List of the Mesozoic life of California

This list of the Mesozoic 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 252.17 and 66 million years of age.

A

 * Abyssochrysos melanioides.png †[[Abyssochrysos]] – tentative report
 * †Abyssochrysos giganteum – type locality for species
 * †Acaeniotyle
 * †Acaeniotyle umbilicata – or unidentified related form
 * †Acanthoceras
 * †Acanthoceras rhotomagense – or unidentified related form
 * †Acanthoceras roguense – or unidentified related form
 * †Acanthoceras sherborni – or unidentified comparable form
 * †Acanthocircus
 * †Acanthocircus aculeatus
 * †Acanthocircus carinatus – or unidentified related form
 * †Acanthocircus dendroacanthos
 * †Acanthocircus dicranocanthos
 * †Acanthocircus meyerhofforum
 * †Acanthocircus multidentatus
 * †Acanthocircus polymorphus
 * †Acanthocircus suboblongus
 * †Acanthocircus trizonalis
 * Acanthosphaera – tentative report
 * †Acanthosphaera lucida
 * †Acastea
 * †Acastea acer
 * †Acastea bipes
 * †Acastea dura
 * †Acastea incontraria
 * †Acastea remusa
 * †Acastea tenuis
 * Acesta
 * Acharax
 * †Acharax stantoni
 * Acila
 * †Acila demessa
 * †Acila princeps
 * †Acrioceras
 * †Acrioceras hamlini
 * †Acrioceras vespertinum
 * Acrodus nobilis Exhibit Museum of Natural History cropped.jpg †[[Acrodus]]
 * †Acrodus wempliae – type locality for species
 * †Acteon
 * †Acteon inornatus
 * †Acteon politus
 * †Acteon sullivanae
 * †Acteonella
 * †Acteonella oviformis
 * †Acteonina
 * †Acteonina berryessensis – type locality for species
 * †Acteonina californica
 * †Acteonina columnaris
 * †Acusten
 * †Acusten ordinarius
 * †Adelodonax
 * †Adelodonax altus
 * †Aechmella
 * †Agnomyax
 * †Agnomyax monilifer
 * †Aguileria – or unidentified comparable form
 * †Alarimella
 * †Alarimella anae – type locality for species
 * †Alarimella veta
 * Aletopelta coombsi.jpg †[[Aletopelta]] – type locality for genus
 * †Aletopelta coombsi – type locality for species
 * †Alievium
 * †Alievium antiquum
 * Amauropsis
 * †Amauropsis pseudoalveata
 * †Ambercyclus
 * †Ambercyclus dilleri
 * †Ambercyclus morganensis
 * †Amphidonte
 * †Amphidonte parasitica
 * Gastropoda - Ampullina sp.JPG †[[Ampullina]]
 * †Ampullina avellana
 * †Ampullina concipio
 * †Ampullina mona
 * †Ampullina oviformis
 * †Ampullina packardi
 * †Ampullina stantoni
 * Amuletum
 * †Anagaudryceras
 * †Anagaudryceras mikobokense
 * †Anagaudryceras sacya – or unidentified comparable form
 * †Anahamulina
 * †Anahamulina wilcoxensis
 * †Anarhynchia
 * †Anarhynchia gabbi – or unidentified comparable form
 * †Anasibirites
 * †Anasibirites desertorum
 * †Anasibirites kingianus – type locality for species
 * †Anasibirites lindgreni
 * †Anatomites
 * †Anatomites adalberti
 * †Anatomites damesi
 * †Anatomites edgari
 * †Anatomites externiplicatus
 * †Anatomites intermittens
 * †Anatomites konnincki
 * †Anatomites mendenhalli
 * †Anatomites obsoletus – type locality for species
 * †Anatomites shastensis – type locality for species
 * †Anatomites subintermittens – type locality for species
 * †Anatropites
 * †Anatropites hauchecornei
 * †Anchura
 * †Anchura ainikta – type locality for species
 * †Anchura baptos – type locality for species
 * †Anchura californica
 * †Anchura callosa
 * †Anchura condoniana
 * †Anchura falciformis
 * †Anchura gibbera
 * †Anchura halberdopsis – type locality for species
 * †Anchura phaba – type locality for species
 * †Anglonautilus
 * †Anglonautilus catarinae
 * †Angulobracchia
 * †Angulobracchia bulbosa
 * †Angulobracchia jasperensis
 * †Angulobracchia ozvoldovae
 * †Angulobracchia purisimaensis
 * †Anisoceras
 * †Anisoceras draconum
 * †Anisomyon
 * †Anisomyon meeki
 * †Anomalina
 * †Anomalina pseudopopillosa
 * Anomia ephippium.jpg †[[Anomia (genus)|Anomia]]
 * †Anomia – type locality for species A – informal
 * †Anomia jalama
 * †Anomia lineata
 * †Anoplophora – tentative report
 * †Anoplophora shastensis – type locality for species
 * †Anthonya
 * †Anthonya cultriformis
 * †Aphaea
 * †Aphaea ignota
 * †Aphanoptyxis
 * †Aphanoptyxis andersoni
 * †Aphanoptyxis californica – type locality for species
 * †Aphrodina
 * †Aphrodina varians
 * †Aphrosaurus
 * †Aphrosaurus furlongi
 * Aporrhais pespelecani 01.JPG [[Aporrhais]]
 * †Aporrhais veta – type locality for species
 * †Archaeocenosphaera
 * †Archaeocenosphaera ruesti – or unidentified related form
 * †Archaeodictyomitra
 * †Archaeodictyomitra apiarium
 * †Archaeodictyomitra inornata
 * †Archaeodictyomitra oleadita
 * †Archaeodictyomitra rigida
 * †Archaeodictyomitra simplex
 * †Archaeodictyomitra siplex
 * †Archaeodictyomitra sliteri
 * †Archaeodictyomitra vulgaris
 * †Archaeohagiastrum
 * †Archaeohagiastrum minutum – or unidentified related form
 * Archaeolithothamnium
 * †Archaeopus
 * †Archaeopus antennatus
 * †Archaeospongoprunum
 * †Archaeospongoprunum carrierensis
 * †Archaeospongoprunum cortinaensis
 * †Archaeospongoprunum elegans – or unidentified related form
 * †Archaeospongoprunum imlayi
 * †Archaeospongoprunum klingi
 * †Archaeospongoprunum macrostylum – or unidentified related form
 * †Archaeospongoprunum praeimlayi
 * †Archaeospongoprunum praelongum
 * †Archaeospongoprunum tehamaensis
 * Architectonica sp. (Marine snail).jpg   [[Architectonica]] – tentative report
 * Arcopagia
 * †Arcopagia tehama
 * Arctica
 * †Arctica anthracocola
 * †Arctica denmanensis – or unidentified related form
 * †Arctoceras
 * †Arctoceras tuberculatum
 * †Areaseris
 * †Areaseris nevadensis
 * Argyrotheca
 * †Argyrotheca retrorsa – type locality for species
 * [[File:Arnioceras acuticarinatu - Naturhistorisches Museum, Braunschweig, Germany - DSC05129 cropped.jpg|thumb|upright=0.724|Fossilized shell of the Early Jurassic ammonoid cephalopod Arnioceras]] †[[Arnioceras]]
 * †Arpadites
 * †Arpadites kingi – type locality for species
 * Arrhoges
 * †Arrhoges californicus
 * †Aspenites – type locality for genus
 * †Aspenites acutus
 * Astarte
 * †Astarte sulcata – tentative report
 * †Astarte sulcuta
 * †Astarte tuscana
 * †Asteroceras
 * †Astrocoenia – report made of unidentified related form or using admittedly obsolete nomenclature
 * Ataphrus
 * †Ataphrus compactus – tentative report
 * †Atira
 * †Atractites
 * †Atractites philippii – type locality for species
 * †Atresius
 * †Atresius liratus
 * †Aucellina – tentative report
 * Saurolophus morrisi.jpg †[[Augustynolophus]]
 * †Augustynolophus morrisi
 * Avicula
 * †Avicula mucronata – type locality for species
 * †Avicula soperi – type locality for species
 * †Axonoceras

B

 * †Bacchites
 * †Bacchites hyatti – type locality for species
 * †Bacchites pinguis
 * Baculites grandis shell.JPG   †[[Baculites]]
 * †Baculites anceps
 * †Baculites bailyi – or unidentified comparable form
 * †Baculites buttensis – type locality for species
 * †Baculites capensis
 * †Baculites chicoensis
 * †Baculites fairbanksi
 * †Baculites inornatus
 * †Baculites lomaensis
 * †Baculites occidentalis
 * †Baculites recta – or unidentified comparable form
 * †Baculites rex – type locality for species
 * †Baculites schencki – type locality for species
 * †Baculites yokoyamai – or unidentified comparable form
 * †Bagotum
 * †Bagotum modestum
 * †Balantiostoma – tentative report
 * Barbatia
 * †Barrettia
 * †Barrettia sparcilirata
 * Basilemys.jpg †[[Basilemys]]
 * †Bathypurpurinopsis
 * †Bathypurpurinopsis stantoni – type locality for species
 * † Belleza
 * †Belleza decora
 * †Belliscala
 * †Belliscala meta
 * Bernaya
 * †Bernaya argonautica – type locality for species
 * †Bernaya berryessae – type locality for species
 * †Bernaya crawfordcatei – type locality for species
 * †Bernaya gualalaensis – type locality for species
 * †Bernaya jeanae – type locality for species
 * †Bernaya kayei – or unidentified related form
 * †Bernaya louellasaulae – type locality for species
 * †Bernaya popenoei – type locality for species
 * †Bernaya rineyi – type locality for species
 * †Bernoullius
 * †Bernoullius brokenkettlensis
 * †Bernoullius cristatus
 * †Bernoullius delnortensis
 * †Bernoullius dicera
 * †Bernoullius irwini
 * †Beudanticeras
 * †Beudanticeras alamoense – type locality for species
 * †Beudanticeras argonauticum – type locality for species
 * †Beudanticeras breweri
 * †Beudanticeras brewerii – or unidentified related form
 * †Beudanticeras haydeni
 * †Bipedis – tentative report
 * †Biplica
 * †Biplica heteroplicata
 * †Biplica isoplicata
 * †Biplica michaeli – or unidentified related form
 * †Biplica miniplicata
 * †Biplica multiplicata
 * †Biplica obliqua
 * †Bistarkum
 * †Bittiscala
 * †Bivallupus
 * †Bivallupus mexicanus
 * †Bochianites
 * †Bochianites paskentaensis
 * †Bolena
 * †Bolena zancajosa
 * †Bositra
 * †Bositra buchi
 * Bostrychoceras polyplocum 01.JPG †[[Bostrychoceras]]
 * †Bostrychoceras brewerii
 * †Bostrychoceras californicum – type locality for species
 * †Bostrychoceras declive
 * †Bostrychoceras occidentale – type locality for species
 * †Bostrychoceras otsukai – or unidentified related form
 * †Brancoceras
 * †Brancoceras parvum
 * †Brasilichnium
 * †Buchia
 * †Buchia concentrica – or unidentified comparable form
 * †Buchia elderensis
 * †Buchia keyserlingi
 * †Buchia pacifica
 * †Buchia piochii
 * †Buchia terebratuloides
 * †Buchia trigonoides
 * †Bulbificopsis – type locality for genus
 * †Bulbificopsis garza – type locality for species
 * Bulimina
 * †Bulimina obtusa
 * Bulimulus limnoides.png [[Bulimulus]]
 * †Bullamirifica
 * †Bullamirifica ainiktos
 * †Bullamirifica elegans
 * Bullaria
 * †Bullaria nortonensis
 * Bullina
 * †Bullina yoloensis – type locality for species
 * †Butticeras
 * †Butticeras studleyi – type locality for species

