List of the Cenozoic life of California

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

A

 * †Abantis
 * †Abantis velifer
 * Abies
 * †Abies concoloroides
 * †Abies klamathensis
 * †Aboma
 * †Aboma antiqua – type locality for species
 * †Acalypha
 * †Acalypha aequalis
 * Acanthina
 * †Acanthina spirata
 * Acanthocardia
 * †Acanthocardia brewerii – type locality for species
 * †Acanthocardia sorrentoense
 * Acar
 * †Acar bailyi – or unidentified comparable form
 * Accipiter
 * †Accipiter velox
 * Acentrophryne
 * †Acentrophryne longidens
 * Acer
 * †Acer aequidentatum
 * †Acer scottiae
 * Acesta
 * †Acesta multiradiata
 * †Achaenodon
 * †Achaenodon robustus – or unidentified comparable form
 * Acila
 * †Acila castrensis
 * †Acila conradi
 * †Acila decisa
 * †Acila gabbiana
 * †Acila muta
 * †Acila semirostrata – or unidentified comparable form
 * †Acila shumardi
 * Acipenser
 * Acipenser medirostris.jpg †[[Acipenser medirostris]] – or unidentified comparable form
 * Acmaea
 * †Acmaea dickersoni – or unidentified related form
 * †Acmaea digitalis – or unidentified comparable form
 * †Acmaea insessa
 * †Acmaea limatula
 * †Acmaea mitra
 * †Acmaea persona
 * †Acmaea ruckmani – or unidentified comparable form
 * †Acmaea tejonensis – or unidentified comparable form
 * Acritohippus isonesus.jpg †[[Acritohippus]]
 * †Acritohippus isonesus – or unidentified comparable form
 * †Acritohippus quinni – type locality for species
 * †Acritohippus stylodontus
 * †Acritohippus tertius – or unidentified comparable form
 * †Acritoparamys – or unidentified comparable form
 * Acteocina
 * †Acteocina culcitella
 * †Acteocina inculta
 * †Acteocina magdalensis
 * Acteon
 * †Acteon boulderanus
 * †Acteon lawsoni
 * †Acteon punctocaelatus
 * †Acteon traski
 * Actinemys
 * 2009-Western-pond-turtle.jpg †[[Actinemys marmorata]]
 * †Acutostrea
 * †Acutostrea idriaensis
 * †Acutostrea miguelensis
 * Admete
 * †Admete rhyssa
 * Adula
 * †Adula californiensis
 * †Adula diegensis
 * Aechmophorus
 * †Aechmophorus elasson
 * †Aechmophorus occidentalis
 * †Aechomophorus
 * †Aechomophorus occidentalis
 * †Aeila
 * †Aeila decisa
 * †Aelurodon
 * †Aelurodon asthenostylus
 * †Aelurodon taxoides
 * Aepycamelus Alticamelus hharder.jpg †[[Aepycamelus]]
 * †Aepycamelus alexandrae
 * Aequipecten
 * †Aequipecten andersoni
 * Aesopus
 * †Aesopus chrysalloides
 * Aethia
 * †Aethia barnesi – type locality for species
 * †Aethia rossmoori – type locality for species
 * †Aethomylos
 * †Aethomylos simplicidens
 * Agaronia
 * †Agaronia mathewsoni – or unidentified comparable form
 * †Agaronia mathewsonii – or unidentified comparable form
 * †Agasoma
 * †Agasoma acuminatum
 * †Agasoma gravida
 * †Agasoma gravidum
 * †Agasoma kerrianum
 * †Agasoma sinuata
 * Agelaius
 * †Agelaius phoeniceuus
 * Agriotherium maraghanus mandible.JPG †[[Agriotherium]]
 * †Ailanthus
 * †Ailanthus lesquereuxi
 * Akera
 * †Akera maga
 * Alaba
 * †Alaba catalinensis
 * †Alaba jeannettae
 * Alabina
 * †Alabina io – or unidentified comparable form
 * †Alabina tenuisculpta
 * †Albicetus
 * †Albicetus oxymycterus – type locality for species
 * †Albireo
 * †Albireo savagei – type locality for species
 * Alca
 * †Alcodes
 * †Alcodes ulnulus – type locality for species
 * Aleochara
 * Aletes
 * †Aletes squamigerus
 * The American journal of science (1880) (17965682808).jpg †[[Aletomeryx]]
 * †Aletomeryx occidentalis – type locality for species
 * †Alforjas
 * Aligena
 * †Aligena cerritensis
 * †Alilepus
 * †Alilepus hibbardi
 * †Alisea – type locality for genus
 * †Alisea grandis – type locality for species
 * †Allodelphis – type locality for genus
 * †Allodelphis pratti – type locality for species
 * †Allodelphis woodburnei – type locality for species
 * Skeleton of Allodesmus.jpg Allodesmus]] †Allodesmus
 * †Allodesmus gracilis – type locality for species
 * †Allodesmus kelloggi – type locality for species
 * †Allodesmus kernensis
 * †Alluvisorex
 * †Alluvisorex chasseae – type locality for species
 * Alnus
 * †Alnus corrallina
 * †Alnus operia
 * †Alopecocyon – type locality for genus
 * †Alopecocyon leardi – type locality for species
 * Alopias
 * †Alopias exigua – or unidentified comparable form
 * †Alopias latidens
 * Pacifica thresher shark.jpg †[[Alopias vulpinus]] – or unidentified comparable form
 * Alvania
 * †Alvania acutelirata
 * †Alvania compacta
 * †Alvania iliuliukensis – or unidentified related form
 * †Alveojunctus
 * †Alveojunctus bowni – type locality for species
 * Amaea
 * Amara
 * †Amara insignis
 * †Amaurellina
 * †Amaurellina caleocia
 * †Amaurellina martinezensis
 * †Amaurellina moragai
 * Amauropsis
 * †Amauropsis alveata
 * Amelanchier grandiflora2.jpg [[Amelanchier]]
 * Amiantis
 * †Amiantis – type locality for species informal
 * †Amiantis callosa
 * †Amiantis diabloensis
 * †Amiantis mathewsoni
 * Ammobaculites
 * †Ammobaculites cubensis
 * †Ammobaculites strathearnensis – type locality for species
 * Ammospermophilus
 * †Ammospermophilus fossilis
 * †Amorpha
 * †Amorpha condonii
 * †Amorpha oklahomensis
 * †Amphicyon
 * †Amphicyon ingens
 * Machairodus giganteus 1.jpg †[[Amphimachairodus]]
 * †Amphimachairodus coloradensis – or unidentified comparable form
 * Amphimorphina
 * †Amphimorphina ignota
 * Amphissa
 * †Amphissa columbiana
 * †Amphissa reticulata
 * †Amphissa ventricosa
 * †Amphissa versicolor
 * Amphiura
 * †Amphiura santaecrucis
 * †Amphora
 * †Amphora ovalis
 * †Amphora perpusilla
 * †Ampullina
 * †Ampullina schencki – or unidentified comparable form
 * Amusium
 * †Amusium lompocensis
 * †Amussiopecten
 * †Amussiopecten vanvlecki
 * †Amynodon
 * †Amynodon advenus – or unidentified comparable form
 * †Amynodon reedi
 * †Amynodontopsis
 * †Amynodontopsis bodei – type locality for species
 * Anachis
 * †Anachis coronata
 * Anadara granosa.jpg [[Anadara]]
 * †Anadara devincta
 * †Anadara obispoana
 * †Anadara osmonti
 * †Anadara perlabiata
 * †Anadara reinharti
 * †Anadara rivulata
 * †Anadara santana – type locality for species
 * †Anadara submontereyana
 * †Anadara trilineata
 * Anaphothrips
 * †Anaphothrips vitreus – type locality for species
 * Anas
 * †Anas americana
 * †Anas carolinense
 * †Anas clypeata
 * †Anas platyrhynchos
 * †Anchitheriomys – or unidentified comparable form
 * Anchitherium fossils cropped.png †[[Anchitherium]]
 * †Anchitherium clarencei
 * †Anchura
 * †Anchura baptos
 * Ancilla
 * †Ancilla fishii
 * †Ancilla gabbi – tentative report
 * †Angelosquilla
 * †Angelosquilla altamirensis
 * Angulogerina
 * Angulus
 * †Angulus buttoni
 * †Angulus castacana
 * †Angulus joaquinensis
 * †Angulus jollaensis – or unidentified comparable form
 * †Angulus longa
 * †Angulus lutea – or unidentified comparable form
 * Anniella
 * Anodontia
 * †Anodontia edentuloides
 * †Anodontia inflata
 * †Anomalina
 * †Anomalina californiensis
 * †Anomalina garzaensis
 * Anomalinoides
 * †Anomalinoides globosa – or unidentified comparable form
 * Anomia
 * †Anomia mcgoniglensis
 * †Anomia peruviana
 * †Anomia vaquerosensis – type locality for species
 * †Ansen
 * †Ansen albifrons
 * Anser
 * †Anser albifrons
 * †Antecalomys
 * †Antecalomys valensis
 * †Antecalomys vasquezi
 * †Antiacodon
 * †Antiacodon venustus
 * Antigona
 * †Antigona undosa
 * †Antilla
 * †Antilla batequensis
 * Antilocapra americana.jpg [[Antilocapra]]
 * Antrozous
 * †Antrozous pallidus
 * †Anzanycteris
 * †Anzanycteris anzensis
 * †Apataelurus – or unidentified comparable form
 * †Apatemys
 * †Apatemys bellus
 * †Apatemys downsi – type locality for species
 * †Apatemys uintensis
 * Aphelocoma
 * †Aphelocoma californica
 * †Aphelophlebodes – type locality for genus
 * †Aphelophlebodes stocki – type locality for species
 * Aphelops.jpg †[[Aphelops]]
 * †Aphelops megalodus
 * Apiotoma
 * †Apiotoma californiana
 * Aplodontia
 * †Aplodontia rufa
 * Aprionodon
 * Apsena
 * †Apsena laticornis – type locality for species
 * †Apsena pubescens
 * †Apsena rufipes
 * Aquila
 * Golden Eagle in flight - 5.jpg [[Aquila chrysaetos]]
 * †Araeosteus
 * †Araeosteus rothi
 * Arbutus
 * †Arbutus matthesii
 * Arca
 * †Arca hornii – type locality for species
 * †Arca montereyana
 * †Arca pacifica – or unidentified comparable form
 * †Arca santaclarana
 * †Arca sisquocensis
 * †Arca terminumbonis
 * †Arceuthobium
 * Cormocyon leptodus.JPG †[[Archaeocyon]]
 * †Archaeocyon pavidus
 * †Archaeohippus
 * †Archaeohippus mourningi
 * †Archaeohippus ultimus
 * †Archaeolagus
 * †Archaeolagus acaricolus – type locality for species
 * †Archaeolithothamnion
 * †Archaeolithothamnion keenanii – or unidentified related form
 * Archaeolithothamnium
 * †Archaeolithothamnium keenani – type locality for species
 * †Archaeoparadoxia
 * †Archaeoparadoxia weltoni – type locality for species
 * †Archibuteo
 * †Archibuteo ferrugineus
 * Architectonica sp. (Marine snail).jpg [[Architectonica]]
 * †Architectonica cognata
 * †Architectonica llajasensis – type locality for species
 * †Architectonica nobilis
 * †Architectonica tuberculata
 * †Architectonica ullreyana – or unidentified comparable form
 * †Archoheia – tentative report
 * Archoplites
 * †Archoplites interruptus
 * Arcinella
 * †Arcinella californica
 * Arctica – tentative report
 * †Arctica weaveri
 * Arctocephalus
 * ArctodusSimusReconstruct.jpg †[[Arctodus]]
 * †Arctodus simus – type locality for species
 * †Arctostaphylos
 * Ardea
 * †Ardea herodias
 * Arenaria
 * †Arenaria melanocephala
 * Arene
 * †Arene mcleani – type locality for species
 * †Argenna
 * †Argenna fossilis – type locality for species
 * Argobuccinum
 * †Argobuccinum katherineae – type locality for species
 * †Argobuccinum oregonensis
 * Argopecten
 * †Argopecten deserti
 * †Argopecten gibbus
 * †Argopecten mendenhalli
 * †Argopecten purpuratus
 * †Argopecten ventricosus
 * †Argyrocetus – type locality for genus
 * †Argyrocetus bakersfieldensis – type locality for species
 * †Argyrocetus joaquinensis – type locality for species
 * Argyropelecus lychnus SI.jpg [[Argyropelecus]]
 * †Argyropelecus bullocki – type locality for species
 * †Argyropelecus bullockii
 * †Arnoldina – type locality for genus
 * †Arnoldina iniistia – type locality for species
 * Arossia
 * †Artocarpus
 * †Artocarpus lessigiana
 * †Asclepiadites
 * †Asclepiadites laterita – type locality for species
 * Asio otus -Battlefield Falconry Centre, Shrewsbury, Shropshire, England-8a.jpg, or long-eared owl]] Asio''
 * †Asio priscus
 * †Asio wilsonianus
 * Asterigerina
 * †Asterigerina crassaformis
 * Astraea
 * †Astraea biangulata – or unidentified comparable form
 * †Astraea gibbosa
 * †Astraea gradata
 * †Astraea morani – type locality for species
 * †Astraea undosa
 * Astrangia
 * †Astrangia grandis – type locality for species
 * †Astrangia insignifica – type locality for species
 * †Astrocoenia – tentative report
 * †Astrocoenta
 * †Astrodapsis
 * †Astrodapsis arnoldi – or unidentified comparable form
 * †Astrodapsis cuyamanus
 * †Astrodapsis fernandoensis
 * †Astrodapsis merriami – tentative report
 * †Astrodapsis spatiosus
 * †Astrodaspis
 * †Astrodaspis arnoldi
 * Astropecten
 * Astyris
 * †Astyris gausapata
 * Athene
 * †Athene cunicularia
 * Athleta
 * †Athleta roddai – type locality for species
 * Atocetus iquensis skull mandible mio med.JPG †[[Atocetus]]
 * †Atocetus nasalis – type locality for species
 * †Atopotarus – type locality for genus
 * †Atopotarus courseni – type locality for species
 * Atrina
 * †Atrina alamedensis
 * †Aturia
 * †Aturia angustata
 * †Aturia dickersoni – type locality for species
 * †Aturia kerniana – type locality for species
 * †Aturia myrlae – type locality for species
 * †Aturoidea
 * †Aturoidea mathewsonii – type locality for species
 * Atys
 * Aulophyseter BW.jpg †[[Aulophyseter]] – type locality for genus
 * †Aulophyseter morricei – type locality for species
 * Austrotrophon
 * †Auxides
 * †Auxides sanctaemonicae
 * †Avipeda
 * Aythya
 * †Aythya affinis
 * †Aythya valisineria
 * †Azalois – type locality for genus
 * †Azalois angelensis – type locality for species

B

 * Baiomys
 * †Baiomys mowi
 * Balaenoptera
 * †Balaenoptera bertae – type locality for species
 * †Balaenoptera cortesi
 * †Balaenoptera davidsonii – type locality for species
 * †Balaenoptera physalus
 * †Balaenoptera ryani
 * Balaenula balaenopsis.jpg †[[Balaenula]]
 * Balanophyllia
 * †Balanophyllia elegans
 * †Balanophyllia variabilis – type locality for species
 * Balanus
 * †Balanus crenatus
 * †Balanus gregarius
 * †Balanus nubilus – or unidentified comparable form
 * †Balanus rostratus
 * Balcis
 * †Balcis micans
 * †Balcis monicensis
 * †Balcis oldroydi
 * †Balcis rutila
 * †Balcis thersites
 * Bankia
 * †Bankia setacea – or unidentified comparable form
 * Barbarofusus
 * †Barbarofusus barbarensis
 * Barbatia
 * †Barbatia cliffensis
 * †Barbatia landesi – or unidentified related form
 * †Barbatia strongi – type locality for species
 * †Barbatia suzzalloi – or unidentified comparable form
 * Barbourofelis fricki.JPG †[[Barbourofelis]]
 * †Barbourofelis loveorum
 * †Barbourofelis whitfordi
 * Barleeia
 * †Barleeia marmorea
 * Barnea
 * †Barnea costata
 * †Basirepomys
 * †Basirepomys pliocenicus – type locality for species
 * Bassariscus
 * †Bassariscus antiquus
 * †Bassariscus astutus – or unidentified comparable form
 * †Bassariscus casei
 * †Bassariscus raptor
 * †Bathylagus – type locality for genus
 * †Bathylagus quiescens – type locality for species
 * †Bathylagus quisquilia – type locality for species
 * †Bathysiphon
 * †Bathysiphon eocenica
 * †Bathysiphon sanctaecrucis
 * Bathytoma
 * †Bathytoma pacifica
 * †Batodonoides
 * †Batodonoides powayensis
 * †Batodonoides walshi – type locality for species
 * Bembidion quadrimaculatum upside.jpg [[Bembidion]]
 * †Bembidion davidae – type locality for species
 * †Bembidion everestae – type locality for species
 * †Benoistia
 * †Benoistia cantonensis
 * †Bensonomys
 * †Bensonomys arizonae
 * †Bensonomys gidleyi
 * †Bensonomys meadensis
 * Beringraja
 * †Beringraja binoculata – or unidentified comparable form
 * †Bestiopeda
 * Betula
 * †Betula ashleyii
 * †Bifarina
 * †Bifarina eleganta
 * Bison
 * †Bison antiquus
 * Bison latifrons fossil buffalo.jpg †[[Bison latifrons]]
 * Bittium
 * †Bittium alternatum – or unidentified comparable form
 * †Bittium asperum
 * †Bittium casmaliense
 * †Bittium catalinense
 * †Bittium dumblei
 * †Bittium eschrichti
 * †Bittium eschrichtii
 * †Bittium inerfossa
 * †Bittium interfossa
 * †Bittium latum
 * †Bittium ornatissimum
 * †Bittium rugatum
 * †Bittium topangensis
 * Bivetopsia
 * †Bivetopsia bullata
 * †Boavus
 * †Boavus affinis – type locality for species
 * Boetica
 * †Boetica hertleini
 * Bolbocara cropped.png †[[Bolbocara]]
 * †Bolbocara gyrinus
 * Bolinichthys
 * Bolivina
 * †Bolivina gracilis
 * Bonasa
 * †Bonasa umbellus
 * †Bonellitia
 * †Bonellitia paucivaricata
 * †Bonellitia stantoni
 * Bornia
 * †Bornia retifera
 * Borophagus cropped.png genus Borophagus preying on a camel. Jay Matternes (1964).]] †Borophagus
 * †Borophagus diversidens
 * †Borophagus littoralis – type locality for species
 * †Borophagus parvus
 * †Borophagus secundus
 * †Borophryne
 * †Borophryne apogon
 * †Bouromeryx
 * †Bouromeryx americanus
 * †Bouromeryx submilleri – or unidentified comparable form
 * Brachidontes
 * †Brachidontes cowlitzensis
 * †Brachidontes dichotomus
 * †Brachidontes lawsoni – or unidentified comparable form
 * †Brachidontes ornatus
 * Brachiodontes
 * †Brachiodontes lawsoni
 * †Brachisphingus
 * †Brachisphingus gabbi
 * †Brachyallodesmus – type locality for genus
 * †Brachyallodesmus packardi
 * Brachycrus.jpg †[[Brachycrus]]
 * †Brachycrus buwaldi
 * †Brachycrus laticeps
 * †Brachyerix
 * †Brachyerix incertis
 * †Brachypsalis
 * †Brachypsalis obliquidens
 * †Brachypsalis pachycephalus – or unidentified comparable form
 * Brachyramphus
 * †Brachyramphus dunkeli – type locality for species
 * †Brachyramphus pliocenum – type locality for species
 * †Brachysphingus
 * †Brachysphingus liratus
 * †Brachysphingus mammilatus – type locality for species
 * †Brachysphingus sinuatus
 * black.brant.slimbridge.march2007.arp.jpg, or black brant]] Branta''
 * †Branta canadensis
 * †Branta nigricans – tentative report
 * †Branta woolfendeni – or unidentified comparable form
 * †Bretzia
 * †Brevirostrodelphis – Type locality for genus
 * †Brevirostrodelphis dividum - Type locality for species (synonym Delphinodon dividum)
 * †Brochopleurus – tentative report
 * †Bruclarkia
 * †Bruclarkia barkerianum
 * †Bruclarkia barkerium
 * †Bruclarkia columbiana
 * †Bruclarkia gravida
 * †Bruclarkia oregonensis – or unidentified comparable form
 * †Bruclarkia santacruzana
 * †Bruclarkia seattlensis
 * Bubo
 * †Bubo sinclairi – type locality for species
 * Bubo virginianus 06.jpg †[[Bubo virginianus]]
 * Buccinum
 * †Buccinum strigillatum
 * Bucephala
 * †Bucephala albeola
 * †Bucida
 * †Bucida eocenica
 * Bufo
 * †Bulbiceps
 * †Bulbiceps raninus
 * †Bulbifusus
 * †Bulbifusus californicus – type locality for species
 * Bulimina
 * †Bulimina chirana
 * †Bulimina debilis
 * †Bulimina jacksonensis
 * †Bulimina ovata
 * †Bulimina ovula
 * †Bulimina rinconensis
 * †Bulimina socialis – or unidentified comparable form
 * Buliminella
 * †Buliminella curta
 * †Buliminella subfusiformis
 * Bulla
 * †Bulla clarki
 * Bulla gouldiana cropped.png †[[Bulla gouldiana]]
 * †Bulla punctulata – or unidentified comparable form
 * †Bulla punctulatus
 * †Bulla striata
 * Bullia
 * †Bullia clarki
 * †Bullinula
 * †Bullinula subglobosa
 * †Bumelia
 * †Bumelia florissanti
 * Bursa
 * †Bursa califomica
 * Buteo
 * †Buteo borealis
 * Buteo jamaicensis -Pillar Point Harbor, California, USA-8.jpg †[[Buteo jamaicensis]]
 * †Buteo swainsoni

