List of the Cenozoic life of Nebraska

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

A

 * Acer
 * †Acer minor
 * †Achlyoscapter
 * Acipenser
 * †Aciprion
 * †Aciprion formosum
 * Acris
 * †Acris crepitans – or unidentified comparable form
 * Acritohippus isonesus.jpg †[[Acritohippus]]
 * †Acritohippus isonesus
 * †Acritohippus tertius
 * †Adeloblarina – or unidentified comparable form
 * †Adjidaumo
 * †Adjidaumo intermedius – type locality for species
 * †Adjidaumo maximus – type locality for species
 * †Adjidaumo minimus
 * †Adjidaumo minutus
 * †Aelurodon
 * †Aelurodon asthenostylus
 * †Aelurodon ferox
 * †Aelurodon mcgrewi – type locality for species
 * †Aelurodon stirtoni
 * †Aelurodon taxoides
 * †Aelurodon wheelerianus – or unidentified comparable form
 * Aepycamelus Alticamelus hharder.jpg †[[Aepycamelus]]
 * †Aepycamelus major
 * †Aepycamelus robustus
 * Agkistrodon
 * †Agkistrodon contortix – or unidentified comparable form
 * †Agnotocastor
 * †Agnotocastor readingi – type locality for species
 * †Agriochoerus
 * †Agriochoerus antiquus
 * †Agriotherium
 * The American journal of science (1880) (17965682808).jpg †[[Aletomeryx]]
 * †Aletomeryx gracilis – type locality for species
 * †Aletomeryx marslandensis – type locality for species
 * †Alforjas
 * †Alilepus
 * †Alilepus vagus
 * Alligator
 * †Alligator mcgrewi – type locality for species
 * †Alligator mefferdi – type locality for species
 * †Alligator thomsoni – type locality for species
 * †Allomys
 * †Allomys harkseni
 * †Allophaiomys
 * †Alluvisorex
 * †Alluvisorex arcadentes – or unidentified comparable form
 * Alnus cropped.png [[Alnus]]
 * †Alphagaulus
 * †Alphagaulus tedfordi – type locality for species
 * †Alphagaulus vetus
 * †Alwoodia
 * †Alwoodia magna – or unidentified comparable form
 * †Ambrosia
 * †Ambystoma
 * †Ambystoma maculatum
 * †Ambystoma minshalli – type locality for species
 * †Ambystoma priscum – type locality for species
 * †Ambystoma tigrinum
 * Amebelodon fricki.jpg †[[Amebelodon]]
 * †Amebelodon fricki – type locality for species
 * †Ameiseophis
 * †Ameiseophis robinsoni
 * Amia
 * †Amia calva
 * Ammospermophilus
 * †Ammospermophilus junturensis
 * †Amphechinus
 * †Amphicyon
 * †Amphicyon frendens – type locality for species
 * †Amphicyon galushai – type locality for species
 * †Amphicyon ingens
 * Machairodus giganteus 1.jpg †[[Amphimachairodus]]
 * †Amphimachairodus coloradensis
 * †Anchigyps
 * †Anchigyps voorhiesi
 * †Anchitheriomys
 * †Anchitheriomys fluminis
 * †Anchitheriomys nanus
 * †Anchitheriomys stouti – type locality for species
 * †Anchitherium
 * Andrias japonicus cropped.jpg †[[Andrias]]
 * †Andrias matthewi – type locality for species
 * †Anilioides
 * †Anilioides nebraskensis – type locality for species
 * †Ankylodon
 * †Ankylodon annectens
 * †Antecalomys
 * †Antecalomys phthanus – type locality for species
 * †Antesorex
 * †Antesorex wilsoni – type locality for species
 * Antrozous – or unidentified comparable form
 * Apalone
 * †Apalone miocaenus – type locality for species
 * †Apalone spinifera
 * †Apatemys
 * †Apatemys downsi – or unidentified related form
 * †Aphelops
 * †Aphelops megalodus
 * †Aphelops mutilus – type locality for species
 * †Apletotomeus
 * †Apletotomeus crassus – type locality for species
 * Aplodinotus
 * †Aplodinotus grunniens
 * †Apternodus
 * †Aramornis
 * †Aramornis longurio – type locality for species
 * Aramus
 * †Archaeocyon
 * †Archaeocyon leptodus
 * †Archaeocyon pavidus
 * †Archaeohippus
 * †Archaeohippus penultimus – type locality for species
 * †Archaeolagus
 * †Archaeolagus primigenius – or unidentified comparable form
 * Archaeotherium.jpg †[[Archaeotherium]]
 * †Archaeotherium mortoni
 * †Arctodus
 * †Arctodus simus
 * Arctomys
 * †Arctomys vetus
 * †Arctonasua
 * †Arctonasua eurybates – type locality for species
 * †Arctonasua gracilis – type locality for species
 * †Arctonasua minima – type locality for species
 * Ardea
 * †Arikareeomys
 * †Arikareeomys skinneri – type locality for species
 * Arizona
 * †Arizona voorhiesi – type locality for species
 * †Arretotherium
 * †Arretotherium acridens
 * †Arretotherium fricki – type locality for species
 * †Artemisia
 * †Astrohippus
 * Atractosteus
 * †Atractosteus spatula
 * †Aulolithomys
 * †Aulolithomys bounites

B

 * Baiomys
 * Balearica
 * Barbourofelis fricki.JPG †[[Barbourofelis]]
 * †Barbourofelis fricki
 * †Barbourofelis morrisi – type locality for species
 * †Barbourofelis whitfordi – type locality for species
 * †Barbouromeryx
 * †Barbouromeryx trigonocorneus
 * Bassariscus
 * †Bassariscus antiquus – type locality for species
 * †Bassariscus minimus – type locality for species
 * †Bassariscus ogallalae – type locality for species
 * †Bathornis
 * †Bathornis veredus
 * †Bathygenys
 * †Bensonomys
 * †Bensonomys meadensis
 * Betula – or unidentified comparable form
 * Bison
 * Bison latifrons fossil buffalo (Pleistocene; North America) 1 (15257877377).jpg †[[Bison latifrons]]
 * †Blackia
 * †Blacktops – type locality for genus
 * †Blacktops latidens – type locality for species
 * †Blacktops longinares – type locality for species
 * Blarina
 * †Blarina brevicauda
 * †Blastomeryx
 * †Blastomeryx gemmifer – type locality for species
 * †Bootherium
 * Harlan's musk ox (cast) - Indiana State Museum - DSC00404.JPG †[[Bootherium bombifrons]] – type locality for species
 * †Boreortalis
 * †Boreortalis phengitis – type locality for species
 * †Borophagus
 * †Borophagus diversidens
 * †Borophagus pugnator
 * †Borophagus secundus
 * †Bothriodon
 * †Bothriodon americanus
 * †Bouromeryx
 * †Bouromeryx americanus
 * †Bouromeryx submilleri – type locality for species
 * Brachycrus.jpg †[[Brachycrus]]
 * †Brachycrus buwaldi
 * †Brachycrus siouense – type locality for species
 * †Brachycrus wilsoni – type locality for species
 * †Brachyerix
 * †Brachyerix incertis – type locality for species
 * †Brachyerix macrotis
 * †Brachyerix richi – type locality for species
 * †Brachyopsigale
 * †Brachyopsigale dubius – or unidentified comparable form
 * †Brachypsalis
 * †Brachypsalis hyaenoides – type locality for species
 * †Brachypsalis matutinus – type locality for species
 * †Brachypsalis modicus
 * †Brachypsalis obliquidens – type locality for species
 * †Brachypsalis pachycephalus
 * Brachyrhynchocyon cropped.png †[[Brachyrhynchocyon]]
 * †Brachyrhynchocyon dodgei
 * †Bretzia – tentative report
 * †Brontops
 * †Brontops brachycephalus
 * †Brontops dispar – type locality for species
 * Bufo
 * †Bufo cognatus
 * †Bufo hibbardi
 * †Bufo holmani – type locality for species
 * †Bufo kuhrei – type locality for species
 * †Bufo pliocompactilis
 * †Bufo repentinus
 * †Bufo rexroadensis
 * †Bufo spongifrons – or unidentified comparable form
 * †Bufo valentinensis – type locality for species
 * †Buisnictis
 * †Buisnictis burrowsi
 * †Buisnictis schoffi
 * Burhinus
 * †Burhinus lucorum – type locality for species
 * Buteo buteo -Netherlands-8.jpg [[Buteo]]
 * †Buteo conterminus – type locality for species
 * †Buteo typhoius