C

 * †Califadesma
 * †Califadesma elaphium
 * †Californigonia – type locality for genus
 * †Californigonia plumasensis – type locality for species. Formerly classified as Trigonia plumasensis.
 * †Californites – type locality for genus
 * †Californites careyi – type locality for species
 * †Californites merriami – type locality for species
 * Californosaurus BW.jpg †[[Californosaurus]]
 * Callianassa – tentative report
 * †Calliconites
 * †Calliconites drakei – type locality for species
 * †Calliomphalus – tentative report
 * Callista – tentative report
 * †Callista pseudoplana – or unidentified related form
 * †Callista subtrigona
 * †Callistalox
 * †Callistalox fragilis
 * †Calva
 * †Calva crassa
 * †Calva elderi
 * †Calva nitida
 * †Calva peninsularis
 * †Calva spissa
 * †Calva taffi
 * †Calva varians
 * Gasteropods - Ammonites - Calycoceras (Newboldiceras) spinosa.JPG †[[Calycoceras]]
 * †Calycoceras naviculare
 * †Camptonectes
 * †Camptonectes curvatus – or unidentified comparable form
 * †Canadoceras
 * †Canadoceras celeste – type locality for species
 * †Canadoceras fraternum
 * †Canadoceras mysticum
 * †Canadoceras newberryanum
 * †Canadoceras subtilobatum – or unidentified related form
 * Cancellaria – tentative report
 * †Canelonus
 * †Canelonus conus
 * †Caneta
 * †Caneta hsui
 * †Canoptum
 * †Canoptum anulatum
 * †Canoptum poissoni
 * †Canoptum rugosum
 * Cantharus
 * †Cantharus occidentalis
 * †Canutus
 * †Canutus giganteus
 * †Canutus rockfishensis
 * Capulus ungaricus 001.jpg [[Capulus]] – or unidentified comparable form
 * †Capulus silverthorni – type locality for species
 * Cardinia
 * †Cardinia gleimi – type locality for species
 * †Cardiomorpha – tentative report
 * †Cardiomorpha digglesi – type locality for species
 * Cardita
 * †Cardita jenkinsi – type locality for species
 * †Cassideus
 * †Cassideus yoloensis
 * †Cecrops
 * †Cecrops septemporata
 * †Cecrops septemporatus
 * †Celtites
 * †Celtites steindachneri
 * Cenodiscus
 * †Cenodiscus alievi
 * Cenosphaera
 * †Cenosphaera boria
 * †Ceriostella
 * †Ceriostella martini
 * Cerithidea
 * Cerithium echinatum.shell001.jpg  [[Cerithium]]
 * †Cerithium alternata
 * †Cerithium totiumsanctorum – or unidentified comparable form
 * †Choristoceras
 * †Choristoceras klamathense – type locality for species
 * †Choristoceras marshi
 * †Christitys – type locality for genus
 * †Christitys delta – type locality for species
 * †Christitys martini – or unidentified comparable form
 * †Christitys medica – type locality for species
 * †Cidarina
 * †Cidarina beta – type locality for species
 * †Cidarina cretacea – type locality for species
 * Cidaris cidaris MHNT.jpg [[Cidaris]]
 * †Cidaris californicus
 * †Cidaris plumasensis
 * †Cidaris taylorensis
 * †Cladoceramus
 * †Cladoceramus undulatoplicatus
 * †Clinura
 * †Clinura anassa
 * †Clisocolus
 * †Clisocolus cordatus
 * †Clisocolus corrugatus
 * †Clisocolus dubius
 * Gasteropods - Ammonites - Collignoniceras woolgari.JPG †[[Collignoniceras]]
 * †Collignoniceras bakeri
 * †Collonia
 * †Collonia occidentalis – type locality for species
 * †Cophocara
 * †Cophocara stantoni
 * †Coralliochama
 * †Coralliochama orcutti
 * Corbicula
 * †Corbicula astartoides
 * Corbula
 * †Corbula cancellifera
 * †Corbula parilis
 * †Corbula pozo
 * †Corbula torta – or unidentified comparable form
 * †Corbula traski
 * †Corbula traskii
 * Cornutella
 * †Cosmonautilus
 * †Cosmonautilus dilleri
 * †Cosmonautilus hersheyi – type locality for species
 * †Cosmonautilus pacificus – type locality for species
 * †Cosmonautilus shastensis – type locality for species
 * †Costispiriferina
 * †Costispiriferina pittensis
 * †Courtilloticeras
 * †Courtilloticeras stevensi – type locality for species
 * Crassatella
 * †Crassatella conradiana
 * †Crassatella mercedensis – tentative report
 * †Crassatella saulae
 * †Crassatella triangulata
 * †Crassatella triangulatus
 * †Crassatellina
 * †Crassatellina saulae
 * Crioceratites_nolani_France_450_mm.jpg †[[Crioceratites]]
 * †Crioceratites latus
 * †Crioceratites tehamaensis – or unidentified comparable form
 * †Crolanium
 * †Crolanium triquetrum
 * †Crucella
 * †Crucella linda
 * †Crucella magna
 * †Crucella messinae
 * †Crucella theokaftensis
 * Cucullaea
 * †Cucullaea alamoensis – type locality for species
 * †Cucullaea bowersiana
 * †Cucullaea gravida
 * †Cucullaea truncata
 * †Cucullaea youngi
 * †Cunningtoniceras
 * †Cunningtoniceras meridionale – or unidentified related form
 * †Cyclothyris
 * †Cyclothyris densleonis
 * Cylichna
 * †Cylichna andersoni
 * †Cylindroteuthis
 * Nautilaceae - Cymatoceras subalbensis.JPG †[[Cymatoceras]]
 * †Cymatoceras carlottense
 * †Cymatoceras hermosus – type locality for species
 * †Cymbophora
 * †Cymbophora asburnerii
 * †Cymbophora ashburnensis – or unidentified related form
 * †Cymbophora ashburnerii
 * †Cymbophora bella – or unidentified comparable form
 * †Cymbophora gabbiana
 * †Cymbophora popenoei
 * †Cymbophora stantoni
 * †Cymbophora tenuissima
 * †Cymbophora triangula
 * †Cymbophora triangulata
 * Cymbospondylus BW.jpg †[[Cymbospondylus]]
 * †Cymbospondylus petrinus
 * †Cymulopora – tentative report
 * †Cyprimeria
 * †Cyprimeria moorei
 * Cyrtocapsa – tentative report
 * †Cyrtocapsa kisoensis – or unidentified related form

D

 * †Damesites
 * †Damesites damesi
 * †Damesites frazierense
 * †Damesites gardeni – or unidentified related form
 * †Damesites hetonaiensis
 * †Damesites richardsoni – type locality for species
 * †Damesites subsugatum
 * Daonella lommeli.JPG †[[Daonella]] – tentative report
 * †Daonella dubia
 * †Darvelus
 * †Darvelus pessagnoi – type locality for species
 * †Darvelus primus – type locality for species
 * Dentalina
 * †Dentalina legumen
 * †Dentalium
 * †Dentalium cooperi
 * †Dentalium nanaimoense
 * †Dentalium whiteavesi
 * Gasteropods - Ammonites - Desmoceras sp. cropped.jpg †[[Desmoceras]]
 * †Desmoceras alamoense – or unidentified comparable form
 * †Desmoceras argonauticum – or unidentified comparable form
 * †Desmoceras dawsoni
 * †Desmoceras inane
 * †Desmoceras japonicum
 * †Desmoceras voyi
 * †Desmophyllites
 * †Desmophyllites diphylloides – type locality for species
 * †Deviatus
 * †Deviatus deweveri
 * †Deviatus hipposidericus
 * †Diacanthocapsa
 * †Dicerosaturnalis
 * †Dicerosaturnalis dicranacanthos
 * †Dicroa
 * †Dicroloma
 * †Dicroloma nodosa
 * †Dictyoconites
 * †Dictyoconites americanus – type locality for species
 * †Dictyomitra
 * †Dictyomitrella
 * †Dictyomitrella kamoensis
 * Didymoceras species.JPG †[[Didymoceras]]
 * †Didymoceras hornbyense – or unidentified comparable form
 * †Didymoceras vancouverense – or unidentified comparable form
 * †Didymoceras vancouverensis
 * †Dieneria – type locality for genus
 * †Dieneria arthaberi – type locality for species
 * †Dieneroceras
 * †Dieneroceras dieneri – type locality for species
 * †Dieneroceras marcoui – type locality for species
 * †Dieneroceras spathi
 * †Dieneroceras subquadratum
 * †Dillerites – type locality for genus
 * †Dillerites shastensis – type locality for species
 * †Dimyodon
 * †Dimyodon storrsi – type locality for species
 * †Diozoptyxis
 * †Diozoptyxis ursana – type locality for species
 * Diplodonta
 * †Diplodonta davisi
 * †Diplomoceras
 * †Diplomoceras ellipticum
 * †Diplomoceras jimboi – type locality for species
 * †Diplomoceras mustangense – type locality for species
 * †Discohelix – tentative report
 * †Discohelix leana
 * †Discophyllites
 * †Discophyllites patens
 * †Discoproptychites
 * †Discoproptychites walcotti – type locality for species
 * DiscoscaphitesirisCretaceous.jpg †[[Discoscaphites]]
 * †Discotropites
 * †Discotropites davisi – type locality for species
 * †Discotropites formosus – type locality for species
 * †Discotropites laurae
 * †Discotropites lineatus
 * †Discotropites mojsvarensis
 * †Discotropites plinii
 * †Discotropites sandlingensis
 * †Discotropites sengeli
 * †Discotropites smithi
 * †Discotropites theron
 * †Distichophyllia
 * †Distichophyllia norica
 * Gasteropods - Ammonites - Douvilleiceras sp. cropped.jpg †[[Douvilleiceras]]
 * †Douvilleiceras mammillatum – or unidentified comparable form
 * †Drepanochilus
 * †Drepanochilus transversus
 * †Drilluta – tentative report
 * †Droltus
 * †Dumitricaella – tentative report
 * †Dumitricaella cucurbitina – or unidentified related form
 * †Durania
 * †Durania californica – type locality for species