C

 * Cadulus
 * †Cadulus fusiformis
 * Caecum
 * †Caecum californicum
 * Calicantharus
 * †Calicantharus dalli
 * †Calicantharus fortis
 * †Calicantharus humerosus
 * †Calicantharus portolaensis – or unidentified comparable form
 * †Calicovatellus – type locality for genus
 * †Calicovatellus petrodytes – type locality for species
 * Calidris
 * †Calidris alba
 * Californiconus
 * †Californiconus californicus
 * †Calilampas
 * †Calilampas californiensis
 * †Calipepla
 * †Calipepla californica
 * Calliostoma
 * †Calliostoma annulata
 * Calliostoma annulatum 1.jpg †[[Calliostoma annulatum]]
 * †Calliostoma augustinensis
 * †Calliostoma canaliculatum
 * †Calliostoma costatum
 * †Calliostoma crassicostatus
 * †Calliostoma doliarium
 * †Calliostoma doliarum – tentative report
 * †Calliostoma gemmulatum
 * †Calliostoma ligatum
 * †Calliostoma nuttalli
 * †Calliostoma supragranosum
 * †Calliostoma tricolor
 * Callista
 * †Callista domenginica
 * †Callista vokesi
 * Callistochiton
 * †Callistochiton palmulatus
 * Callithaca
 * †Callithaca tenerrima
 * Callorhinus
 * †Callorhinus gilmorei – type locality for species
 * Northfursealbull.jpg †[[Callorhinus ursinus]]
 * Calopsectra
 * †Calorebama
 * †Calorebama inornata
 * †Calorhadia – tentative report
 * Calosoma
 * †Calosoma semilaeve
 * †Calycites
 * †Calycites mikanoides
 * Calyptraea chinensis 001.jpg [[Calyptraea]]
 * †Calyptraea calabasasensis
 * †Calyptraea contorta
 * †Calyptraea costellata
 * †Calyptraea dalliana
 * †Calyptraea diegoana
 * †Calyptraea excentrica
 * †Calyptraea fastigiata
 * †Calyptraea filosa
 * †Calyptraea inornata
 * †Calyptraea mamillaris
 * †Calyptraea mammilaris – or unidentified comparable form
 * †Calyptranthes
 * †Calyptranthes myrtifolia – type locality for species
 * Camelops hesternus Sergiodlarosa.jpg †[[Camelops]]
 * †Camelops hesternus
 * †Camelops minidokae
 * †Cammackacetus – Type locality for genus
 * †Cammackacetus hazenorum - Type locality for species
 * Campanile
 * †Campanile dilloni
 * Camponotus – type locality for genus
 * †Camponotus festinatus – type locality for species
 * †Canarium
 * †Canarium californicum
 * Cancellaria
 * †Cancellaria arnoldi
 * †Cancellaria dalliana
 * †Cancellaria fernandoensis
 * †Cancellaria obesa
 * †Cancellaria planospira
 * †Cancellaria posunculensis
 * †Cancellaria subtuberosa
 * †Cancellaria tritonidea
 * Cancer
 * Cancris
 * †Cancris mexicanus
 * Canis
 * Canis lupus & dirus.jpg, the grey wolf, to scale with a fossilized skeleton of the Pleistocene wolf Canis dirus, or dire wolf]] †Canis dirus''
 * †Canis edwardii
 * †Canis latrans
 * †Canis lepophagus
 * †Canis lupus
 * †Canis rufus
 * Canthon
 * †Canthon praticola
 * †Canthon simplex
 * †Cantius
 * †Cantius actius
 * †Capricamelus – type locality for genus
 * †Capricamelus gettyi – type locality for species
 * †Capromeryx
 * Capromeryx minor p1350725.jpg]] †Capromeryx minor''
 * Caracara
 * †Caracara cheriway
 * †Caracara plancus
 * Carcharhinus
 * Carcharias
 * †Carcharias clavatus
 * †Carcharinus
 * Carcharodon
 * †Carcharodon arnoldi
 * †Carcharodon carcharias
 * †Carcharodon hastalis
 * †Carcharodon leviathan
 * †Carcharodon morricei
 * †Carcharodon sulcidens
 * †Carcharodon tembloris – type locality for species
 * Cardium
 * †Cardium brewerii, alternative of Acanthocardia brewerii (see )
 * Carpelimus
 * †Carpites
 * †Carpites egregia
 * †Carpocyon
 * †Carpocyon robustus
 * Carya Morton 29-U-10.jpg [[Carya]]
 * †Carya bendirei
 * †Carya sessilis
 * Caryophyllia
 * †Caryophyllia arnoldi
 * †Caryophyllia californica – type locality for species
 * †Caryophyllia capayensis – type locality for species
 * †Caryophyllia pedroensis – type locality for species
 * Cassidulina
 * †Cassidulina crassipunctata
 * †Cassidulina diversa – or unidentified comparable form
 * †Cassidulina globosa
 * Castanea
 * †Castanea spokanensis
 * Castanopsis
 * †Castanopsis longipetiolatum
 * Castor
 * †Castor californicus – or unidentified comparable form
 * †Catharista
 * †Catharista shastensis – type locality for species
 * Cathartes
 * Eastern Turkey Vulture (Canada).jpg †[[Cathartes aura]]
 * Catoptrophorus
 * †Catoptrophorus semipalmatus
 * †Catoptrophus
 * †Catoptrophus inornatus
 * †Catostomus
 * †Catostomus occidentalis
 * Ceanothus
 * †Ceanothus tuolumnensis
 * †Ceanothus turlockensis
 * Cedrela
 * †Cedrela eolancifolia – type locality for species
 * †Cedrela trainii
 * †Celastrus
 * †Celastrus preangulata – type locality for species
 * Celtis
 * †Celtis kansana
 * †Centetodon
 * †Centetodon aztecus
 * †Centetodon bembicophagus – or unidentified comparable form
 * †Centetodon magnus – or unidentified comparable form
 * Centrifuga
 * †Centrifuga leeana
 * Cepphus
 * Pigeon guillemot.jpg †[[Cepphus columba]]
 * †Cepphus olsoni – type locality for species
 * Cercidiphyllum
 * †Cercidiphyllum elongatum
 * †Cercocarpus
 * †Cercocarpus nevadensis
 * Cerithidea
 * †Cerithidea californica
 * Cerithiopsis
 * †Cerithiopsis antefilosa
 * †Cerithiopsis carpenteri
 * †Cerithiopsis columna – or unidentified comparable form
 * †Cerithiopsis cosmia
 * †Cerithiopsis halia – or unidentified related form
 * †Cerithiopsis paramoea
 * †Cerithiopsis pedroana
 * †Cerithiopsis rowelli
 * †Cerithiopsis stejnegeri – or unidentified comparable form
 * Cerithium
 * †Cerithium incisum
 * †Cerithium topangensis
 * †Cernictis
 * †Cernictis hesperus – type locality for species
 * †Cernina
 * †Cernina hannibali
 * †Cerorhinca
 * †Cerorhinca dubia – type locality for species
 * †Cerorhinca reai – type locality for species
 * Cervus
 * †Cervus elaphus
 * Cetorhinus
 * †Cetorhinus maximus
 * Cetotherium BW.jpg †[[Cetotherium]]
 * †Cetotherium furlongi – type locality for species
 * †Chaceia
 * †Chaceia fulcherae – type locality for species
 * †Chaenophryne
 * †Chaenophryne melanorhabdus
 * Chaetodipus
 * †Chaetodipus formosus – or unidentified comparable form
 * †Chaetoptelea
 * †Chaetoptelea pseudofulva
 * †Chalcidichthys – type locality for genus
 * †Chalcidichthys malacopterygius – type locality for species
 * Chama
 * †Chama arcana
 * †Chama frondosa
 * †Chama grunski
 * †Chamaecyparis
 * †Chamaecyparis cordillerae
 * Charadrius
 * †Charadrius semipalmatus
 * NOAA Ocean Exploration Viperfish Chauliodus danae.jpg [[Chauliodus]] – type locality for genus
 * †Chauliodus eximias
 * †Chauliodus eximius – type locality for species
 * †Chedevillia
 * †Chedevillia saltonensis – type locality for species
 * †Chedevillia stewarti – type locality for species
 * Chelonia
 * †Chelonia californiensis – type locality for species
 * Chen
 * †Chen caerulescens
 * Chendytes cropped.png †[[Chendytes]] – type locality for genus
 * †Chendytes lawi – type locality for species
 * Chilostomella
 * †Chilostomella hadleyi
 * †Chilostomelloides
 * †Chilostomelloides ovicula
 * †Chilostomelloides oviformis
 * Chione
 * †Chione californiensis
 * †Chione cryptolineata – or unidentified comparable form
 * †Chione latilaminosa
 * †Chione lineolata – or unidentified comparable form
 * †Chione panzana
 * †Chione schencki
 * †Chione securis
 * †Chione undatella
 * Chionista
 * †Chionista fluctifraga
 * Chionopsis
 * †Chionopsis gnidia
 * †Chionopsis richthofeni
 * †Chionopsis temblorensis
 * Chlamys
 * †Chlamys bartschi
 * †Chlamys branneri – or unidentified comparable form
 * †Chlamys corteziana – or unidentified comparable form
 * Chlamys hastata.jpg †[[Chlamys hastata]]
 * †Chlamys hertleini
 * †Chlamys mediacostatus – type locality for species
 * †Chlamys rubida
 * †Chlamys sespeensis
 * †Chlamys swifti
 * Chlorostoma
 * †Chlorostoma gallina
 * †Chorizanthe
 * †Chrisodomus
 * †Chrysobalanus
 * †Chrysobalanus eoicaco
 * Maned Wolf 11, Beardsley Zoo, 2009-11-06.jpg, or maned wolf]] †Chrysocyon''
 * †Chrysocyon nearcticus
 * †Chrysodomus – report made of unidentified related form or using admittedly obsolete nomenclature
 * †Chrysodomus martini
 * †Chrysolepis
 * †Chrysolepis sonomensis
 * †Chumashius
 * †Chumashius balchi – type locality for species
 * Cibicides
 * †Cibicides cushmani
 * †Cibicides martinezensis
 * †Cibicides pseudoungerianus
 * Cibicidoides
 * †Cibicidoides midwayensis – or unidentified comparable form
 * Cicindela
 * †Cicindela haemorrhagica
 * †Cicindela oregona
 * Cidaris
 * †Cidaris martinezensis
 * Starr 010419 0038 cinnamomum camphora.jpg [[Cinnamomum]]
 * †Cinnamomum acrodromum
 * †Cinnamomum dilleri
 * Cissus
 * †Cissus pyriformis
 * †Citellus
 * †Citellus bensoni
 * Citharichthys
 * †Citharichthys stigmaeus
 * †Claibornites
 * †Claibornites diegoensis
 * †Claibornites muirensis
 * †Claibornites turneri
 * Clathrodrillia flavidula 001.jpg [[Clathrodrillia]]
 * †Clathrodrillia coalingensis
 * Clathurella
 * †Clathurella conradiana
 * Clavilithes
 * †Clavilithes tabulatus
 * Clavus
 * †Clavus hartleyensis – type locality for species
 * †Clavus hemphilli
 * †Clavus pallidus – or unidentified related form
 * †Clavus temblorensis
 * Clementia
 * †Clementia brioniana
 * †Clementia conradiana
 * †Clementia pertenius
 * †Clementia pertenuis
 * Clethrionomys
 * Cletocamptus
 * Clinocardium cropped.png [[Clinocardium]]
 * †Clinocardium meekianum
 * †Clinocardium nuttallii
 * Cliona
 * Clupea
 * †Clupea hadleyi – type locality for species
 * †Clupea tiejei – type locality for species
 * Clypeaster
 * †Clypeaster bowersi
 * †Clypeaster carrizoensis – type locality for species
 * †Clypeaster deserti
 * Aruba-Cnemidophorus-arubensis.JPG [[Cnemidophorus]]
 * †Coalingodea
 * †Coalingodea tuberculiformis
 * Coccodentalium
 * †Coccodentalium emersoni – type locality for species
 * †Cocconeis
 * †Cocconeis disculus
 * †Cocconeis placentula
 * †Cochlespiropsis – tentative report
 * †Cochlespiropsis jenkinsi – type locality for species
 * Cochliomyia – type locality for genus
 * †Cochliomyia macellaria – type locality for species
 * Lucinidae - Codakia punctata.JPG [[Codakia]]
 * †Codakia colpoica
 * †Codakia distinguenda
 * Colaptes
 * †Colaptes cafer
 * †Colodon
 * Coluber
 * †Coluber constrictor
 * Colubraria
 * Columba – or unidentified comparable form
 * †Columba fasciata
 * Columbarium
 * Colymbus
 * †Colymbus nigricollis
 * †Colymbus parvus
 * †Colymbus subparvus – type locality for species
 * Compsomyax
 * †Compsomyax subdiaphana
 * Conus cancellatus 1.jpg †[[Conasprelloides]]
 * †Conasprelloides planiliratus
 * Concavus
 * †Concavus concavus
 * †Conchocele
 * †Conchocele bisecta
 * Coniontis
 * †Coniontis abdominalis – type locality for species
 * †Coniontis elliptica
 * †Coniontis lamentabilis
 * †Coniontis puncticollis
 * †Coniontis remnans – type locality for species
 * †Coniontis robusta
 * †Coniontis rugosa
 * Conus
 * †Conus caleocius
 * †Conus fergusoni
 * †Conus hornii
 * †Conus owenana
 * †Conus owenianus
 * †Conus redmondii – or unidentified comparable form
 * Gradiconus regularis.JPG †[[Conus regularis]]
 * †Conus remondii
 * †Conus scalaris
 * Cooperella
 * †Cooperella subdiaphana
 * †Copemys
 * †Copemys barstowensis – type locality for species
 * †Copemys esmeraldensis
 * †Copemys longidens – type locality for species
 * †Copemys pagei
 * †Copemys russelli
 * †Copemys tenuis – type locality for species
 * †Cophocara
 * †Cophocara stantoni
 * †Cophocetus – tentative report
 * Copris fricator.jpg [[Copris]]
 * †Copris pristinus – type locality for species
 * Coragyps
 * Coralliophaga
 * Corbicula
 * †Corbicula dumblei
 * Corbula
 * †Corbula diaboli – type locality for species
 * †Corbula dickersoni
 * †Corbula dilatata
 * †Corbula fragilis
 * †Corbula hornii – or unidentified comparable form
 * †Corbula parilis
 * †Corbula tomulata – or unidentified comparable form
 * Ashfall Fossil Beds - Teleoceras and Cormohipparion.jpg †[[Cormohipparion]]
 * †Cormohipparion occidentale – or unidentified comparable form
 * Cornus
 * †Cornus kelloggii
 * †Cornus ovalis – or unidentified comparable form
 * †Coronadus – type locality for genus
 * †Coronadus agilis – type locality for species
 * Coronula – tentative report
 * Corvus
 * †Corvus brachyrhynchos
 * †Corvus corax
 * †Cosomys
 * †Cosomys primus – type locality for species
 * †Cosoryx
 * †Cosoryx cerroensis – or unidentified comparable form
 * Costacallista
 * †Costacallista hornii – or unidentified comparable form
 * Cranioceras unicornis life restoration.jpg Cranioceras, a relative of modern deer, with anachronistic human to scale]] †Cranioceras
 * †Cranioceras teres
 * †Cranioceras unicornis – or unidentified comparable form
 * †Craseops
 * †Craseops sylvestris – type locality for species
 * Crassadoma
 * †Crassadoma gigantea
 * Crassatella
 * †Crassatella – type locality for species A informal
 * †Crassatella claytonensis
 * †Crassatella compacta
 * †Crassatella granti
 * †Crassatella meganosensis – type locality for species
 * †Crassatella unioides
 * †Crassatella uvasana
 * †Crassatella washingtonensis
 * Crassinella
 * †Crassinella nuculiformis
 * †Crassinella pacifica
 * Crassispira incrassata 001.jpg [[Crassispira]]
 * †Crassispira montereyensis – or unidentified related form
 * †Crassispira zizyphus
 * Crassostrea
 * †Crassostrea ashleyi
 * †Crassostrea titan
 * †Crassostrea vaquerosensis
 * Crataegus
 * †Crataegus pacifica
 * Crawfordina
 * †Crawfordina weaveri
 * †Crenaturricula
 * †Crenaturricula crenatospira
 * Crepidula
 * †Crepidula adunca
 * †Crepidula coei – or unidentified comparable form
 * †Crepidula diminutiva – type locality for species
 * †Crepidula excavata
 * †Crepidula lessoni
 * †Crepidula nummaria
 * †Crepidula nunimaria
 * Crepidula onyx 01.JPG †[[Crepidula onyx]]
 * †Crepidula pileum – or unidentified comparable form
 * †Crepidula praerupta
 * †Crepidula princeps
 * †Crepidula ungana – or unidentified comparable form
 * Crepipatella
 * †Crepipatella lingulata
 * †Crommium
 * †Crommium andersoni
 * †Crommium pinyonensis
 * Crossata
 * †Crossata ventricosa
 * Crotalus
 * Crotalus viridis nuntius.jpg †[[Crotalus viridis]]
 * Crucibulum
 * †Crucibulum spinosum
 * †Crypholestes
 * †Crypholestes vaughni
 * †Cryptocarya
 * †Cryptocarya praesamarensis
 * †Cryptoconus
 * †Cryptoconus cooperi
 * Cryptomya
 * †Cryptomya californica
 * Cryptonatica
 * †Cryptonatica affinis
 * †Cryptonatica aleutica
 * Cryptotermes brevis.jpg [[Cryptotermes]]
 * †Cryptotermes ryshkoffi – type locality for species
 * Cryptotis
 * Ctenocardia
 * †Ctenocardia biangulata
 * Cucullaea
 * †Cucullaea mathewsoni
 * †Cucullaea mathewsonii
 * Culicoides
 * †Culicoides carri – type locality for species
 * †Culicoides fossilis – type locality for species
 * †Culicoides laurae – type locality for species
 * †Culicoides megacanthus – type locality for species
 * †Culicoides mioceneus – type locality for species
 * Cumingia
 * †Cumingia lamellosa
 * †Cunnolites – tentative report
 * †Cupania
 * †Cupania oregona
 * †Cupidinimus
 * †Cupidinimus avawatzensis
 * †Cupidinimus bidahochiensis – or unidentified comparable form
 * †Cupidinimus boronensis – type locality for species
 * †Cupidinimus halli
 * †Cupidinimus lindsayi – type locality for species
 * †Cupidinimus tertius
 * Cypress Halefka.JPG †[[Cupressus]]
 * †Cupressus goveniana
 * †Cupressus mokelumnensis
 * Cuspidaria
 * †Cuspidaria hannibali
 * †Cuyamacamelus
 * †Cuyamacamelus jamesi
 * †Cuyamalagus
 * †Cuyamalagus dawsoni – type locality for species
 * Cyanocitta
 * †Cyanocitta stelleri
 * Cybocephalus
 * †Cybocephalus californicus – or unidentified comparable form
 * Cyclammina
 * †Cyclammina clarki
 * †Cyclammina incisa – or unidentified comparable form
 * Cyclinella
 * Cyclocardia
 * †Cyclocardia californica
 * †Cyclocardia montereyana – type locality for species
 * †Cyclocardia ventricosa
 * †Cyclocorystes
 * †Cyclocorystes aldersoni – type locality for species
 * †Cyclosthone – or unidentified comparable form
 * Cyclothone microdon1.jpg [[Cyclothone]]
 * Cygnus
 * †Cygnus columbianus
 * Cylichna
 * †Cylichna attonsa
 * Cylichnella
 * †Cylichnella attonsa
 * †Cylichnella culcitella
 * Cymatium
 * †Cymatium elsemerense
 * †Cymatium janetae – type locality for species
 * Cymatogaster
 * †Cymatogaster aggregata
 * †Cymbophora
 * †Cynarctoides
 * †Cynarctoides acridens
 * †Cynarctoides whistleri – type locality for species
 * †Cynarctus
 * †Cynarctus galushai – type locality for species
 * Cynelos lemanensis.JPG †[[Cynelos]]
 * †Cynelos malasi – type locality for species
 * †Cynelos sinapius – or unidentified comparable form
 * †Cynorca
 * †Cynorca occidentale
 * Cynoscion
 * †Cynoscion eprepes
 * Cyperus
 * Cypraea
 * Cyrena
 * †Cyrena dumblei
 * †Cyrena studleyi – or unidentified comparable form
 * Cyrtonyx montezumaeEBP20A.jpg [[Cyrtonyx]]
 * †Cyrtonyx tedfordi – type locality for species
 * Cystiscus
 * †Cystiscus subtrigona
 * Cythara
 * †Cythara cetolaca
 * †Cythara hecetae
 * †Cythara interlirata
 * Cytherea
 * †Cytherea mathewsoni

