List of the Mesozoic life of Wyoming

This list of the Mesozoic life of Wyoming contains the various prehistoric life-forms whose fossilized remains have been reported from within the US state of Wyoming and are between 252.17 and 66 million years of age.

A

 * †Abielites
 * †Abielites angusticarpus
 * Sturgeon2.jpg [[Acipenser]]
 * †Acipenser eruciferus
 * †Acutostrea
 * †Acutostrea plumosa
 * †Adocus
 * †Agathaumas – type locality for genus
 * †Agathaumas sylvestris – type locality for species
 * †Agerostrea
 * †Agerostrea mesenterica
 * †Agialopous – type locality for genus
 * †Agialopous wyomingensis – type locality for species
 * Albanerpeton BW.jpg †[[Albanerpeton]]
 * †Albanerpeton galaktion
 * †Albanerpeton nexuosus – type locality for species
 * †Albertosaurus – or unidentified comparable form
 * †Alethesaurus – type locality for genus
 * †Alethesaurus quadratus – type locality for species
 * †Allacodon
 * †Allacodon lentus – type locality for species
 * †Allacodon pumilis – type locality for species
 * †Allognathosuchus
 * Allosaurus Revised.jpg †[[Allosaurus]] – type locality for genus
 * †Allosaurus fragilis – type locality for species
 * †Allosaurus jimmadseni
 * †Alostera
 * †Alostera saskatchewanensis – type locality for species
 * †Alphadon
 * †Alphadon attaragos – type locality for species
 * †Alphadon halleyi
 * †Alphadon marshi
 * †Alphadon sahnii
 * †Altacreodus
 * †Altacreodus magnus
 * †Alzadites
 * †Alzadites westonensis – type locality for species
 * †Amblotherium – type locality for genus
 * †Amblotherium gracilis – type locality for species
 * †Amborellites – type locality for genus
 * †Amborellites wyomingensis – type locality for species
 * Amia calva 4.jpg [[Amia (genus)|Amia]]
 * †Amia fragosa
 * †Amia uintaensis
 * †Amphicoelias
 * †Amphicoelias brontodiplodocus – type locality for species
 * †Amphidon – type locality for genus
 * †Amphidon superstes – type locality for species
 * †Anaklinoceras
 * †Anaklinoceras mortoni
 * †Anaschisma – type locality for genus
 * †Anaschisma brachygnatha – type locality for species
 * †Anaschisma browni – type locality for species
 * †Anceptophyllum – type locality for genus
 * †Anceptophyllum pulcrum – type locality for species
 * †Anchura – tentative report
 * †Ancorichnus
 * †Andromeda
 * †Andromeda grayana
 * †Anemia
 * †Anemia fremonti
 * †Anemia subcretacea
 * Angistorhinus grandis.jpg †[[Angistorhinus]] – type locality for genus
 * †Angistorhinus aeolamnis – type locality for species
 * †Angistorhinus gracilis – type locality for species
 * †Angistorhinus grandis – type locality for species
 * †Angistorhinus maximus – type locality for species
 * †Anisoceras
 * †Anisomyon
 * †Anisomyon borealis
 * †Anisomyon centrale
 * †Anisomyon patelliformis
 * †Anisomyon subovatus – or unidentified related form
 * †Anisomyon subovulatus
 * †Ankistrorhynchus
 * †Ankistrorhynchus washakiensis – type locality for species
 * Ankylosaurus magniventris reconstruction.png †[[Ankylosaurus]]
 * †Ankylosaurus magniventris
 * †Anomalofusus – tentative report
 * Anomia
 * †Anomia tellinoides
 * Anona
 * †Anona robusta – tentative report
 * †Anthrotaxopsis
 * †Anthrotaxopsis tenuicaulis
 * Antrimpos
 * †Apatodonosaurus
 * †Apatodonosaurus grayi
 * †Apatosaurinae
 * †Apatosaurinae – type locality for genus – informal
 * Apatosaurus louisae by durbed.jpg †[[Apatosaurus]]
 * †Apatosaurus louisae
 * †Apatosaurus minimus
 * †Apeibopsis – tentative report
 * †Apeibopsis discolor
 * †Aploconodon – type locality for genus
 * †Aploconodon comoensis – type locality for species
 * Aporrhais
 * †Aporrhais biangulata
 * †Aquilina – type locality for genus
 * †Aquilina grossidentata – type locality for species
 * Aralia
 * †Aralia veatchii
 * †Araliaephyllum
 * †Araliaephyllum artocarpoides
 * Araucaria araucana cones.jpg [[Araucaria]]
 * †Araucarites
 * †Araucarites cuneatus – type locality for species
 * †Araucarites longifolia
 * †Araucarites wyomingensis – type locality for species
 * Arca – report made of unidentified related form or using admittedly obsolete nomenclature
 * †Arcellites
 * †Arcellites disciformis
 * †Archaeotriakis
 * †Archaeotriakis ornatus – type locality for species
 * †Archaeotriakis rochelleae
 * †Archaeotrigon – type locality for genus
 * †Archaeotrigon brevimaxillus – type locality for species
 * Arcticoceras.jpg †[[Arcticoceras]]
 * †Arenicolites
 * †Aristolochites
 * †Aristolochites brittoni
 * †Ascarinites – type locality for genus
 * †Ascarinites communis – type locality for species
 * Aspideretes
 * †Aspideretoides
 * †Aspideretoides foveatus – or unidentified comparable form
 * †Asplenites
 * †Asplenites tenellum
 * Asplenium trichomanes subsp quadrivalens.jpg †[[Asplenium]]
 * †Asplenium haguei
 * †Asplenium neomexicanum
 * †Asplenium occidentale
 * †Astandes
 * †Astandes densatus
 * †Astarta
 * †Astarta packardi
 * Astarte
 * †Astarte gregaria
 * †Astarte livingstonensis
 * †Astarte meeki
 * †Astarte morion
 * †Athrotaxopsis
 * †Athrotaxopsis tenuicaulis
 * † Atira – tentative report
 * †Atira nebrascensis
 * †Atokatheridium – or unidentified comparable form
 * Aublysodon.jpg †[[Aublysodon]]
 * †Aublysodon mirandus
 * †Austrotindaria
 * †Austrotindaria antiqua
 * †Austrotindaria canalensis
 * †Austrotindaria svalbardensis
 * †Avernalia – type locality for genus
 * †Avernalia solida – type locality for species

