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.

• Acer
  • †Acer minor
• †Achlyoscapter
• Acipenser
• †Aciprion
  • †Aciprion formosum
• Acris
  • †Acris crepitans – or unidentified comparable form

• 

  †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
  • †Aepycamelus major
  • †Aepycamelus robustus
• Agkistrodon
  • †Agkistrodon contortix – or unidentified comparable form
• †Agnotocastor
  • †Agnotocastor readingi – type locality for species
• †Agriochoerus
  • †Agriochoerus antiquus
• †Agriotherium

• 

  †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
• †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
  • †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

• 

  †Amphimachairodus
  • †Amphimachairodus coloradensis
• †Anchigyps
  • †Anchigyps voorhiesi
• †Anchitheriomys
  • †Anchitheriomys fluminis
  • †Anchitheriomys nanus
  • †Anchitheriomys stouti – type locality for species
• †Anchitherium

• 

  †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
  • †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

• Baiomys
• Balearica

• 

  †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
• †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

  • 

    †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
  • †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
  • †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 conterminus – type locality for species
  • †Buteo typhoius

• †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

• 

  †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
  • †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

• 

  †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

• 

  †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
  • †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
  • †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
  • †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
  • †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
  • †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

• †Dakotaophis
  • †Dakotaophis greeni
• †Daphoenictis
  • †Daphoenictis tedfordi
• †Daphoenodon
  • †Daphoenodon falkenbachi
  • †Daphoenodon niobrarensis – type locality for species
  • †Daphoenodon robustum
  • †Daphoenodon superbus

• 

  †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

• 

  †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
  • †Dromomeryx borealis – type locality for species

• †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

• 

  †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
  • †Epicyon haydeni
  • †Epicyon saevus
• Equus
  • †Equus conversidens – or unidentified comparable form
  • †Equus excelsus
  • †Equus francisci
  • †Equus simplicidens
• Erethizon
  • †Erethizon dorsatum
• Esox

• 

  †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

• 

  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

• †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

• 

  †Fraxinus
  • †Fraxinus coulteri

• 

  †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
  • †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
  • †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

• †Harrisonsaurus – type locality for genus
  • †Harrisonsaurus fossilis – type locality for species
• †Harrymys
  • †Harrymys magnus

• 

  †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

• 

  †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
  • †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
  • †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

• 

  †Hyracodon
  • †Hyracodon leidyanus
  • †Hyracodon nebraskensis
• †Hystricops
  • †Hystricops venustus

• 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
  • †Indarctos oregonensis
• †Ischyrocyon
  • †Ischyrocyon gidleyi
• †Ischyromys
  • †Ischyromys douglassi
  • †Ischyromys typus
  • †Ischyromys veterior

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

• 

  †Kalobatippus
  • †Kalobatippus agatensis
• †Kansasimys
• Kinosternon
  • †Kinosternon flavescens
• †Kirkomys
  • †Kirkomys nebraskensis

• †Lambdoceras
  • †Lambdoceras siouxensis

• 

  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

• 

  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
  • †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
  • †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

• 

  Lontra
• †Loupomys
• †Lowesaurus
  • †Lowesaurus matthewi
• Lycopodium

• †Machaeromeryx
  • †Machaeromeryx tragulus – type locality for species

• 

  †Machairodus
• Macrochelys
  • †Macrochelys schmidti
  • †Macrochelys temminckii
• †Macrogenis
  • †Macrogenis crassigenis
• †Macrognathomys
• Mahonia
  • †Mahonia marginata
• †Mammacyon
• †Mammut
  • †Mammut matthewi
• †Mammuthus

  • 

    †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
  • †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
  • †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
  • †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
  • †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
• †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
  • †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
  • †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
• Myotis
• †Mystipterus
  • †Mystipterus martini

• †Namatomys
  • †Namatomys lloydi

• 

  †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
  • †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
  • †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
  • †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

• †Ocajila
  • †Ocajila makpiyahe
• Ochotona
  • †Ochotona spanglei – or unidentified comparable form
• Odocoileus

  • 

    †Odocoileus virginianus
• Ogmodontomys
  • †Ogmodontomys poaphagus
• †Ogmophis
  • †Ogmophis compactus
  • †Ogmophis miocompactus
• †Oligobunis
• †Oligomyotis
• †Oligoryctes
  • †Oligoryctes cameronensis
• †Oligoscalops
  • †Oligoscalops galbreathi
• †Oligospermophilus
  • †Oligospermophilus douglassi

• 

  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

  • 

    †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
  • †Oxydactylus longipes

• †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
• †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

  • 

    †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

• 

  †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
  • †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
  • †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

• 

  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
  • †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

• 

  †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
  • †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
  • †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
  • †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

• 

  †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
  • †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
  • †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

• 

  Quercus
  • †Quercus argentum
  • †Quercus parvula – type locality for species
  • †Quercus preturbinella – type locality for species
  • †Quercus remingtoni

• †Rakomeryx
  • †Rakomeryx sinclairi

• 

  †Ramoceros
  • †Ramoceros osborni
• †Rana
  • †Rana catesbeiana
  • †Rana clamitans
  • †Rana pipiens
  • †Rana sylvatica
• †Regina
  • †Regina grahami
• Reithrodontomys
  • †Reithrodontomys pratincola
• †Repomys
  • †Repomys gustelyi

• 

  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

• 

  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

• 

  †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
  • †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
  • †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
  • †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

• 

  †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
  • †Synthetoceras tricornatus

• 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
  • †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

  • 

    †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
• †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

• 

  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

• 

  Vitis
  • †Vitis pannosa – type locality for species
• Vulpes
  • †Vulpes stenognathus
  • †Vulpes velox

• †Wilsoneumys
  • †Wilsoneumys planidens
• †Wrightohyus
  • †Wrightohyus yatkolai

• †Yatkolamys
  • †Yatkolamys edwardsi – type locality for species

• 

  †Ysengrinia
  • †Ysengrinia americana
• †Yumaceras
  • †Yumaceras figginsi

• Zapus
  • †Zapus hudsonius
  • †Zapus sandersi
• †Zemiodontomys
  • †Zemiodontomys burkei
• †Zetamys
  • †Zetamys nebraskensis
• †Ziamys
  • †Ziamys hugeni
• †Zodiolestes
  • †Zodiolestes daimonelixensis – type locality for species

• 

  †Zygolophodon

• Various Contributors to the Paleobiology Database. "Fossilworks: Gateway to the Paleobiology Database". Retrieved 17 December 2021.