D

 * †Dalbergia
 * †Dalbergia rubra – type locality for species
 * Dallocardia
 * †Dallocardia quadragenarium
 * Damalichthys
 * †Damalichthys vacca
 * †Daphoenodon – or unidentified comparable form
 * Daphoenus vetus skeleton.jpg †[[Daphoenus]]
 * †Daphoenus ruber – type locality for species
 * †Darbyella
 * Dardanus
 * †Dardanus arrosor
 * †Dasceles – type locality for genus
 * †Dasceles dassurus – type locality for species
 * Dasyatis
 * †Dasyatis dipterus
 * Dasyhelea
 * †Dasyhelea antiqua
 * †Dasyhelea browneae – type locality for species
 * †Dasyhelea dara – type locality for species
 * †Dasyhelea judithae – type locality for species
 * †Dasyhelea kanakoffi – type locality for species
 * †Dasyhelea stenoceras – type locality for species
 * Decapterus koheru (koheru).jpg †[[Decapterus]]
 * †Decapterus hopkinsi
 * Delectopecten
 * †Delectopecten lillisi
 * †Delectopecten peckhami
 * †Delphinavus – type locality for genus
 * †Delphinavus newhalli – type locality for species
 * Deltochilum – tentative report
 * Deltocyathus
 * †Deltocyathus whitei – type locality for species
 * Dendostrea
 * †Dendostrea vespertina
 * Dendragapus
 * †Dendragapus fuliginosus
 * Dendragapus obscurus USNPS.jpg †[[Dendragapus obscurus]]
 * Dendraster
 * †Dendraster coalingaensis – or unidentified comparable form
 * †Dendraster excentricus
 * †Dendraster gibbsi
 * Dendrophyllia
 * †Dendrophyllia californiana – type locality for species
 * †Dendrophyllia oldroydi – tentative report
 * †Dendrophyllia tejonensis – type locality for species
 * Dendryphantes rudis - Springspinne 4253.JPG [[Dendryphantes]]
 * Dentalina
 * †Dentalina approximata
 * †Dentalina consobrina
 * †Dentalina cooperensis
 * †Dentalina jarvisi
 * †Dentalina legumen – or unidentified comparable form
 * †Dentalina nasuta
 * †Dentalina pauperata
 * †Dentalina quadrulata
 * †Dentalina spinosa
 * Dentalium
 * †Dentalium conradi
 * †Dentalium cooperi
 * †Dentalium laneensis
 * †Dentalium mcganna – type locality for species
 * †Dentalium neohexagonum
 * †Dentalium radiolineata – or unidentified comparable form
 * †Dentalium rectius
 * †Dentalium stentor
 * †Dentalium stramineum
 * Leatherback sea turtle Tinglar, USVI (5839996547).jpg [[Dermochelys]] – or unidentified related form
 * Deroceras
 * †Derrhias – type locality for genus
 * †Derrhias enantius – type locality for species
 * †Desmathyus – or unidentified related form
 * †Desmatippus
 * †Desmatippus avus
 * †Desmatochoerus
 * †Desmatochoerus hesperus
 * †Desmocyon
 * †Desmocyon thomsoni
 * †Desmodium
 * †Desmodium indentum – type locality for species
 * Desmostylus2DB.jpg †[[Desmostylus]]
 * †Desmostylus hesperus – type locality for species
 * Diacria
 * †Diacria trispinosa
 * Diaphana
 * †Diaphana brunnea
 * †Diceratherium
 * Dichocoenia
 * †Dichocoenia merriami
 * †Dinohippus
 * †Dinohippus interpolatus
 * †Dinohippus leardi
 * †Dinohippus leidyanus
 * †Dinohippus mexicanus
 * †Dinohyus
 * †Dinohyus hollandi
 * Diodora
 * †Diodora arnoldi
 * †Diodora aspera
 * †Diodora inaequalis
 * †Diomeda
 * Diomedea
 * †Diomedea milleri – type locality for species
 * †Diomedia
 * †Diomedia albatrus
 * †Diomedia nigripes
 * †Dioplotherium
 * †Dioplotherium allisoni
 * [[File:04495jfConstructions Diospyros blancoi Dampol Rueda Plaridel Bulacan Roadfvf 48.jpg|upright|thumb|A living member of Diospyros, the tree genus including ebonies and persimmons]] †[[Diospyros]]
 * †Diospyros oregoniana
 * †Diospyros retinervis
 * Diplodonta
 * †Diplodonta buwaldana
 * †Diplodonta cretacea
 * †Diplodonta orbella
 * †Diplodonta pariiis
 * †Diplodonta parilis
 * †Diplodonta sericata
 * Diploria
 * †Diploria bowersi – type locality for species
 * Dipodomys
 * †Dipodomys agilis – or unidentified comparable form
 * †Dipodomys compactus
 * †Dipodomys deserti – or unidentified comparable form
 * †Dipodomys heermanni – or unidentified comparable form
 * †Dipodomys hibbardi
 * Merriam's Kangaroo Rat, Chihuahuan Desert, New Mexico.jpg †[[Dipodomys merriami]]
 * †Dipodomys minor
 * †Dipodomys ordii
 * †Dipoides
 * †Dipoides vallicula
 * †Diprionomys
 * †Diprionomys parvus – or unidentified comparable form
 * Discammina – tentative report
 * †Discammina eocenica
 * Discinisca
 * †Discinisca cumingi
 * Discohelix tunisiensis apical.jpg †[[Discohelix]]
 * †Discohelix californicus
 * †Dissacus
 * Distorsio
 * Divalinga
 * †Divalinga eburnea
 * Divaricella
 * †Divaricella cumulata
 * †Domnina
 * †Domninoides
 * Donax
 * †Donax californicus
 * †Donax gouldii
 * †Dorothia
 * †Dorothia californica
 * Dosinia
 * †Dosinia conradi
 * †Dosinia dunkeri
 * †Dosinia jacalitosana
 * †Dosinia margaritana
 * †Dosinia mathewsoni
 * †Dosinia mathewsonii
 * †Dosinia merriami
 * †Dosinia milthoidea – tentative report
 * †Dosinia ponderosa
 * †Dosinia santana – type locality for species
 * †Dosinia semiobliterata – or unidentified comparable form
 * †Dosinia whitneyi
 * †Dosiniopsis
 * †Dosiniopsis stewartvillensis – type locality for species
 * †Drimys – type locality for genus
 * †Drimys defensor – type locality for species
 * †Dromomeryx
 * †Duchesneodus
 * †Duchesneodus uintensis
 * †Dusignathus – type locality for genus
 * †Dusignathus santacruzensis – type locality for species
 * †Dusignathus seftoni – type locality for species
 * Dusisiren jordani life restoration.jpg †[[Dusisiren]]
 * †Dusisiren dewana
 * †Dusisiren jordani – type locality for species
 * †Dyseohyus – type locality for genus
 * †Dyseohyus fricki – type locality for species
 * †Dyseolemur
 * †Dyseolemur pacificus – type locality for species
 * Dytiscus
 * †Dytiscus marginicollis

E

 * Echinarachnius
 * †Echinarachnius fairbanksi
 * Echinorhinus brucus.jpg [[Echinorhinus]]
 * †Echinorhinus blakei
 * Eclipes – type locality for genus
 * †Eclipes extensus
 * †Eclipes manni
 * †Eclipes santamonicae – type locality for species
 * †Eclipes veternus – type locality for species
 * †Ectasis – type locality for genus
 * †Ectasis proriger – type locality for species
 * †Ectinochilus
 * †Ectinochilus macilentus
 * †Ectopistes
 * Ectopistes migratorius (passenger pigeon).jpg †[[Ectopistes migratorius]]
 * Eleodes
 * †Eleodes acuticaudus
 * †Eleodes giganteus
 * †Eleodes gracilis
 * †Eleodes grandicollis – type locality for species
 * †Eleodes laticollis
 * †Eleodes omissus
 * †Eleodes osculans – type locality for species
 * Elgaria
 * †Elgaria multicarinata
 * †Ellimma
 * †Ellimma barbarae – type locality for species
 * †Ellimma elmodenae – type locality for species
 * †Ellipsonodosaria
 * †Ellipsonodosaria alexanderi – or unidentified comparable form
 * †Ellipsonodosaria atlantisae
 * †Ellipsonodosaria recta
 * †Ellipsonodosaria spinulosa
 * Elliptotellina
 * †Elliptotellina townsendensis – or unidentified comparable form
 * Elomeryx armatus.JPG †[[Elomeryx]]
 * †Elomeryx armatus
 * †Emmachaere – type locality for genus
 * †Emmachaere rhachites – type locality for species
 * †Emmachaere rhomalea
 * †Enaliarctos
 * †Enaliarctos mealsi
 * †Enaliarctos mitchelli
 * †Enallagma – type locality for genus
 * †Enallagma kirkbyae – type locality for species
 * Encope
 * †Encope tenuis – type locality for species
 * Engelhardtia
 * †Engelhardtia nevadensis
 * Engina
 * †Engina strongi
 * †Engraulites – type locality for genus
 * †Engraulites remifer – type locality for species
 * Enhydra
 * Sea otter cropped.jpg †[[Enhydra lutris]]
 * †Enhydra macrodonta – type locality for species
 * †Enhydritherium
 * †Enhydritherium terraenovae
 * Ensis
 * †Ensis myrae
 * Entomobrya
 * †Entomobrya atrocincta
 * †Entomobrya kirkbyae – type locality for species
 * †Eocernia
 * †Eocernia hannibali
 * †Eocypraea
 * †Eocypraea castacensis – or unidentified comparable form
 * †Eocypraea maniobraensis – type locality for species
 * †Eogryphus
 * †Eogryphus tolmani – or unidentified comparable form
 * †Eohaplomys
 * †Eohaplomys matutinus – type locality for species
 * †Eohaplomys serus – type locality for species
 * †Eohaplomys tradux – type locality for species
 * †Eomellivora
 * †Eomellivora wimani – or unidentified comparable form
 * Eopelobates wagneri 34.JPG †[[Eopelobates]]
 * †Eopleurotoma
 * †Eopleurotoma whitakerpeakensis – type locality for species
 * †Eoscorpius – type locality for genus
 * †Eoscorpius primaevus – type locality for species
 * †Eosurcula
 * †Eosurcula inconstans – or unidentified related form
 * †Eotaria – type locality for genus
 * †Eotaria citrica – type locality for species
 * †Eotaria crypta – type locality for species
 * †Eotibia
 * †Eotibia llajasensis – type locality for species
 * †Eotylopus
 * †Epelichthys – type locality for genus
 * †Epelichthys michaelis – type locality for species
 * Epicyon haydeni skeleton.jpg †[[Epicyon]]
 * †Epicyon haydeni
 * †Epicyon saevus
 * †Epihippus
 * Epilucina
 * †Epilucina californica
 * Epinephelus
 * †Epiphragmophora
 * †Epiphragmophora mormonum
 * †Epistomina
 * †Epistomina eocenica
 * Epitonium scalare shell.jpg [[Epitonium]]
 * †Epitonium bellastriata
 * †Epitonium bellastriatum
 * †Epitonium clarki
 * †Epitonium condoni
 * †Epitonium cookii – or unidentified related form
 * †Epitonium cooperi
 * †Epitonium indianorum
 * †Epitonium insculptum
 * †Epitonium rugiferum – or unidentified comparable form
 * †Epitonium sawinae
 * Eponides
 * †Eponides keenani
 * †Eponides kleinpelli
 * †Eponides lodoensis
 * †Eponides umbonatus
 * Eptesicus
 * †Eptesicus fuscus – or unidentified comparable form
 * †Equisetum
 * Equus
 * †Equus conversidens
 * †Equus enormis
 * †Equus idahoensis
 * †Equus pacificus
 * †Equus scotti
 * Equus simplicidens UMNH.jpg †[[Equus simplicidens]]
 * Eremophila
 * †Eremophila alpestris
 * Erethizon
 * †Erethizon bathygnathum
 * †Erethizon cascoensis – type locality for species
 * †Erethizon dorsatum
 * †Eriquius
 * †Eriquius plectrodes
 * †Erisceles – type locality for genus
 * †Erisceles pristinus – type locality for species
 * †Eritima
 * †Eritima evides – type locality for species
 * †Escharion – type locality for genus
 * †Escharion townleyi – type locality for species
 * Eschrichtius
 * †Eschrichtius robustus – or unidentified comparable form
 * †Etringus
 * †Etringus scintillans
 * Eubalaena – or unidentified comparable form
 * †Eucastor
 * Euceratherium cropped.png †[[Euceratherium]] – type locality for genus
 * †Euceratherium collinum – type locality for species
 * Eucrassatella
 * †Eucrassatella semidentata
 * †Eucrassatella subgibbosus – type locality for species
 * †Eucyon
 * †Eucyon davisi
 * Euleptorhamphus
 * †Euleptorhamphus peronides
 * Eumetopias
 * †Eumetopias jubata
 * †Euoplocyon
 * †Euoplocyon brachygnathus
 * Eupatagus
 * †Eupatagus stevensi
 * Euphagus
 * †Euphagus cyanocephalus
 * Eurytellina
 * †Eurytellina lorenzoensis
 * Euscelis
 * †Euscelis palmeri – type locality for species
 * Eusmilia fastigiata large.jpg [[Eusmilia]]
 * †Eusmilia carrizensis – type locality for species
 * Euspira
 * †Euspira gesteri
 * †Euspira hornii
 * †Euspira lewisii
 * †Euspira muriciformis
 * †Euspira nuciformis
 * †Euspirocromium
 * †Euspirocromium martinezensis
 * †Euspirocrommium
 * †Euspirocrommium martinezensis
 * Streifenhoernchen.jpg [[Eutamias]]
 * †Eutrephoceras
 * †Eutrephoceras hallidayi
 * †Eutrephoceras hannai
 * †Eutrephoceras marksi
 * †Eutrephoceras stephensoni – type locality for species
 * Euvola
 * †Euvola keepi
 * †Euvola vogdesi
 * †Evesthes
 * †Evesthes jordani
 * †Exaeretoptera – report made of unidentified related form or using admittedly obsolete nomenclature
 * †Exaeretoptera fosteri – type locality for species
 * †Exilia
 * †Exilia fausta
 * †Exilia talliaferroi – or unidentified comparable form

F

 * Falco
 * †Falco peregrinus
 * AmericanKestrel02.jpg †[[Falco sparverius]]
 * Falsifusus
 * Farrea
 * †Farrea rugosa – type locality for species
 * Fartulum
 * †Fartulum hemphilli
 * †Fartulum occidentale
 * Felaniella
 * †Felaniella harfordi
 * Felis
 * †Felis lacustris
 * †Felis rexroadensis
 * †Ficopsis
 * †Ficopsis cooperiana
 * †Ficopsis crescentensis
 * †Ficopsis horni
 * †Ficopsis meganosensis – type locality for species
 * †Ficopsis redmondii
 * †Ficopsis remondi
 * †Ficopsis remondii
 * Sycomoros old.jpg [[Ficus]]
 * †Ficus decussata
 * †Ficus densifolia
 * †Ficus gesteri
 * †Ficus goshenensis
 * †Ficus modesta – or unidentified comparable form
 * †Ficus nodiferum
 * †Ficus ocoyana
 * †Ficus pyriformis
 * Fimbria
 * †Fimbria pacifica
 * †Fimbria susanensis – type locality for species
 * Fissurella
 * †Fissurella behri – or unidentified related form
 * †Fissurella volcano
 * Pectinidae - Flabellipecten flabelliformis.jpg [[Flabellipecten]]
 * †Flabellipecten carrizoensis
 * †Flabellipecten stearnsii
 * Flabellum
 * †Flabellum californicum
 * †Flabellum clarki – type locality for species
 * †Flabellum cuneiforme
 * †Flabellum stantoni
 * †Forestiera
 * †Forestiera buchananensis
 * †Forfex – type locality for genus
 * †Forfex hypuralis – type locality for species
 * Forreria
 * †Forreria belchei
 * †Forreria belcheri
 * †Forreria carisaensis
 * †Forreria coalingensis
 * †Fragilaria
 * †Fragilaria brevistriata
 * †Fragilaria construens
 * †Fragilaria pinnata
 * Fratercula
 * Tufted Puffin Alaska (cropped).jpg †[[Fratercula cirrhata]]
 * †Fratercula dowi – type locality for species
 * †Fraxinus
 * †Fraxinus yubaensis – type locality for species
 * Frondicularia
 * †Frondicularia tenuissima
 * Fulgoraria
 * †Fulgoraria prevostiana
 * †Fulgoraria zinsmeisteri – type locality for species
 * †Fulica
 * †Fulica americana
 * Fulmarus
 * †Fulmarus glacialis
 * †Fulmarus griseus
 * †Fulmarus hammeri – type locality for species
 * †Fulmarus miocaenus – type locality for species
 * Fusimitra – tentative report
 * †Fusimitra simplicissima – or unidentified comparable form
 * Fusinus
 * †Fusinus barbarensis
 * †Fusinus calabasensis
 * †Fusinus chehalisensis – or unidentified comparable form
 * †Fusinus hecoxi
 * †Fusinus lincolnensis – or unidentified related form
 * †Fusinus luteopictus
 * †Fusinus meganosensis – type locality for species
 * †Fusinus merriami – or unidentified related form
 * †Fusinus simiensis

G

 * Tiger shark.jpg, or tiger shark]] Galeocerdo''
 * †Galeocerdo aduncus
 * †Galeocerdo medius
 * Galeodea
 * †Galeodea calfornica
 * †Galeodea carinata – or unidentified related form
 * †Galeodea meganosensis
 * †Galeodea petersoni – or unidentified related form
 * †Galeodea susanae
 * †Galeodea sutterensis
 * Galeorhinus galeus SI3 cropped.jpg school shark]] Galeorhinus''
 * †Galeorhinus hannibali
 * †Galeorhinus latus – or unidentified comparable form
 * †Galeorhinus zopterus
 * †Ganolytes
 * †Ganolytes aratus
 * †Ganolytes cameo
 * †Ganolytes clepsydra – type locality for species
 * Gari
 * †Gari californica
 * †Gari diegoensis – or unidentified comparable form
 * †Gari furcata
 * †Gari hornii
 * †Gari texta
 * †Gasterosternus
 * †Gasterosternus aculeatus
 * Gasterosteus
 * Gasterosteus aculeatus.jpg †[[Gasterosteus aculeatus]]
 * Gastrochaena
 * †Gastrochaena dubitata – tentative report
 * Gaudryina
 * †Gaudryina laevigata
 * †Gaudryina triangularis – or unidentified comparable form
 * Gavia
 * †Gavia arctica
 * †Gavia brodkorbi – type locality for species
 * †Gavia concinna
 * †Gavia howardae – type locality for species
 * †Gavia immer
 * †Gavia pacifica
 * Gavia Stellata Ölfusá 20090606.jpg †[[Gavia stellata]]
 * †Gemelliporella – tentative report
 * †Gemelliporella punctata – or unidentified related form
 * Gemmula
 * †Gemmula diabloensis – type locality for species
 * †Gemmula wattsi
 * Genota
 * †Genota keepi
 * Genyonemus
 * †Genyonemus lineatus
 * Geochelone
 * †Geococcyx
 * The Greater Roadrunner Walking.jpg †[[Geococcyx californianus]]
 * Geomys
 * Geranoaetus
 * Gerrhonotus
 * Gibbolucina
 * †Gibbolucina gyrata
 * †Gibbolucina turneri
 * †Gila – tentative report
 * †Gilbertia
 * †Gisortia
 * †Gisortia clarki
 * Glans
 * †Glans carpenteri
 * Glaucidium
 * Mountain Pygmy Owl Glaucidium gnoma Arizona.jpg †[[Glaucidium gnoma]]
 * Glebocarcinus
 * †Glebocarcinus amphioetus
 * Globigerina
 * †Globigerina bulloides
 * †Globigerina decepta
 * †Globigerina ouachitaensis
 * †Globigerina triloculinoides
 * Globorotalia
 * †Globorotalia crassata
 * Globularia
 * †Globularia hannabali – or unidentified comparable form
 * Glossus
 * †Glossus susukii – type locality for species
 * Glycimeris
 * Glycymerididae - Glycymeris inflata.JPG [[Glycymeris]]
 * †Glycymeris branneri
 * †Glycymeris gigantea
 * †Glycymeris major
 * †Glycymeris perrini
 * †Glycymeris rosecanyonensis
 * †Glycymeris sagittata
 * †Glycymeris septentrionalis
 * †Glycymeris veatchi
 * †Glycymeris veatchii
 * Glyptoactis
 * †Glyptoactis domenginica
 * †Glyptoactis keenae
 * †Glyptoactis mcmasteri
 * †Glyptoactis sandiegoensis
 * Glyptostrobus
 * †Glyptostrobus oregonensis
 * †Gnathamitermes
 * †Gnathamitermes rousei – type locality for species
 * Gnathotermes
 * †Golerdelphys – type locality for genus
 * †Golerdelphys stocki – type locality for species
 * †Goleremys – type locality for genus
 * †Goleremys mckennai – type locality for species
 * †Gomphotaria – type locality for genus
 * †Gomphotaria pugnax – type locality for species
 * Gomphotherium productum.jpg †[[Gomphotherium]]
 * †Gomphotherium obscurum
 * †Goniobasis – tentative report
 * Goniopora
 * †Goniopora vaughani – type locality for species
 * Gopherus
 * †Gopherus agassizi
 * †Gopherus agassizii
 * †Gopherus mohavetus – type locality for species
 * †Gordonia
 * †Gordonia egregia
 * Granulina
 * †Granulina margaritula
 * †Gripholagomys – tentative report
 * †Griphomys
 * †Griphomys alecer – type locality for species
 * †Griphomys toltecus – type locality for species
 * Gymnogyps
 * Gymnogyps californianus -San Diego Zoo-8a.jpg †[[Gymnogyps californianus]] – type locality for species
 * Gyroidina
 * †Gyroidina condoni
 * †Gyroidina orbicularis
 * †Gyroidina planulata
 * †Gyroidina soldanii