B

 * Baculites grandis shell.JPG †[[Baculites]]
 * †Baculites asper
 * †Baculites asperiformis
 * †Baculites baculus
 * †Baculites clinolobatus
 * †Baculites cobbani
 * †Baculites codyensis
 * †Baculites crickmayi
 * †Baculites elaisi
 * †Baculites eliasi
 * †Baculites gilberti
 * †Baculites grandis
 * †Baculites gregoryensis
 * †Baculites haresi
 * †Baculites jenseni – or unidentified comparable form
 * †Baculites mariasensis
 * †Baculites mclearni
 * †Baculites obtusus
 * †Baculites perplexus
 * †Baculites reesidei
 * †Baculites rugosus
 * †Baculites scotti
 * †Baena
 * †Baena hatcheri – type locality for species
 * †Baena hayi – type locality for species
 * †Baena marshi – type locality for species
 * †Baieropsis
 * †Baieropsis adiantifolia
 * †Baieropsis pluripartita
 * †Baptanodon
 * †Baptanodon discus
 * †Baptanodon reedi – type locality for species
 * †Baptanodon robustus – type locality for species
 * Barbatia – tentative report
 * Barosaurus lentus1.jpg †[[Barosaurus]]
 * †Barosaurus lentus
 * †Basilemys
 * †Basilemys sinuosa
 * †Batodon
 * †Batodon tenuis – type locality for species
 * †Belonostomus
 * †Belonostomus longirostris
 * Berenicea
 * Bombur
 * †Borealosuchus
 * †Borealosuchus sternbergii – type locality for species
 * †Boremys
 * †Borissiakoceras
 * †Borissiakoceras orbiculatum
 * Botula
 * †Botula ripleyana
 * Blindshark.jpg [[Brachaelurus]]
 * †Brachaelurus bighornensis – type locality for species
 * †Brachiosaurus
 * †Brachybrachium – type locality for genus
 * †Brachybrachium brevipes – type locality for species
 * †Brachychampsa
 * †Brachychampsa montana
 * †Brachyphyllum
 * †Brachyphyllum crassum
 * †Brontopodus – or unidentified comparable form
 * †Brontopodus birdi
 * Brontosaurus NT small.jpg †[[Brontosaurus]] – type locality for genus
 * †Brontosaurus excelsus – type locality for species
 * †Brontosaurus parvus – type locality for species
 * †Brontosaurus yahnahpin – type locality for species
 * †Bryceomys
 * †Bullopsis
 * †Bullopsis cretacea – or unidentified related form