C

 * †Calamagras
 * †Calamagras angulatus
 * †Calamagras murivorus
 * †Calamagras platyspondyla – type locality for species
 * †Calippus
 * †Calippus cerasinus
 * †Calippus large informal
 * †Calippus martini
 * †Calippus placidus
 * †Calippus proplacidus
 * †Calippus regulus
 * Camelus hesternus Sergiodlarosa.jpg †[[Camelops]]
 * †Camelops hesternus
 * †Campestrallomys
 * †Campestrallomys annectens – type locality for species
 * †Campestrallomys siouxensis – type locality for species
 * Canis
 * †Canis dirus
 * †Canis edwardii
 * †Canis ferox
 * †Canis latrans
 * †Canis lepophagus
 * †Capacikala
 * Capromeryx minor p1350725.jpg †[[Capromeryx]]
 * †Capromeryx arizonensis
 * †Capromeryx furcifer
 * †Capromeryx tauntonensis
 * †Carpocyon
 * †Carpocyon compressus
 * †Carpocyon limosus
 * †Carpocyon robustus
 * †Carpocyon webbi – type locality for species
 * Carya
 * †Carya libbeyi
 * Castor
 * †Castor californicus – or unidentified comparable form
 * Giant-beaver-fieldmuseum.jpg †[[Castoroides]]
 * Cedrela
 * †Cedrela trainii
 * †Cedromus
 * †Cedromus savannae – type locality for species
 * †Cedromus wardi
 * Celtis
 * †Celtis kansana
 * †Centetodon
 * †Centetodon chadronensis
 * †Centetodon divaricatus – type locality for species
 * †Centetodon hendryi
 * †Centetodon magnus
 * †Centetodon marginalis
 * †Centimanomys
 * †Centimanomys major
 * †Cephalogale
 * Nsthornedgopher-hlmwh-rbh13.jpg †[[Ceratogaulus]]
 * †Ceratogaulus anecdotus
 * †Ceratogaulus hatcheri
 * †Ceratogaulus rhinocerus
 * †Cervalces
 * †Chadronia – type locality for genus
 * †Chadronia margaretae – type locality for species
 * †Chadronycteris
 * †Chadronycteris rabenae – type locality for species
 * Chaetodipus
 * †Chaetodipus hispidus
 * †Chamaecyparis
 * †Chamaecyparis linguaefolia
 * Charina
 * †Charina prebottae
 * †Cheilophis
 * †Cheilophis huerfanoensis
 * Chelydra
 * †Chelydra serpentina
 * †Chelydrops
 * †Chelydrops stricta – type locality for species
 * Chrysemys
 * †Chrysemys picta
 * †Chumashius
 * Cladrastis-kentukea-00.JPG [[Cladrastis]]
 * †Cladrastis prelutea – type locality for species
 * Clethrionomys
 * †Clethrionomys gapperi – or unidentified comparable form
 * Cnemidophorus
 * †Cnemidophorus sexlineatus
 * Cocculus
 * †Cocculus rotunda – type locality for species
 * †Colodon
 * †Colodon cingulatus
 * †Colodon occidentalis
 * Coluber
 * †Coluber constrictor
 * Conuropsis carolinensis (Carolina parakeet).jpg, or Carolina parakeet]] †Conuropsis''
 * †Conuropsis fratercula – type locality for species
 * †Copedelphys
 * †Copedelphys stevensoni
 * †Copemys
 * †Copemys lindsayi
 * †Copemys longidens
 * †Copemys mariae
 * †Copemys pisinnus
 * †Copemys shotwelli
 * †Cordia
 * †Cordia prealba – type locality for species
 * Cormocyon leptodus.JPG Cormocyon]] †Cormocyon
 * †Cormocyon copei
 * †Cormocyon haydeni
 * †Cormohipparion
 * †Cormohipparion goorisi
 * †Cormohipparion johnsoni – type locality for species
 * †Cormohipparion matthewi – type locality for species
 * †Cormohipparion merriami – type locality for species
 * †Cormohipparion occidentale
 * †Cormohipparion quinni
 * †Cosoryx
 * †Cosoryx furcatus
 * Cranioceras unicornis life restoration.jpg Cranioceras, a relative of modern deer, with anachronistic human to scale]] †Cranioceras
 * †Cranioceras unicornis
 * Crataegus
 * †Crataegus nupta
 * †Craterogale – type locality for genus
 * †Craterogale simus – type locality for species
 * Crotalus
 * †Crotalus horridus
 * †Crusafontina
 * †Crusafontina magna
 * Cryptotis
 * †Crytonyx
 * †Crytonyx cooki – type locality for species
 * †Cupidinimus
 * †Cupidinimus nebraskensis
 * †Cupidinimus prattensis – type locality for species
 * †Cupidinimus tertius – or unidentified comparable form
 * †Cylindrodon
 * †Cylindrodon nebraskensis
 * †Cynarctoides
 * †Cynarctoides acridens
 * †Cynarctoides emryi – type locality for species
 * †Cynarctoides roii
 * †Cynarctus
 * †Cynarctus crucidens – type locality for species
 * †Cynarctus saxatilis
 * †Cynarctus voorhiesi – type locality for species
 * Cynelos lemanensis.JPG †[[Cynelos]]
 * †Cynelos idoneus
 * †Cynelos sinapius
 * †Cynodesmus
 * †Cynodesmus martini – type locality for species
 * †Cynodesmus thooides
 * †Cynomyoides
 * †Cynomyoides vatis – type locality for species
 * Cynomys
 * †Cynomys niobrarius
 * †Cynomys sappaensis – type locality for species
 * †Cynomys spenceri – type locality for species

D

 * †Dakotaophis
 * †Dakotaophis greeni
 * †Daphoenictis
 * †Daphoenictis tedfordi
 * †Daphoenodon
 * †Daphoenodon falkenbachi
 * †Daphoenodon niobrarensis – type locality for species
 * †Daphoenodon robustum
 * †Daphoenodon superbus
 * Daphoenus vetus restoration.jpg †[[Daphoenus]] – type locality for genus
 * †Daphoenus felinus
 * †Daphoenus hartshornianus
 * †Daphoenus vetus – type locality for species
 * Dasypus
 * †Dasypus bellus
 * †Delotrochanter
 * †Delotrochanter oryktes – type locality for species
 * †Delotrochanter petersoni
 * †Desmatippus
 * †Desmatippus integer
 * †Desmatippus nebrascensis – type locality for species
 * †Desmatippus nebraskensis
 * †Desmatippus tyleri – type locality for species
 * †Desmatochoerus
 * †Desmatochoerus megalodon
 * †Desmatolagus
 * †Desmatolagus gazini – type locality for species
 * †Desmocyon
 * †Desmocyon matthewi
 * †Desmocyon thomsoni
 * Subhyracodon tridactylus.jpg Diceratherium. Robert Bruce Horsfall (1913).]] †Diceratherium
 * †Diceratherium annectens
 * †Diceratherium armatum
 * †Diceratherium niobrarense – type locality for species
 * †Diceratherium radtkei
 * Dicrostonyx
 * †Dicrostonyx torquatus
 * †Dikkomys
 * †Dikkomys matthewi – type locality for species
 * †Dinictis
 * †Dinictis felina
 * †Dinogale
 * †Dinogale siouxensis – type locality for species
 * †Dinohippus
 * †Dinohippus leidyanus – type locality for species
 * †Dinohyus
 * †Dinohyus hollandi – type locality for species
 * †Diospyros
 * †Diospyros miotexana – type locality for species
 * †Diplolophus
 * †Diplolophus insolens
 * Dipodomys
 * †Dipoides
 * †Dipoides rexroadensis
 * †Dipoides stirtoni
 * †Dipoides tanneri – type locality for species
 * †Dipoides williamsi
 * †Dipoides wilsoni – or unidentified comparable form
 * †Diprionomys
 * †Diprionomys agrarius – type locality for species
 * †Domnina
 * †Domnina dakotensis
 * †Domnina gradata
 * †Domnina thompsoni
 * †Domninoides
 * †Domninoides mimicus
 * †Domninoides valentinensis – type locality for species
 * †Douglassciurus
 * †Douglassciurus jeffersoni
 * †Downsimus
 * †Downsimus chadwicki
 * †Drepanomeryx
 * †Drepanomeryx falciformis – type locality for species
 * Dromomeryx borealis.jpeg †[[Dromomeryx]]
 * †Dromomeryx borealis – type locality for species