H

 * †Hadrogyps – type locality for genus
 * †Hadrogyps aigialeus – type locality for species
 * Haliaeetus
 * †Haliaeetus leucocephalus
 * †Haliaetus
 * †Haliaetus leucocephalus
 * †Halonanus
 * †Halonanus horni
 * †Hamamelites
 * †Hamamelites voyana
 * Haminoea.png [[Haminoea]]
 * †Haminoea postangulata – type locality for species
 * †Haminoea vesicula
 * Hanetia
 * †Hanetia elegans
 * †Hantkenina
 * †Hantkenina alabamensis
 * Haplophragmoides
 * †Haplophragmoides flagleri
 * †Haplophragmoides obliquicameratus
 * Harpagolestes immanis.jpg †[[Harpagolestes]] – or unidentified comparable form
 * †Harrymys
 * †Harrymys magnus
 * Harvella
 * †Harvella elegans
 * †Hastigerinella
 * †Hastigerinella eocenica
 * †Hayia – type locality for genus
 * †Hayia daulica – type locality for species
 * †Heliscomys
 * †Heliscomys walshi – type locality for species
 * Heloderma
 * †Hemiacodon
 * †Hemiacodon gracilis
 * Fossil maxilla Hemiauchenia Boulle.png relative Hemiauchenia]] †Hemiauchenia
 * †Hemiauchenia macrocephala
 * Hemipristis
 * †Hemipristis heteropleurus
 * †Hemipristis serra
 * Hemitelia
 * †Hemitelia pinnata – type locality for species
 * Hemitoma
 * †Hemitoma cantonensis – type locality for species
 * †Hercoglossa
 * †Hercoglossa merriami – type locality for species
 * †Hercoglossa simiensis – type locality for species
 * Here
 * †Here excavata
 * †Herpetocetus
 * †Herpetocetus bramblei – type locality for species
 * †Herpetocetus morrowi – type locality for species
 * Herpetotherium.jpg †[[Herpetotherium]]
 * †Herpetotherium innominatum – or unidentified comparable form
 * †Herpetotherium knighti – or unidentified comparable form
 * †Herpetotherium valens
 * †Hesperaletes
 * †Hesperaletes borineyi – type locality for species
 * †Hesperaletes walshi – type locality for species
 * Hespererato
 * †Hespererato columbella
 * †Hesperhys
 * †Hesperhys vagrans
 * †Hesperocamelus – or unidentified comparable form
 * †Hesperocetus – type locality for genus
 * †Hesperocetus californicus – type locality for species
 * †Hesperolagomys
 * Hesperomys
 * †Hesperomys nematodon
 * †Hesperotestudo
 * †Hesperotestudo orthopygia
 * Hornhai (Heterodontus francisci).JPG [[Heterodontus]]
 * †Heterodontus francisi – or unidentified comparable form
 * †Heteropliohippus
 * †Heteropliohippus hulberti – type locality for species
 * Heterosilpha
 * †Heterosilpha ramosa
 * Heteroterma
 * †Heteroterma striata
 * †Heteroterma trochoidea
 * †Hexacanthus
 * Hexagrammos
 * †Hexagrammos achrestus – type locality for species
 * Hexanchus griseus (Bluntnose sixgill shark).gif [[Hexanchus]]
 * †Hexanchus aus
 * †Hexanchus bus
 * Hiatella
 * †Hiatella arctica
 * †Hilgardia – tentative report
 * †Hilgardia parkei
 * †Hiltonius
 * †Hiltonius australis – type locality for species
 * Hipparion3.jpg †[[Hipparion]]
 * †Hipparion forcei
 * †Hipparion tehonense
 * †Hippidion
 * †Hippipeda
 * †Hippnoe
 * †Hippnoe californica
 * Hipponix
 * †Hipponix craniodes
 * †Hipponix tumens
 * †Hipponoe
 * †Hipponoe californica
 * †Hippotherium
 * Histrionicus
 * †Histrionicus histrionicus – tentative report
 * Hodomys
 * Homalopoma
 * †Homalopoma carpenteri
 * †Homalopoma domenginensis
 * †Homalopoma pacifica
 * †Homalopoma wattsi
 * Homo
 * †Homo sapiens
 * †Homomya
 * Homotherium serum.jpg †[[Homotherium]]
 * †Homotherium serum – or unidentified comparable form
 * †Hopkinsina
 * †Hopkinsina compressa
 * †Hoplictis
 * †Hoplictis grangerensis – or unidentified comparable form
 * †Hoplophoneus
 * †Hoplophoneus cerebralis
 * †Humilaria
 * †Humilaria perlaminosa
 * Hyaenodon NT small.jpg †[[Hyaenodon]]
 * †Hyaenodon venturae
 * †Hyaenodon vetus – type locality for species
 * Hyalina
 * †Hyalina californica
 * †Hyalinonetrion
 * †Hyalinonetrion clavatum
 * Hydrangea
 * †Hydrangea californica – type locality for species
 * †Hydrodamalis
 * †Hydrodamalis cuestae – type locality for species
 * Em - Hydrodamalis gigas model.jpg †[[Hydrodamalis gigas]]
 * Hydrophilus
 * Hyla
 * †Hyopsodus – or unidentified comparable form
 * †Hyperbaena
 * †Hyperbaena diforma
 * †Hypertragulus
 * †Hypertragulus calcaratus
 * †Hypertragulus hesperius
 * †Hypohippus
 * †Hypolagus
 * †Hypolagus edensis – type locality for species
 * †Hypolagus fontinalis
 * †Hypolagus furlongi
 * †Hypolagus gidleyi
 * †Hypolagus parviplicatus – or unidentified comparable form
 * †Hypolagus tedfordi
 * †Hypolagus vetus
 * †Hyrachyus

I

 * †Ibarus
 * †Ibarus ignotus – or unidentified comparable form
 * †Idiophyseter – type locality for genus
 * †Idiophyseter merriami – type locality for species
 * †Ignacius
 * †Ignacius frugivorus
 * †Ilingoceros
 * Imagotaria downsi cropped.png †[[Imagotaria]] – type locality for genus
 * †Imagotaria downsi – type locality for species
 * †Indarctos
 * †Inga
 * †Inga ionensis – type locality for species
 * †Interchlamys
 * †Interchlamys interlineata – or unidentified comparable form
 * †Ioscion
 * †Ioscion morgani
 * Ischnochiton
 * †Ischnochiton sanctaemonicae
 * †Ischyrocyon
 * †Ischyrocyon gidleyi
 * Ischyromys.jpg †[[Ischyromys]]
 * Iselica
 * †Iselica fenestrata
 * Isognomon
 * †Isognomon clarki
 * Isurus
 * †Isurus aus
 * †Isurus benedini
 * †Isurus bus
 * †Isurus oxyrhynchus
 * †Isurus oxyrinchus
 * †Isurus planus

J

 * †Jacobsomys
 * †Jacobsomys dailyi – type locality for species
 * †Jamilcotatus
 * †Jamilcotatus boreios – type locality for species
 * Jaton
 * †Jaton eldridgei
 * †Jaton festivus
 * †Johannsenomyia
 * †Johannsenomyia hotchkissae – type locality for species
 * Jouannetia
 * Juliacorbula
 * †Juliacorbula luteola
 * †Julus
 * †Julus cavicola – type locality for species
 * †Julus occidentalis – type locality for species
 * †Jumaraina
 * †Jumaraina rinconensis – type locality for species
 * †Juncus
 * JuniperRockCreek.JPG [[Juniperus]]

K

 * Kalolophus
 * †Kalolophus antillarum – or unidentified comparable form
 * †Kampholophos – type locality for genus
 * †Kampholophos serrulus – type locality for species
 * Karreriella
 * †Karreriella barbati
 * †Karreriella mediaaquaensis
 * Katherinella
 * Kelletia
 * †Kelletia kelletii
 * Kellia
 * †Kellia suborbicularis
 * Kentriodon BW.jpg †[[Kentriodon]] – type locality for genus
 * †Kentriodon obscurus – type locality for species
 * †Keteleeria
 * †Keteleeria heterophylloides
 * †Kewia – tentative report
 * †Kewia fairbanksi – or unidentified comparable form
 * †Kingena
 * †Kingena simiensis
 * †Kirkomys – or unidentified comparable form
 * †Knightomys – or unidentified comparable form
 * †Kummelonautilus
 * Kurtiella
 * †Kurtiella tumida
 * Kurtzia
 * †Kurtzia arteaga
 * Kurtziella
 * †Kurtziella plumbea

L

 * Lampadion plicatus 000a.jpg †[[Labyrinthus]]
 * †Labyrinthus obtusus – type locality for species
 * Lacuna
 * †Lacuna carinata
 * †Lacuna porrecta
 * †Lacuna solidula
 * †Lacuna unifasciata
 * †Lacunaria
 * †Lacunaria striata – or unidentified related form
 * Laevicardium
 * Cardiidae - Acrosterigma magnum.JPG †[[Laevicardium elatum]]
 * †Laevicardium substriatum
 * Lagena
 * †Lagena isabella
 * †Lagena strumosa
 * †Lagena substriata
 * †Lagena sulcata
 * †Lagena vulgaris
 * Lamelliconcha
 * †Lamelliconcha clarki
 * Lamna
 * Lampanyctus
 * †Lampris – type locality for genus
 * Lampris zatima.jpg †[[Lampris zatima]] – type locality for species
 * †Lamprolithax – type locality for genus
 * †Lamprolithax annectens – type locality for species
 * †Lamprolithax simulans – type locality for species
 * Lampropeltis
 * †Lampropeltis getulus
 * †Lantanotherium
 * †Lantanotherium dehmi
 * †Lantanotherium sawini
 * †Lapparia
 * †Lapparia eomagna
 * Larus
 * California Gull (Larus californicus RWD2.jpg †[[Larus californicus]]
 * †Larus delawarensis
 * †Larus glaucescens
 * †Larus philadelphia
 * Latirus
 * †Latirus buwaldana
 * †Latirus nightingalei – or unidentified comparable form
 * †Latirus roseburgensis – or unidentified comparable form
 * †Laurophyllum
 * †Laurophyllum fremontensis
 * †Laurophyllum litseaefolia
 * †Laytonia – type locality for genus
 * †Laytonia californica – type locality for species
 * Lechytia
 * Leda
 * †Leda gabbi
 * †Legionarictis – type locality for genus
 * †Legionarictis fortidens – type locality for species
 * †Leidymys
 * †Lembicus – type locality for genus
 * †Lembicus meiklejohni – type locality for species
 * Lenticulina
 * †Lenticulina convergens
 * Lepeta
 * †Lepeta concentrica
 * Lepidochitona cinerea.JPG [[Lepidochitona]]
 * †Lepidochitona keepiana
 * †Lepidogobias
 * †Lepidogobias lepidus
 * Lepidozona
 * †Lepidozona pectinulatus
 * Lepisosteus
 * †Lepisosteus spatula – or unidentified comparable form
 * †Leptacanthichthys
 * †Leptacanthichthys gracilispinis
 * †Leptarctus
 * †Leptarctus ancipidens
 * †Leptarctus wortmani
 * Leptocyon gregorii holotype AMNH 12879.jpg †[[Leptocyon]]
 * †Leptocyon leidyi
 * †Leptocyon tejonensis – type locality for species
 * †Leptocyon vafer
 * †Leptocyon vulpinus
 * †Leptodontomys
 * †Leptodontomys stirtoni
 * †Leptomeryx
 * †Leptomeryx blacki
 * Leptopecten
 * †Leptopecten andersoni
 * [[File:Juvenile Crassodoma gigantea, Fitzgerald Marine Reserve, 2012-11-24, side view, mantle open, eyes visible cropped.jpg|thumb|upright|A living Leptopecten latiauratus, or kelp scallop]] †[[Leptopecten latiauratus]]
 * †Leptoreodon
 * †Leptoreodon edwardsi – type locality for species
 * †Leptoreodon golzi – type locality for species
 * †Leptoreodon leptolophus – type locality for species
 * †Leptoreodon major – type locality for species
 * †Leptoreodon marshi – or unidentified comparable form
 * †Leptoreodon pusillus – type locality for species
 * †Leptoreodon stocki – type locality for species
 * †Leptotomus
 * †Leptotomus caryophilus
 * Lepus
 * †Lepus americanus
 * †Lepus californicus
 * †Lepus callotis
 * Leukoma
 * †Leukoma staminea
 * Lima
 * Limaria
 * †Limaria hemphilli
 * Limnocyon ventral.png †[[Limnocyon]]
 * †Limnoecus
 * †Limnoecus tricuspis – type locality for species
 * †Limosa
 * †Limosa fedoa
 * †Limosa vanrossemi – type locality for species
 * Linga
 * †Linophryne
 * †Linophryne indica
 * †Liolithax – type locality for genus
 * †Liolithax kernensis – type locality for species
 * Liquidambar
 * †Liquidambar californicum
 * Lirobittium – tentative report
 * †Lirosceles
 * †Lirosceles elegans – type locality for species
 * Lirularia
 * †Lirularia funiculata
 * †Lirularia lirulata
 * Lissodelphis – or unidentified comparable form
 * †Lithocarpus
 * †Lithocarpus klamathensis
 * †Lithocarpus nevadensis
 * Lithophaga
 * †Lithophaga plumula
 * Lithophyllum
 * †Lithophyllum sierraeblancae – type locality for species
 * Lithornis.png †[[Lithornis]] – or unidentified comparable form
 * Lithothamnion
 * †Lithothamnion grahami
 * †Lithothamnion laminosum – type locality for species
 * †Lithothamnion luxurum
 * †Lithothamnion manni
 * †Lithothamnion meganosium
 * †Lithothamnion validum – or unidentified related form
 * †Lithothamnion wallisium
 * †Litorhadia
 * †Litorhadia washingtonensis – or unidentified comparable form
 * Littorina
 * †Littorina petricola
 * †Littorina planaxis
 * †Littorina scutulata
 * †Lituyapecten
 * †Lituyapecten purisimaensis
 * Lompoquia retropes.JPG †[[Lompoquia]] – type locality for genus
 * †Lompoquia retropes – type locality for species
 * †Lonchodelphis
 * †Lonchodelphis occiduus – type locality for species
 * Lontra
 * †Lontra canadensis
 * †Lophar – type locality for genus
 * †Lophar miocaenus – type locality for species
 * †Lophocetus
 * †Lophocetus repenningi – type locality for species
 * †Lophortyx
 * †Lophortyx californica
 * †Lora
 * †Losinia
 * Lottia
 * †Lottia limatula
 * Macklintockia scabra 001.jpg †[[Lottia scabra]]
 * †Loxolithax – type locality for genus
 * †Loxolithax sinuosa – type locality for species
 * †Loxotrema
 * †Loxotrema turritum
 * Lucapinella
 * †Lucapinella callomarginata
 * Lucina
 * †Lucina gaylordi
 * †Lucina wattsi
 * Lucinisca
 * †Lucinisca nuttalli
 * Lucinoma
 * †Lucinoma acutilineata
 * †Lucinoma annulatum
 * Luidia
 * †Luidia etchegoinensis – type locality for species
 * †Luidia sanjoaquinensis – type locality for species
 * †Lutianus
 * †Lutianus hagari – type locality for species
 * Lycophocyon skull lateral.png †[[Lycophocyon]] – type locality for genus
 * †Lycophocyon hutchisoni – type locality for species
 * †Lygisma – type locality for genus
 * †Lygisma tenax – type locality for species
 * Lygodium
 * †Lygodium kaulfussi
 * Lynx
 * †Lynx fasciatus
 * †Lynx rufus
 * Lyonsia
 * †Lyonsia califomica
 * †Lyonsia venturaensis – type locality for species
 * Lyria
 * †Lyria andersoni
 * †Lyrischapa
 * †Lyrischapa lajollaensis
 * †Lyropecten
 * †Lyropecten bowersi
 * †Lyropecten crassicardo
 * †Lyropecten magnolia
 * †Lyropecten miguelensis
 * †Lyropecten perrini
 * †Lyrosurcula – tentative report