C

 * †Cadoceras
 * Callista
 * †Callista deweyi
 * †Callista peplucida
 * †Calycoceras
 * †Calycoceras canitaurinum
 * Camarasaurs1.jpg †[[Camarasaurus]] – type locality for genus
 * †Camarasaurus grandis – type locality for species
 * †Camarasaurus lentus – type locality for species
 * †Camborygma
 * Campeloma
 * †Camptomus
 * †Camptomus amplus – type locality for species
 * †Camptonectes
 * †Camptonectes bellistriatus
 * †Camptonectes distans – or unidentified comparable form
 * †Camptonectes platessiformis
 * †Camptonectes stygius
 * Camptosaurus.jpg †[[Camptosaurus]]
 * †Camptosaurus dispar – type locality for species
 * † Canna
 * †Canna magnifolia – tentative report
 * †Capillirhynchia
 * †Capillirhynchia gallatinensis – type locality for species
 * Cardium sp.
 * †Carpites
 * †Carpites lancensis
 * †Carpites verrucosus
 * †Carpites walcotti
 * †Carpolithus
 * †Carpolithus barrensis – type locality for species
 * †Carpolithus fasciculatus
 * †Carpolithus foenarius – type locality for species
 * †Carpolithus montiumnigrorum – type locality for species
 * †Carpolithus virginiensis
 * †Carthaginites
 * †Carthaginites aquilonius – type locality for species
 * †Cataceramus
 * †Cataceramus tenuilineatus
 * †Cedrobaena
 * †Cedrobaena brinkman
 * †Celastrophyllum
 * †Celastrophyllum gyminaefolium
 * Celastrus scandens.jpg †[[Celastrus]] – tentative report
 * †Celastrus taurinensis
 * †Cemeterius – type locality for genus
 * †Cemeterius monstrosus – type locality for species
 * †Centrophoroides
 * †Centrophoroides worlandensis – type locality for species
 * †Cephalotaxopsis
 * †Cephalotaxopsis magnifolia
 * †Ceramornis – type locality for genus
 * †Ceramornis major – type locality for species
 * †Ceratodus
 * †Ceratodus frazieri
 * †Ceratodus guentheri
 * Ceratosaurus nasicornis DB.jpg †[[Ceratosaurus]]
 * Cercidiphyllum
 * †Cercidiphyllum arcticum
 * †Cercidiphyllum ellipticum
 * †Cercomya
 * †Cercomya punctata
 * †Ceritella
 * Cerithium – tentative report
 * †Chamops – type locality for genus
 * †Chamops segnis – type locality for species
 * Champsosaurus BW.jpg †[[Champsosaurus]]
 * †Champsosaurus natator
 * †Chelonipus – or unidentified comparable form
 * Chiloscyllium
 * †Chiloscyllium missouriense
 * †Chirotherium
 * †Chirotherium barthii
 * Chlamys
 * †Chlamys nebrascensis
 * †Chondroceras
 * †Cimexomys
 * †Cimexomys minor
 * †Cimolestes
 * †Cimolestes incisus – type locality for species
 * †Cimolestes stirtoni – type locality for species
 * †Cimolodon
 * †Cimolodon nitidus – type locality for species
 * †Cimolodon peregrinus – type locality for species
 * Ptilodus.jpg †[[Cimolomys]]
 * †Cimolomys clarki
 * †Cimolomys gracilis – type locality for species
 * †Cimolomys parvus – type locality for species
 * †Cimolopteryx
 * †Cimolopteryx maxima – type locality for species
 * †Cimolopteryx rara
 * Cinnamomum
 * †Cinnamomum hesperium
 * †Cissitis
 * †Cissitis rocklandensis
 * Cissus
 * †Cissus lobato-crenata – tentative report
 * †Cladoceramus
 * †Cladoceramus undulatoplicatus – or unidentified related form
