapes.jpg [[Vitis]]
 * †Vitis olriki
 * †"Vitis" stantoni
 * †Viverravus
 * †Viverravus acutus
 * †Viverravus acutus/gracilis informal
 * †Viverravus browni
 * †Viverravus gracilis – type locality for species
 * †Viverravus laytoni
 * †Viverravus lutosus
 * †Viverravus minutus – type locality for species
 * †Viverravus politus
 * †Viverravus rosei – type locality for species
 * †Viverravus sicarius
 * Viviparus
 * Vulpavus ovatus.JPG †[[Vulpavus]]
 * †Vulpavus australis
 * †Vulpavus canavus
 * †Vulpavus farsonensis – type locality for species
 * †Vulpavus hargeri
 * †Vulpavus ovatus – type locality for species
 * †Vulpavus palustris – type locality for species
 * †Vulpavus profectus – type locality for species
 * †Vulpavus simplex
 * Vulpes
 * Fox - British Wildlife Centre (17429406401).jpg †[[Vulpes vulpes]]

W

 * †Washakius
 * †Washakius insignis
 * †Washakius izetti
 * †Wickia
 * †Wickia brevirhinus – or unidentified comparable form
 * †Wilsoneumys
 * †Wilsoneumys planidens
 * Wradicans.jpg †[[Woodwardia]]
 * †Woodwardia arctica
 * †Woodwardia gravida
 * †Woodwardia preareolata
 * †Worlandia
 * †Worlandia inusitata – type locality for species
 * †Wrightohyus
 * †Wrightohyus yatkolai
 * †Wyolestes
 * †Wyolestes apheles
 * †Wyolestes dioctes – type locality for species
 * †Wyomomys
 * †Wyomomys bridgeri – type locality for species
 * †Wyomylus – type locality for genus
 * †Wyomylus whitei – type locality for species
 * †Wyonycteris – type locality for genus
 * †Wyonycteris chalix – type locality for species

X

 * †Xanclomys
 * †Xanclomys mcgrewi – type locality for species
 * †Xenicohippus
 * †Xenicohippus craspedotum
 * †Xenicohippus grangeri
 * †Xenochelys
 * †Xenochelys bridgerensis – type locality for species
 * †Xenochelys formosa
 * †Xenochelys lostcabinensis – type locality for species
 * †Xenocranium
 * †Xestops
 * †Xestops gracilis – type locality for species
 * †Xestops lentus – type locality for species
 * †Xestops microdus – type locality for species
 * †Xestops minutus – type locality for species
 * †Xestops piercei – type locality for species
 * †Xestops savagei – type locality for species
 * †Xestops vagans – type locality for species
 * †Xestops vagrans
 * †Xyronomys
 * †Xyronomys swainae – type locality for species

Y

 * †Yoderimys – type locality for genus
 * †Yoderimys bumpi – type locality for species
 * †Yoderimys stewarti
 * Ysengrinia.jpg †[[Ysengrinia]]
 * †Ysengrinia americana

Z

 * †Zamia
 * †Zamia coloradensis
 * †Zamia colorodensis
 * †Zamia wyomingensis
 * †Zangerlichelys
 * †Zangerlichelys aequa
 * †Zanycteris
 * †Zanycteris paleocenus
 * Zelkova
 * †Zelkova nervosa
 * †Zemiodontomys
 * †Zemiodontomys burkei
 * Zenaida
 * †Zenaida rnacroura
 * †Ziamys – or unidentified comparable form
 * †Zingiberopsis
 * †Zingiberopsis isonervosa
 * Zizyphus
 * †Zizyphus serrulatus
 * †Zodiolestes
 * Zonotrichia
 * Zonotrichia albicollis CT1.jpg †[[Zonotrichia albicollis]]