E

 * †Echinocorys
 * †Echinocorys yoloensis – type locality for species
 * †Elimia
 * †Elimia veatchii
 * †Ellipsoscapha
 * †Ellipsoscapha nortonensis – or unidentified comparable form
 * †Ellipsoscapha skaios
 * †Emiluvia
 * †Emiluvia chica
 * †Emiluvia dollarbendensis
 * †Emiluvia fontana
 * †Emiluvia hopsoni
 * †Emiluvia lowercoonensis
 * †Emiluvia nana
 * †Emiluvia pessagnoi
 * †Emiluvia premyogii
 * Enchodus petrosus cropped.png †[[Enchodus]]
 * †Endoptygma
 * †Endoptygma hermax – type locality for species
 * †Entobia
 * †Entolium
 * †Entolium equabile
 * †Entolium meeki
 * †Entolium pittensis – type locality for species
 * †Eocomoseris
 * †Eocomoseris ramosa
 * †Eocypraea
 * †Eocypraea louellae – type locality for species
 * †Eodanubites
 * †Eodanubites judae – type locality for species
 * †Eogaudryceras
 * †Eogaudryceras wintunius
 * †Eogunnarites
 * †Eogunnarites matsumotoi
 * †Eospongosaturninus
 * †Eospongosaturninus protoformis
 * †Eripachla
 * †Eripachla ponderosa
 * †Eripachya
 * †Eripachya ponderosa
 * †Eriphyla
 * †Eriphyla lapida
 * †Eriphyla lapidus
 * †Eriphyla umbonata
 * †Etea
 * †Etea occidentalis
 * †Eucalycoceras
 * †Eucalycoceras diabloense – type locality for species
 * Euclastes.jpg †[[Euclastes]]
 * †Eucymatoceras
 * †Eucymatoceras plicatum
 * †Eucyrtidiellum
 * †Eucyrtidiellum ptyctum
 * †Eucyrtidiellum takemurai
 * †Eucyrtidiellum unumaense
 * †Eucyrtidium – tentative report
 * †Euidothyris
 * †Euidothyris lucerna – type locality for species
 * †Euomphaloceras
 * †Euomphaloceras septemseriatum
 * †Eupachydiscus
 * †Eupachydiscus arbucklensis – type locality for species
 * †Eupachydiscus haradai
 * †Eupachydiscus lamberti – or unidentified related form
 * †Eupachydiscus willgreeni – type locality for species
 * †Euspira
 * †Euspira compressa
 * †Euspira marianus
 * †Euspira popenoei
 * †Euspira shumardiana
 * †Eutrephoceras
 * †Eutrephoceras campbelli
 * Exiteloceras jenneyi 1.jpg †[[Exiteloceras]]
 * †Exiteloceras bennisoni – type locality for species
 * †Exiteloceras desertense – type locality for species
 * †Exiteloceras diabloense – tentative report
 * †Exiteloceras ortigalitoense – type locality for species
 * †Exiteloceras vancouverense
 * †Exogyra

F

 * Fagesia spheroidalis.jpg †[[Fagesia]]
 * †Fagesia catinus – type locality for species
 * †Fagesia klamathensis – type locality for species
 * Fissurella – tentative report
 * †Flabellina
 * †Flabellina pilulifera
 * †Flabellirhynchia
 * †Flabellirhynchia concinna – type locality for species
 * †Flabellirhynchia falconis – type locality for species
 * †Flabellum
 * †Flabellum fresnoense – type locality for species
 * †Flaventia
 * †Flaventia lens
 * †Foremanina
 * †Francisciconcha
 * †Francisciconcha maslennikovi
 * †Fresnosaurus – type locality for genus
 * †Fresnosaurus drescheri – type locality for species
 * Frondicularia
 * †Frondicularia undulosa – or unidentified comparable form

G

 * †Gabbioceras
 * †Gabbioceras angulatum
 * †Garzasia
 * †Garzasia diabla
 * †Garzasia intermedia – or unidentified comparable form
 * Gastrochaena – tentative report
 * Gaudryceratidae - Gaudryceras species.JPG †[[Gaudryceras]]
 * †Gaudryceras alamedense
 * †Gaudryceras aureum – type locality for species
 * †Gaudryceras cinctum – or unidentified related form
 * †Gaudryceras debnabebse – or unidentified comparable form
 * †Gaudryceras denmanense – or unidentified comparable form
 * †Gaudryceras kayei – type locality for species
 * †Gaudryceras tenuiliratum – tentative report
 * †Gaudryceras texanum – type locality for species
 * †Gervillia
 * †Gervillia shastensis
 * Glans – tentative report
 * †Glans veneriformis
 * †Glauconia
 * †Globigerinelloides
 * †Globirhynchia
 * †Globirhynchia gnathophora – type locality for species
 * †Globirhynchia oblatopinguis – type locality for species
 * †Globirhynchia rhacta – type locality for species
 * †Globirhynchia schucherti – type locality for species
 * Glossus
 * †Glossus delta
 * Glycymerididae - Glycymeris inflata.JPG [[Glycymeris]]
 * †Glycymeris anae
 * †Glycymeris apletos
 * †Glycymeris banosensis – type locality for species
 * †Glycymeris pacifica – or unidentified comparable form
 * †Glycymeris pacificus
 * †Glycymeris shastensis – type locality for species
 * †Glycymeris suciensis
 * †Glycymeris veatchii
 * †Glycymeris yoloensis
 * †Glyptoxoceras
 * †Glyptoxoceras largesulcatum – or unidentified comparable form
 * †Glyptoxoceras subcompressum – or unidentified comparable form
 * †Gnathorhynchia
 * †Gnathorhynchia perplicata – type locality for species
 * †Gnomohalorites
 * †Gnomohalorites americanus
 * Gongylothorax
 * †Gongylothorax oblongus – or unidentified related form
 * †Goniojuvavites
 * †Goniojuvavites kellyi – type locality for species
 * †Gonionotites
 * †Gonionotites northi – type locality for species
 * †Gorgansium
 * †Gorgansium pulchrum
 * †Goricanites – type locality for genus
 * †Goricanites noblei – type locality for species
 * Grallator.jpg †[[Grallator]]
 * †Grammatodon
 * †Grammatodon vancouverensis
 * †Gryphaea
 * †Gryponautilus
 * †Gryponautilus cooperi – type locality for species
 * †Guexella
 * †Guineana
 * †Guineana alta
 * †Guodunites
 * †Guodunites hooveri – type locality for species
 * †Gymnotropites
 * †Gymnotropites americanus – type locality for species
 * †Gymnotropites laevis – type locality for species
 * †Gymnotropites rotundus – type locality for species
 * Gyrodes
 * †Gyrodes allisoni
 * †Gyrodes californicus
 * †Gyrodes canadensis
 * †Gyrodes conradiana
 * †Gyrodes dowelli
 * †Gyrodes expansa
 * †Gyrodes expansus
 * †Gyrodes greeni – type locality for species
 * †Gyrodes pacificum
 * †Gyrodes pacificus – or unidentified comparable form
 * †Gyrodes quercus
 * Gyroidina
 * †Gyroidina depressa