E

 * †Ecclesimus
 * †Ecclesimus tenuiceps
 * †Ectopocynus
 * †Ectopocynus simplicidens – type locality for species
 * †Ectypodus
 * †Ectypodus lovei
 * †Edaphocyon
 * †Edaphocyon lautus – type locality for species
 * †Ekgmowechashala
 * †Ekgmowechashala philotau
 * Elaphe
 * †Elaphe guttata
 * †Elaphe kansensis – or unidentified comparable form
 * †Elaphe nebraskensis – type locality for species
 * †Elaphe obsoleta
 * †Elaphe vulpina
 * Bothriodon brachyrhynchus.jpg †[[Elomeryx]] – tentative report
 * Emydoidea
 * †Emydoidea blandingii
 * †Emydoidea hutchisoni – type locality for species
 * †Enhydrocyon
 * †Enhydrocyon pahinsintewakpa
 * †Entoptychus
 * †Entoptychus grandiplanus – type locality for species
 * †Eotylopus
 * †Eotylopus reedi
 * †Epeiromys
 * †Epeiromys spanius – type locality for species
 * Epicyon haydeni skeleton.jpg †[[Epicyon]]
 * †Epicyon haydeni
 * †Epicyon saevus
 * Equus
 * †Equus conversidens – or unidentified comparable form
 * †Equus excelsus
 * †Equus francisci
 * †Equus simplicidens
 * Erethizon
 * †Erethizon dorsatum
 * Esox
 * Eubelodon cropped.jpg †[[Eubelodon]]
 * †Eubelodon morrilli
 * †Eucastor
 * †Eucastor tortus
 * †Eucyon
 * †Eucyon davisi
 * †Eucyon skinneri – type locality for species
 * †Euhapsis
 * †Euhapsis breugerorum – type locality for species
 * †Euhapsis ellicottae – type locality for species
 * †Euhapsis platyceps – type locality for species
 * Schneiders skink 001.jpg [[Eumeces]]
 * †Eumeces antiquus – type locality for species
 * †Eumeces minimus
 * †Eumeces striatulatus – or unidentified comparable form
 * †Eumys
 * †Eumys brachyodus
 * †Eumys elegans
 * †Eumys parvidens – type locality for species
 * †Euoplocyon
 * †Euoplocyon brachygnathus
 * †Euroxenomys
 * †Euroxenomys wilsoni
 * †Eutypomys
 * †Eutypomys thomsoni

F

 * †Fanimus
 * †Fanimus ultimus – type locality for species
 * Felis
 * †Felis rexroadensis – or unidentified comparable form
 * †Florentiamys
 * †Florentiamys tiptoni
 * †Floridatragulus
 * †Fossorcastor
 * †Fossorcastor greeni – type locality for species
 * Koeh-062.jpg †[[Fraxinus]]
 * †Fraxinus coulteri

G

 * Gaillardia in Aspen (91273).jpg †[[Gaillardia]]
 * †Gaillardia thomsoni – type locality for species
 * †Galbreathia
 * †Galbreathia bettae
 * †Galbreathia novellus
 * †Galushaceras – type locality for genus
 * †Galushaceras levellorum – type locality for species
 * Geochelone
 * †Geochelone nordensis – type locality for species
 * †Geochelone oelrichi
 * Geomys
 * †Geomys bursarius
 * †Geomys lutescens
 * †Geomys quinni
 * †Geomys tobinensis – or unidentified comparable form
 * Geranoaetus melanoleucus.JPG [[Geranoaetus]]
 * †Geranoaetus contortus
 * †Geringia
 * †Geringia mcgregori
 * †Geringophis
 * †Geringophis depressus
 * †Geringophis vetus – type locality for species
 * †Geringophis yatkolae – type locality for species
 * Gerrhonotus
 * †Gerrhonotus mungerorum – or unidentified comparable form
 * †Gigantocamelus
 * †Gigantocamelus spatulus – type locality for species
 * Glyptemys
 * †Glyptemys valentinensis – type locality for species
 * †Glyptosaurus
 * †Goinophis – type locality for genus
 * †Goinophis minusculus – type locality for species
 * Gomphotherium productum.jpg †[[Gomphotherium]]
 * †Gomphotherium productum – type locality for species
 * †Goniodontomys
 * †Goniodontomys disjunctus
 * Gopherus
 * †Gopherus laticuneus
 * Graptemys
 * †Gregorymys
 * †Gregorymys formosus
 * †Gripholagomys
 * †Gripholagomys lavocati
 * Grus
 * †Grus pratensis
 * †Guildayomys
 * †Guildayomys hibbardi – type locality for species

H

 * †Harrisonsaurus – type locality for genus
 * †Harrisonsaurus fossilis – type locality for species
 * †Harrymys
 * †Harrymys magnus
 * Hayoceros.jpg †[[Hayoceros]]
 * †Hayoceros barbouri – type locality for species
 * †Helagras
 * †Helagras orellanensis – type locality for species
 * †Heliscomys
 * †Heliscomys hatcheri
 * †Heliscomys macdonaldi – type locality for species
 * †Heliscomys mcgrewi – type locality for species
 * †Heliscomys vetus
 * †Helodermoides
 * †Helodermoides tuberculatus
 * †Hemiauchenia
 * †Hemiauchenia macrocephala
 * †Heptacodon
 * †Heptacodon occidentale – or unidentified comparable form
 * †Herpetotherium
 * †Herpetotherium fugax
 * †Herpetotherium youngi
 * †Hesperhys
 * †Hesperhys vagrans
 * Cynodictis.jpg †[[Hesperocyon]]
 * †Hesperocyon gregarius
 * †Hesperolagomys
 * †Hesperolagomys fluviatilis
 * †Hesperolagomys galbreathi – or unidentified comparable form
 * †Hesperoscalops
 * †Hesperoscalops mcgrewi
 * †Hesperotestudo
 * †Hesperotestudo angusticeps – type locality for species
 * †Hesperotestudo orthopygia
 * Heterodon
 * †Heterodon nasicus
 * †Heterodon platyrhinos
 * †Heteromeryx
 * †Heteromeryx dispar
 * †Hibbardomys
 * †Hibbardomys marthae – type locality for species
 * †Hibbardomys skinneri – type locality for species
 * †Hibbardomys voorhiesi – type locality for species
 * †Hipparion
 * †Hipparion forcei
 * †Hipparion tehonense
 * †Hippotherium
 * †Hitonkala
 * †Hitonkala macdonaldtau – type locality for species
 * Holbrookia – tentative report
 * †Holbrookia antiqua – type locality for species
 * Homotherium serum.jpg †[[Homotherium]]
 * †Homotherium crusafonti
 * †Hoplophoneus
 * †Hoplophoneus mentalis
 * †Hoplophoneus primaevus
 * †Hyaenodon
 * †Hyaenodon crucians
 * Hyla
 * †Hyla gratiosa – or unidentified comparable form
 * †Hyla squirella – or unidentified comparable form
 * †Hyla versicolor – or unidentified comparable form
 * †Hypertragulus
 * †Hypertragulus calcaratus
 * †Hypertragulus chadronensis – type locality for species
 * †Hypertragulus crawfordensis – type locality for species
 * †Hypertragulus minor – type locality for species
 * †Hypertragulus quadratus – type locality for species
 * †Hypertragulus sequens – type locality for species
 * †Hypisodus
 * †Hypisodus alacer
 * †Hypisodus ironsi – type locality for species
 * †Hypisodus minimus
 * †Hypisodus paululus – type locality for species
 * †Hypisodus retallacki – type locality for species
 * Hypohippus.jpg †[[Hypohippus]]
 * †Hypohippus affinis
 * †Hypohippus osborni
 * †Hypohippus pertinax – or unidentified comparable form
 * †Hypolagus
 * †Hypolagus fontinalis
 * †Hypolagus furlongi
 * †Hypolagus parviplicatus
 * †Hypolagus regalis
 * †Hypolagus ringoldensis
 * †Hypolagus vetus
 * †Hypolagus voorhiesi
 * †Hypsiops
 * †Hypsiops breviceps
 * Knight Hyracodon cropped.png †[[Hyracodon]]
 * †Hyracodon leidyanus
 * †Hyracodon nebraskensis
 * †Hystricops
 * †Hystricops venustus