 * Cladophlebis fossil cropped.png [[Cladophlebis]]
 * †Cladophlebis parva
 * †Cladophlebis readi – type locality for species
 * †Cladophlebis readii
 * †Cladophlebis wyomingensis – type locality for species
 * †Claraia
 * †Claraia clarai
 * †Claraia mulleri
 * †Claraia stachei
 * †Clemensodon – type locality for genus
 * †Clemensodon megaloba – type locality for species
 * †Clioscaphites
 * †Clioscaphites saxitonianus
 * †Clioscaphites vermiformis
 * †Coahuilites
 * †Coahuilites sheltoni
 * †Coelostylina
 * †Coelosuchus – type locality for genus
 * †Coelosuchus reedii – type locality for species
 * Coelurus.jpg †[[Coelurus]] – type locality for genus
 * †Coelurus fragilis – type locality for species
 * †Collignoniceras
 * †Collignoniceras woollgari
 * †Colpodontosaurus – type locality for genus
 * †Colpodontosaurus cracens – type locality for species
 * †Comobatrachus – type locality for genus
 * †Comobatrachus aenigmaticus – type locality for species
 * †Comodactylus – type locality for genus
 * †Comodactylus ostromi – type locality for species
 * †Comodon – type locality for genus
 * †Comodon gidleyi – type locality for species
 * †Comonecturoides – type locality for genus
 * †Comonecturoides marshi – type locality for species
 * †Comotherium – type locality for genus
 * †Comotherium richi – type locality for species
 * †Compsemys
 * †Compsemys victa
 * †Confusionella
 * †Confusionella loczyi – type locality for species
 * Coniophis Marsh 1892.png †[[Coniophis]] – type locality for genus
 * †Coniophis precedens – type locality for species
 * †Coniopteris – tentative report
 * †Contogenys – or unidentified comparable form
 * †Corax
 * †Corbicella – tentative report
 * Corbula
 * †Corbula crassimarginata
 * †Corbula kanabensis
 * †Corbula munda
 * †Coriops
 * †Coriops amnicolus
 * †Cornophyllum
 * †Cornophyllum wardii
 * Corosaurus.png †[[Corosaurus]]
 * †Corosaurus alcovensis
 * Cossmannea
 * Crassatella
 * †Crassatella evansi
 * †Crassidenticulum
 * †Crassidenticulum aquilae – type locality for species
 * †Crassidenticulum decurrens
 * Crenella
 * †Cretorectolobus
 * †Cretorectolobus olsoni
 * †Cryptometoicoceras – type locality for genus
 * †Cryptometoicoceras mite – type locality for species
 * †Cryptorhytis
 * †Cryptorhytis cheyennensis
 * †Ctenacodon – type locality for genus
 * †Ctenacodon laticeps – type locality for species
 * †Ctenacodon scindens – type locality for species
 * †Ctenacodon serratus – type locality for species
 * †Cteniogenys – type locality for genus
 * †Cteniogenys antiquus – type locality for species
 * †Ctenostreon
 * †Ctenostreon gikshanensis – or unidentified comparable form
 * Cucullaea labiata 3.JPG [[Cucullaea]]
 * †Cucullaea haguei
 * †Cucullaea shumardi
 * †Cunningtoniceras
 * Cuspidaria
 * †Cuspidaria variablis
 * †Cycadeospermum
 * †Cycadeospermum rotundatum
 * †Cyclurus
 * †Cyclurus fragosus
 * †Cylindricum
 * †Cymbophora
 * †Cymbophora canonensis – or unidentified comparable form
 * †Cymbophora formosa
 * †Cymbophora holmesi
 * †Cyperacites
 * †Czekanowskia
 * †Czekanowskia nervosa