M

 * †Machaeromeryx – tentative report
 * †Machaeromeryx tragulus
 * [[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]]
 * Macoma
 * †Macoma andersoni
 * †Macoma calcarea
 * †Macoma carlottensis
 * †Macoma copelandi
 * †Macoma diabloensis
 * †Macoma expansa
 * †Macoma indentata
 * †Macoma inquinata
 * †Macoma moesta
 * FMIB 34796 Shell of Macoma nasuta.jpeg †[[Macoma nasuta]]
 * †Macoma pabloensis – or unidentified comparable form
 * †Macoma panzana
 * †Macoma planiuscula – or unidentified comparable form
 * †Macoma secta
 * †Macoma viticola
 * Macrarene
 * Macrocallista
 * †Macrocallista furlongi – or unidentified comparable form
 * †Macrocallista horni – or unidentified comparable form
 * †Macrocallista meganosensis – type locality for species
 * †Macrocallista pittsburgensis
 * †Macrocallista squalida
 * †Macrocallista squalidus
 * †Macrocallista weaveri
 * †Macrochlamis
 * †Macrochlamis magnolia
 * Macrodelphinus kelloggi.jpg †[[Macrodelphinus]] – type locality for genus
 * †Macrodelphinus kelloggi – type locality for species
 * †Macrotarsius
 * †Macrotarsius roederi – type locality for species
 * Mactromeris
 * †Mactromeris abbotti
 * †Mactromeris acutirostrata – or unidentified comparable form
 * †Mactromeris albaria
 * †Mactromeris bisculpturata – or unidentified comparable form
 * †Mactromeris brevirostrata
 * †Mactromeris catilliformis
 * †Mactromeris hemphillii
 * †Mactromeris mercedensis – or unidentified comparable form
 * †Mactromeris merriami
 * †Mactromeris montereyana – type locality for species
 * †Mactromeris muliniaformis – type locality for species
 * †Mactromeris pittsburgensis – or unidentified comparable form
 * †Mactromeris polynyma
 * †Mactromeris ramonensis
 * †Mactromeris rushi
 * †Mactromeris sectoris
 * †Mactromeris tejonensis
 * Mactrotoma
 * †Mactrotoma californica
 * †Mactrotoma nasuta
 * Madracis
 * †Madracis wellsi – type locality for species
 * Madrepora
 * †Madrepora solida – type locality for species
 * Sweetbay Magnolia Magnolia virginiana Flower Closeup 2146px.jpg [[Magnolia]]
 * †Magnolia corrallina
 * †Magnolia dayana
 * Mahonia
 * †Mahonia macginitiei
 * †Mahonia reticulata
 * †Mahonia simplex
 * Makaira
 * Malea
 * †Malea ringens
 * Malletia
 * Mallotus
 * †Mallotus riparius
 * †Mambrinia
 * †Mambrinia gallica – type locality for species
 * †Mammut
 * †Mammut americanum – all local specimens previously referred to this species have since been reclassified in the new species M. pacificus.
 * †Mammut cosoensis
 * †Mammut matthewi
 * †Mammut pacificus – type locality for species. Many specimens were previously regarded as specimens of M. americanum.
 * †Mammuthus
 * †Mammuthus columbi
 * †Mammuthus exilis
 * †Mammuthus hayi
 * Ice age fauna of northern Spain - Mauricio Antón cropped.png †[[Mammuthus primigenius]]
 * †Mancalla – type locality for genus
 * †Mancalla californiensis – type locality for species
 * †Mancalla cedrosensis – or unidentified comparable form
 * †Mancalla diegenesis
 * †Mancalla diegensis – type locality for species
 * †Mancalla emlongi – type locality for species
 * †Mancalla lucasi – type locality for species
 * †Mancalla milleri – type locality for species
 * †Mancalla vegrandis
 * †Mancalla vergrandis – type locality for species
 * †Mangelia
 * †Mangelia variegata
 * †Margaritana
 * †Margaritana falcata – or unidentified comparable form
 * Margarites
 * †Margarites pupillus
 * MargRosea.jpg [[Marginella]]
 * Marginulina
 * †Marginulina adunca – or unidentified comparable form
 * †Marginulina dubia
 * †Marginulina eximia
 * †Marginulina munda
 * Marmota
 * †Marshochoerus
 * †Marshochoerus socialis
 * Martes martes crop cropped.jpg [[Martes]]
 * Martesia
 * †Martesia meganosensis – type locality for species
 * †Martinogale
 * †Martinogale faulli – type locality for species
 * Martinottiella
 * †Martinottiella eocenica
 * Maxwellia
 * †Maxwellia gemma
 * †Mayena – tentative report
 * †Mayena kewi – or unidentified comparable form
 * †Mealanitta
 * †Mealanitta deglandi
 * †Mediochoerus
 * †Mediochoerus mohavensis
 * †Megacamelus
 * †Megacamelus merriami
 * Megachasma
 * †Megachasma applegatei – type locality for species
 * Megachile
 * †Megachile gentilis
 * †Megahippus
 * †Megahippus matthewi
 * †Megahippus mckennai – type locality for species
 * Megalonyx wheatleyi - AMNH - DSC06327.JPG †[[Megalonyx]]
 * †Megalonyx jeffersonii
 * †Megalonyx mathisi – type locality for species
 * †Megalonyx wheatleyi
 * Megalops – tentative report
 * †Megalops vigilax
 * †Megapaloelodus
 * †Megapaloelodus connectens
 * †Megapetalus
 * Megaptera
 * †Megaptera miocaena – type locality for species
 * Megatebennus
 * †Megatebennus bimaculata
 * †Megatebennus bimaculatus
 * Megathura – tentative report
 * †Megatylopus
 * †Megatylopus matthewi – or unidentified comparable form
 * †Megistostoma
 * †Megistostoma gabbiana – or unidentified comparable form
 * Melampus
 * †Melampus olivaceous
 * †Melampus olivaceus
 * Melanella
 * †Melanella hastata
 * †Melanella micans
 * Melanitta
 * †Melanitta ceruttii – type locality for species
 * †Melanitta deglandi – tentative report
 * †Melanitta fusca
 * †Melanitta perspicillata
 * Melanoplus
 * †Melanoplus differentialis
 * Melanthrips
 * Meleagris
 * †Meleagris richmondi – type locality for species
 * †Meliosma
 * †Meliosma truncata – type locality for species
 * †Melosira
 * †Melosira solida
 * Melospiza
 * †Melospiza melodia
 * †Meniscomys
 * †Meniscotherium
 * †Meniscotherium tapiacitum
 * Menoceras NT small.jpg †[[Menoceras]]
 * †Menoceras barbouri
 * Mephitis
 * †Mephitis mephitis
 * †Mercyhippus – report made of unidentified related form or using admittedly obsolete nomenclature
 * †Mercyhippus brevidontus
 * Meretrix
 * †Meretrix californica
 * †Meretrix conradi
 * †Meretrix hornii
 * †Meretrix lorenzana
 * †Meretrix palmeri – type locality for species
 * †Meretrix stantoni
 * †Meretrix uvasana – type locality for species
 * Mergus
 * †Mergus serrator
 * Merluccius
 * †Merluccius productus
 * †Merriamina – type locality for genus
 * †Merriamina ectenes – type locality for species
 * Merriamoceros coronatus life restoration.jpg †[[Merriamoceros]]
 * †Merriamoceros coronatus – type locality for species
 * †Merychippus
 * †Merychippus brevidontus – type locality for species
 * †Merychippus californicus – type locality for species
 * †Merychippus relictus – or unidentified comparable form
 * †Merychippus stevensi
 * †Merychyus
 * †Merychyus elegans
 * †Merychyus minimus
 * †Merychyus novomexicanus
 * †Merychyus smithi
 * †Merycobunodon
 * †Merycobunodon littoralis – type locality for species
 * Merycodus cf. nectatus - National Museum of Natural History - IMG 2024.JPG †[[Merycodus]]
 * †Merycodus joraki
 * †Merycodus necatus
 * Mesalia
 * †Mesalia clarki – type locality for species
 * †Mesalia martinezensis
 * †Mesocyon
 * †Mesocyon brachyops
 * †Mesocyon coryphaeus
 * †Mesodma – tentative report
 * †Mesohippus
 * Mesophyllum
 * †Mesophyllum californicum
 * †Mesophyllum fructiferum
 * †Mesophyllum obsitum
 * †Mesophyllum schenckii – type locality for species
 * †Mesophyllum schenki
 * Mesoreodonskull.jpg mammal Mesoreodon]] †Mesoreodon
 * †Mesoreodon chelonyx
 * †Metacerithium
 * †Metacerithium packardi
 * †Metalopex
 * †Metalopex merriami
 * †Metanoiamys
 * †Metanoiamys agorus – type locality for species
 * †Metanoiamys fantasma
 * †Metanoiamys korthi – type locality for species
 * †Metanoiamys marinus – type locality for species
 * †Metarhinus
 * †Metarhinus pater – type locality for species
 * †Metatomarctus
 * †Metatomarctus canavus
 * Metaxytherium floridanum.jpg †[[Metaxytherium]]
 * †Metaxytherium arctodites
 * †Metechinus
 * †Metechinus amplior
 * †Miacis
 * †Miacis hookwayi – type locality for species
 * †Michenia
 * †Michenia agatensis
 * †Michenia mudhillsensis
 * Micranellum
 * †Micranellum crebricinctum
 * †Microcosmodon – or unidentified comparable form
 * Microdipodops
 * Poulamon2 cropped.jpg [[Microgadus]] – tentative report
 * †Micropallus
 * †Micropallus whitneyi
 * †Microparamys
 * †Microparamys minutus – or unidentified comparable form
 * †Microparamys tricus – type locality for species
 * †Microparamys woodi – type locality for species
 * †Microsula
 * †Microsyops
 * †Microsyops annectens – or unidentified comparable form
 * †Microsyops kratos – type locality for species
 * †Microtomarctus
 * †Microtomarctus conferta
 * Microtus
 * California Vole (Microtus californicus) cropped.jpg †[[Microtus californicus]]
 * †Microtus meadensis
 * †Microtus miguelensis – type locality for species
 * Mictomys
 * †Mictomys kansasensis
 * †Mictomys vetus
 * Miltha
 * †Miltha meganosensis – type locality for species
 * †Miltha packi
 * †Miltha sanctaecrucis
 * †Miltha xantusi
 * †Mimomys
 * †Mimotricentes
 * †Mimotricentes tedfordi – type locality for species
 * †Miochlorotettix – type locality for genus
 * †Miochlorotettix gibroni – type locality for species
 * †Miochlorotettix kirkbyi – type locality for species
 * †Miocryptorhopalum – type locality for genus
 * †Miocryptorhopalum kirkbyae – type locality for species
 * †Miocyon
 * †Miocyon scotti – or unidentified comparable form
 * †Miodelphis – type locality for genus
 * †Miodelphis californicus – type locality for species
 * †Miogonates – type locality for genus
 * †Miogonates subimpunctatus – type locality for species
 * †Miohierax – type locality for genus
 * †Miohierax stocki – type locality for species
 * †Miohippus
 * †Miohippus annectens
 * †Miolabis
 * †Miolabis californicus – type locality for species
 * †Miolabis fricki – type locality for species
 * [[File:Photograph and line drawing of the skull of Miomancalla howardi compared with the skull of Pinguinus impennis.jpg|thumb|upright|Fossilized skull (top) and interpretive line drawing (middle) of the Miocene auk relative Miomancalla compared with the skull of a Holocene Pinguinus impennis, or great auk]] †[[Miomancalla]]
 * †Miomancalla howardi – type locality for species
 * †Miomancalla wetmorei – type locality for species
 * †Miomesamia – type locality for genus
 * †Miomesamia juliae – type locality for species
 * †Miomonalonion – type locality for genus
 * †Miomonalonion conoidifrons – type locality for species
 * †Miomustela
 * †Mionictis
 * †Mionictis angustidens
 * †Miospermophilus
 * †Miospermophilus wyomingensis – or unidentified comparable form
 * †Miosula – type locality for genus
 * †Miosula media – type locality for species
 * †Miotapirus
 * †Miotomodon
 * †Miotomodon mayi – type locality for species
 * †Miotroctes – type locality for genus
 * †Miotroctes rousei – type locality for species
 * †Miotylopus
 * †Miotylopus gibbi
 * Miracinonyx inexpectatus.jpg †[[Miracinonyx]]
 * †Miracinonyx studeri – tentative report
 * Mirounga
 * †Mirounga angustirostris – or unidentified comparable form
 * Mitra
 * †Mitra fultoni
 * †Mitra idae
 * †Mitra idea
 * †Mitra simplicissima
 * Mitrella
 * †Mitrella carinata
 * †Mitrella gausapata
 * †Mitrella gouldi
 * †Mitrella tuberosa
 * †Mixocetus – type locality for genus
 * †Mixocetus elysius – type locality for species
 * Modiolatus
 * †Modiolatus rectus
 * Modiolus
 * Mytilidae - Modiolus capax.JPG †[[Modiolus capax]] – or unidentified comparable form
 * †Modiolus carpenteri
 * †Modiolus multiradiatus
 * †Modiolus ornatus
 * †Modiolus veronensis
 * †Modiolus ynezianus
 * Modulus
 * †Modulus unidens
 * †Mojavemys
 * †Mojavemys alexandrae – type locality for species
 * †Mojavemys lophatus
 * †Mojavemys wilsoni
 * †Molopophorus
 * †Molopophorus aequicostatus – or unidentified comparable form
 * †Molopophorus antiquatus
 * †Molopophorus biplicatus
 * †Molopophorus californicus – type locality for species
 * †Molopophorus dalli
 * †Molopophorus tejonensis
 * Moniliopsis
 * †Moniliopsis incisa
 * Monoplex nicobaricus 01.JPG [[Monoplex]]
 * †Monoplex amictus
 * †Monosaulax
 * †Monosaulax pansus
 * Montipora
 * †Mookomys
 * †Mookomys formicarum
 * †Mookomys subtilis
 * Mopalia
 * †Mopalia acuta
 * †Mopalia ciliata
 * †Mopalia lignosa – or unidentified comparable form
 * Moropus elatus.jpg †[[Moropus]]
 * Morula
 * †Morula lugubris
 * Morus – or unidentified comparable form
 * Morus
 * †Morus humeralis – type locality for species
 * †Morus lompocanus – type locality for species
 * †Morus magnus – type locality for species
 * †Morus recentior – type locality for species
 * †Morus reyana – type locality for species
 * †Morus reyma
 * †Morus reyna
 * †Morus vagabundus – type locality for species
 * Mulinia
 * †Mulinia pallida
 * Murex – or unidentified related form
 * †Murex mansfieldi – or unidentified related form
 * Musculus
 * Mustela
 * †Mustela americana – type locality for species
 * †Mustela frenata
 * †Mya
 * †Mya dickersoni
 * †Mya fujiei
 * †Mya truncata
 * †Myadesma
 * †Myadesma pacifica
 * Myctophum
 * Myliobatis
 * †Myliobatis californicus
 * Mylohyus nasutus.jpg †[[Mylohyus]]
 * †Mylohyus fossilis
 * †Mylopharodon
 * †Mylopharodon conocephalus
 * Mysella
 * †Mysella aleutica
 * Mytilimeria
 * Mytilimeria nuttalli
 * Mytilus
 * †Mytilus arnoldi
 * California Mussels 002.jpg †[[Mytilus californianus]]
 * †Mytilus edulis
 * †Mytilus expansus
 * †Mytilus loeli
 * †Mytilus mathewsoni
 * †Mytilus mathewsonii
 * †Mytilus middendorffi
 * †Mytonolagus
 * †Mytonomys
 * †Mytonomys burkei – type locality for species
 * †Mytonomys mytonensis – or unidentified comparable form
 * Myurella
 * †Myurella martini

N

 * Nannippus jaw.JPG †[[Nannippus]]
 * †Nannocetus – type locality for genus
 * †Nannocetus eremus – type locality for species
 * †Nannolithax – type locality for genus
 * †Nannolithax gracilis – type locality for species
 * †Nanotragulus
 * †Nanotragulus ordinatus – tentative report
 * Narona
 * †Narona clavatula
 * Nassa
 * †Nassa cerritensis
 * †Nassa delosi
 * †Nassa fossata
 * †Nassa mendica
 * †Nassa perpinguis
 * †Nassa tegula
 * Nassarius
 * †Nassarius californianus
 * †Nassarius cerritensis
 * Nassarius tiarula.jpg †[[Nassarius fossatus]]
 * †Nassarius grammatus
 * †Nassarius hamlini
 * †Nassarius inquus
 * †Nassarius mendicus
 * †Nassarius perpinguis
 * †Nassarius stocki
 * †Nassarius tegula
 * †Nassarius whitneyi
 * Natica
 * †Natica lewisi – or unidentified related form
 * †Natica recluziana
 * †Natica uvasana
 * Naticarius
 * †Naticarius unifasciata
 * Navahoceros fricki.jpg, or American mountain deer]] †Navahoceros''
 * Nectandra
 * †Nectandra presanguinea
 * Negaprion
 * †Negaprion antiquus
 * †Negaprion elongata – or unidentified comparable form
 * †Nekrolagus
 * †Nelumbium
 * †Nelumbium lacunosum – type locality for species
 * Nemocardium
 * †Nemocardium centifilosum
 * †Nemocardium linteum
 * †Neobernaya
 * †Neobernaya fernandoensis
 * †Neobernaya spadicea
 * †Neoculicoides – type locality for genus
 * †Neoculicoides jeanneae – type locality for species
 * †Neogyps
 * †Neogyps errans
 * †Neohipparion
 * †Neohipparion eurystyle
 * †Neohipparion gidleyi – type locality for species
 * †Neohipparion leptode
 * †Neohipparion trampasense
 * †Neoliotomus – or unidentified comparable form
 * †Neolitsea
 * †Neolitsea lata – type locality for species
 * Paleoparadoxia Natural History Museum of Los Angeles County 20110330.jpg †[[Neoparadoxia]] – type locality for genus
 * †Neoparadoxia cecilialina – type locality for species
 * †Neoparadoxia repenningi – type locality for species
 * Neophrontops
 * †Neophrontops americanus
 * †Neoplagiaulax
 * Neotamias
 * †Neotamias senex
 * †Neotherium – type locality for genus
 * †Neotherium mirum – type locality for species
 * Neotoma
 * †Neotoma cinerea – type locality for species
 * †Neotoma fossilis
 * †Neotoma fuscipes
 * †Neotoma lepida
 * †Neotoma quadriplicata
 * †Neotoma sawrockensis
 * †Neotoma taylori
 * Neptunea
 * †Neptunea andersoni
 * †Neptunea eurekaensis
 * †Neptunea lawsoni
 * †Neptunea lirata
 * †Neptunea mucronata
 * †Neptunea pulchra
 * †Neptunea scotiaensis
 * †Neptunea tabiilata – or unidentified comparable form
 * †Neptunea tabulata
 * Nerita
 * †Nerita beali – tentative report
 * Neritina-natalensis cropped.jpg [[Neritina]]
 * †Neritina picta
 * †Nerium
 * †Nerium hinoidea – type locality for species
 * †Nerterogeomys
 * †Nerterogeomys anzensis
 * †Nerterogeomys garbanii
 * Neverita
 * †Neverita alta
 * †Neverita callosa
 * †Neverita globosa
 * †Neverita reclusiana
 * †Neverita reclusianus
 * †Neverita recluziana
 * †Neverita recluzianus
 * †Neverita secta – or unidentified comparable form
 * †Neverita thomsonae
 * Nicrophorus
 * †Nicrophorus guttula
 * †Nicrophorus marginatus – type locality for species
 * †Nicrophorus nigrita
 * †Nimravides
 * †Nimravides thinobates
 * Nimravus gomphodus.jpg †[[Nimravus]]
 * Niso – tentative report
 * †Niso antiselli
 * †Nitzschia
 * †Nitzschia reinholdi
 * †Nitzschia romana
 * Nodipecten
 * †Nodipecten cerrosensis
 * †Nodipecten estrellanus
 * †Nodipecten subnodosus
 * Nodogenerina
 * †Nodogenerina adolphina
 * †Nodogenerina advena
 * †Nodogenerina sanctaecrucis
 * †Nodogenerina wegemanni
 * Nodosaria
 * †Nodosaria holserica
 * †Nodosaria longiscata
 * †Nodosaria pyrula
 * Nonion
 * †Nonion incisum
 * †Nonomys
 * †Nonomys gutzleri – type locality for species
 * Norrisia
 * †Norrisia norrisii
 * †Nothroptheriops
 * †Nothroptheriops shastense – or unidentified comparable form
 * Nothrotheriops.jpg †[[Nothrotheriops]]
 * †Nothrotheriops texanus
 * †Nothrotherium
 * †Nothrotherium shastense – type locality for species
 * Notiosorex
 * †Notiosorex crawfordi
 * †Notiosorex jacksoni
 * Notoacmea
 * †Notoacmea inessa
 * Notorhynchus
 * †Nototamias
 * Nucella
 * †Nucella elsmerensis
 * †Nucella emarginata
 * †Nucella lamellosa
 * †Nucella lima
 * †Nucella spirata
 * †Nucella trancosana
 * Nucula
 * †Nucula exigua
 * †Nucula gabbiana
 * †Nucula washingtonensis
 * Nuculana
 * †Nuculana gabbi – or unidentified comparable form
 * †Nuculana ochsneri
 * †Nuculana ramonensis
 * Numenius
 * Whimbrel Numenius phaeopus.jpg †[[Numenius phaeopus]]
 * Nutricola
 * †Nutricola cymata
 * †Nutricola ovalis
 * †Nutricola salmonea
 * †Nutricola tantilla
 * Nuttallia
 * †Nuttallia nuttallii
 * †Nyctitherium – or unidentified comparable form
 * Nyctoporis
 * †Nyctoporis carinata
 * †Nyssa
 * †Nyssa californica
 * †Nyssa copeana