I

 * Ictalurus
 * †Ictalurus echinatus
 * †Ictalurus lambda
 * †Ictalurus leidyi – or unidentified comparable form
 * †Ictalurus punctatus – or unidentified comparable form
 * †Idiogenomys – type locality for genus
 * †Idiogenomys ozziei – type locality for species
 * Ilex
 * Indarctos atticus.jpg †[[Indarctos]]
 * †Indarctos oregonensis
 * †Ischyrocyon
 * †Ischyrocyon gidleyi
 * †Ischyromys
 * †Ischyromys douglassi
 * †Ischyromys typus
 * †Ischyromys veterior

J

 * †Jimomys
 * †Jimomys labaughi – type locality for species
 * Juglans

K

 * Kimberly Mural - Roger Witter Kalobatippus cropped.png †[[Kalobatippus]]
 * †Kalobatippus agatensis
 * †Kansasimys
 * Kinosternon
 * †Kinosternon flavescens
 * †Kirkomys
 * †Kirkomys nebraskensis

L

 * †Lambdoceras
 * †Lambdoceras siouxensis
 * Lampropeltis getula getula.jpg, or eastern kingsnake]] Lampropeltis''
 * †Lampropeltis calligaster
 * †Lampropeltis getulus
 * †Lampropeltis similis – type locality for species
 * †Lampropeltis triangulum
 * †Lantanotherium
 * †Lantanotherium observatum – type locality for species
 * Lasiurus
 * †Leidymys
 * †Leidymys blacki
 * †Leidymys cerasus – type locality for species
 * Leiocephalus
 * †Leiocephalus nebraskensis
 * †Leiocephalus septentrionalis – type locality for species
 * †Lemoynea
 * †Lemoynea biradicularis – type locality for species
 * Longnose gar.png [[Lepisosteus]]
 * †Lepoides
 * †Lepoides lepoides – type locality for species
 * Lepomis
 * †Lepomis microlophus
 * †Leptarctus
 * †Leptarctus martini – type locality for species
 * †Leptarctus oregonensis
 * †Leptarctus primus
 * †Leptarctus wortmani – type locality for species
 * †Leptauchenia
 * †Leptauchenia decora
 * †Leptauchenia major
 * †Leptochoerus
 * †Leptochoerus elegans
 * †Leptochoerus emilyae
 * †Leptochoerus spectabilis
 * †Leptochoerus supremus
 * Leptocyon gregorii holotype AMNH 12879.jpg †[[Leptocyon]]
 * †Leptocyon gregorii – or unidentified comparable form
 * †Leptocyon leidyi – type locality for species
 * †Leptocyon matthewi – type locality for species
 * †Leptocyon vafer
 * †Leptocyon vulpinus
 * †Leptodontomys
 * †Leptodontomys douglassi
 * †Leptodontomys stirtoni – or unidentified comparable form
 * Leptomeryx BW.jpg †[[Leptomeryx]]
 * †Leptomeryx elissae – type locality for species
 * †Leptomeryx esulcatus
 * †Leptomeryx evansi
 * †Leptomeryx speciosus
 * †Leptotomus
 * Lepus
 * †Lepus californicus – or unidentified comparable form
 * Lichanura
 * †Lignimus
 * †Lignimus montis
 * †Limnoecus
 * †Limnoecus compressus
 * †Limnoecus niobrarensis – type locality for species
 * Liquidambar
 * †Longirostromeryx
 * †Longirostromeryx wellsi
 * LutraCanadensis fullres.jpg [[Lontra]]
 * †Loupomys
 * †Lowesaurus
 * †Lowesaurus matthewi
 * Lycopodium