H

 * LivingAbalone.JPG [[Haliotis]]
 * †Halobia
 * †Halobia austriaca
 * †Halobia cordillerana
 * †Halobia gigantea
 * †Halobia ornatissima
 * †Halobia rugosa
 * †Halobia superba
 * †Hauericeras
 * †Hauericeras angustum
 * †Hauericeras churchi – type locality for species
 * †Hauericeras mickeyi – type locality for species
 * †Hauerites
 * †Hauerites lawsoni – type locality for species
 * †Haydenia
 * †Haydenia impressa
 * †Hecticoceras
 * Hedenstroemiidae - Hedenstroemia tscherskii.JPG †[[Hedenstroemia]]
 * †Hedenstroemia kossmati
 * †Helena
 * †Helena exquisita
 * †Helicaulax
 * †Helicaulax popenoei – type locality for species
 * Hemiaster
 * †Hemiaster californicus
 * †Hemicidaris
 * †Hemicidaris intumescens
 * †Hemicryptocapsa
 * †Hemicryptocapsa ruesti – or unidentified related form
 * Sharpnose sevengill shark ( Heptranchias perlo ).jpg genus Heptranchias]] Heptranchias
 * †Hertleinites
 * †Hertleinites aguila
 * †Hertleinites pecki
 * †Heteroderma
 * †Hexasaturnalis
 * †Hexasaturnalis hexagonus
 * †Hexasphaera
 * †Hexasphaera baumgartneri
 * †Higumastra
 * †Higumastra boucoti
 * †Higumastra devilsgapensis
 * †Higumastra dumitricai
 * †Higumastra imbricata
 * †Higumastra inflata – or unidentified related form
 * †Higumastra transversa
 * †Hilarisirex
 * [[File:Hipponix antiquatus (white hoof snail) (San Salvador Island, Bahamas) 2 (16003468958).jpg|thumb|upright=0.641|Shell of a Hipponix, or hoof sea snail]] [[Hipponix]]
 * †Hipponix dichotomus
 * †Hiscocapsa
 * †Hiscocapsa acuta
 * †Hiscocapsa japonica – or unidentified comparable form
 * †Hiscocapsa robusta
 * †Hokkaidoconcha
 * †Hokkaidoconcha bilirata – type locality for species
 * †Hokkaidoconcha morenoensis – type locality for species
 * †Hokkaidoconcha occidentalis
 * †Hokkaidoconcha tehamaensis – type locality for species
 * †Holcodiscoides
 * †Holcodiscoides gorrilli – type locality for species
 * †Holcophylloceras – tentative report
 * †Hollisites
 * †Hollisites inflatus
 * †Hollisites lucasi
 * †Holocryptocanium
 * †Holocryptocanium astiensis
 * †Holocryptocanium barbui
 * †Holocryptocanium geysersensis
 * †Holocryptocanium tuberculatum
 * †Homerites
 * †Homerites semiglobosus
 * †Homoeoparonaella
 * †Homoeoparonaella barbata
 * †Homoeoparonaella elegans
 * †Homoeoparonaella gigantea
 * †Homoeoparonaella glinesi
 * †Homoeoparonaella radians
 * †Homoeoparonaella scurrae
 * †Homolsomites
 * †Homolsomites mutabilis
 * †Hoplocrioceras
 * †Hoplocrioceras ducanense
 * †Hoplocrioceras duncanense
 * †Hoplocrioceras remondi
 * †Hoplotropites
 * †Hoplotropites jokelyi
 * †Hormathospongia – type locality for genus
 * †Hormathospongia dictyota – type locality for species
 * †Hsuum
 * †Hsuum baldfacense
 * †Hsuum brevicostatum
 * †Hsuum maxwelli
 * †Hsuum mclaughlini
 * †Hsuum naturale
 * †Hsuum obispoensis
 * †Hsuum rutogense
 * †Hsuum santamariaense
 * †Hsuum speciosum
 * Hybodus NT.jpg †[[Hybodus]]
 * †Hybodus shastensis – type locality for species
 * †Hydrotherosaurus – type locality for genus
 * †Hydrotherosaurus alexandrae – type locality for species
 * †Hyphantoceras
 * †Hyphantoceras ceratopse
 * †Hyphantoceras venustum – or unidentified comparable form
 * †Hypophylloceras
 * †Hypophylloceras onoense – or unidentified related form

I

 * †Icantia
 * Ichthyornis restoration.jpeg †[[Ichthyornis]]
 * †Ichthyosaurus
 * †Ichthyosaurus californicus – type locality for species
 * †Ichthyosaurus franciscanus – type locality for species
 * †Igonoia
 * †Igonoia shastana
 * †Indonesites
 * †Indonesites sphaericus
 * Inoceramus steenstrup, world's largest fossil mollusk.jpg †[[Inoceramus]]
 * †Inoceramus aduncas
 * †Inoceramus aduncus
 * †Inoceramus amakusensis – or unidentified comparable form
 * †Inoceramus angulatus – or unidentified comparable form
 * †Inoceramus balticus
 * †Inoceramus chicoensis – type locality for species
 * †Inoceramus cordiformis – or unidentified comparable form
 * †Inoceramus cymbaeformis – or unidentified related form
 * †Inoceramus digitatus – or unidentified related form
 * †Inoceramus ezoensis – or unidentified comparable form
 * †Inoceramus glennensis
 * †Inoceramus goldfussi – or unidentified comparable form
 * †Inoceramus gradilis
 * †Inoceramus incertus – or unidentified comparable form
 * †Inoceramus jacksonensis – type locality for species
 * †Inoceramus japonicus – or unidentified comparable form
 * †Inoceramus klamathensis
 * †Inoceramus naumanni
 * †Inoceramus pembertoni – or unidentified related form
 * †Inoceramus regularis – or unidentified related form
 * †Inoceramus shikotanensis – or unidentified comparable form
 * †Inoceramus stanislausensis
 * †Inoceramus steinmanni – or unidentified comparable form
 * †Inoceramus subundantus
 * †Inoceramus subundatus
 * †Inoceramus teshioensis – or unidentified comparable form
 * †Inoceramus turgidus – type locality for species
 * †Inoceramus vancouverensis
 * †Inoceramus whitneyi – or unidentified related form
 * †Inoperna
 * †Inoperna bellarugosa
 * †Inyoceras
 * †Inyoceras bittneri – type locality for species
 * †Inyoceras multicameratus – type locality for species
 * †Inyoites – type locality for genus
 * †Inyoites oweni – type locality for species
 * Isocrinus
 * †Isocrinus californicus
 * Pteriidae - Isognomon maxillatus.JPG [[Isognomon]]
 * †Isognomon – type locality for species – informal

J

 * †Jeanbesseiceras – tentative report
 * †Jeanbesseiceras jacksoni
 * †Joaquinites – type locality for genus
 * †Joaquinites fascicostatum – type locality for species
 * †Jovites
 * †Jovites pacificus – type locality for species
 * Jupiteria
 * †Juvavites
 * †Juvavites knowltoni
 * †Juvavites subinterruptus
 * †Juvenites
 * †Juvenites dieneri – type locality for species

K

 * Tetrarhynchiidae - Kallirhynchia major cropped.jpg †[[Kallirhynchia]]
 * †Kallirhynchia phylarchus – type locality for species
 * †Kallirhynchia valliculae – type locality for species
 * †Katroma
 * †Katroma neagui – or unidentified related form
 * †Keyserlingites
 * †Keyserlingites pacificus – type locality for species
 * †Keyserlingites subrobustus
 * †Kilianella
 * †Kilianella crassiplicata
 * †Kilinora
 * †Kilinora catenarum
 * †Kilinora spiralis
 * †Klamathites
 * †Klamathites kellyi
 * †Klamathites schucherti – type locality for species
 * Kossmaticeratidae - Kossmaticeras species.JPG †[[Kossmaticeras]]
 * †Kossmaticeras japonicum – or unidentified related form
 * †Kozurium
 * †Kozurium corningensis
 * †Kozurium zingulai
 * †Kuhnastraea
 * †Kuhnastraea decussata

L

 * †Laballa
 * †Laballa suessi – or unidentified comparable form
 * †Lacunaria
 * †Lacunaria striata
 * †Lampasa
 * †Lampasa blomei
 * †Lanceolites – type locality for genus
 * †Lanceolites bicarinatus
 * †Lanceolites compactus
 * †Lanubus
 * Laternula – tentative report
 * †Laternula alisoensis
 * †Latidorsella
 * †Latidorsella barryae – type locality for species
 * †Latimaeandra – report made of unidentified related form or using admittedly obsolete nomenclature
 * †Latimaeandra eucystis
 * †Leconteia – type locality for genus
 * †Leconteia californica – type locality for species
 * †Leconteiceras
 * †Leconteiceras occidentale – type locality for species
 * †Leconteites
 * †Leconteites lecontei – tentative report
 * Leda – tentative report
 * †Leda translucidus – tentative report
 * †Legumen
 * †Legumen ooides
 * †Leptosolen
 * †Leugeo
 * †Leugeo ordinarius
 * †Leugeo parvispinata
 * †Levileugeo
 * Lima
 * †Lima – type locality for species A – informal
 * †Lima beta
 * †Lima costata
 * †Lima kimballi – type locality for species
 * †Lima terqueni
 * Limopsis
 * †Limopsis silveradoensis
 * †Linaresia
 * †Linearis
 * †Linearis multicostata – or unidentified comparable form
 * †Lingula
 * †Lipmanium – tentative report
 * †Lipmanium caseyi
 * †Lisopithia
 * †Lisopithia ana
 * †Lispodesthes
 * †Lispodesthes rotundatus
 * †Lispodesthes rotundus
 * †Lithiotis
 * †Lithiotis problematica
 * †Lithomphalus
 * †Lithomphalus enderlini
 * Lithophaga
 * †Loboidothyris
 * †Loboidothyris meeki – type locality for species
 * †Loboidothyris mormonensis – type locality for species
 * †Longoconcha – tentative report
 * Bivalvia - Lopha sp.JPG [[Lopha]]
 * Loripes – tentative report
 * †Loripes dubia
 * †Loxo
 * †Loxo decore
 * †Lucina
 * †Lyriochlamys
 * †Lyriochlamys traskii
 * †Lysis
 * †Lysis californica
 * †Lysis duplicosta
 * †Lysis suciensis – or unidentified comparable form
 * Lytoceras fimbriatum.JPG †[[Lytoceras]]
 * †Lytoceras aulaeum
 * †Lytoceras batesi
 * †Lytoceras saturnale
 * †Lytoceras traski – or unidentified comparable form
 * †Lytoceras whitneyi