O

 * †Ocajila – or unidentified comparable form
 * Oceanodroma
 * Oceanodroma furcata 1.jpg †[[Oceanodroma furcata]]
 * †Oceanodroma homochroa
 * †Oceanodroma hubbsi – type locality for species
 * †Ocenbra
 * †Ocenbra topangensis – or unidentified comparable form
 * Ocenebra
 * †Ocenebra barbarensis – or unidentified comparable form
 * †Ocenebra circumtexta
 * †Ocenebra foveolata
 * †Ocenebra interfossa
 * †Ocenebra lurida
 * †Ocenebra poulsoni
 * †Ocenebra tenuisculpta
 * †Ocenebra topangensis
 * Ocotea
 * †Ocotea ovoidea
 * †Ocotea perseaformis
 * †Ocystias
 * †Ocystias sagitta
 * †Odaxosaurus
 * Odobenus
 * Pacific walrus bull odobenus rosmarus.jpg †[[Odobenus rosmarus]]
 * Odocoileus
 * †Odocoileus hemionus
 * †Odocoileus virginianus – or unidentified comparable form
 * Odontaspis
 * †Odontaspis ferox
 * †Odontogryphaea – tentative report
 * †Odontogryphaea haleyi
 * Odostomia
 * †Odostomia avellana
 * †Odostomia beringi – or unidentified comparable form
 * †Odostomia californica – or unidentified comparable form
 * †Odostomia callimene – or unidentified related form
 * †Odostomia columbiana – or unidentified comparable form
 * †Odostomia diaboli
 * Odostomia donilla 001.png †[[Odostomia donilla]]
 * †Odostomia eugena
 * †Odostomia farallonensis
 * †Odostomia fetella
 * †Odostomia gravida
 * †Odostomia helena
 * †Odostomia minutissima – or unidentified comparable form
 * †Odostomia nemo
 * †Odostomia nota
 * †Odostomia stephensae
 * †Odostomia tacomoensis
 * †Odostomia tenuisculpta – or unidentified comparable form
 * †Oedolithax – type locality for genus
 * †Oedolithax mira – type locality for species
 * Oenopota
 * †Oenopota fidicula
 * Oenopota tabulata 001.jpg †[[Oenopota tabulata]]
 * Ogmodontomys
 * †Ogmodontomys sawrockensis
 * †Olequahia
 * †Olequahia domenginica
 * †Olequahia lorenzana
 * †Oligoryctes
 * Oliva
 * †Oliva californica
 * †Oliva meganosensis – type locality for species
 * †Oliva spicata
 * Olivella
 * †Olivella baetica
 * †Olivella biplicata
 * †Olivella gracilis
 * †Olivella mathewsoni
 * †Olivella mathewsonii
 * †Olivella pedroana
 * †Olivella santana – type locality for species
 * †Omomys
 * †Omomys carteri – or unidentified comparable form
 * Oncorhynchus
 * Oncorhynchus_rastrosus_reconstruction_by_Ray_Troll.png †[[Oncorhynchus rastrosus]]
 * Ondatra
 * †Ondatra idahoensis
 * †Ondatra minor
 * Oneirodes
 * Onthophagus
 * †Onthophagus everestae – type locality for species
 * Onychomys
 * †Onychomys gidleyi
 * †Onychomys torridus
 * Ophiodermella
 * †Ophiodermella graciosana
 * †Ophiodermella inermis
 * †Ophiomys
 * †Ophiomys parvus
 * †Opisima – tentative report
 * †Opisima pacifica – or unidentified comparable form
 * †Opisthonema
 * †Opisthonema palosverdensis – type locality for species
 * Oreamnos
 * †Oreamnos americanus
 * Oreortyx
 * †Oreortyx picta
 * Orthemis
 * †Orthemis ferruginea
 * Orthodon
 * †Osbornodon
 * †Osbornodon fricki
 * Osteodontornis BW cropped.png †[[Osteodontornis]] – type locality for genus
 * †Osteodontornis orri – type locality for species
 * Ostrea
 * †Ostrea angelica
 * †Ostrea atwoodii
 * †Ostrea bourgeosi
 * †Ostrea conchaphila
 * †Ostrea hertleini
 * †Ostrea lincolnensis – or unidentified related form
 * †Ostrea lurida
 * †Ostrea subtitan
 * †Ostrea weaveri
 * Otodus obliquus multiple 021313.JPG †[[Otodus]]
 * †Otodus angustidens
 * †Otodus megalodon
 * †Ottoceros
 * †Ottoceros peacevalleyensis – type locality for species
 * Otus
 * †Otus asio
 * †Ourayia
 * Ovibos
 * †Ovibos moschatus
 * Ovis
 * †Ovis canadensis
 * †Oxyrhina
 * †Oxyrhina crassa
 * †Oxyura
 * Ruddy Duck (Oxyura jamaicensis) RWD2 cropped.jpg †[[Oxyura jamaicensis]]
 * †Ozymandias – type locality for genus
 * †Ozymandias gilberti – type locality for species

P

 * †Pachycrommium
 * †Pachycrommium clarki
 * †Paciculus
 * †Pacifichelys
 * †Pacifichelys hutchisoni – type locality for species
 * †Pacipecten
 * †Pacipecten discus
 * †Pacipecten pabloensis – or unidentified comparable form
 * †Palaeolagus
 * †Palaeolama
 * †Palaeolama mirifica – or unidentified related form
 * †Palaeopsammia
 * †Palaeopsammia zitteli
 * †Palaeoxantusia
 * †Palaeoxantusia allisoni
 * †Palaeoxantusia kyrentos
 * Paleoparadoxia BW.jpg †[[Paleoparadoxia]]
 * †Paleoparadoxia tabatai
 * †Paleosula – type locality for genus
 * †Paleosula stocktoni – type locality for species
 * Palpomyia – type locality for genus
 * †Palpomyia freyi – type locality for species
 * †Palpomyia multispinosa – type locality for species
 * †Palpomyia ryshkoffi – type locality for species
 * †Palpomyia shilo – type locality for species
 * Pandora
 * †Pandora punctata
 * †Pandora wardiana
 * †Panolax
 * †Panolax sanctaefidei
 * Panomya
 * †Panomya ampla
 * Panopea
 * †Panopea abrupta
 * †Panopea estrellana – or unidentified related form
 * †Panopea ramonensis
 * †Panopea smithii
 * †Panopea tenuis
 * Panthera
 * Lion (Panthera leo) (30941994012) cropped.jpg †[[Panthera leo]]
 * †Panthera onca – or unidentified comparable form
 * †Parabalaenoptera – type locality for genus
 * †Parabalaenoptera baulinensis – type locality for species
 * Paraconcavus
 * †Paraconcavus margaritanus
 * †Paraconcavus pacificus
 * †Paracontogenys
 * †Paracontogenys estesi
 * †Paracosoryx
 * †Paracosoryx alticornis
 * †Paracosoryx furlongi
 * †Paraculicoides – type locality for genus
 * †Paraculicoides rouseae – type locality for species
 * Paracyathus
 * †Paracyathus pedroensis – type locality for species
 * †Paracyathus stearnsii
 * †Paracynarctus
 * †Paracynarctus kelloggi
 * †Paradjidaumo
 * †Paradjidaumo reynoldsi – type locality for species
 * †Paradomnina
 * †Paradomnina relictus – or unidentified comparable form
 * †Parafundulus
 * †Parafundulus erdisi
 * Parahippus Cognatus.jpg †[[Parahippus]]
 * †Parahippus maxsoni – type locality for species
 * †Parahippus pawniensis
 * †Parahyus
 * †Paralichthyes
 * Paralichthys – type locality for genus
 * †Paralichthys antiquus
 * †Paramerychyus
 * †Paramerychyus harrisonensis
 * †Paramerychyus relictus
 * †Paramiolabis
 * †Paramiolabis minutus – type locality for species
 * †Paramiolabis singularis – or unidentified comparable form
 * †Paramiolabis taylori
 * †Paramiolabis tenuis
 * San Diego Paramylodon.jpg Paramylodon]] †Paramylodon
 * †Paramylodon harlani
 * †Paramys
 * †Paramys compressidens – or unidentified comparable form
 * †Paramys leptodus – or unidentified comparable form
 * †Parapavo
 * †Parapavo californica
 * †Parapavo californicus
 * †Parapliohippus
 * †Parapliohippus carrizoensis – type locality for species
 * Parapontoporia Piscolithax.jpg †[[Parapontoporia]]
 * †Parapontoporia sternbergi – type locality for species
 * †Parapontoporia wilsoni – type locality for species
 * †Parasauromalus
 * †Parasauromalus olseni
 * Paraseraphs
 * †Paraseraphs erraticus
 * †Parastylotermes
 * †Parastylotermes calico – type locality for species
 * †Parastylotermes frazieri – type locality for species
 * †Paratomarctus
 * †Paratomarctus temerarius
 * †Pareumys
 * †Pareumys grangeri
 * †Pareumys milleri
 * Parietobalaena yamaokai life restoration cropped.png †[[Parietobalaena]]
 * †Parietobalaena securis – type locality for species
 * †Paromomys
 * †Paromomys depressidens
 * †Paronychomys
 * †Parribacus
 * †Parribacus caesius – type locality for species
 * Parvamussium
 * †Parvicornus – type locality for genus
 * †Parvicornus occidentalis – type locality for species
 * Parvilucina
 * †Parvilucina approximata
 * †Parvilucina tenuisculpta
 * †Parvisipho – tentative report
 * †Parvisipho meganosensis – type locality for species
 * Patelloida corticata.JPG [[Patelloida]]
 * †Patelloida tejonensis
 * †Patelloida triquetrus
 * Patinopecten
 * †Patinopecten caurinus
 * †Patinopecten coosensis
 * †Patinopecten healeyi
 * †Patinopecten healyi
 * †Patinopecten lohri
 * †Patinopecten propatulus
 * †Patriolestes
 * †Patriolestes novaceki – type locality for species
 * †Pauromys
 * †Pauromys lillegraveni – type locality for species
 * †Pecoripeda
 * Pecten maximus Pilgermuschel.jpg [[Pecten (genus)|Pecten]]
 * †Pecten bellus
 * †Pecten bowersi
 * †Pecten dickersoni
 * †Pecten estrellanis
 * †Pecten magnolia
 * †Pecten nevadensis
 * †Pecten perrini
 * †Pecten sespeensis
 * †Pedalion
 * †Pedalion panzana – or unidentified comparable form
 * †Pediomeryx
 * †Pediomeryx hemphillensis
 * †Pedipes
 * †Pedipes liratus
 * †Pedipes unisulcatus
 * †Pelagiarctos – type locality for genus
 * †Pelagiarctos thomasi – type locality for species
 * Pelagornis mauretanicus.png †[[Pelagornis]]
 * Pelecanus
 * †Pelecanus erythrorhynchus – or unidentified comparable form
 * †Pelecanus occidentalis
 * †Peltosaurus
 * †Peltosaurus macrodon – type locality for species
 * Penitella
 * †Penitella penita
 * †Peraceras
 * †Peraceras superciliosum
 * †Peradectes
 * †Peradectes californicus
 * †Periaster
 * Pericosmus
 * †Peridiomys
 * †Peridiomys oregonensis – or unidentified comparable form
 * Antigona listeri (J. E. Gray, 1838) 2013 001.JPG [[Periglypta]]
 * †Periglypta multicostata
 * Periploma
 * †Periploma planiuscula
 * †Periploma stewartvillensis – type locality for species
 * †Peripolocetus – type locality for genus
 * †Peripolocetus vexillifer – type locality for species
 * †Perissitys
 * †Perissitys stewarti
 * †Perissolax
 * †Perissolax blakei
 * †Perissolax tricarinatus
 * †Perognathoides
 * †Perognathoides eurekensis
 * Pacific pocket mouse cropped.jpg [[Perognathus]]
 * †Perognathus furlongi
 * †Perognathus minutus
 * Peromyscus
 * †Peromyscus baumgartneri
 * †Peromyscus boylei
 * †Peromyscus complexus – type locality for species
 * †Peromyscus dentalis
 * †Peromyscus hagermanensis
 * †Peromyscus irvingtonensis – type locality for species
 * †Peromyscus maximus – type locality for species
 * †Peromyscus truei – or unidentified comparable form
 * †Perse
 * †Perse lincolnensis
 * Persea
 * †Persea coalingensis
 * †Persea praelingue
 * †Persea pseudocarolinensis
 * Strombidae - Persististrombus nodosus.JPG [[Persististrombus]]
 * †Persististrombus obliteratus – type locality for species
 * †Petauristodon
 * †Petauristodon jamesi
 * †Petauristodon mathewsi
 * †Petauristodon minimus
 * †Petauristodon uphami
 * Petricola
 * †Petricola carditoides
 * †Petricola cognata
 * †Petricola denticulata
 * †Petricola parallela
 * Petrophyllia
 * †Petrophyllia clarki
 * †Petrophyllia weaveri
 * †Pewelagus
 * †Pewelagus dawsonae
 * Phacoides
 * †Phacoides actulineatus
 * †Phacoides sactaecrucis – tentative report
 * Phalacrocorax
 * Phalacrocorax-auritus-007.jpg †[[Phalacrocorax auritus]]
 * †Phalacrocorax femoralis – type locality for species
 * †Phalacrocorax kennelli – type locality for species
 * †Phalacrocorax pelagicus
 * †Phalacrocorax penicillatus
 * †Phalacrocorax penincillatus
 * †Phalacrocorax penincullatus
 * †Phalacrocorax rogersi – type locality for species
 * Phalaropus
 * †Phalaropus fulicaria
 * †Phalaropus lobatus
 * †Phanaeus
 * †Phanaeus labreae – type locality for species
 * †Phelosaccomys
 * †Phelosaccomys shotwelli – type locality for species
 * †Phenacolemur
 * †Phenacolemur shifrae
 * Phlaocyon.png †[[Phlaocyon]]
 * †Phlaocyon taylori
 * †Phlepsius
 * †Phlepsius weissmanae – type locality for species
 * Phloeodes
 * †Phloeodes diabolicus
 * †Phloeodes plicatus
 * †Phoberogale
 * †Phoberogale shareri – type locality for species
 * Phoca
 * †Phoca vitulina – or unidentified comparable form
 * Phocoena – or unidentified comparable form
 * †Phoebastria
 * †Phoebastria albatrus – type locality for species
 * †Phoebastria anglica – type locality for species
 * Flamingos Laguna Colorada.jpg [[Phoenicopterus]] – or unidentified comparable form
 * Pholadidea
 * Pholadomya
 * †Pholadomya mounti
 * †Pholadomya nasuta
 * Pholas
 * †Pholas gabbi
 * Phos
 * †Phos blakianus – or unidentified comparable form
 * †Phos dumbleanus
 * †Photinia
 * †Photinia miocenica
 * Horned lizard 032507 kdh.jpg [[Phrynosoma]]
 * †Phyllites
 * †Phyllites californica
 * †Phyllites coalingensis
 * †Phyllites cordiaefolia – type locality for species
 * †Phyllites daturaefolia – type locality for species
 * †Phyllites domenginensis
 * †Phyllites ellipticus
 * †Phyllites laurinea
 * †Phyllites temblorensis
 * Phyllonotus
 * †Phyllonotus hippocastanum
 * †Phyllonotus radix
 * Physa marmorata.png]] Physa''
 * †Physiculua
 * Phytocrene
 * †Phytocrene sordida
 * Picea
 * †Picea lahontense
 * †Picea magna
 * †Picea sonomensis
 * †Pimelometopodon
 * †Pimelometopodon pulchrum – or unidentified comparable form
 * Pimelometopon
 * †Pimelometopon pulchrum
 * Pinna
 * †Pinna alamedaensis
 * †Pinna latrania – type locality for species
 * †Pinna lewisi
 * †Pinna llajasensis – type locality for species
 * †Pinna mendenhalli – type locality for species
 * †Pinnarctidion – type locality for genus
 * †Pinnarctidion bishopi – type locality for species
 * Pinus
 * †Pinus carmelensis – type locality for species
 * †Pinus muricata
 * †Pinus prelambertiana – or unidentified comparable form
 * †Pinus radiata
 * †Pinus sturgisii
 * †Pinus temblorensis
 * Piranga
 * †Piranga ludoviciana
 * †Piscolithax
 * Veneridae - Pitar lupanaria.JPG [[Pitar]]
 * †Pitar avenalensis – tentative report
 * †Pitar behri
 * †Pitar california – or unidentified comparable form
 * †Pitar californiana
 * †Pitar campi – or unidentified comparable form
 * †Pitar dalli
 * †Pitar joaquinensis
 * †Pitar newcombianus
 * †Pitar quadratus
 * †Pitar stantoni – or unidentified comparable form
 * †Pitar tejonensis – or unidentified comparable form
 * †Pitar uvasana
 * †Pitar uvasanus
 * †Pithanodelphis
 * †Pithanotaria – type locality for genus
 * †Pithanotaria starri – type locality for species
 * Pituophis
 * Suwanee County FL Pine Snake.jpg †[[Pituophis melanoleucus]]
 * Pitymys
 * †Pitymys mcnowni – or unidentified comparable form
 * Placunanomia
 * †Placunanomia granti
 * Planularia
 * †Planularia caribbeana
 * †Platanophyllum
 * †Platanophyllum angustiloba
 * †Platanophyllum whitenyi
 * †Platanophyllum whitneyi
 * Platanus
 * †Platanus angustilobus – type locality for species
 * †Platanus appendiculata
 * †Platanus coloradensis
 * †Platanus dissecta – or unidentified comparable form
 * †Platanus paucidentata
 * Platygonus leptorhinus cropped.png of the genus Platygonus. Charles R. Knight (1922).]] †Platygonus
 * †Platygonus bicalcaratus
 * †Platygonus vetus
 * †Platylithax – type locality for genus
 * †Platylithax robusta – type locality for species
 * Platynus
 * †Platynus funebris – or unidentified comparable form
 * Platyodon
 * †Platyodon cancellata
 * †Platyodon cancellatus
 * †Platyoptera
 * †Platyoptera pacifica
 * Platytrochus
 * †Platytrochus diabloensis – type locality for species
 * †Platytrochus merriami – type locality for species
 * †Plectina
 * †Plectina garzaensis
 * †Plectina ruthenica – or unidentified comparable form
 * Plectofrondicularia
 * †Plectofrondicularia kerni
 * †Plectofrondicularia miocenica
 * †Plectofrondicularia packardi
 * †Plectofrondicularia trinitatensis
 * †Plectofrondicularia vaughani
 * †Plectrites
 * †Plectrites classeni
 * Plegadis
 * †Plegadis chihi
 * †Pleiolama
 * †Pleiolama vera
 * Plesiadapis NT.jpg †[[Plesiadapis]]
 * †Plesiadapis anceps – or unidentified comparable form
 * †Plesiadapis churchilli – or unidentified comparable form
 * †Plesiogulo
 * †Plesiogulo lindsayi
 * †Plesiogulo marshalli
 * Pleurofusia
 * †Pleurofusia fresnoensis
 * †Pleurofusia lindavistaensis – or unidentified related form
 * †Pleuroncodes
 * †Pleuronichthys
 * †Pleuronichthys veliger
 * †Pliauchenia
 * †Pliauchenia magnifontis – or unidentified comparable form
 * †Plioceros
 * †Pliocyon
 * †Pliocyon medius
 * Pliohippus Pernix.jpg †[[Pliohippus]]
 * †Pliohippus coalingensis – type locality for species
 * †Pliohippus fairbanksi – type locality for species
 * †Pliohippus spectans – tentative report
 * †Pliometanastes
 * †Pliometanastes protistus
 * †Plionarctos
 * †Plionarctos edensis – type locality for species
 * †Plionictis
 * †Plionictis ogygia – or unidentified comparable form
 * Pliopedia pacifica cropped.png †[[Pliopedia]] – type locality for genus
 * †Pliopedia pacifica – type locality for species
 * †Pliotaxidea
 * †Pliotaxidea garberi – type locality for species
 * †Pliotomodon
 * †Pliotomodon primitivus – type locality for species
 * †Plithocyon
 * †Plithocyon barstowensis
 * †Plotopterum – type locality for genus
 * †Plotopterum joaquinensis – type locality for species
 * Pluvialis
 * †Pluvialis squatarola
 * Pneumatophorus
 * †Pneumatophorus grex – or unidentified comparable form
 * †Poabromylus – tentative report
 * †Poabromylus robustus
 * Pocillopora meandrina with a resident fish.jpg [[Pocillopora]]
 * Podiceps
 * †Podiceps arndti
 * †Podiceps auritus
 * †Podiceps discors
 * †Podiceps nigricolis
 * †Podiceps parvus
 * †Podiceps subparvus
 * Podilymbus
 * †Podilymbus podiceps
 * Pododesmus
 * †Pododesmus macrochisma
 * †Poebrodon
 * †Poebrodon californicus – type locality for species
 * Pogonodon platycopis.jpg †[[Pogonodon]]
 * †Pogonodon brachyops
 * Polinices
 * †Polinices – type locality for species informal
 * †Polinices draconis
 * †Polinices horni – or unidentified comparable form
 * †Polinices hornii
 * †Polinices lewisii
 * †Polinices pinyonensis – or unidentified comparable form
 * †Polinices recluzianys
 * †Polinices rectus – or unidentified related form
 * †Polinices susanaensis
 * †Polinices uber
 * †Polinices washingtonensis – or unidentified comparable form
 * Polydora
 * Polymesoda artacta 001 cropped.jpg [[Polymesoda]]
 * †Polymesoda tenuis – or unidentified comparable form
 * Polystira
 * †Polystira barretti
 * †Pongamia
 * †Pongamia ovata – type locality for species
 * †Pontolis – or unidentified comparable form
 * †Pontolis magnus
 * Populus
 * †Populus alexanderii
 * †Populus bonhamii
 * †Populus coalingensis
 * †Populus garberii
 * Porichthys
 * †Porichthys myriaster
 * Plainfin Midshipman cropped.jpg †[[Porichthys notatus]]
 * Porites
 * †Porites carrizensis – type locality for species
 * †Portunites
 * †Portunites insculpta
 * †Potamides
 * †Potamides carbonica – or unidentified comparable form
 * †Potamides sespeensis
 * †Praemancalla – type locality for genus
 * †Praemancalla lagunensis – type locality for species
 * †Presbychen – type locality for genus
 * †Presbychen abavus – type locality for species
 * †Presbymys
 * †Presbymys lophatus – type locality for species
 * Priene
 * †Priene amoldi
 * †Priene oregonensis
 * †Priene scotiaensis
 * Prionace
 * Prionace glauca 1 cropped.jpg †[[Prionace glauca]]
 * †Priscoficus
 * †Priscoficus caudata
 * †Priscofusus
 * †Priscofusus carlsoni – tentative report
 * †Priscofusus hecoxi
 * †Priscofusus lincolnensis
 * †Priscofusus robustus
 * †Pristichampsus
 * Pristiophorus
 * †Pristophorus
 * †Proboscipeda
 * †Procamelus
 * †Procamelus grandis – or unidentified comparable form
 * †Procymophyes – type locality for genus
 * †Procymophyes lithax – type locality for species
 * †Procynodictis
 * †Procynodictis progressus
 * Procyon
 * †Procyon lotor
 * †Procyon psora
 * †Prodipodomys
 * †Prodipodomys idahoensis
 * †Prodipodomys riversidensis – type locality for species
 * †Prodipodomys timoteoensis – type locality for species
 * †Prodipoides
 * †Prodipoides lecontei – type locality for species
 * Progabbia
 * †Proharrymys – or unidentified comparable form
 * †Proheteromys
 * †Proheteromys maximus
 * †Proheteromys sulculus
 * †Promartes
 * †Pronotolagus
 * †Pronotolagus apachensis – or unidentified comparable form
 * †Protadjidaumo
 * †Protanthias – type locality for genus
 * †Protanthias fossilis – type locality for species
 * †Protepicyon
 * †Protepicyon raki – type locality for species
 * †Proterixoides
 * †Proterixoides davisi – type locality for species
 * †Prothomomys
 * †Prothomomys warrenensis – type locality for species
 * Protitanops NT small.jpg †[[Protitanops]]
 * †Protitanops curryi – type locality for species
 * †Protoarrenurus
 * †Protoarrenurus convergens – type locality for species
 * †Protochlorotettix – type locality for genus
 * †Protochlorotettix calico – type locality for species
 * †Protohepialus – type locality for genus
 * †Protohepialus comstocki – type locality for species
 * †Protolabis
 * †Protolabis barstowensis – type locality for species
 * †Protomarctus
 * †Protomarctus optatus
 * †Protoreodon
 * †Protoreodon pacificus – type locality for species
 * †Protoreodon parvus – or unidentified comparable form
 * †Protoreodon pumilus
 * †Protoreodon transmontanus
 * †Protoreodon walshi
 * †Protosciurus
 * †Protosciurus tecuyensis
 * †Protosegestes – report made of unidentified related form or using admittedly obsolete nomenclature
 * †Protosegestes lloydi – type locality for species
 * †Protospermophilus
 * †Protospermophilus quatalensis – type locality for species
 * †Protostrix
 * †Protostrix californiensis – type locality for species
 * †Protosurcula – tentative report
 * Protothaca
 * †Protothaca staleyi
 * †Protothore – type locality for genus
 * †Protothore explicata – type locality for species
 * Protylopus petersoni skull.jpg †[[Protylopus]]
 * †Protylopus pearsonensis – type locality for species
 * †Protylopus petersoni – or unidentified comparable form
 * †Protylopus robustus – type locality for species
 * †Protylopus stocki – type locality for species
 * Proximitra – tentative report
 * †Proximitra cretacea
 * Prunus
 * †Prunus turlockensis
 * Psammacoma
 * †Psammacoma acolasta
 * †Psammacoma arctata
 * †Psammacoma yoldiformis
 * Psammotreta
 * †Psammotreta dombei
 * †Psammotreta obesa
 * †Psammotreta rostellata
 * †Psammotreta viridotincta
 * Psephophorus NT small cropped.png †[[Psephophorus]]
 * †Psephophorus calvertensis – or unidentified comparable form
 * †Pseudaelurus
 * †Pseudaelurus intrepidus
 * †Pseudaelurus marshi
 * †Pseudoblastomeryx
 * †Pseudoblastomeryx advena
 * Pseudochama
 * †Pseudochama exogyra
 * †Pseudoglandulina
 * †Pseudoglandulina conica
 * †Pseudoglandulina ovata
 * †Pseudoglandulina turbinata
 * Pseudoliva
 * †Pseudoliva dilleri
 * †Pseudoliva inornata – or unidentified comparable form
 * Pseudomelatoma torosa 1.jpg [[Pseudomelatoma]]
 * †Pseudomelatoma penicillata
 * †Pseudoparablastomeryx
 * †Pseudoparablastomeryx scotti – or unidentified comparable form
 * †Pseudoparella
 * †Pseudoperrisolax
 * †Pseudoperrisolax blakei
 * †Pseudoseriola – type locality for genus
 * †Pseudoseriola gillilandi – type locality for species
 * †Pseudotheridomys
 * †Pseudotheridomys cuyamensis – type locality for species
 * †Pseudotomus
 * †Pseudotomus californicus
 * †Pseudotomus littoralis – type locality for species
 * Pseudotsuga menziesii 28236.JPG †[[Pseudotsuga]]
 * †Pseudotsuga sonomensis
 * Pteria
 * †Pteria berryi
 * †Pteria hertleini
 * †Pteria pellucida
 * †Pteroplatea
 * †Pteroplatea lapislutosa – type locality for species
 * Pteropurpura
 * †Pteropurpura festiva
 * †Pteropurpura trialatus
 * Pterostichus
 * Pterynotus
 * †Pterynotus petri
 * †Pterynotus washingtonicus
 * Ptilodus skull BW cropped.jpg †[[Ptilodus]]
 * Ptinus
 * †Ptinus priminidi – type locality for species
 * Ptychoramphus
 * †Ptychoramphus aleuticus
 * Puffinus
 * †Puffinus barnesi – type locality for species
 * †Puffinus calhouni – type locality for species
 * †Puffinus diatomicus – type locality for species
 * †Puffinus felthami – type locality for species
 * †Puffinus gilmorei – type locality for species
 * †Puffinus gresus
 * †Puffinus grisesus
 * †Puffinus griseus
 * †Puffinus inceptor – type locality for species
 * †Puffinus kanakoffi
 * †Puffinus mitchelli – type locality for species
 * †Puffinus opisthomelas
 * †Puffinus priscus – type locality for species
 * †Puffinus tenuirostris
 * Pullenia
 * †Pullenia eocenica
 * †Pullenia quinqueloba
 * CMM MountainLion.jpg †[[Puma (genus)|Puma]]
 * †Puma concolor – type locality for species
 * Puncturella
 * †Puncturella galeata
 * †Puncturella multistriata
 * Pupillaria
 * †Pupillaria optabilis
 * †Pupillaria pupilla
 * Purpura
 * †Purpura barbarensis
 * †Purpura festiva
 * †Purpura lima
 * †Purpura lurida
 * †Purpura milicentana – type locality for species
 * †Purpura nuttallii
 * †Purpura poulsoni
 * †Purpura topangensis
 * Triviidae - Pusula radians.jpg [[Pusula]]
 * †Pusula californiana
 * †Pusula solandri
 * Pycnodonte
 * †Pycnodonte eldridgei
 * †Pycnodonte heermanni
 * †Pycnodonte pacifica – or unidentified comparable form
 * †Pycnodonte stewarti – or unidentified related form
 * Pyramidella
 * †Pyramidella adamsi – or unidentified comparable form
 * †Pyramidella mucronis
 * †Pyramidella preblei
 * Pyrene
 * †Pyrene carinata