M

 * †Machaeromeryx
 * †Machaeromeryx tragulus – type locality for species
 * [[File:Machairodus aphanistus - Cerro de los Batallones - Museo Arqueológico Regional CAM.JPG|thumb|upright|Fossilized cranium of the Miocene-Pleistocene saber-toothed cat Machairodus]] †[[Machairodus]]
 * Macrochelys
 * †Macrochelys schmidti
 * †Macrochelys temminckii
 * †Macrogenis
 * †Macrogenis crassigenis
 * †Macrognathomys
 * Mahonia
 * †Mahonia marginata
 * †Mammacyon
 * †Mammut
 * †Mammut matthewi
 * †Mammuthus
 * Columbian mammoth cropped.png †[[Mammuthus columbi]]
 * Martes
 * †Martes parviloba
 * †Martinogale
 * †Martinogale alveodens
 * Masticophis
 * †Masticophis flagellum
 * †Matthewlabis
 * †Matthewlabis cedrensis
 * †Mediochoerus
 * †Mediochoerus blicki – type locality for species
 * †Mediochoerus johnsoni – type locality for species
 * †Megacamelus
 * †Megacamelus merriami – or unidentified comparable form
 * Megahippus mckennai.jpg †[[Megahippus]]
 * †Megahippus matthewi
 * †Megahippus mckennai
 * †Megalagus
 * †Megalagus brachyodon
 * †Megalagus primitivus
 * †Megalagus turgidus
 * †Megalictis
 * †Megalictis ferox
 * †Megalonyx
 * †Megalonyx curvidens
 * †Megalonyx leptostomus
 * †Megantereon – tentative report
 * †Megantereon hesperus
 * †Megasminthus
 * †Megasminthus gladiofex
 * †Megasminthus tiheni
 * †Megatylopus
 * †Megatylopus cochrani
 * †Megatylopus gigas
 * †Megatylopus primaevus – or unidentified comparable form
 * †Meliakrouniomys
 * †Meliosma
 * †Meliosma predentata – type locality for species
 * †Meniscomys
 * Menoceras NT small.jpg †[[Menoceras]]
 * †Menoceras arikarense – type locality for species
 * †Menoceras barbouri
 * Mephitis
 * †Mephitis mephitis
 * †Merychippus
 * †Merychippus calamarius – or unidentified comparable form
 * †Merychippus coloradense
 * †Merychippus insignis
 * †Merychippus primus
 * †Merychippus quintus
 * †Merychippus republicanus
 * Merychyus cropped.png †[[Merychyus]]
 * †Merychyus arenarum
 * †Merychyus crabilli – type locality for species
 * †Merychyus elegans
 * †Merychyus minimus – type locality for species
 * †Merychyus novomexicanus
 * †Merychyus relictus
 * †Merychyus siouxensis – or unidentified comparable form
 * †Merycochoerus
 * †Merycochoerus magnus – type locality for species
 * †Merycochoerus matthewi
 * †Merycochoerus proprius
 * Merycodus cf. nectatus - National Museum of Natural History - IMG 2024.JPG †[[Merycodus]]
 * †Merycodus necatus
 * †Merycodus prodromus – type locality for species
 * †Merycodus sabulonis
 * †Merycodus warreni
 * †Merycoides
 * †Merycoides longiceps
 * †Merycoidodon
 * †Merycoidodon bullatus
 * †Merycoidodon culbertsoni – type locality for species
 * †Merycoidodon major
 * †Mesocyon – report made of unidentified related form or using admittedly obsolete nomenclature
 * †Mesocyon temnodon
 * †Mesogaulus
 * †Mesogaulus paniensis
 * †Mesohippus
 * †Mesohippus bairdi
 * †Mesoreodon
 * †Mesoreodon chelonyx
 * †Mesoreodon minor
 * †Mesoscalops
 * †Mesoscalops scopelotemos
 * †Metadjidaumo
 * †Metadjidaumo hendryi – or unidentified comparable form
 * Metailurus (Metailurus sp) Asenovgrad2.jpg †[[Metailurus]]
 * †Metalopex
 * †Metalopex merriami
 * †Metatomarctus
 * †Metatomarctus canavus
 * †Metechinus
 * †Metechinus amplior
 * †Michenia
 * †Michenia agatensis – type locality for species
 * †Micronatrix – type locality for genus
 * †Micronatrix juliescottae – type locality for species
 * †Micropternodus
 * †Micropternodus borealis
 * †Micropternodus montrosensis – type locality for species
 * Micropterus
 * †Microtomarctus
 * †Microtomarctus conferta
 * Microtus
 * †Microtus ochrogaster
 * †Microtus pennsylvanicus
 * Micrurus
 * Mictomys
 * †Mictomys kansasensis
 * †Mictomys meltoni
 * †Mictomys vetus – or unidentified comparable form
 * †Migmacastor – type locality for genus
 * †Migmacastor procumbodens – type locality for species
 * Miniochoerus.jpg †[[Miniochoerus]]
 * †Miniochoerus affinis
 * †Miniochoerus chadronensis
 * †Miniochoerus forsythae
 * †Miniochoerus gracilis
 * †Miniochoerus helprini – type locality for species
 * †Miniochoerus starkensis – type locality for species
 * †Mioheteromys
 * †Mioheteromys amplissimus – type locality for species
 * †Mioheteromys subterior – type locality for species
 * Miohippus cropped.jpg †[[Miohippus]]
 * †Miohippus intermedius – or unidentified comparable form
 * †Miolabis
 * †Miolabis princetonianus – type locality for species
 * †Miomustela
 * †Miomustela madisonae
 * †Mionictis
 * †Mionictis elegans – type locality for species
 * †Mionictis incertus – type locality for species
 * †Mionictis letifer – type locality for species
 * †Mionictis pristinus
 * †Miosicista
 * †Miosicista angulus – type locality for species
 * †Miospermophilus
 * †Miospermophilus bryanti
 * †Miospermophilus wyomingensis
 * †Miotapirus
 * †Miotapirus harrisonensis
 * †Miotylopus
 * †Miotylopus gibbi
 * †Miotylopus leonardi
 * †Monosaulax
 * †Monosaulax curtus
 * †Monosaulax pansus
 * †Monosaulax skinneri – type locality for species
 * †Monosaulax tedi – type locality for species
 * †Mookomys
 * †Mookomys altifluminis
 * †Mookomys altifluminus
 * †Moropus
 * †Moropus elatus
 * †Moropus hollandi – type locality for species
 * †Moropus merriami
 * Mustela
 * †Mustela frenata
 * †Mustela nigripes
 * †Mustela rexroadensis – or unidentified comparable form
 * †Mustela vison
 * Mycteria
 * †Mycteria milleri
 * †Mylagaulus
 * †Mylagaulus cambridgensis
 * Mylohyus nasutus.jpg †[[Mylohyus]]
 * Myotis
 * †Mystipterus
 * †Mystipterus martini

N

 * †Namatomys
 * †Namatomys lloydi
 * Nannippus jaw.JPG †[[Nannippus]]
 * †Nannippus lenticularis
 * †Nanodelphys
 * †Nanodelphys hunti
 * †Nanotragulus
 * †Nanotragulus loomisi
 * †Nanotragulus ordinatus
 * Natrix – or unidentified comparable form
 * †Nebraskomys
 * †Nebraskomys mcgrewi – type locality for species
 * †Nebraskophis – type locality for genus
 * †Nebraskophis skinneri – type locality for species
 * Neohipparion cropped.png †[[Neohipparion]]
 * †Neohipparion affine
 * †Neohipparion eurystyle – or unidentified comparable form
 * †Neohipparion leptode
 * †Neohipparion trampasense
 * †Neonatrix – type locality for genus
 * †Neonatrix elongata – type locality for species
 * †Neonatrix infera – or unidentified comparable form
 * †Neonatrix magna – type locality for species
 * Neophrontops americanus fossil cropped.jpg [[Neophrontops]]
 * †Neophrontops vetustus – type locality for species
 * Neotamias
 * Neotoma
 * †Neotoma quadriplicata – or unidentified comparable form
 * †Neotoma sawrockensis – or unidentified comparable form
 * †Neotragocerus
 * †Neotragocerus improvisus – type locality for species
 * Nerodia
 * †Nerodia hillmani
 * †Nerodia rhombifera
 * †Nerodia sipedon
 * †Nexuotapirus
 * †Nexuotapirus marslandensis – type locality for species
 * Nimravides catacopis.JPG †[[Nimravides]]
 * †Nimravides galiani
 * †Nimravides pedionomus – type locality for species
 * †Nimravides thinobates
 * †Nordenosaurus
 * †Nordenosaurus magnus – type locality for species
 * †Nothodipoides
 * †Nothodipoides planus
 * †Nothodipoides stirtoni – type locality for species
 * †Nothotylopus
 * †Nototamias
 * †Nototamias quadratus – type locality for species
 * †Nyssa
 * †Nyssa copeana

O

 * †Ocajila
 * †Ocajila makpiyahe
 * Ochotona
 * †Ochotona spanglei – or unidentified comparable form
 * Odocoileus
 * White-tailed deer.jpg †[[Odocoileus virginianus]]
 * Ogmodontomys
 * †Ogmodontomys poaphagus
 * †Ogmophis
 * †Ogmophis compactus
 * †Ogmophis miocompactus
 * †Oligobunis
 * †Oligomyotis
 * †Oligoryctes
 * †Oligoryctes cameronensis
 * †Oligoscalops
 * †Oligoscalops galbreathi
 * †Oligospermophilus
 * †Oligospermophilus douglassi
 * Muskrat Foraging.JPG [[Ondatra]]
 * †Ondatra annectens – or unidentified comparable form
 * †Ondatra idahoensis
 * †Ondatra meadensis
 * †Ondatra zibethicus
 * Onychomys
 * †Onychomys larabeei – or unidentified comparable form
 * †Onychomys leucogaster – or unidentified comparable form
 * †Onychomys pedroensis – or unidentified comparable form
 * Opheodrys – or unidentified comparable form
 * †Ophiomys
 * †Ophiomys fricki
 * †Ophiomys magilli
 * †Ophiomys parvus
 * Ophisaurus
 * Eastern Glass Lizard.jpg †[[Ophisaurus ventralis]]
 * †Orelladjidaumo
 * †Orelladjidaumo xylodes – type locality for species
 * †Oreolagus
 * †Oreolagus nebrascensis – type locality for species
 * †Oropyctis
 * †Oropyctis pediasius – type locality for species
 * Ortalis
 * †Ortalis tantala – type locality for species
 * †Osbornodon
 * †Osbornodon fricki
 * †Osbornodon iamonensis
 * †Osbornodon renjiei
 * †Oxetocyon
 * †Oxetocyon cuspidatus
 * Oxydactylus longipes.jpg †[[Oxydactylus]]
 * †Oxydactylus longipes