M

 * Macrocallista
 * †Macrocallista cordata – or unidentified related form
 * Macrocephalites rotundus 01.JPG †[[Macrocephalites]]
 * †Madrasites
 * †Madrasites voyanum – type locality for species
 * †Mammites – tentative report
 * †Mantelliceras
 * †Mantelliceras lecontei – or unidentified comparable form
 * Margarella
 * †Margarella crenulata
 * †Margariella – tentative report
 * †Margaritella
 * †Margaritella globosa
 * Margarites
 * †Margarites inornatus
 * †Margarites ornatissima
 * †Margarites senilis
 * †Margarites septentrionalis – type locality for species
 * †Margaritropites
 * †Margaritropites johnsoni – type locality for species
 * †Margaritropites kokeni – type locality for species
 * †Marginotruncana
 * †Marginotruncana marginata
 * †Marginotruncana renzi
 * Marginulina
 * †Marginulina elongata
 * Mariella lewesiensis.jpg †[[Mariella]]
 * †Mariella bergeri
 * †Mariella fricki
 * Martesia
 * †Martesia clausa
 * †Mataxa
 * †Mataxa arida – type locality for species
 * †Mediaster
 * †Mediaster hayi – type locality for species
 * †Meekia
 * †Meekia bella
 * †Meekia daileyi
 * †Meekia iberica
 * †Meekia lirata – tentative report
 * †Meekia louella
 * †Meekia mygale
 * †Meekia radiata
 * †Meekia sella
 * †Meekia takeoana – tentative report
 * †Meekoceras
 * †Meekoceras gracilitatis
 * †Meekoceras newberryi
 * †Meekoceras strongi
 * †Melchiorites
 * †Melchiorites shastensis
 * [[File:Menuites soyaensis - National Museum of Nature and Science, Tokyo - DSC06958 cropped.jpg|thumb|upright|Assemblage of fossilized shells of the Late Cretaceous ammonoid cephalopod Menuites]] †[[Menuites]]
 * †Menuites arrialoorensis – or unidentified related form
 * †Menuites siskiyouensis
 * †Merriamia
 * †Merriamia zitteli
 * †Mesopuzosia
 * †Mesopuzosia colusaense
 * †Mesopuzosia intermedia – or unidentified comparable form
 * †Mesopuzosia pacifica – or unidentified comparable form
 * †Metacerithium – tentative report
 * †Metaplacenticeras
 * †Metaplacenticeras californicum
 * †Metaplacenticeras pacificum
 * †Metaplacenticeras transitionale
 * †Metasibirites
 * †Metasibirites brockensis – type locality for species
 * †Metasibirites coei – type locality for species
 * †Metasibirites frechi – type locality for species
 * †Metasibirites gracilis – type locality for species
 * †Metasibirites modestus – type locality for species
 * †Metasibirites mojsvarensis – type locality for species
 * †Metasibirites pusillus – type locality for species
 * †Metasibirites pygmaeus – type locality for species
 * †Metasibirites shastensis – type locality for species
 * †Metatirolites
 * †Metatirolites foliaceus
 * †Metatirolites quadrangulus
 * †Metatirolites subpygmaeus
 * †Microsciadiocapsa
 * †Microsciadiocapsa sutterensis
 * †Microtropites
 * †Microtropites tubercularis
 * †Millerocaulis
 * †Millerocaulis embreei – type locality for species
 * †Minasteria – report made of unidentified related form or using admittedly obsolete nomenclature
 * †Minasteria shastensis
 * †Minocapsa
 * †Minocapsa aitai
 * †Minocapsa tansinhoki
 * †Minytropis
 * †Minytropis melilota
 * †Mirifusus
 * †Mirifusus baileyi
 * †Mirifusus chenodes – or unidentified related form
 * †Mirifusus fragilis
 * †Mirifusus guadalupensis
 * †Mirifusus mediodilatatus
 * † Mita – tentative report
 * † Mita
 * †Mita magnifica
 * †Modiolus
 * †Modiolus cylindricus
 * †Modiolus sikiyouensis
 * †Modiolus siskiyouensis
 * †Mojsvaroceras
 * †Mojsvaroceras turneri – type locality for species
 * †Monotis
 * †Monotis subcircularis
 * †Morenosaurus – type locality for genus
 * †Morenosaurus stocki – type locality for species
 * Mortoniceras inflatum 01.JPG †[[Mortoniceras]]
 * †Mortoniceras chicoense
 * †Mortoniceras gainesana
 * †Mortoniceras inflata
 * †Mortoniceras kiliani
 * †Mortoniceras tehamaensis
 * †Msopuzosia
 * †Msopuzosia densicostata – or unidentified comparable form
 * †Murphitys – type locality for genus
 * †Murphitys corona – type locality for species
 * †Murphitys madonna – type locality for species
 * †Murphitys michaeli – type locality for species
 * Musculus – or unidentified related form
 * †Myoconcha
 * †Myoconcha nana
 * Myophorella-1.jpg †[[Myophorella]]
 * †Myophorella argo
 * †Myophorella dawsoni – or unidentified related form
 * †Myophorella yellowstonensis
 * †Myophoria
 * †Myophoria brockensis – type locality for species
 * Myrtea
 * †Myrtea gabbi – tentative report
 * †Mytiloides
 * †Mytiloides labiatus
 * †Mytiloides mytiloides
 * †Mytiloides opalensis
 * †Mytiloides stantoni – or unidentified comparable form
 * Miesmuscheln Mytilus 1.jpg †[[Mytilus (genus)|Mytilus]]
 * †Mytilus pauperculus – or unidentified comparable form
 * †Mytilus quadratus
 * †Mytilus ursensis – type locality for species

N

 * †Nanonavis
 * †Nanonavis breweriana
 * Napora
 * †Napora bearensis – or unidentified comparable form
 * †Napora bukryi
 * †Napora collieri
 * †Napora dumitricai
 * †Napora durhami
 * †Napora elkcampensis
 * †Napora espinosa
 * †Napora latissima – or unidentified related form
 * †Napora lomoalta
 * †Napora nipponica
 * †Napora pacifica
 * †Napora praespinifera
 * †Napora pyramidalis
 * †Napora redonda
 * †Napora saginata – or unidentified related form
 * †Napora sixi
 * †Napora spinifera
 * Natica
 * †Natica allisoni
 * †Natica conradiana
 * †Navahopus
 * Thalattosauridae.jpg †[[Nectosaurus]]
 * †Neithea
 * †Neithea grandicosta
 * †Nelltia
 * †Nelltia roddana – tentative report
 * †Nelltia salsa – type locality for species
 * †Nemodon
 * †Neocardioceras – tentative report
 * †Neohibolites
 * †Neohibolites fontinalis
 * †Neoparonaella
 * †Neoparonaella delicata
 * †Neophylloceras
 * †Neophylloceras hetonaiense
 * †Neophylloceras ramosum
 * †Neophylloceras vaculae
 * †Neopopanoceras
 * †Neopopanoceras haugi – type locality for species
 * †Neopuzosia
 * †Neopuzosia ishikawai
 * Nerineidae - Nerinea sp..JPG †[[Nerinea]]
 * †Nerinea stewarti – type locality for species
 * †Nerinella
 * †Nerinella santana – type locality for species
 * Nerita
 * †Nerita orovillensis – tentative report
 * Nodosarella
 * Nodosaria
 * †Nodosaria monile
 * †Nodosaria pomuligera
 * †Nodosaria spinifera
 * †Nolita
 * †Nolita ramosa
 * †Nonactaeonina
 * †Nonactaeonina obesa
 * †Nonactaeonina tensa – or unidentified comparable form
 * Nostoceras species cropped.jpg †[[Nostoceras]]
 * †Nostoceras excelsus – type locality for species
 * †Nostoceras splendidum
 * †Notidanodon
 * †Notidanodon lanceolatus
 * †Notodonax
 * †Notodonax bolsae
 * †Novitripus
 * †Novitripus placitus
 * †Novitripus varius
 * †Novixitus
 * †Novixitus jurassicus
 * †Novixitus mclaughlini
 * †Nowakites
 * †Nowakites dobbinsi – type locality for species
 * †Nowakites klamathonis – type locality for species
 * †Nowakites puertoensis – type locality for species
 * †Nowakites rumseyensis – type locality for species
 * Nucinella
 * Nucleolites – report made of unidentified related form or using admittedly obsolete nomenclature
 * †Nucleolites mercedensis
 * Nuculidae - Nucula piacentina.jpg [[Nucula]]
 * †Nucula gabbi
 * †Nucula storrsi
 * Nuculana
 * †Nuculana grandensis – or unidentified related form
 * †Nuculana translucida
 * †Nudivagus – tentative report
 * †Nudivagus califus – type locality for species

O

 * †Obesacapsula
 * †Obesacapsula cetia
 * †Obesacapsula morroensis
 * †Obesacapsula rotunda
 * †Obnixia – type locality for genus
 * †Obnixia thaynesiana
 * †Octopodichnus
 * †Olanda
 * †Olanda olorina
 * †Omphaloptycha
 * †Omphaloptycha obesa – type locality for species
 * †Omphaloptycha shastensis – type locality for species
 * Opalia
 * †Ophiceras
 * †Ophiceras involutum
 * †Opis
 * †Opis anae – type locality for species
 * †Opis californica – type locality for species
 * †Opis holzana
 * †Opis pacifica
 * †Opis popenoei – type locality for species
 * †Opis rosarioensis
 * †Opis triangulata – type locality for species
 * †Opis vancouverensis
 * †Orbiculiforma
 * †Orbiculiforma maxima
 * †Orbiculiforma multangula
 * †Orbiculiforma nevadaensis
 * †Orbiculiforma railensis
 * †Orbiculiformella
 * †Orbiculiformella teres
 * †Ornithella
 * †Ornithella curticensis – type locality for species
 * †Ornithella gemina – type locality for species
 * †Ornithella syringothyrides – type locality for species
 * †Orthoceras
 * †Orthoceras shastense – type locality for species
 * †Orthotrigonia
 * Ostrea
 * †Ostrea crescentica
 * †Owenites
 * †Owenites carpenteri
 * †Owenites koeneni – type locality for species
 * †Oxybeloceras
 * †Oxybeloceras petrolense
 * †Oxybeloceras taffi – type locality for species
 * †Oxyeurax
 * †Oxyeurax trapezoidalis
 * †Oxynautilus
 * †Oxynautilus acutus
 * †Oxytoma
 * †Oxytropidoceras
 * †Oxytropidoceras peruvianum