D

 * †Dakotasaurus – type locality for genus
 * †Dakotasaurus browni – type locality for species
 * †Daspletosaurus
 * Deinonychus_ewilloughby.png †[[Deinonychus]]
 * †Deinonychus antirrhopus
 * †Delphodon
 * †Delphodon comptus – type locality for species
 * †Deltatheroides – or unidentified comparable form
 * †Dennstaedtia
 * †Dennstaedtia fremonti
 * Dentalium
 * †Dentalium gracile
 * †Dentalium pauperculum
 * †Derrisemys
 * †Derrisemys sterea
 * Desmatosuchus spurensis.jpg with an anachronistic human to scale]] †Desmatosuchus''
 * †Desmoscaphites
 * †Desmoscaphites bassleri
 * †Dewalquea
 * †Dewalquea pulchella
 * †Diastopora
 * †Diastopora cutleri – type locality for species
 * †Dicellonema
 * †Dicellonema abrekensis
 * †Dicotyledon
 * Didelphodon NT small.jpg †[[Didelphodon]]
 * †Didelphodon vorax – type locality for species
 * †Didymoceras
 * †Didymoceras nebrascense
 * †Didymoceras stevensoni
 * †Dillenites
 * †Dillenites cleburni
 * †Dinochelys
 * †Dinochelys whitei
 * †Diospyros
 * †Diospyros stenosepala
 * †Diploconcha
 * †Diplocraterion
 * †Diplodocinae
 * †Diplodocinae – type locality for genus – informal
 * Diplodocus carnegii.jpg †[[Diplodocus]]
 * †Diplodocus carnegii – type locality for species
 * †Diplodocus hallorum
 * †Diplodocus longus
 * †Discoscaphites
 * †Docodon – type locality for genus
 * †Docodon affinis – type locality for species
 * †Docodon crassus – type locality for species
 * †Docodon striatus – type locality for species
 * †Docodon superus – type locality for species
 * †Docodon victor – type locality for species
 * †Dolichobrachium – type locality for genus
 * †Dolichobrachium gracile – type locality for species
 * Dolichorhynchops.jpg †[[Dolichorhynchops]]
 * †Dolichorhynchops osborni
 * †Dombeyopsis
 * †Dombeyopsis colgatensis
 * †Dombeyopsis obtusa
 * †Dombeyopsis platanoides
 * †Dombeyopsis trivialis
 * †Doratodon – tentative report
 * †Dorsetisaurus
 * †Dosiniopsis
 * †Dosiniopsis deweyi
 * †Drepanocheilus
 * †Drepanocheilus evansi
 * †Drepanocheilus nebrascensis
 * †Drepanocheilus obesus
 * †Drepanocheilus scotti – or unidentified comparable form
 * †Drinker – type locality for genus
 * †Drinker nisti – type locality for species
 * Dromaeosaurus Restoration.png †[[Dromaeosaurus]]
 * †Dryandroides
 * †Dryandroides lanceolata
 * †Dryolestes – type locality for genus
 * †Dryolestes priscus – type locality for species
 * †Dryolestes vorax
 * †Dryophyllum – type locality for genus
 * †Dryophyllum lanceolatum
 * †Dryophyllum polymorphum – type locality for species
 * †Dryophyllum subfalcatum
 * Dryopteris
 * †Dryopteris coloradensis
 * †Dryosaurus
 * †Dryosaurus altus – type locality for species
 * †Dryptosaurus – or unidentified comparable form
 * †Dunveganoceras
 * †Dunveganoceras pondi
 * †Dunveganoceras problematicum
 * †Dyslocosaurus – type locality for genus
 * †Dyslocosaurus polyonychius – type locality for species

E

 * †Echidnocephalus – tentative report
 * †Edmontonia
 * †Edmontonia rugosidens – or unidentified comparable form
 * †Edmontosaurus
 * Anatotitan BW.jpg †[[Edmontosaurus annectens]] – type locality for species
 * †Egertonodus
 * †Elaphrosaurus – tentative report
 * †Elasmosaurus
 * †Elatides
 * †Ellipsoscapha
 * †Ellipsoscapha occidentalis
 * †Emarginachelys
 * †Empo
 * †Enneabatrachus – type locality for genus
 * †Enneabatrachus hechti – type locality for species
 * Entalis
 * †Entalis paupercula – tentative report
 * †Entalophora
 * †Entalophora stokesi – type locality for species
 * †Eobatrachus – type locality for genus
 * †Eobatrachus agilis – type locality for species
 * †Eocephalites
 * †Eocephalites primus
 * †Eokainaster – type locality for genus
 * †Eokainaster pewei
 * Eopelobates wagneri 34.JPG †[[Eopelobates]]
 * †Equisetites
 * †Equisetum
 * †Equisetum FF014 – informal
 * †Equisetum RS016 – informal
 * †Equisetum virginicum
 * †Essonodon
 * †Essonodon browni
 * †Estescincosaurus – type locality for genus
 * †Estescincosaurus cooki – type locality for species
 * †Eubaena – type locality for genus
 * †Eubaena cephalica – type locality for species
 * Eubostrychoceras japonicum.jpg †[[Eubostrychoceras]]
 * †Eubostrychoceras matsumotoi – type locality for species
 * †Eubrachiosaurus – type locality for genus
 * †Eubrachiosaurus browni – type locality for species
 * †Eucalycoceras
 * †Eucalycoceras templetonense
 * †Eucrossorhinus
 * †Eucrossorhinus microcuspidatus
 * †Eumorphotis
 * †Eumorphotis multiformis
 * †Euomphaloceras
 * †Euomphaloceras merewetheri
 * †Eurysalenia
 * †Eurysalenia minima
 * †Euspira
 * †Euspira obliquata
 * †Euthlastus – type locality for genus
 * †Euthlastus cordiformis – type locality for species
 * Eutrephoceras dekayi - Coon Creek Tennessee.jpg †[[Eutrephoceras]]
 * †Eutrephoceras montanaense
 * †Eutretauranosuchus
 * †Eutretauranosuchus delfsi
 * †Exiteloceras
 * †Exiteloceras jenneyi
 * †Exogyra
 * †Exogyra costata
 * †Exostinus – type locality for genus
 * †Exostinus lancensis – type locality for species