P

 * †Paciculus
 * †Paciculus nebraskensis – type locality for species
 * †Paenemarmota
 * †Paenemarmota barbouri
 * †Paenemarmota nevadensis – or unidentified comparable form
 * †Paenemarmota sawrockensis
 * †Palaealectoris – type locality for genus
 * †Palaealectoris incertus – type locality for species
 * †Palaeastur – type locality for genus
 * †Palaeastur atavus – type locality for species
 * Palaeocastor.jpg †[[Palaeocastor]]
 * †Palaeogale
 * †Palaeogale dorothiae
 * †Palaeogale minuta – or unidentified comparable form
 * †Palaeolagus
 * †Palaeolagus burkei
 * †Palaeolagus haydeni – type locality for species
 * †Palaeolagus hemirhizis – type locality for species
 * †Palaeolagus hypsodus
 * †Palaeolagus intermedius
 * †Palaeolagus philoi
 * †Palaeolagus temnodon
 * †Paleoheterodon – type locality for genus
 * †Paleoheterodon tiheni – type locality for species
 * Panthera
 * Lion (Panthera leo) (30941994012) cropped.jpg †[[Panthera leo]]
 * †Parablastomeryx
 * †Parablastomeryx gregorii – type locality for species
 * †Paracoluber
 * †Paracoluber storeri
 * †Paracosoryx
 * †Paracosoryx dawesensis
 * †Paracosoryx wilsoni
 * †Paracryptotis
 * †Paractiornis – type locality for genus
 * †Paractiornis perpusillus – type locality for species
 * †Paracynarctus
 * †Paracynarctus kelloggi
 * †Paracynarctus sinclairi – type locality for species
 * †Paradaphoenus
 * †Paradaphoenus minimus
 * †Paradaphoenus tooheyi – type locality for species
 * †Paradjidaumo
 * †Paradjidaumo trilophus
 * †Paradjidaumo validus – type locality for species
 * †Paraenhydrocyon
 * †Paraenhydrocyon wallovianus
 * †Paragerrhonotus – or unidentified comparable form
 * †Paragerrhonotus ricardensis
 * †Parahippus
 * †Parahippus atavus
 * †Parahippus cognatus
 * †Parallomys
 * †Parallomys americanus – type locality for species
 * †Paramerychyus
 * †Paramerychyus harrisonensis
 * †Paramerychyus relictus
 * †Paramicrotoscoptes
 * †Paramicrotoscoptes hibbardi
 * †Paramiolabis
 * †Paramiolabis tenuis
 * San Diego Paramylodon.jpg Paramylodon]] †Paramylodon
 * †Paramylodon harlani
 * †Paramys
 * †Paramys relictus
 * †Paranamatomys
 * †Paranamatomys storeri
 * †Parapliosaccomys
 * †Parapliosaccomys annae
 * †Parapliosaccomys hibbardi
 * Parascalops – or unidentified comparable form
 * †Parataxidea – or unidentified comparable form
 * †Paratomarctus
 * †Paratomarctus euthos
 * †Paratomarctus temerarius
 * Paratylopus.jpeg †[[Paratylopus]]
 * †Paratylopus labiatus
 * †Paratylopus primaevus
 * †Parictis
 * †Parictis gilpini
 * †Paronychomys
 * †Parophisaurus
 * †Parophisaurus pawneensis
 * †Parvericius
 * †Parvericius montanus
 * †Parvericius voorhiesi – type locality for species
 * †Parvitragulus – tentative report
 * †Pediohierax – type locality for genus
 * †Pediohierax ramenta – type locality for species
 * †Pediolophodon
 * †Pediomeryx
 * †Pediomeryx hemphillensis – or unidentified comparable form
 * Peltosaurus.JPG †[[Peltosaurus]]
 * †Peltosaurus granulosus
 * †Pelycomys
 * †Pelycomys brulanus – type locality for species
 * †Pelycomys placidus – or unidentified comparable form
 * †Penetrigonias
 * †Penetrigonias dakotensis – type locality for species
 * †Peraceras
 * †Peraceras profectum
 * †Peraceras superciliosum
 * †Perchoerus
 * †Perchoerus probus – tentative report
 * †Peridiomys
 * †Peridiomys borealis
 * †Peridiomys rusticus – type locality for species
 * Pacific pocket mouse cropped.jpg [[Perognathus]]
 * †Perognathus brevidens
 * †Perognathus coquorum
 * †Perognathus furlongi – or unidentified comparable form
 * †Perognathus minutus – or unidentified comparable form
 * †Perognathus pearlettensis
 * †Perognathus trojectioansrum
 * Peromyscus
 * †Peromyscus kansasensis – or unidentified comparable form
 * †Petauristodon
 * †Petenyia – or unidentified comparable form
 * †Phasianus
 * †Phasianus mioceanus – type locality for species
 * †Phelosaccomys
 * †Phenacocoelus
 * †Phenacocoelus typus – type locality for species
 * Phenacomys
 * †Phenacomys intermedius – or unidentified comparable form
 * Phlaocyon.png †[[Phlaocyon]]
 * †Phlaocyon annectens
 * †Phlaocyon leucosteus
 * †Phlaocyon mariae – type locality for species
 * †Phlaocyon marslandensis
 * †Phlaocyon minor
 * †Phlaocyon yatkolai – type locality for species
 * Phrynosoma
 * †Phrynosoma cornutum
 * Picea
 * Pinus
 * †Pipestoneomys
 * †Pipestoneomys bisulcatus
 * Pituophis
 * †Pituophis catenifer
 * †Pituophis melanoleucus
 * †Planisorex
 * †Planisorex dixonensis
 * Platanus
 * †Platanus vitifolia – type locality for species
 * WPHubeiPlatybeladon.jpg †[[Platybelodon]]
 * †Platybelodon barnumbrowni
 * †Platybelodon loomisi
 * †Platygonus
 * †Platygonus compressus
 * †Platygonus pollenae – type locality for species
 * †Pleiolama
 * †Pleiolama mckennai – type locality for species
 * †Pleiolama vera – or unidentified comparable form
 * †Plesiogulo
 * †Plesiogulo lindsayi – or unidentified comparable form
 * †Plesiosorex
 * †Plesiosorex coloradensis
 * †Plesiosorex donroosai
 * †Plesiosorex greeni
 * †Pleurolicus
 * †Pleurolicus exiguus – type locality for species
 * †Pleurolicus hemingfordensis
 * †Pleurolicus sulcifrons – or unidentified comparable form
 * †Pliauchenia