Q

 * †Quercophyllum
 * †Quercophyllum platanoides – type locality for species
 * Eiche bei Schönderling, 2.jpg [[Quercus]]
 * †Quercus acorns
 * †Quercus coalingensis
 * †Quercus dispersa
 * †Quercus distincta
 * †Quercus domenginensis
 * †Quercus douglasoides
 * †Quercus eoxalapensis – type locality for species
 * †Quercus hannibali
 * †Quercus hannibalii
 * †Quercus lakevillensis
 * †Quercus merriami
 * †Quercus nevadensis
 * †Quercus pasadorii – type locality for species
 * †Quercus pliopalmerii
 * †Quercus pollardiana
 * †Quercus pseudolyrata
 * †Quercus remingtonii
 * †Quercus sayana
 * †Quercus simulata
 * †Quercus temblorensis
 * †Quercus wislizenoides

R

 * Raja
 * †Rakomeryx
 * †Rakomeryx sinclairi – type locality for species
 * Rallus
 * †Rallus limicola
 * Merycodus osborni cropped.png †[[Ramoceros]]
 * †Ramoceros brevicornis – type locality for species
 * †Rana
 * †Ranellina
 * †Ranellina pilsbry – or unidentified related form
 * Raninoides
 * †Raninoides slaki – type locality for species
 * †Rapamys
 * †Rapamys fricki – type locality for species
 * Rapana
 * †Rapana vaquerosensis
 * †Rectoguembelina
 * †Rectoguembelina trinitatensis – or unidentified comparable form
 * Pied Avocet Recurvirostra avosetta.jpg [[Recurvirostra]]
 * Reithrodontomys
 * †Reithroparamys – or unidentified comparable form
 * Reophax
 * †Reophax pilulifer – or unidentified comparable form
 * †Repomys
 * †Repomys gustelyi – type locality for species
 * †Repomys maxumi – type locality for species
 * Reticulitermes
 * †Reticulitermes laurae – type locality for species
 * †Reticulitermes tibalis
 * Reticutriton
 * †Reticutriton elsmerensis
 * †Retipirula
 * †Retipirula crassitesta
 * Retusa.png [[Retusa]]
 * †Retusa carinata
 * †Retusa culcitella
 * †Retusa harpa
 * †Retusa tantilla
 * †Reynoldsomys
 * †Reynoldsomys timoteoensis – type locality for species
 * †Rhabdammina
 * †Rhabdammina eocenica
 * †Rhamnidium
 * †Rhamnidium chaneyi
 * †Rhamnus
 * †Rhamnus calyptus
 * †Rhamnus moragensis
 * †Rhamnus plenus
 * †Rhamnus precalifornica
 * †Rhomarchus – type locality for genus
 * †Rhomarchus ensiger – type locality for species
 * †Rhomurus
 * †Rhomurus fulcratus
 * Rhus
 * †Rhus diablana
 * †Rhus mixta
 * Rhynchotherium falconeri.png †[[Rhynchotherium]]
 * †Rhynchotherium falconeri
 * †Rhynconella – tentative report
 * †Rhyssomatus
 * †Rhyssomatus miocenae – type locality for species
 * †Rhythmias
 * †Rhythmias gaviotae – type locality for species
 * †Rhythmias slarri
 * Rimella
 * †Rimella macilentus
 * †Rimella supraplicata
 * †Rimella supraplicatus
 * Rissa
 * †Rissa estesi – type locality for species
 * †Rissa tridactyla
 * Rissoina
 * †Rissoina pleistocena
 * Robina9146.JPG †[[Robinia]]
 * †Robinia californica
 * Robulus
 * †Robulus alatolimbatus
 * †Robulus arcuatostriatus
 * †Robulus clericii
 * †Robulus clypeiformis – or unidentified comparable form
 * †Robulus inornatus
 * †Robulus insuetus
 * †Robulus kincaidi
 * †Robulus mayi
 * †Robulus mexicanus
 * †Robulus nikobarensis
 * †Robulus propinquus
 * †Robulus simplex
 * †Robulus terryi – or unidentified comparable form
 * †Robulus warmani
 * †Robulus welchi
 * †Rogenio
 * †Rogenio bowersi
 * †Rogenio solitudinis
 * †Rogenio vanclevei – type locality for species
 * †Rotularia
 * †Rotularia tejonense
 * †Russellagus

S

 * SabalPalm.jpg [[Sabal]]
 * †Sabal miocenica
 * †Sabalites
 * †Sabalites californicus
 * Saccella
 * †Saccella alaeformis
 * †Saccella gabbi
 * †Saccella taphria
 * Sagmatias
 * †Sainguinolaria
 * †Sainguinolaria toulai – or unidentified comparable form
 * Salix
 * †Salix boisiensis
 * †Salix edenensis
 * †Salix hesperia
 * †Salix ionensis
 * †Salix laevigatoides
 * †Salix pelviga
 * †Salix storeyana
 * †Salix wildcatensis
 * †Salumiphocaena
 * †Salumiphocaena stocktoni – type locality for species
 * Saniwa ensidens.jpg †[[Saniwa]]
 * †Saniwa ensidens – type locality for species
 * †Sapindus
 * †Sapindus oklahomensis
 * Saracenaria – tentative report
 * †Saracenaria acutiauricularis – or unidentified comparable form
 * †Sarda
 * †Sarda stockii – type locality for species
 * Sassia
 * †Sassia bilineata
 * Saxidomus
 * †Saxidomus gigantea
 * †Saxidomus giganteus
 * †Saxidomus nuttalli
 * †Saxidomus vaquerosensis
 * †Saxolucina
 * Scaldicetus grandis cropped.jpg †[[Scaldicetus]]
 * †Scaldicetus grandis – or unidentified comparable form
 * †Scalopoides
 * Scapanus
 * †Scapanus latimanus
 * †Scapanus malatinus
 * †Scapanus shultzi – type locality for species
 * Scaphander
 * †Scaphander costatus
 * †Scaphander jugularis
 * Scapharca
 * †Scapharca obispoana
 * Scaphinotus
 * †Scaphinotus interruptus
 * Merychippus sumani.jpg †[[Scaphohippus]]
 * †Scaphohippus intermontanus – type locality for species
 * †Scaphohippus sumani – type locality for species
 * Sceloporus
 * †Sceloporus occidentalis
 * †Scenopagus
 * †Scenopagus curtidens
 * †Scenopagus priscus – or unidentified comparable form
 * †Schaubeumys
 * †Schedocardia – tentative report
 * †Schistomerus – type locality for genus
 * †Schistomerus californense – type locality for species
 * Schizaster
 * †Schizaster diabloensis
 * †Schizaster lecontei
 * †Schizaster martinezensis
 * †Schizodontomys
 * †Sciuravus
 * †Sciuravus powayensis
 * Sciurus
 * Scomber
 * †Scomber sanctaemonicae
 * †Scomberesox
 * †Scomberesox acutillus – type locality for species
 * †Scomberesox edwardsi – type locality for species
 * Scopelogadus mizolepis mizolepis.png [[Scopelogadus]]
 * †Scopelogadus mizolepis
 * †Scutella
 * †Scutella fairbanksi
 * †Scutella fairbanski
 * †Scutella merriami
 * †Scutella norrisi
 * †Scutella vaquerosensis
 * †Scutellaster
 * Acuario Sevilla crias alitan.JPG [[Scyliorhinus]]
 * †Scymnorhinus
 * †Scymnorhinus occidentalis
 * Searlesia
 * †Searlesia dira
 * †Sebastavus – type locality for genus
 * †Sebastavus vertebralis – type locality for species
 * †Sebastodes
 * †Sebastodes apostates
 * †Sebastodes haroldi – type locality for species
 * †Sebastodes ineziae
 * †Sebastodes porteousi
 * †Sebastodes porteus
 * †Sebastodes rosae
 * Seila
 * †Seila montereyensis
 * Semelangulus
 * †Semelangulus tenuilirata
 * Semele – tentative report
 * Semele
 * †Semele decisa
 * †Semele diabloi
 * †Semele morani
 * †Semele packardi
 * †Semele pulchra
 * †Semele rubropicta
 * †Semele venusta
 * Semicassis
 * †Semicassis louella – type locality for species
 * †Semicassis tuberculiformis
 * Semicossyphus
 * †Semirostrum – type locality for genus
 * †Semirostrum ceruttii – type locality for species
 * Septifer
 * †Septifer bifurcatus
 * General Grant Tree in Kings Canyon National Park.jpg †[[Sequoiadendron]]
 * †Sequoiadendron chaneyi
 * †Serbelodon
 * †Serbelodon burnhami
 * Serica
 * †Serica kanakoffi – type locality for species
 * Seriola
 * †Seriola sanctaebarbarae
 * Seriphus
 * †Seriphus politus
 * Serpula
 * †Serpula coreyi
 * Serpulorbis
 * †Serpulorbis llajasensis
 * †Sespedectes
 * †Sespedectes singularis – type locality for species
 * †Sespedectes stocki
 * †Sespemys
 * †Sespemys thurstoni – type locality for species
 * Sespia ultima californica cropped.png †[[Sespia]]
 * †Sespia californica – type locality for species
 * †Sespia nitida
 * Siderastrea
 * †Siderastrea clarki – type locality for species
 * †Siderastrea mendenhalli – type locality for species
 * Sigmodon
 * †Sigmodon lindsayi
 * †Sigmodon minor
 * Sigmoilina – tentative report
 * Siliqua
 * †Siliqua lucida
 * †Siliqua media – or unidentified comparable form
 * †Siliqua patula – or unidentified related form
 * †Simiacritomys
 * †Simiacritomys whistleri – type locality for species
 * †Simidectes
 * †Simidectes medius – or unidentified comparable form
 * †Simidectes merriami – type locality for species
 * †Simimeryx
 * †Simimeryx hudsoni – type locality for species
 * †Simimys
 * †Simimys landeri – type locality for species
 * †Simimys simplex
 * Simomactra
 * †Simomactra dolabriformis
 * †Simomactra falcata
 * †Simomactra planulata
 * †Sinomactra
 * †Sinomactra falcata
 * Sinum cymba 01.JPG [[Sinum]]
 * †Sinum debile – or unidentified comparable form
 * †Sinum obliquum
 * †Sinum scopulosum
 * Siphonalia
 * †Siphonalia andersoni
 * †Siphonalia lineata
 * †Siphonalia merriami
 * †Siphonalia sutterensis – or unidentified comparable form
 * Skenea
 * †Skenea californica
 * †Smilax
 * †Smilax diforma
 * †Smilax labidurommae
 * †Smilax magna – or unidentified comparable form
 * †Smilax remingtonii
 * Smilodon fatalis.jpg †[[Smilodon]]
 * †Smilodon fatalis
 * †Smilodon gracilis
 * †Smilodonichthyes
 * †Smilodonichthyes rastrosus
 * †Smilodonichthys
 * †Smilodonicthyes
 * †Smilodonicthyes rastrosus
 * †Smithites – type locality for genus
 * †Smithites elegans – type locality for species
 * Solariella
 * †Solariella hartleyensis – type locality for species
 * †Solariella peramabilis
 * †Solariella walkeri – type locality for species
 * Solemya elarraichensis holotype.jpg [[Solemya]]
 * †Solemya ventricosa
 * Solen
 * †Solen curtis – or unidentified comparable form
 * †Solen rosaceus
 * †Solen sicarius
 * Solena
 * †Solena conradi
 * †Solena gravidus
 * †Solena lorenzana
 * †Solena parallelus – or unidentified comparable form
 * †Solena perrini
 * †Solena stantoni
 * †Solena subverticala
 * Solenastrea
 * †Solenastrea fairbanksi
 * Solenosteira
 * †Solenosteira anomala
 * MaskedShrew23.jpg [[Sorex]]
 * †Sorex leahyi
 * Spathipora
 * Spermophilus
 * †Spermophilus argonautus
 * †Spermophilus beecheyi
 * †Spermophilus lateralis
 * †Sphaeroidina
 * †Sphaeroidina gredalensis
 * Sphenia – tentative report
 * †Sphenia meganosensis – type locality for species
 * †Sphenophalos – tentative report
 * Hammerhead shark.jpg [[Sphyrna]]
 * †Sphyrna aus
 * †Sphyrna bus
 * Spilogale
 * †Spilogale putorius
 * †Spirocrypta
 * †Spirocrypta inornata
 * †Spirocrypta pileum
 * Spiroglyphus
 * †Spiroglyphus lituella
 * †Spiroglyphus tinajasensis
 * Spiroloculina
 * †Spiroloculina lamposa
 * Spiroplectammina
 * †Spiroplectammina coreyi – type locality for species
 * †Spiroplectammina eocenica
 * †Spiroplectammina kewi – type locality for species
 * Spirotropis
 * †Spirotropis bulimoides
 * †Spirotropis perversa
 * Spisula aequilatera (triangle shell).JPG [[Spisula]]
 * †Spisula coosensis
 * †Spisula densatum – type locality for species
 * †Spisula meganosensis – type locality for species
 * †Spisula pabloensis
 * †Spisula packardi
 * †Spisula panzanum
 * Spondylus
 * †Spondylus bostrychites
 * †Spondylus calcifer
 * †Spondylus carlosensis
 * †Spondylus perrini
 * †Spondylus vaquerosensis
 * Squalus acanthias2.jpg [[Squalus]]
 * †Squalus sericulus
 * †Squalus serriculus
 * Squatina
 * †Squatina californica – or unidentified comparable form
 * †Squatina claifornica
 * †Squatina lerichei
 * Squilla
 * †Squilla laingae
 * †Starrias – type locality for genus
 * †Starrias ischyrus – type locality for species
 * Stegomastodon mirificus - Smithsonian.JPG †[[Stegomastodon]]
 * †Stegomastodon mirificus – or unidentified comparable form
 * Stenella
 * †Stenomylus
 * †Stenomylus hitchcocki – or unidentified comparable form
 * Stenoplax
 * †Stenoplax conspicua
 * †Stenoplax magdalenensis
 * Stephanodiscus
 * †Stephanodiscus asteroides
 * †Stephanodiscus carconensis
 * †Stephanodiscus excentricus
 * †Stephanodiscus hantzchii
 * †Stephanodiscus hantzschii
 * †Stephanophyllia
 * †Stephanophyllia californica – type locality for species
 * †Stephanophyllia vacavillensis
 * Stercorarius
 * Sterna
 * †Sterna neglecta
 * †Sternbergia – type locality for genus
 * †Sternbergia waitei – type locality for species
 * Sthenictis
 * †Stichocassidulina
 * †Stichocassidulina thalmanni
 * †Stictocarbo
 * †Stictocarbo kumeyaay – type locality for species
 * †Stockia – type locality for genus
 * †Stockia powayensis – type locality for species
 * Fossil ruminant.jpg †[[Stockoceros]] – or unidentified comparable form
 * Stomias
 * †Stomias affinis
 * Stramonita
 * †Stramonita biserialis
 * †Stramonita canaliculata
 * †Stramonita imperialis
 * †Strepsidura
 * †Strepsidura diabloensis – type locality for species
 * †Strepsidura ficus – tentative report
 * †Strepsidura lincolnensis
 * †Streptochetus
 * †Streptochetus californiana – type locality for species
 * Odontaspididae - Striatolamia whitei.JPG †[[Striatolamia]]
 * †Striatolamia macrota
 * †Striostrea
 * †Striostrea freudenbergi
 * Strioterebrum
 * †Strioterebrum gausapatum
 * †Strobilites
 * †Strobilites temblorensis
 * Strombiformis
 * †Strombiformis raymondi
 * Strombus
 * †Strombus galeatus
 * †Strombus gracilior
 * †Strongyliscus – type locality for genus
 * †Strongyliscus robustus – type locality for species
 * Strongylocentrotus
 * †Strongylodon
 * †Strongylodon falcata
 * Strophocardia
 * †Strophocardia megastropha
 * Sturnella
 * †Sturnella negecta
 * †Stylemys
 * †Stylemys neglectus – type locality for species
 * Subcancilla
 * †Subcancilla sulcata
 * Knight Caenopus.jpg †[[Subhyracodon]]
 * †Subhyracodon kewi
 * Succinea
 * †Suggrunda
 * Sula
 * †Sula clarki – type locality for species
 * †Sula pohli – type locality for species
 * †Sula willetti – type locality for species
 * †Sulcocypraea
 * †Sulcocypraea moumieti
 * Sulcoretusa
 * †Sulcoretusa xystrum
 * Surculites
 * †Surculites aequilateralis
 * †Surculites carpentaria
 * †Surculites carpenteriana
 * †Surculites carpenterianus
 * †Surculites isoformis
 * †Surculites keepi – or unidentified comparable form
 * †Surculites mathewsoni
 * †Surculites mathewsonii
 * †Surculites remondi
 * †Surculites remondii
 * †Surculities – tentative report
 * †Syllomus – or unidentified comparable form
 * †Syllomus aegyptiacus
 * Sylvilagus
 * †Sylvilagus audubonii
 * †Sylvilagus bachmani
 * †Sylvilagus floridanus
 * †Sylvilagus hibbardi
 * Syncera
 * †Syncera translucens
 * Syngnathus acus.jpg [[Syngnathus]]
 * †Syngnathus avus – type locality for species
 * †Synthiboramphus
 * †Synthiboramphus antiquus
 * Synthliboramphus
 * †Synthliboramphus antiquus
 * †Synthliboramphus hypoleucas
 * †Synthliboramphus hypoleucus
 * †Synthliboramphus rineyi – type locality for species
 * †Synthliboraramphus
 * †Synthliboraramphus antiquus