F

 * †Falepetrus
 * †Falepetrus barwini – type locality for species
 * Fasciolaria tulipa.png [[Fasciolaria]]
 * †Fasciolaria flexicostata – tentative report
 * †Feistmantelia – type locality for genus
 * †Feistmantelia oblonga – type locality for species
 * †Ficophyllum
 * †Ficophyllum serratum
 * Ficus
 * †Ficus fremonti
 * †Ficus Fremontii
 * †Ficus inaequalis
 * †Ficus paryearensis
 * †Ficus planicosta
 * †Ficus planicostata
 * †Ficus rockvalensis
 * †Ficus trinervis
 * †Filicites
 * †Filicites knowltoni
 * †Forresteria
 * †Forresteria stantoni
 * Fosterovenator.png †[[Fosterovenator]] – type locality for genus
 * †Fosterovenator churei – type locality for species
 * †Foxraptor – type locality for genus
 * †Foxraptor atrox – type locality for species
 * †Fraxinus
 * †Fraxinus denticulata
 * †Fraxinus leii

G

 * Galeamopus hayi AMNH 969.jpg †[[Galeamopus]]
 * †Galeamopus hayi
 * †Galeamopus pabsti – type locality for species
 * †Gargoyleosaurus
 * †Gargoyleosaurus parkpinorum
 * †Geinitzia
 * †Geinitzia Jenneyi – type locality for species
 * †Geonomites
 * †Geonomites schimperi
 * Gerrhonotus – or unidentified comparable form
 * †Gervillaria
 * †Gervillaria montanaensis
 * †Gervillia
 * †Gervillia dolabrata
 * †Gervillia ussurica – or unidentified comparable form
 * †Gilmoremys
 * †Gilmoremys lancensis – type locality for species
 * Ginglymostoma
 * †Ginglymostoma globidens
 * Ginkgo biloba MacAbee BC.jpg [[Ginkgo]]
 * †Ginkgo adiantoides – tentative report
 * †Glasbius
 * †Glasbius intricatus – type locality for species
 * †Gleichenites
 * †Gleichenites sepulta
 * †Glyptops – type locality for genus
 * †Glyptops pervicax
 * †Glyptops plicatulus – type locality for species
 * Glyptostrobus
 * †Glyptostrobus brookensis
 * Gobiconodon ostromi.JPG †[[Gobiconodon]]
 * †Gobiconodon ostromi
 * †Goniomya
 * †Goniomya montanaensis
 * †Goniopholis
 * †Gracilimanus
 * †Gracilimanus obscurus
 * †Grammatodon
 * †Grammatodon haguei
 * †Graphidula
 * †Graphidula alleni – or unidentified comparable form
 * GryphaeaCretaceousTexas.jpg]] †Graphidula culbertsoni''
 * †Grewiopsis
 * †Grewiopsis saportana
 * †Gryphaea
 * †Gryphaea nebrascensis
 * †Gryphaea planoconvexa
 * †Gypsonictops
 * †Gypsonictops hypoconus – type locality for species
 * †Gypsonictops lewisi
 * †Gypsonicus
 * †Gypsonicus wyomingensis

H

 * †Habrosaurus – type locality for genus
 * †Habrosaurus dilatus – type locality for species
 * †Hadrosauropodus
 * †Halymenites
 * †Halymenites major
 * †Hamites
 * †Hamites cimarronensis
 * †Hamites novimexicanus
 * †Hamites salebrosus
 * Haplocanthosaurus.jpg †[[Haplocanthosaurus]]
 * †Haptosphenus – type locality for genus
 * †Haptosphenus placodon – type locality for species
 * †Haresiceras
 * †Haresiceras natronense
 * †Harpactognathus – type locality for genus
 * †Harpactognathus gentryii – type locality for species
 * †Hatcheritherium – type locality for genus
 * †Hatcheritherium alpha – type locality for species
 * †Hausmannia
 * †Hausmannia AF017
 * †Helopanoplia
 * †Helopanoplia distincta
 * Hemiaster
 * †Hemiaster humphreysanus
 * Hepta Skel.jpg †[[Heptasuchus]] – type locality for genus
 * †Heptasuchus clarki – type locality for species
 * †Herpetarius
 * †Herpetarius humilis
 * †Hesperornithoides – type locality for genus
 * †Hesperornithoides miessleri – type locality for species
 * †Hesperosaurus – type locality for genus
 * †Hesperosaurus mjosi – type locality for species
 * †Heteroceras
 * †Heteroceras cochleatum – tentative report
 * †Homomya
 * †Homomya gallatinensis
 * †Hoploscaphites
 * †Hoploscaphites birkelundae – type locality for species
 * †Hoploscaphites gilli
 * †Hoploscaphites macer
 * †Hoploscaphites nodosus
 * †Hoploscaphites plenus
 * †Hoploscaphites quadrangularis
 * †Hummelichelys
 * †Hummelichelys beecheri – type locality for species
 * Hyperodapedon BW2.jpg]] †Hybodus''
 * †Hybodus montanensis
 * †Hybodus wyomingensis – type locality for species
 * †Hyperodapedon
 * †Hyperodapedon sanjuanensis – or unidentified comparable form
 * †Hypotodus
 * †Hypotodus grandis
 * †Hypsodon – tentative report
 * †Hypsodon radiatulus