P

 * †Pachecocrinus
 * †Pachydesmoceras
 * †Pachydesmoceras colusaense
 * †Pachydesmoceras pachydiscoide – type locality for species
 * Pachydiscus neubergicus cropped.jpg †[[Pachydiscus]]
 * †Pachydiscus ashlandicus – or unidentified related form
 * †Pachydiscus averilli – type locality for species
 * †Pachydiscus binodatus – or unidentified comparable form
 * †Pachydiscus buckhami
 * †Pachydiscus catarinae – or unidentified related form
 * †Pachydiscus coalingense
 * †Pachydiscus egertoni – or unidentified comparable form
 * †Pachydiscus henleyensis
 * †Pachydiscus japonicus – or unidentified comparable form
 * †Pachydiscus neevesi – or unidentified comparable form
 * †Pachydiscus ootacodensis
 * †Pachydiscus subcompressus
 * †Pachyoncus
 * †Pachyoncus kamiasoensis
 * †Paladmete – tentative report
 * †Palaeastraea – report made of unidentified related form or using admittedly obsolete nomenclature
 * †Palaeastraea grandissima
 * †Palaeobates
 * †Palaeobates shastensis – type locality for species
 * †Palaeocypraea
 * †Palaeocypraea fontana – type locality for species
 * †Palaeocypraea wilfredi – type locality for species
 * †Palaeomoera
 * †Palaeomoera dyskritos
 * †Paleopsephaea
 * †Paleopsephaea sacramentica
 * †Paleotractus
 * †Paleotractus crassus
 * †Palinandromeda
 * †Palinandromeda fimbria
 * †Palinandromeda podbielensis
 * Panopea
 * †Panopea californica – or unidentified related form
 * †Pantanellium
 * †Pantanellium buntonense – or unidentified comparable form
 * †Pantanellium darlingtonense
 * †Pantanellium deflectum
 * †Pantanellium fishcreekensis
 * †Pantanellium foveatum
 * †Pantanellium josephinense
 * †Pantanellium meraceibaense
 * †Pantanellium rarum
 * †Pantanellium riedeli
 * †Pantanellium squinaboli
 * †Pantanellium ultrasincerum
 * †Paraganides – type locality for genus
 * †Paraganides californicus – type locality for species
 * †Parahauerites
 * †Parahauerites ashleyi – type locality for species
 * †Parahoplites
 * †Parahoplites sjogreni – or unidentified related form
 * †Parahsuum
 * †Parahsuum izeense
 * †Parahsuum mostleri
 * †Parahsuum ovale
 * †Parahsuum publicum
 * †Parahsuum simplum
 * †Parahsuum stanleyense
 * †Parahsuum transiens – or unidentified comparable form
 * †Parallelodon
 * †Parallelodon brewerianus
 * †Parallelodon vancouverensis
 * †Paranannites
 * †Paranannites oviformis – type locality for species
 * †Parapachydiscus
 * †Parapachydiscus bidwelli – type locality for species
 * †Parapachydiscus catarinae
 * †Parapachydiscus cortinaensis – type locality for species
 * †Parapachydiscus panochensis – type locality for species
 * †Parapachydiscus peninsularis – or unidentified related form
 * †Parapachydiscus stanislausensis – type locality for species
 * Parapuzosia seppenradensis 3.jpg †[[Parapuzosia]]
 * †Parapuzosia arenaica – type locality for species
 * †Parapuzosia giganteum – type locality for species
 * †Parapuzosia hearni – type locality for species
 * †Parapuzosia hindsi – type locality for species
 * †Parapuzosia klamathonrae – type locality for species
 * †Parapuzosia waringi
 * †Paratropites
 * †Paratropites colei
 * †Paratropites shastensis
 * †Parisculites
 * †Parisculites obolinus
 * †Paronaella
 * †Paronaella aranae
 * †Paronaella bandyi
 * †Paronaella broennimanni – or unidentified related form
 * †Paronaella cleopatraensis
 * †Paronaella coalescenda
 * †Paronaella egregia
 * †Paronaella inornata
 * †Paronaella nipomoensis
 * †Paronaella obesa
 * †Paronaella panda
 * †Paronaella solanoensis – or unidentified comparable form
 * †Partschiceras
 * †Partschiceras grantzi – or unidentified comparable form
 * †Parussuria
 * †Parussuria compressa – type locality for species
 * Parvamussium
 * †Parvicingula
 * †Parvicingula alamoensis
 * †Parvicingula blowi
 * †Parvicingula bluefordae
 * †Parvicingula boesi
 * †Parvicingula broqueta
 * †Parvicingula citae
 * †Parvicingula colemani
 * †Parvicingula corona
 * †Parvicingula cuyamaensis
 * †Parvicingula deadhorsensis
 * †Parvicingula dhimenaensis – or unidentified related form
 * †Parvicingula excelsa
 * †Parvicingula gorda
 * †Parvicingula gracila
 * †Parvicingula jonesi
 * †Parvicingula khabakovi – or unidentified comparable form
 * †Parvicingula obstinata
 * †Parvicingula rothwelli
 * †Parvicingula sanfilippoae
 * †Parvicingula satura
 * †Parvicingula thomesensis
 * †Parvicingula turrita
 * †Parvicingula whalenae
 * †Parvicingula yehae
 * †Parvivacca
 * †Parvivacca coraforma
 * †Parvivacca immodica
 * †Parvivacca marina
 * †Parvivacca robusta
 * †Parvivacca simplex
 * †Parvivacca varica
 * †Paskentana
 * †Paskentana berryessaensis – type locality for species
 * †Paskentana globosa – type locality for species
 * †Paskentana paskentaensis
 * Patella – report made of unidentified related form or using admittedly obsolete nomenclature
 * †Patella sheehani – type locality for species
 * †Patella stuarti – type locality for species
 * †Patulibracchium
 * †Patulibracchium grapevinensis
 * †Patulibracchium henlei – or unidentified related form
 * †Paxitropis
 * †Paxitropis dicriota
 * Pecten maximus Pilgermuschel.jpg †[[Pecten (genus)|Pecten]]
 * †Pecten cowperi
 * †Pecten deformis – type locality for species
 * †Pedalion
 * †Pegaster – type locality for genus
 * †Pegaster stichos – type locality for species
 * †Pentacrinus
 * †Pentacrinus asteriscus – tentative report
 * †Pentzia
 * †Pentzia hilgardi
 * Periploma
 * †Periploma subgracile – or unidentified related form
 * †Periplomya – tentative report
 * †Perispyridium
 * †Perispyridium alinchakense – or unidentified related form
 * †Perispyridium bacatum
 * †Perispyridium dangerpointense
 * †Perispyridium gujohachimanense
 * †Perispyridium neotamanense
 * †Perispyridium ordinarium
 * †Perissitys
 * †Perissitys brevirostris
 * †Perissitys colocara – type locality for species
 * †Perissitys cretacea
 * †Perissitys elaphia – type locality for species
 * †Perissitys pacifica – type locality for species
 * †Perissitys stantoni
 * Gasteropods - Ammonites - Peroniceras tricarinatum.JPG †[[Peroniceras]]
 * †Peroniceras leei – or unidentified related form
 * †Peroniceras shastensis
 * †Pervinquieria
 * †Pervinquieria furberi – type locality for species
 * †Pervinquieria gainesana – type locality for species
 * †Petasiforma
 * †Petasiforma foremanae
 * †Petasiforma inusitata
 * Phanerolepida
 * †Phanerolepida onoensis – type locality for species
 * †Phantum
 * †Phantum insperatum – or unidentified comparable form
 * Pharella
 * †Pharella alta
 * †Phelopteria
 * †Phillippiella
 * Pholadomya
 * †Pholadomya diegoensis – or unidentified comparable form
 * †Pholadomya subelongata
 * Phylloceras NT.jpg †[[Phylloceras]]
 * †Phylloceras gargantuum – type locality for species
 * †Phylloceras pachecoense – type locality for species
 * †Phylloceras velledae
 * †Phyllopachyceras
 * †Phyllopachyceras aldersona
 * †Piarorhynchia
 * †Piarorhynchia howardi – type locality for species
 * †Piarorhynchia winnemae – type locality for species
 * †Piestochilus – tentative report
 * †Pinacoceras
 * †Pinacoceras rex
 * †Pinna
 * †Pinna calamitoides
 * †Pinna expansa – or unidentified comparable form
 * †Pityostrobus
 * †Pityostrobus calforniensis – type locality for species
 * †Plesiotylosaurus
 * †Plesiotylosaurus crassidens
 * †Pleuromya
 * †Pleurotropites
 * †Pleurotropites gabbi – type locality for species
 * †Pleurotropites gracilis – type locality for species
 * Plicatula
 * †Plicatula perimbricata
 * †Plicatula variata
 * Plotosaurus Los Angeles.jpg   †[[Plotosaurus]]
 * †Plotosaurus bennisoni
 * †Plotosaurus tuckeri
 * †Podobursa
 * †Podobursa basilica
 * †Podobursa helvetica
 * †Podobursa lanza
 * †Podobursa rosea
 * †Podobursa spinellifera
 * †Podobursa spinosa
 * †Podobursa tamanensis
 * †Podobursa triacantha
 * †Podocapsa
 * †Podocapsa amphitreptera
 * Polinices
 * †Polinices mercedensis – type locality for species
 * †Polinices shumardianus – tentative report
 * †Polycyclus
 * †Polycyclus henseli
 * †Polyptychites
 * †Polyptychites trichotomus
 * Diplomoceratidae - Polyptychoceras species.JPG †[[Polyptychoceras]]
 * †Polyptychoceras obstrictum – or unidentified comparable form
 * †Posidonia
 * †Posidonia alpina
 * †Posidonia jacksoni – type locality for species
 * †Posidonia madisonensis – type locality for species
 * †Potamides – tentative report
 * †Potamides diadema
 * †Potamides grovesi – type locality for species
 * †Praeconocaryomma
 * †Praeconocaryomma decora – or unidentified comparable form
 * †Praeconocaryomma fasciata – tentative report
 * †Praeconocaryomma immodica
 * †Praeconocaryomma magnimamma – or unidentified comparable form
 * †Praeconocaryomma media – or unidentified comparable form
 * †Praeconocaryomma parvimamma – or unidentified comparable form
 * †Praeconocaryomma prisca
 * †Praeconocaryomma uhlensis
 * †Praeconocaryomma whiteavesi – or unidentified comparable form
 * †Praeconosphaera
 * †Praeconosphaera spinosa
 * †Praeparvicingula
 * †Praeparvicingula decora
 * †Praeparvicingula discors – or unidentified related form
 * †Praeparvicingula gemmata
 * †Praeparvicingula holdsworthi
 * †Praeparvicingula hurdygurdyensis
 * †Praeparvicingula nebulosa
 * †Praeparvicingula packsaddlensis
 * †Praeparvicingula rotunda
 * †Praeparvicingula saltata
 * †Praeparvicingula sencilla
 * †Praeparvicingula siskiyouensis
 * †Praeparvicingula turpicula
 * †Praewilliriedellum
 * †Praewilliriedellum cephalospinosum
 * †Preflorianites
 * †Preflorianites strongi – type locality for species
 * †Preflorianites toulai
 * †Prionocycloceras
 * †Prionocycloceras californicum
 * †Prionocycloceras crenulatum
 * †Prionolobus
 * †Prionolobus waageni – type locality for species
 * †Prionotropis
 * †Prionotropis casperi
 * †Prionotropis hiltensis – type locality for species
 * †Priscoficus – tentative report
 * †Prisconatica
 * †Prisconatica hesperia
 * †Proarcestes
 * †Proarcestes carpenteri – type locality for species
 * †Proarcestes pacificus
 * †Proarcestes shastensis – type locality for species
 * †Proarcestes traski – type locality for species
 * †Proarcestes whitneyi
 * †Proarcestes winnemae – type locality for species
 * †Proclydonautilus
 * †Proclydonautilus hessi – type locality for species
 * †Proclydonautilus spirolobus
 * †Proclydonautilus squawensis – type locality for species
 * †Proclydonautilus stantoni – type locality for species
 * †Proclydonautilus triadicus
 * †Proclydonautilus ursensis – type locality for species
 * Prognath waipar2DB.jpg †[[Prognathodon]]
 * †Prognathodon waiparaensis – or unidentified comparable form
 * †Projuvavites
 * †Projuvavites brockensis – type locality for species
 * †Projuvavites strongi – type locality for species
 * Propeamussium
 * †Prosphingitoides
 * †Prosphingitoides austini – type locality for species
 * †Protexanites
 * †Protexanites thompsoni
 * †Protocardia
 * †Protocardia remondianum
 * †Protocardia translucidum
 * †Protovallupus
 * †Protovallupus tetlamaensis
 * Trachyceratidae - Protrachyceras psaeudoarchelonus.JPG †[[Protrachyceras]]
 * †Protrachyceras storrsi – type locality for species
 * †Protunuma
 * †Protunuma japonicus
 * †Protunuma multicostatus – or unidentified related form
 * †Pseudacrochordiceras
 * †Pseudacrochordiceras inyoense – type locality for species
 * †Pseudanchura
 * †Pseudanchura biangulata
 * †Pseudhelicoceras
 * †Pseudhelicoceras petersoni – type locality for species
 * †Pseudocrucella
 * †Pseudocrucella ehrenbergi
 * †Pseudocymia – type locality for genus
 * †Pseudocymia aitha – type locality for species
 * †Pseudocymia aurora – type locality for species
 * †Pseudocymia cahalli – type locality for species
 * †Pseudodiadema
 * †Pseudodiadema emersoni
 * †Pseudodictyomitra
 * †Pseudodictyomitra lodogaensis
 * †Pseudodictyomitra pentacolaensis
 * †Pseudodictyomitra pseudomacrocephala
 * †Pseudodictyomitra vestalensis
 * †Pseudoeucyrtis
 * †Pseudoeucyrtis firmus
 * †Pseudoeucyrtis hannai – or unidentified comparable form
 * †Pseudoeucyrtis paskentaensis
 * †Pseudogaleodea
 * †Pseudoheliodiscus
 * Pseudomelania shell cropped.png †[[Pseudomelania]]
 * †Pseudomelania colusaensis – type locality for species
 * †Pseudoperna
 * †Pseudoperna toxidonta
 * †Pseudophyllites
 * †Pseudoptera – tentative report
 * †Pseudoristola
 * †Pseudoristola clava
 * †Pseudoristola nova
 * †Pseudosageceras
 * †Pseudosageceras multilobatum
 * †Pseudothurmannia – tentative report
 * †Pseudothurmannia jupiter
 * †Pseudothurmannia russelli
 * †Pseudoxybeloceras
 * †Pseudoxybeloceras lineatum – or unidentified comparable form
 * †Pteraichnus
 * †Pteroluter
 * †Pteroluter othnius – type locality for species
 * Megatrigoniidae - Pterotrigonia caudata.JPG †[[Pterotrigonia]]
 * †Pterotrigonia evansana
 * †Pterotrigonia klamathonia
 * †Pterotrigonia oregana – or unidentified comparable form
 * †Ptilorhynchia – type locality for genus
 * †Ptilorhynchia plumasensis – type locality for species
 * †Ptiloteuthis – type locality for genus
 * †Ptiloteuthis foliatus – type locality for species
 * †Ptychoceras – type locality for genus
 * †Ptychoceras laeve – type locality for species
 * †Ptyctothyris
 * †Ptyctothyris hardgravensis – type locality for species
 * †Ptyctothyris phlegethontis – type locality for species
 * †Pugnellus
 * †Pugnellus hammulus – or unidentified related form
 * †Pugnellus hamulus
 * †Pugnellus manubriatus
 * †Puzosia
 * †Puzosia hannai – type locality for species
 * †Puzosia puma
 * †Puzosia sullivanae
 * Pycnodonte pulaskiensis Clayton.jpg [[Pycnodonte]]
 * †Pyktes
 * †Pyktes hamulus
 * †Pyramispongia
 * †Pyramispongia glascockensis
 * †Pyropsis