 * †Pliauchenia magnifontis
 * †Plioceros
 * †Plioceros dehlini – type locality for species
 * †Plioceros floblairi – type locality for species
 * †Pliocyon
 * †Pliocyon medius – type locality for species
 * †Pliogale
 * †Pliogale furlongi
 * †Pliogeomys
 * †Pliogeomys russelli – type locality for species
 * Pliohippus Pernix.jpg †[[Pliohippus]]
 * †Pliohippus mirabilis
 * †Pliohippus nobilis
 * †Pliohippus pernix
 * †Pliolemmus
 * †Pliolemmus antiquus
 * †Pliometanastes
 * †Plionarctos
 * †Plionictis
 * †Plionictis ogygia
 * †Pliophenacomys
 * †Pliophenacomys osborni
 * †Pliophenacomys primaevus
 * †Pliosaccomys
 * †Pliotaxidea
 * †Pliotaxidea garberi
 * †Pliotaxidea nevadensis
 * †Pliozapus
 * †Pliozapus solus – or unidentified comparable form
 * †Plithocyon
 * †Poebrotherium
 * †Poebrotherium eximium
 * †Poebrotherium wilsoni
 * Pogonodon platycopis.jpg †[[Pogonodon]]
 * †Pogonodon brachyops
 * Populus
 * †Populus crassa
 * †Populus gallowayi – type locality for species
 * †Populus washoensis
 * †Potamonycteris – type locality for genus
 * †Potamonycteris biperforatus – type locality for species
 * †Priusaulax
 * †Priusaulax browni – type locality for species
 * †Proantilocapra
 * †Proantilocapra platycornea – type locality for species
 * †Probassariscus
 * †Probassariscus matthewi
 * †Problastomeryx
 * †Problastomeryx primus
 * †Procamelus
 * †Procamelus grandis
 * †Procamelus leptocolon
 * †Procamelus occidentalis
 * †Procastoroides
 * †Procastoroides idahoensis
 * †Procastoroides sweeti – type locality for species
 * †Procranioceras
 * †Procranioceras skinneri
 * †Prodipodomys
 * †Prodipoides
 * †Prodipoides burgensis – type locality for species
 * †Prodipoides dividerus
 * †Prodipoides katensis
 * †Proharrymys
 * †Proharrymys fedti
 * †Proharrymys schlaikjeri
 * †Proharrymys wahlerti – type locality for species
 * †Proheteromys
 * †Proheteromys ironcloudi
 * †Promartes
 * †Promartes darbyi
 * †Promartes lepidus – or unidentified comparable form
 * †Promartes olcotti – type locality for species
 * Promerycochoerus cropped.png-like oreodont Promerycochoerus both onshore and in the water. Robert Bruce Horsfall (1913).]] †Promerycochoerus
 * †Promerycochoerus carrikeri
 * †Promerycochoerus superbus
 * †Promilio
 * †Promilio efferus – type locality for species
 * †Promylagaulus
 * †Promylagaulus riggsi
 * †Pronotolagus
 * †Pronotolagus albus
 * †Pronotolagus apachensis
 * †Pronotolagus whitei – type locality for species
 * †Proscalops
 * †Proscalops miocaenus – or unidentified comparable form
 * †Proscalops secundus
 * †Proscalops tertius
 * †Prosciurus
 * †Prosciurus albiclivus
 * †Prosciurus dawsonae
 * †Prosciurus magnus – type locality for species
 * †Prosciurus parvus – type locality for species
 * †Prosciurus vetustus
 * †Prosomys
 * †Prosomys mimus
 * †Prosthennops
 * †Prosthennops niobrarensis
 * †Prosthennops serus
 * †Prosthennops xiphodonticus
 * †Prosynthetoceras
 * †Protemnocyon – type locality for genus
 * †Protemnocyon inflatus – type locality for species
 * †Proterix
 * †Proterix bicuspis
 * Knight Protoceras.jpg †[[Protoceras]]
 * †Protoceras skinneri
 * †Protohippus
 * †Protohippus gidleyi
 * †Protohippus perditus
 * †Protohippus supremus
 * †Protolabis
 * †Protolabis gracilis – or unidentified comparable form
 * †Protolabis heterodontus
 * †Protolabis saxeus – type locality for species
 * †Protomarctus
 * †Protomarctus optatus
 * †Protoprocyon
 * †Protoprocyon savagei – type locality for species
 * †Protosciurus
 * †Protosciurus mengi – type locality for species
 * †Protospermophilus
 * †Protospermophilus kelloggi
 * †Protospermophilus quatalensis – or unidentified comparable form
 * Prunus
 * †Prunus acuminata – type locality for species
 * †Psalidocyon
 * †Psalidocyon marianae
 * Pseudacris
 * †Pseudacris clarki – or unidentified comparable form
 * †Pseudacris nordensis – type locality for species
 * Pseudaelurus cropped.png †[[Pseudaelurus]]
 * †Pseudaelurus aeluroides – type locality for species
 * †Pseudaelurus intrepdius – or unidentified comparable form
 * †Pseudaelurus intrepidus
 * †Pseudaelurus marshi – type locality for species
 * †Pseudaelurus stouti
 * †Pseudaelurus validus
 * †Pseudhipparion
 * †Pseudhipparion gratum – type locality for species
 * †Pseudhipparion retrusum
 * †Pseudhipparion skinneri
 * †Pseudoblastomeryx
 * †Pseudoblastomeryx advena – type locality for species
 * †Pseudoceras
 * †Pseudoceras skinneri – type locality for species
 * †Pseudocylindrodon
 * †Pseudocylindrodon neglectus
 * †Pseudocyon
 * †Pseudolabis
 * †Pseudolabis dakotensis
 * †Pseudomyscus
 * †Pseudomyscus bathygnathus – type locality for species
 * †Pseudoparablastomeryx
 * †Pseudoparablastomeryx francescita
 * †Pseudoparablastomeryx scotti
 * Pseudoprotoceras fossil.jpg †[[Pseudoprotoceras]]
 * †Pseudoprotoceras longinaris – type locality for species
 * †Pseudotheridomys
 * †Pseudotrimylus
 * †Pseudotrimylus blacki – type locality for species
 * †Pseudotrimylus roperi
 * Pterocarya
 * †Pterocarya oregoniana
 * †Pterogaulus
 * †Pterogaulus barbarellae – type locality for species
 * †Pterogaulus laevis
 * †Pterygoboa
 * †Pterygoboa miocenica
 * †Pylodictis
 * †Pylodictis olivaris