I

 * Ichthyodectes_ctenodon.jpg †[[Ichthyodectes]]
 * †Icthyodectes – tentative report
 * †Icthyodesctes – tentative report
 * †Idiohamites
 * †Idiohamites bispinosus
 * †Iguanavus
 * †Iguanavus teres – type locality for species
 * Inoceramus steenstrup, world's largest fossil mollusk.jpg †[[Inoceramus]]
 * †Inoceramus agdjakendensis – or unidentified comparable form
 * †Inoceramus americanus – type locality for species
 * †Inoceramus anglicus
 * †Inoceramus balchii
 * †Inoceramus barabini
 * †Inoceramus crispii
 * †Inoceramus deformis
 * †Inoceramus dimidius
 * †Inoceramus erectus – or unidentified related form
 * †Inoceramus fibrosus
 * †Inoceramus fragilis – or unidentified related form
 * †Inoceramus gibbosus
 * †Inoceramus glacierensis
 * †Inoceramus grandis
 * †Inoceramus incurvus
 * †Inoceramus lundbreckensis
 * †Inoceramus perplexus
 * †Inoceramus prefragilis
 * †Inoceramus proximus – or unidentified related form
 * †Inoceramus sagensis
 * †Inoceramus subcircularis
 * †Inoceramus subcompressus
 * †Inoceramus sublaevis
 * †Inoceramus tenuirostratus
 * †Inoceramus tenuiumbonatus – or unidentified comparable form
 * †Inoceramus turgidus – or unidentified related form
 * †Inoceramus typicus
 * †Inoceramus umbonatus
 * †Inoceramus undabundus
 * †Ischyrhiza
 * Pteriidae - Isognomon maxillatus.JPG]] †Ischyrhiza avonicola'' – type locality for species
 * †Ischyrhiza basinensis – type locality for species
 * †Ischyrhiza mira
 * Isocrinus
 * †Isocrinus knighti
 * †Isocrinus wyomingensis
 * †Isocyprina
 * †Isocyprina cinnabarensis
 * Isognomon
 * †Isognomon perplana – or unidentified comparable form
 * Isurus – tentative report

J



 * †Janumys
 * †Jeletzkytes
 * †Jeletzkytes dorfi – type locality for species
 * †Jensensispermum
 * †Judithemys
 * †Judithemys backmani

K



 * †Kaatedocus – type locality for genus
 * †Kaatedocus siberi – type locality for species
 * †Koskinonodon – type locality for genus
 * †Koskinonodon perfectus – type locality for species