Q

 * Quadrans – tentative report
 * †Quinquecapsularia
 * †Quinquecapsularia spinosa

R

 * †Radioceras
 * †Radioceras evolvens
 * †Remondia
 * †Remondia oregonensis – type locality for species
 * †Reptolunulites
 * Retusa
 * †Rhabdoceras
 * †Rhabdoceras suessi
 * †Rhactorhynchia
 * †Rhactorhynchia trigona – type locality for species
 * †Rhaetina – tentative report
 * †Rhaetina pyriformis
 * †Rhectomax
 * †Rhectomax undulatus
 * †Rhectomyax
 * †Rhectomyax undulatus
 * Rhynchonellidae - Rhynchonella species.JPG †[[Rhynchonella]]
 * †Rhynchonella richardsoni – type locality for species
 * †Rhynchonella varians – or unidentified comparable form
 * †Riedelius
 * †Ristola
 * †Ristola altissima
 * †Ristola bala
 * †Ristola procera
 * †Ristola turpicula
 * Robulus
 * †Robulus inornatus
 * Rogerella
 * †Romaniceras
 * †Romaniceras deverioide

S

 * †Sagenites
 * †Sagenites dickersoni – type locality for species
 * †Saghalinites
 * †Sandlingites
 * †Sandlingites andersoni – type locality for species
 * †Sandlingites oribasus
 * †Sarasinella
 * †Sarasinella angulata
 * †Saturniforma
 * †Saturniforma peregrina
 * †Scalarites
 * Scapanorhynchus raphiodon cropped.jpg †[[Scapanorhynchus]]
 * Scaphander
 * †Scaphander costatus
 * †Scaphites
 * †Scaphites hippocrepis – or unidentified related form
 * †Scaphites inermis – or unidentified related form
 * †Scaphites pittensis – type locality for species
 * †Scaphotrigonia
 * †Scaphotrigonia naviformis
 * †Sciponoceras
 * †Sciponoceras gracile – type locality for species
 * Scobinella
 * †Scobinella dilleri
 * †Semihsuum
 * †Semihsuum biscuithillense
 * †Semihsuum brokencotense
 * †Semihsuum inexploratum
 * †Semihsuum sourdoughense
 * †Senis
 * Septifer
 * †Sequoia
 * †Sequoia reichenbachi
 * Serpula
 * Species of Shastasaurus.jpg †[[Shastasaurus]]
 * †Shastasaurus alexandrae
 * †Shastasaurus pacificus
 * †Shasticrioceras
 * †Shasticrioceras whitneyi – or unidentified related form
 * †Shastites
 * †Shastites compactus – type locality for species
 * †Shastites compressus – type locality for species
 * †Shastites whitneyi – type locality for species
 * †Shastoceras
 * †Silberlingia
 * †Silberlingia sanctaeanae
 * †Simbirskites
 * †Simbirskites broadi
 * †Simbirskites lecontei
 * Siphonalia
 * †Siphonalia dubius
 * †Sirenites
 * †Sirenites lawsoni – type locality for species
 * †Skolithos
 * Solariella
 * †Solariella occidentalis
 * †Solariella stewarti
 * Solemya – tentative report
 * Solen
 * †Solen cuneatus – or unidentified comparable form
 * †Solenoceras
 * †Spiriferina – report made of unidentified related form or using admittedly obsolete nomenclature
 * †Spiriferina coreyi – type locality for species
 * †Spirigera – report made of unidentified related form or using admittedly obsolete nomenclature
 * †Spirigera milesi – type locality for species
 * †Spirogmoceras
 * †Spirogmoceras shastense – type locality for species
 * †Spondylospira
 * †Spondylospira lewesensis
 * †Spondylospira parmata
 * Spondylus
 * †Spondylus subnodosus
 * †Spongiomorpha
 * †Spongiomorpha tenuis
 * †Spongocapsula
 * †Spongocapsula dumitricai
 * †Spongocapsula hooveri
 * †Spongocapsula palmerae
 * †Spongocapsula zamoraensis
 * †Spongosaturninus
 * †Spongosaturninus bispinus
 * Squalicorax2DB.jpg [[Squalicorax]]
 * †Staurolonche
 * Stichocapsa
 * †Stichocapsa convexa
 * †Stichocapsa japonica
 * Stichomitra – tentative report
 * †Stichomitra takanoensis
 * †Stoliczkaia
 * †Stoliczkaia praecursor – type locality for species
 * †Stomechinus
 * †Stomechinus hyatti
 * †Striatojaponocapsa
 * †Striatojaponocapsa conexa
 * †Striatojaponocapsa plicarum
 * †Stromatomorpha
 * †Stromatomorpha californica – type locality for species
 * †Sturia
 * †Sturia woodini
 * †Subhungarites
 * †Subhungarites yatesi – type locality for species
 * †Submeekoceras
 * †Submeekoceras mushbachanum
 * †Submortoniceras
 * †Submortoniceras buttense
 * †Submortoniceras buttensis – type locality for species
 * †Submortoniceras chicoense
 * †Submortoniceras gabbi
 * †Submortoniceras pentzanum – type locality for species
 * †Submortoniceras randalli
 * †Submortoniceras studleyi
 * †Subprinocyclus
 * †Subprionocyclus
 * †Subprionocyclus branneri
 * †Subprionocyclus neptuni – or unidentified comparable form
 * †Subprionocyclus normalis – or unidentified comparable form
 * †Subprionocyclus oregonense
 * † Suna
 * †Suna ehrenbergi
 * †Suna haeckeli
 * †Suna harperi
 * †Sympolycyclus
 * †Sympolycyclus kellyi – type locality for species
 * †Sympolycyclus nodifer – type locality for species
 * †Syncyclonema
 * †Syncyclonema latum – type locality for species
 * †Syncyclonema operculiformis