T

 * Tabernaemontana divaricata by kadavoor.jpg †[[Tabernaemontana]]
 * †Tabernaemontana chrysophylloides
 * Tadorna
 * †Tadorna tadorna
 * Tagelus
 * †Tagelus affinis
 * †Tagelus californianus
 * †Tagelus clarki – type locality for species
 * †Tagelus subteres
 * Tamias
 * †Tamias ateles – type locality for species
 * Tamiasciurus
 * †Tamiasciurus hudsonicus
 * Tamiosoma
 * †Tamiosoma gregaria – type locality for species
 * †Tanymykter
 * †Tanymykter brachyodontus
 * Tapirus
 * †Tapirus californicus
 * †Tapirus haysii
 * †Tapirus merriami – type locality for species
 * †Tapochoerus
 * †Tapochoerus egressus – type locality for species
 * †Tapochoerus mcmillini – type locality for species
 * Tapocyon robustus.jpg †[[Tapocyon]]
 * †Tapocyon dawsonae – type locality for species
 * †Tapocyon robustus
 * †Tapomys
 * †Tapomys tapensis
 * Taranis
 * †Taranis incultus
 * Taricha
 * Taxidea
 * †Taxidea taxus
 * Tayassu
 * †Tayassu edensis
 * Tegula
 * †Tegula – type locality for species informal
 * †Tegula aureotincta
 * †Tegula eiseni
 * †Tegula ligulata
 * †Tejonia
 * †Tejonia lajollaensis – or unidentified comparable form
 * Teleoceras Horsfall cropped.jpg †[[Teleoceras]]
 * †Teleoceras fossiger
 * †Teleoceras hicksi
 * †Teleoceras mediocronutum
 * †Teleoceras meridianum
 * †Teletaceras
 * †Teletaceras mortivallis
 * Tellina fabula.jpg [[Tellina]]
 * †Tellina bodegensis
 * †Tellina cowlitzensis – or unidentified related form
 * †Tellina emacerata
 * †Tellina eugenia
 * †Tellina idae
 * †Tellina kewi
 * †Tellina lebecki – or unidentified comparable form
 * †Tellina martinezensis
 * †Tellina meropsis
 * †Tellina nuculoides
 * †Tellina ocoyana
 * †Tellina oldroydi
 * †Tellina oregonensis
 * †Tellina piercei
 * †Tellina pittsburgensis
 * †Tellina remondii
 * †Tellina soledadensis – or unidentified comparable form
 * †Tellina tehachapi
 * †Tellina undulifera
 * †Tellina vancouverensis – or unidentified comparable form
 * †Tellina wilsoni
 * †Temnocyon
 * †Temnocyon subferox – or unidentified comparable form
 * Tenagodus
 * †Tenagodus californiensis
 * †Tenudomys
 * †Tenudomys bodei
 * Teratornis BW.jpg †[[Teratornis]]
 * †Teratornis merriami
 * Terebellum
 * Terebra
 * †Terebra albocincta
 * †Terebra californica
 * †Terebra danai
 * †Terebra pedroana
 * †Terebra protexta
 * †Terebra santana – type locality for species
 * Terebratalia
 * †Terebratalia batequia – or unidentified related form
 * Terebratula maugerii Boni, 1933.JPG [[Terebratula]]
 * Terebratulina
 * †Terebratulina tejonensis
 * †Terebratulina tejonensis waringi
 * Teredo
 * Terminalia
 * †Terminalia estamina
 * †Tessarolax – tentative report
 * †Tessarolax inconspicua
 * Testudo
 * †Testudoolithus – or unidentified comparable form
 * †Tetraclaenodon
 * †Tetraclaenodon puercensis
 * Tetraclita
 * †Tetrameryx
 * †Tetrameryx irvingtonensis – type locality for species
 * †Texoceros
 * †Texoceros altidens – or unidentified comparable form
 * †Texoceros edensis – type locality for species
 * Thais
 * †Thais carrizoensis
 * †Thais lamellosa
 * †Thais packi
 * Thalassoleon mexicanus.jpg †[[Thalassoleon]]
 * †Thalassoleon macnallyae – type locality for species
 * †Thalassoleon mexicanus
 * †Thamnasteria
 * †Thamnasteria sinuata – type locality for species
 * Thamnophis
 * Thanatophilus
 * †Thanatophilus lapponicus
 * †Thelyphonus
 * †Thelyphonus hadleyi – type locality for species
 * Thomomys
 * †Thomomys bottae
 * †Thomomys gidleyi
 * †Thomomys leucodon
 * †Thomomys microdon – type locality for species
 * †Thomomys monticola
 * †Thouinopsis
 * †Thouinopsis myricaefolia
 * Thracia
 * †Thracia pedroana
 * †Thracia sorrentoensis – or unidentified comparable form
 * †Thracia undulata
 * Thunnus – type locality for genus
 * †Thunnus starksi – type locality for species
 * Thyasira
 * †Thyasira folgeri
 * †Thyrsites
 * †Thyrsites kriegeri – type locality for species
 * †Ticholeptus
 * †Ticholeptus zygomaticus
 * Timoclea
 * †Timoclea picta
 * Tinosaurus
 * †Tinosaurus stenodon – or unidentified comparable form
 * †Tiphyocetus – type locality for genus
 * †Tiphyocetus temblorensis – type locality for species
 * Titanotylopus nebraskensis skeleton.jpg †[[Titanotylopus]]
 * Tivela
 * †Tivela diabloensis
 * †Tivela gabbi
 * †Tivela inezana
 * †Tivela kelloggensis
 * †Tivela stultorum
 * †Tomarctus
 * †Tomarctus brevirostris
 * †Tomarctus hippophaga
 * †Tomarctus hippophagus – or unidentified comparable form
 * †Topangasquilla
 * †Topangasquilla gravesi
 * Torcula
 * †Torcula inezana
 * †Tornatellaea
 * †Tornatellaea pinguis
 * Totanus
 * Toxicodendron radicans.jpg †[[Toxicodendron]]
 * †Toxicodendron franciscana
 * Toxopneustes
 * †Toxopneustes roseus – or unidentified comparable form
 * Toxostoma
 * †Toxostoma redivivum
 * Trachycardium
 * †Trachycardium procerum
 * †Trachycardium schencki
 * †Trachycardium vaquerosensis
 * †Trachycardium woodringi – type locality for species
 * Transennella
 * †Transennella joaquinensis – or unidentified comparable form
 * Spectacled Bear - Houston Zoo.jpg [[Tremarctos]]
 * †Tremarctos floridanus
 * Tresus
 * †Tresus capax
 * †Tresus nuttallii
 * †Tresus pajaroanus
 * Triakis – tentative report
 * Trichotropis
 * †Trichotropis cancellata
 * †Trichotropis insignis – or unidentified comparable form
 * Tricolia
 * †Tricolia compta
 * †Tricolia pulloides
 * †Trigonictis
 * †Trigonictis macrodon
 * Trionyx
 * Triphora
 * †Triphora pedroana
 * Pleuroploca gigantea cropped.jpg [[Triplofusus]]
 * †Triplofusus princeps
 * †Triplopus – tentative report
 * †Triplopus woodi – type locality for species
 * Trochammina
 * †Trochammina albertensis
 * †Trochammina palea – type locality for species
 * Trochita
 * †Trochita filosa
 * Trochocyathus
 * †Trochocyathus crooki
 * †Trochocyathus durhami – type locality for species
 * †Trochocyathus grahami – type locality for species
 * †Trochocyathus imperialis – type locality for species
 * †Trochocyathus nomlandi – type locality for species
 * †Trochocyathus stantoni – type locality for species
 * †Trogomys
 * †Trogomys rupinimenthae – type locality for species
 * †Trogosus
 * Trophon
 * †Trophon carisaensis – or unidentified comparable form
 * †Trophon eucymata
 * †Trophon fleenerensis
 * †Trophon gillulyi
 * †Trophon hernensis – or unidentified comparable form
 * †Trophon kernensis
 * †Trophon multicostatus
 * †Trophon pacificus
 * †Trossulus – tentative report
 * †Trossulus exoletus
 * †Trypanotoma
 * †Trypanotoma stocki
 * †Tubulodon – or unidentified comparable form
 * †Tubulostium – report made of unidentified related form or using admittedly obsolete nomenclature
 * †Tubulostium tejonensis
 * Glycymerididae - Tucetona laticostata.jpg [[Tucetona]]
 * †Tucetona multicostata
 * Tudicla
 * †Tudicla blakei
 * †Tunita – type locality for genus
 * †Tunita octavia – type locality for species
 * †Turbinolia
 * †Turbinolia capayasensis – type locality for species
 * †Turbinolia clarki – type locality for species
 * †Turbinolia dickersoni – type locality for species
 * †Turbinolia imbulata
 * †Turbinolia pusillanima – type locality for species
 * Turbonilla
 * †Turbonilla aepynota
 * †Turbonilla almo
 * †Turbonilla asser
 * †Turbonilla canfieldi
 * †Turbonilla carpenteri
 * †Turbonilla keepi
 * Turbonilla laminata 001.png †[[Turbonilla laminata]]
 * †Turbonilla lowei
 * †Turbonilla marshensis – type locality for species
 * †Turbonilla pedroana
 * †Turbonilla pentalopha
 * †Turbonilla raymondi
 * †Turbonilla regina
 * †Turbonilla stylina
 * †Turbonilla tenuicula
 * †Turbonilla torquata
 * †Turbonilla tridentata
 * †Turbonilla weldi
 * Turcica
 * †Turcica caffea
 * Turdus
 * †Turio
 * †Turio culveri – type locality for species
 * Turricula
 * †Turricula cooperi
 * †Turricula merriami
 * †Turricula praeattenuata – or unidentified comparable form
 * †Turricula waringi
 * Turris
 * †Turris fresnoensis
 * †Turris perissolaxoides
 * Turritellatricarinata.jpg [[Turritella]]
 * †Turritella andersoni
 * †Turritella bosei
 * †Turritella bulwaldana
 * †Turritella buwaldana
 * †Turritella carisaensis
 * †Turritella carrisaensis
 * †Turritella cooperi
 * †Turritella hendoni
 * †Turritella imperialis – type locality for species
 * †Turritella inezana
 * †Turritella inezani
 * †Turritella infragranulata
 * †Turritella lajollaensis – or unidentified comparable form
 * †Turritella lawsoni
 * †Turritella lorenzana – type locality for species
 * †Turritella mariana
 * †Turritella meganosensis – type locality for species
 * †Turritella merriami
 * †Turritella ocoyana
 * †Turritella pachecoensis
 * †Turritella reversa
 * †Turritella stocki
 * †Turritella temblorensis
 * †Turritella uvasana
 * †Turritella variata
 * †Turritella wittichi
 * Turritriton
 * †Turritriton gibbosus
 * Bottlenose Dolphin KSC04pd0178.jpg [[Tursiops]] – or unidentified comparable form
 * Typha
 * †Typha lesquereuxii
 * Typhis
 * Tyto
 * †Tyto alba

U

 * Uca
 * †Uca hamlini
 * †Uintasorex
 * †Uintasorex montezumicus – type locality for species
 * Uinttather DB.jpg †[[Uintatherium]]
 * Ulmus
 * †Ulmus affinis
 * †Umbellularia
 * †Umbellularia salicifolia
 * †Umpquaia
 * Uria
 * †Uria aalgae
 * Common Murre Uria aalge.jpg †[[Uria aalge]]
 * †Uria algae
 * †Uria brodkorbi – type locality for species
 * †Uria paleohesperis – type locality for species
 * †Uriscus
 * †Uriscus californicus
 * †Urobatis
 * †Urobatis halleri
 * †Urocitellus
 * †Urocitellus beldingi
 * Urocyon
 * †Urocyon californicus
 * †Urocyon cinereoargenteus
 * †Urocyon galushai
 * Urolophus
 * †Urolophus halleri – tentative report
 * Ursus
 * 01 Schwarzbär cropped.jpg †[[Ursus americanus]]
 * †Ustatochoerus
 * †Ustatochoerus major
 * Uta
 * †Uta stansburiana
 * Uvigerina
 * †Uvigerina garzaensis
 * †Uvigerinella
 * †Uvigerinella obesa

V

 * †Valenictus – type locality for genus
 * †Valenictus chulavistensis – type locality for species
 * †Valenictus imperialensis – type locality for species
 * Valvulineria
 * †Valvulineria californica
 * †Valvulineria casitasensis
 * †Valvulineria tumeyensis
 * †Valvulineria wilcoxensis – or unidentified comparable form
 * †Vanderhoofius
 * †Vanderhoofius coalingensis
 * †Vaquerosella
 * †Vaquerosella andersoni
 * †Vaquerosella coreyi
 * †Vaquerosella durhami
 * †Vaquerosella fairbanksi
 * †Vaquerosella merriami
 * †Vaquerosella vaquerosensis
 * Vasum
 * †Vasum caestum
 * †Vauquelinia
 * †Vauquelinia exigua – type locality for species
 * Neritidae - Velates species.JPG †[[Velates]]
 * †Velates californicus – type locality for species
 * †Velates perversus
 * Velutina
 * †Velutina velutina
 * Venericardia
 * †Venericardia hornii
 * †Venericardia mulleri
 * †Venericardia planicosta
 * †Venericardia sandiegoensis
 * Venus
 * †Venus purpurissata
 * Vermicularia
 * †Vermicularia ebunea
 * Veromessor
 * †Veromessor andrei
 * †Vertipecten
 * †Vertipecten alexclarki – type locality for species
 * †Vertipecten nevadanus
 * †Vertipecten perrini
 * †Vertipecten yneziana – or unidentified related form
 * †Viburnum
 * †Viburnum variabilis
 * Vireo-flavifrons-001.jpg †[[Vireo]]
 * †Virgulina
 * †Virgulina bramlettei
 * †Virgulina bramlettrei
 * †Virgulina dibollensis
 * Vitrinella – tentative report
 * Volsella
 * †Volsella merriami
 * †Volsella porterensis – or unidentified comparable form
 * Voluta ebraea THELMA DIAS 01(pode usar).JPG [[Voluta]]
 * †Volutilithes
 * †Volutilithes orocopiaensis – type locality for species
 * Volutopsius
 * †Volutopsius eurekaensis
 * Volvulella
 * †Volvulella cylindrica
 * †Vouapa
 * †Vouapa geminifolia – type locality for species
 * Vulpes
 * †Vulpes cascadensis
 * †Vulpes kernensis – type locality for species
 * †Vulpes stenognathus
 * †Vulpes velox
 * Vulvulina
 * †Vulvulina curta

W

 * †Washakius
 * †Washakius woodringi – type locality for species
 * †Whitneyella
 * †Whitneyella sinuata
 * Williamia
 * †Williamia peltoides
 * Wodnika striatula.jpg †[[Wodnika]]
 * †Wodnika ocoyae – type locality for species
 * †Woodburnehyus – type locality for genus
 * †Woodburnehyus grenaderae – type locality for species

X

 * Xenophoridae - Xenophora infundibulum.jpg [[Xenophora]]
 * †Xenophora stocki
 * †Xenophora zitteli
 * †Xenothrissa – type locality for genus
 * †Xenothrissa aphrasta – type locality for species
 * †Xyne – type locality for genus
 * †Xyne grex – type locality for species
 * †Xyrinius – type locality for genus
 * †Xyrinius houshi – type locality for species

Y

 * †Yaquius
 * †Yaquius travisi
 * †Yatkolamys
 * Yoldia
 * †Yoldia cooperii
 * †Yoldia impressa
 * †Yoldia mortuasusensis – type locality for species
 * †Yoldia packardi – or unidentified comparable form
 * †Yoldia scissurata
 * †Yoldia tenuissima
 * †Yumaceras – tentative report
 * †Yumaceras ruminalis – type locality for species

Z

 * †Zachrysia
 * †Zachrysia fraterna – type locality for species
 * Zalophus
 * †Zalophus californianus
 * Zamites mariposana.jpg †[[Zamites]]
 * †Zamites californica
 * †Zanteclites – type locality for genus
 * †Zanteclites hubbsi – type locality for species
 * †Zaphleges
 * †Zaphleges longurio
 * †Zapteryx
 * †Zapteryx californicus – or unidentified comparable form
 * †Zarhinocetus
 * †Zarhinocetus errabundus – type locality for species
 * Zelkova
 * †Zelkova oregoniana
 * Zenaida
 * †Zenaida macroura
 * Zirfaea
 * †Zirfaea dentata – or unidentified comparable form
 * †Zirfaea pilsbryi
 * Zonotrichia
 * †Zonotrichia leucophrys
 * Mammut borsoni from Milia.jpg †[[Zygolophodon]]