Q

 * Eiche bei Schönderling, 2.jpg [[Quercus]]
 * †Quercus argentum
 * †Quercus parvula – type locality for species
 * †Quercus preturbinella – type locality for species
 * †Quercus remingtoni

R

 * †Rakomeryx
 * †Rakomeryx sinclairi
 * Merycodus osborni cropped.png †[[Ramoceros]]
 * †Ramoceros osborni
 * †Rana
 * †Rana catesbeiana
 * †Rana clamitans
 * †Rana pipiens
 * †Rana sylvatica
 * †Regina
 * †Regina grahami
 * Reithrodontomys
 * †Reithrodontomys pratincola
 * †Repomys
 * †Repomys gustelyi
 * Amphisbaenia 1.jpg, or North American worm lizard]] Rhineura''
 * †Rhineura hatcherii
 * †Rhineura marslandensis – type locality for species
 * Rhinocheilus
 * †Rhinocheilus lecontei
 * †Ribes
 * †Ribes infrequens – type locality for species
 * †Robinia
 * †Robinia lesquereuxi
 * †Russellagus
 * †Russellagus vonhofi

S

 * Salix alba Morton.jpg [[Salix]]
 * Salvadora
 * †Salvadora paleolineata – type locality for species
 * †Sanctimus
 * †Sanctimus falkenbachi – type locality for species
 * †Sanctimus stouti – or unidentified comparable form
 * †Sanctimus stuartae
 * †Sarcobatus – or unidentified comparable form
 * †Satherium
 * †Satherium piscinarium
 * †Scalopoides
 * †Scalopoides hutchisoni – type locality for species
 * †Scalopoides isodens
 * †Scalopoides ripafodiator
 * Scalopus
 * †Scalopus aquaticus
 * Scaphiopus
 * †Scaphiopus wardorum – type locality for species
 * Merychippus sumani.jpg †[[Scaphohippus]]
 * †Scaphohippus intermontanus
 * †Scaphohippus sumani
 * Sceloporus
 * †Sceloporus robustus
 * †Sceloporus undulatus
 * †Schaubeumys
 * †Schaubeumys cartomylos
 * †Schaubeumys clivosus
 * †Schaubeumys grangeri
 * †Schaubeumys sabrae
 * †Schizodontomys
 * †Schizodontomys amnicolus – type locality for species
 * †Schizodontomys harkseni – or unidentified comparable form
 * †Scottimus
 * †Scottimus lophatus – type locality for species
 * †Scottimus viduus – type locality for species
 * Sequoia – or unidentified comparable form
 * †Serbelodon
 * †Serbelodon barbourensis
 * Sespia ultima californica cropped.png †[[Sespia]]
 * †Sespia nitida
 * Sigmodon
 * †Sigmodon minor
 * †Simimys – tentative report
 * †Sinclairella
 * †Sinclairella dakotensis
 * †Sinclairomeryx
 * †Sinclairomeryx riparius – type locality for species
 * Siren
 * Sistrurus
 * †Sistrurus catenatus
 * †Skinnerhyus – type locality for genus
 * †Skinnerhyus shermerorum – type locality for species
 * †Skinneroceras – type locality for genus
 * †Skinneroceras manningi – type locality for species
 * Smilodon fatalis.jpg †[[Smilodon]]
 * †Smilodon fatalis – or unidentified comparable form
 * †Sminthosinis
 * Sorex
 * †Sorex arcticus
 * †Sorex cinereus
 * †Sorex edwardsi – type locality for species
 * †Sorex palustris
 * †Sorex sandersi
 * †Sorex yatkolai – type locality for species
 * Spea
 * †Spea bombifrons
 * †Spea neuter
 * Spermophilus
 * †Spermophilus boothi
 * †Spermophilus cyanocittus – type locality for species
 * †Spermophilus elegans
 * †Spermophilus franklinii – or unidentified comparable form
 * †Spermophilus johnstoni
 * †Spermophilus matthewi – type locality for species
 * †Spermophilus meltoni
 * †Spermophilus richardsonii
 * †Spermophilus shotwelli – or unidentified comparable form
 * †Spermophilus tridecemlineatus
 * †Sphenophalos
 * †Sphenophalos middleswarti – type locality for species
 * Spizaetus
 * †Spizaetus tanneri – type locality for species
 * Stegomastodon mirificus - Smithsonian.JPG †[[Stegomastodon]]
 * †Stegomastodon aftoniae
 * †Stegomastodon primitivus
 * †Stehlinia – tentative report
 * †Steneofiber
 * †Steneofiber barbouri
 * †Steneofiber fossor
 * †Stenomylus
 * †Stenomylus crassipes – type locality for species
 * †Stenomylus gracilis
 * †Stenomylus hitchcocki – type locality for species
 * Sthenictis
 * †Sthenictis bellus – type locality for species
 * †Sthenictis dolichops – type locality for species
 * †Stibarus
 * †Stibarus obtusilobus
 * †Stibarus quadricuspis
 * †Stratimus
 * †Stratimus strobeli – type locality for species
 * †Stuckyhyus
 * †Stuckyhyus siouxensis – type locality for species
 * †Stylemys
 * †Stylemys nebrascensis
 * Dromomeryx cropped.jpg †[[Subdromomeryx]]
 * †Subdromomeryx antilopinus
 * †Subhyracodon
 * †Subhyracodon mitis
 * †Submeryceros
 * †Submeryceros minor
 * †Sunkahetanka
 * †Sunkahetanka geringensis
 * Sylvilagus
 * †Sylvilagus floridanus
 * Synaptomys
 * †Synaptomys cooperi
 * †Syndyoceras
 * †Syndyoceras cooki – type locality for species
 * Synthetoceras BW.jpg †[[Synthetoceras]]
 * †Synthetoceras tricornatus

T

 * Tamias
 * †Tamias ateles
 * †Tanymykter
 * †Tanymykter brachyodontus
 * †Tanymykter longirostris – type locality for species
 * Tapirus
 * †Tapirus johnsoni – type locality for species
 * †Tapirus polkensis – or unidentified comparable form
 * †Tapirus simpsoni
 * Taxidea
 * †Taxidea taxus
 * Teleoceras Horsfall cropped.jpg †[[Teleoceras]]
 * †Teleoceras americanum
 * †Teleoceras fossiger
 * †Teleoceras hicksi
 * †Teleoceras major – type locality for species
 * †Teleoceras medicornutum
 * †Teleoceras meridianum
 * †Temnocyon
 * †Temnocyon percussor – type locality for species
 * †Temnocyon typicus – type locality for species
 * †Temperocastor
 * †Temperocastor valentinensis
 * †Tenudomys
 * †Tenudomys basilaris – type locality for species
 * †Tenudomys ridgeviewensis – type locality for species
 * †Tenudomys titanus
 * †Tephrocyon
 * †Tephrocyon scitulus
 * Terrapene
 * †Terrapene corneri – type locality for species
 * Ornate and desert.jpg †[[Terrapene ornata]] – type locality for species
 * †Tetrabelodon
 * †Tetrabelodon osborni
 * †Texasophis
 * †Texoceros
 * †Texoceros altidens – type locality for species
 * †Texoceros guymonensis
 * Thamnophis
 * †Thamnophis proximus
 * †Thamnophis radix
 * †Thamnophis sirtalis
 * Thinobadistes cropped.jpg †[[Thinobadistes]]
 * †Thinohyus
 * Thomomys
 * †Thylacaelurus
 * †Thylacaelurus montanus
 * †Ticholeptus
 * †Ticholeptus zygomaticus
 * Tilia
 * †Titanotylopus
 * †Titanotylopus nebraskensis – type locality for species
 * †Tomarctus
 * †Tomarctus brevirostris
 * †Tomarctus hippophaga – type locality for species
 * Trachemys
 * †Trachemys inflata – or unidentified comparable form
 * †Tregophis
 * †Tregophis brevirachis
 * †Trigenicus
 * †Trigenicus profectus
 * †Trigonias
 * †Trigonias osborni
 * †Trigonias wellsi
 * †Trigonictis
 * †Trigonictis cookii
 * †Trigonictis macrodon
 * †Trilaccogaulus
 * †Trilaccogaulus ovatus
 * Trionyx
 * †Trionyx quinni – type locality for species
 * Tropidoclonion – or unidentified comparable form
 * †Tylionomys
 * †Tylionomys voorhiesi – type locality for species
 * †Tylionomys woodi
 * †Tylocephalonyx
 * †Tylocephalonyx skinneri – type locality for species

U

 * East Coker elm, 2.jpg [[Ulmus]]
 * †Ulmus speciosa
 * †Umbogaulus
 * †Umbogaulus galushai – type locality for species
 * †Umbogaulus monodon – type locality for species
 * †Untermannerix
 * †Untermannerix copiosus
 * Urocyon
 * †Ursavus
 * †Ursavus brevirhinus – or unidentified comparable form
 * †Urubitinga
 * †Urubitinga enecta – type locality for species
 * †Ustatochoerus
 * †Ustatochoerus major
 * †Ustatochoerus medius

V

 * Vitis californica with grapes.jpg [[Vitis]]
 * †Vitis pannosa – type locality for species
 * Vulpes
 * †Vulpes stenognathus
 * †Vulpes velox

W

 * †Wilsoneumys
 * †Wilsoneumys planidens
 * †Wrightohyus
 * †Wrightohyus yatkolai

Y

 * †Yatkolamys
 * †Yatkolamys edwardsi – type locality for species
 * Ysengrinia.jpg †[[Ysengrinia]]
 * †Ysengrinia americana
 * †Yumaceras
 * †Yumaceras figginsi

Z

 * Zapus
 * †Zapus hudsonius
 * †Zapus sandersi
 * †Zemiodontomys
 * †Zemiodontomys burkei
 * †Zetamys
 * †Zetamys nebraskensis
 * †Ziamys
 * †Ziamys hugeni
 * †Zodiolestes
 * †Zodiolestes daimonelixensis – type locality for species
 * Zygolophodon skull fossil.jpg †[[Zygolophodon]]