T

 * †Tappanella
 * †Tappanella novacubica
 * †Tardeceras – type locality for genus
 * †Tardeceras parvum – type locality for species
 * †Tegula
 * †Tegula jeanae
 * †Tehamatea
 * †Tehamatea ovalis
 * †Teichertus
 * †Teichertus cavernosus
 * †Teichertus notus
 * Tellina fabula.jpg [[Tellina]]
 * †Tellina – type locality for species A – informal
 * †Tellina alisoensis
 * †Tellina ashburnerii
 * †Tellina ooides
 * †Tellina paralis
 * †Tellina quadrata
 * †Tellina whitneyi
 * †Tenea
 * †Tenea inflata
 * †Teneposita – type locality for genus
 * †Teneposita laeva – type locality for species
 * Terebralia palustris 2.png [[Terebralia]] – tentative report
 * †Terebralia juliana
 * Terebratella
 * †Terebratella densleonis
 * Terebratulina
 * †Terebratulina indomita – type locality for species
 * †Tessarolax
 * †Tessarolax distorta
 * †Tessarolax trinalis
 * †Tethysetta
 * †Tethysetta boesii
 * †Tetracapsa
 * †Tetracapsa horokanaiensis
 * †Tetraditryma
 * †Tetraditryma coldspringensis
 * †Tetraditryma corralitosensis
 * †Tetraditryma oregonensis
 * †Tetraditryma praeplena
 * †Tetraditryma pseudoplena
 * †Tetragonites
 * †Tetragonites cala
 * †Tetragonites epigonum
 * †Tetragonites glabrus – or unidentified comparable form
 * †Tetragonites popetensis – type locality for species
 * †Tetrahoplitoides
 * †Tetrahoplitoides stantoni
 * Thalattosaurus alexandrae Merriam cropped.jpg †[[Thalattosaurus]]
 * †Thanarla
 * †Thanarla brouweri
 * †Thanarla elegantissima
 * †Thanarla praeveneta
 * †Thanarla veneta
 * †Thetironia
 * †Thetironia annulata
 * †Thisbites
 * †Thisbites uhligi
 * †Thurmanniceras
 * †Thurmanniceras californicum
 * †Thurmanniceras jenkinsi
 * †Thurmanniceras stippi
 * Thyasira
 * †Thyasira cretacea
 * †Tibetothyris – report made of unidentified related form or using admittedly obsolete nomenclature
 * †Tibetothyris julica
 * †Tibiaporrhais – tentative report
 * †Tollia
 * †Tollia giganteus
 * †Tornatellaea
 * †Tornatellaea impressa
 * †Tornquistites – type locality for genus
 * †Tornquistites evolutus – type locality for species
 * †Trachybaculites
 * †Trachybaculites columna
 * †Trachysagenites
 * †Trachysagenites erinaceus
 * †Trachysagenites herbichi
 * †Trachysagenites shastensis – type locality for species
 * †Trachystenoceras
 * †Trachystenoceras gabbi – type locality for species
 * †Tragodesmoceras
 * †Tragodesmoceras ashlandicum
 * †Trajanella
 * †Trajanella californica
 * †Transhsuum
 * †Transhsuum brevicostatum
 * †Traskites
 * †Traskites americanus – type locality for species
 * †Traskites californicus – type locality for species
 * †Traskites evolutus – type locality for species
 * †Traskites fairbanksi – type locality for species
 * †Traskites minutus – type locality for species
 * †Traskites nanus – type locality for species
 * †Traskites osmonti – type locality for species
 * †Traskites robustus – type locality for species
 * †Traskites rugosus – type locality for species
 * †Traskites stantoni – type locality for species
 * †Traskites tornquisti – type locality for species
 * †Triactoma
 * †Triactoma blakei
 * †Triactoma jonesi
 * †Triactoma kellumi
 * †Triactoma longoriai
 * †Trichinopolia
 * †Trichinopolia californica – type locality for species
 * Tricolocapsa
 * †Trigonarca
 * †Trigonarca californica – or unidentified related form
 * †Trigonarca californicus
 * †Trigonarca excavata
 * Trigoniidae - Trigonia interlaevigata.JPG †[[Trigonia]]
 * †Trigonia aequicostata
 * †Trigonia denticulata – or unidentified comparable form
 * †Trigonia evansana
 * †Trigonia fitchi
 * †Trigonia hemisphaerica – or unidentified related form
 * †Trigonia hemphilli
 * †Trigonia inezana – or unidentified related form
 * †Trigonia jacksonensis – type locality for species
 * †Trigonia leana
 * †Trigonia perrinsmithi – type locality for species
 * †Trigonia plumasensis – type locality for species. Later reclassified in the new genus Californigonia as C. plumasensis.
 * †Trigonia spinulosa – or unidentified comparable form
 * †Trigonia tryoniana
 * †Trigonia undulata
 * †Trigonia vcostata – or unidentified comparable form
 * †Trigonocallista
 * †Trigonocallista bowersiana
 * †Trigonocallista nitida
 * †Trigonocallista varians
 * †Trillus
 * †Trillus elkhornensis
 * †Trillus seiderense – or unidentified comparable form
 * †Trinacria
 * †Trinacria cor
 * †Tripocyclia
 * †Tripocyclia brooksi
 * †Tripocyclia foremanae
 * †Tripocyclia frenchflatensis
 * †Tripocyclia highdomensis
 * †Tripocyclia mascula
 * †Tripocyclia saleebyi
 * †Tritrabs
 * †Tritrabs casmaliaensis
 * †Tritrabs ewingi
 * †Tritrabs exotica
 * †Tritrabs hayi
 * †Tritrabs rhododactylus
 * †Tritrabs suavia
 * †Tritrabs worzeli
 * †Triversus
 * †Triversus fastigatus
 * Trochactaeon conicus 01.jpg †[[Trochactaeon]]
 * †Trochactaeon frazierensis
 * †Trochactaeon packardi
 * Trochocyathus
 * †Trochocyathus pergranulatus – type locality for species
 * Trophon
 * †Trophon condoni
 * †Tropiceltites
 * †Tropiceltites caducus
 * †Tropites
 * †Tropites arthaberi
 * †Tropites brockensis – type locality for species
 * †Tropites dieneri – type locality for species
 * †Tropites dilleri – type locality for species
 * †Tropites fusobullatus
 * †Tropites hessi – type locality for species
 * †Tropites keili
 * †Tropites kellyi – type locality for species
 * †Tropites mojsvarensis – type locality for species
 * †Tropites morani – type locality for species
 * †Tropites reticulatus
 * †Tropites rotatorius – type locality for species
 * †Tropites rothpletzi – type locality for species
 * †Tropites schellwieni – type locality for species
 * †Tropites shastensis – type locality for species
 * †Tropites stearnsi – type locality for species
 * †Tropites ursensis – type locality for species
 * †Tropites welleri – type locality for species
 * †Tropites wodani
 * †Turanta
 * †Turanta chetcoensis
 * †Turanta flexa
 * †Turanta luminosa
 * †Turanta okamurai – or unidentified comparable form
 * †Turrilites
 * †Turrilites acutus
 * †Turrilites costatus – or unidentified comparable form
 * †Turrilites petersoni – type locality for species
 * Turritellatricarinata.jpg [[Turritella]]
 * †Turritella chaneyi
 * †Turritella chicoensis
 * †Turritella hearni
 * †Turritella infralineata
 * †Turritella peninsularis – or unidentified related form
 * †Turritella pescaderoensis
 * †Turritella peterseni – or unidentified related form
 * †Turritella petersoni
 * †Turritella robertiana – or unidentified comparable form
 * †Turritella webbi
 * †Turritella xylina
 * †Tylostoma
 * †Tylostoma garzana – type locality for species

U

 * †Unuma
 * †Unuma echinatus
 * †Unuma gordus
 * †Unuma typicus

V

 * †Vallupus
 * †Vallupus hopsoni
 * †Vaugonia
 * †Vaugonia kobayashii – or unidentified comparable form
 * †Vaugonia obliqua
 * †Vaugonia yukonensis – tentative report
 * †Vitorfus
 * †Vitorfus campbelli
 * Volsella
 * †Volsella siskiyouensis
 * †Volutoderma
 * †Volutoderma averilli
 * †Volutoderma averillii
 * †Volutoderma californica
 * †Volutoderma dilleri
 * †Volutoderma gabbi
 * †Volutoderma jacksonensis
 * †Volutoderma magna
 * †Volutoderma santana

W

 * †Wilbertopora
 * †Wilbertopora sannerae – type locality for species
 * †Willimactra
 * †Willimactra mathewsonii
 * †Willimactra popenoei
 * †Willimactra putida
 * †Willimactra truncata
 * †Williriedellum
 * †Williriedellum carpathicum
 * †Williriedellum frequens
 * †Williriedellum madstonense
 * †Wilvemia
 * †Wilvemia whiskeyensis
 * †Worthenia
 * †Worthenia klamathensis – type locality for species
 * †Wrangellium
 * †Wyomingites
 * †Wyomingites aplanatus

X

 * †Xiphostylus
 * †Xiphostylus gasquetensis
 * †Xiphostylus humboldtensis
 * †Xitus
 * †Xitus antelopensis
 * †Xitus antiquus
 * †Xitus plenus
 * †Xitus pulcher
 * †Xitus singularis
 * †Xitus spicularius
 * †Xitus spineus

Y

 * †Yaadia
 * †Yaadia branii – or unidentified comparable form
 * †Yaadia hemphilli
 * †Yaadia robusta
 * †Yaadia tryoniana
 * †Yezoites
 * †Yezoites puerculus – or unidentified comparable form
 * Yoldia
 * †Yoldia diminutiva
 * †Yoldia leana
 * †Yoldia nasuta

Z

 * †Zanola
 * †Zanola cornuta – or unidentified comparable form
 * †Zartus
 * †Zealandites
 * †Zhamoidellum
 * †Zhamoidellum exquisita
 * †Zhamoidellum kiesslingi
 * †Zhamoidellum kozuri
 * †Zhamoidellum parva
 * †Zhamoidellum triangulosa
 * †Zifondium
 * †Zifondium lassenensis
 * †Zifondium paupera
 * †Zimmerella – type locality for genus
 * †Zimmerella eastoni
 * †Zinsitys – tentative report
 * †Zugmayerella
 * †Zugmayerella americana
 * †Zugmeyeria