L

 * †Lamarqueavis
 * †Lamarqueavis minima – type locality for species
 * †Lamarqueavis petra – type locality for species
 * †Lamiasaura – type locality for genus
 * †Lamiasaura ferox – type locality for species
 * †Lanceosaurus – type locality for genus
 * †Lanceosaurus compressus – type locality for species
 * †Lanceosaurus hatcheri – type locality for species
 * †Laolestes – type locality for genus
 * †Laolestes eminens – type locality for species
 * †Laolestes goodrichi – type locality for species
 * †Laolestes oweni – type locality for species
 * †Laopteryx – type locality for genus
 * †Laopteryx priscus – type locality for species
 * †Laosaurus – type locality for genus
 * †Laosaurus celer – type locality for species
 * †Laurophyllum
 * †Laurophyllum coloradensis
 * †Laurophyllum meeki
 * †Laurophyllum salicifolium
 * †Laurophyllum wardiana
 * Laurus
 * †Laurus aspensis – type locality for species
 * †Lepidotes – or unidentified related form
 * Lepisosteus
 * †Lepisosteus occidentalis
 * †Leptalestes
 * †Leptalestes cooki – type locality for species
 * †Leptalestes krejcii
 * Leptoceratops BW.jpg †[[Leptoceratops]]
 * †Leptoceratops gracilis
 * †Leptochamops
 * †Leptochamops denticulatus – type locality for species
 * †Leptochamops thrinax
 * †Leptochondria
 * †Leptochondria occidanea
 * †Leptostrobus
 * †Leptostrobus alatus – type locality for species
 * †Leptostrobus longifolia
 * †Leptostrobus longifolius
 * †Lesterwardia – type locality for genus
 * †Lesterwardia palustris – type locality for species
 * †Leucichthyops
 * †Leucichthyops vagans
 * †Leucicthyops
 * †Leucicthyops vagans
 * Lima
 * †Lima occidentalis
 * Lingula
 * †Lingula nitida – or unidentified comparable form
 * †Lingularia
 * †Lingularia borealis
 * †Lioplacodes – or unidentified comparable form
 * †Liostrea
 * †Liostrea strigilecula
 * Liquidambar
 * †Liquidambar fontanella – type locality for species
 * †Lisserpeton
 * †Lisserpeton bairdi
 * Lissodus fossil cropped.png †[[Lissodus]]
 * †Lissodus griffisi – type locality for species
 * †Litakis – type locality for genus
 * †Litakis gilmorei – type locality for species
 * †Lonchidion – type locality for genus
 * †Lonchidion selachos – type locality for species
 * †Lonchisaurus – type locality for genus
 * †Lonchisaurus trichurus – type locality for species
 * †Lonchodytes – type locality for genus
 * †Lonchodytes estesi – type locality for species
 * †Lonchodytes pterygius – type locality for species
 * †Lophochelys
 * Euspira lewisii 3 cropped.jpg moon sea snail]] Lucina''
 * †Lucina mattiformis – or unidentified comparable form
 * †Lucina occidentalis
 * †Lucina subundata
 * Lunatia – tentative report
 * Lygodium
 * †Lygodium AF030 – informal
 * †Lyosoma
 * †Lyosoma powelli

M

 * Macelognathus vagans.jpg †[[Macelognathus]] – type locality for genus
 * †Macelognathus vagans – type locality for species
 * Mactra
 * †Mactra emmonsi
 * †Mactromya – tentative report
 * †Magadiceramus
 * †Magadiceramus soukupi
 * †Magadiceramus subquadratus
 * †Magnoliophyllum
 * †Magnoliophyllum cordatum
 * †Malapoenna
 * †Malapoenna weediana – tentative report
 * Malletia
 * †Malletia stephensoni
 * †Manihotites
 * †Manihotites georgiana
 * †Martinectes
 * †Martinectes bonneri – type locality for species
 * †Matonidium
 * †Matonidium Althaausii
 * †Matonidium Althausii
 * †Mecochirus
 * Megalneusaurus027 cropped.png †[[Megalneusaurus]]
 * †Megalneusaurus rex – type locality for species
 * †Megasphaeroceras
 * †Megasphaeroceras rotundum – or unidentified comparable form
 * †Meleagrinella
 * †Meleagrinella curta
 * †Melvius
 * †Melvius thomasi
 * †Meniscoessus
 * †Meniscoessus gracilis – type locality for species
 * †Meniscoessus intermedius
 * †Meniscoessus robustus – type locality for species
 * †Meniscoessus seminoensis – type locality for species
 * †Meniscognathus – type locality for genus
 * †Meniscognathus altmani – type locality for species
 * †Menispermites
 * †Menispermites belli
 * †Menispermites cockerelli
 * †Menispermites knightii
 * [[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 complexus
 * †Mesembrioxylon
 * †Mesodma
 * †Mesodma formosa
 * †Mesodma hensleighi
 * †Mesodma primaeva
 * †Mesodma thompsoni – type locality for species
 * †Metaptychoceras
 * †Metoicoceras
 * †Metoicoceras geslinianum
 * †Metoicoceras mosbyense – or unidentified comparable form
 * †Metoicoceras praecox
 * †Micrabacia
 * †Micrabacia radiata
 * †Microtaenia
 * †Microtaenia paucifolia
 * †Microtaenia variabilis
 * Microvenator.jpg †[[Microvenator]]
 * †Microvenator celer
 * †Minerisporites
 * †Minerisporites pseudorichardsonii
 * Modiolus
 * †Modiolus meekii
 * †Modiolus subimbricatus
 * †Montania – type locality for genus
 * †Montania glandulosa – type locality for species
 * †Moremanoceras
 * †Moremanoceras costatum
 * †Moremanoceras scotti
 * †Moriconia
 * †Moriconia cyclotoxon
 * †Morosaurus
 * †Myalina
 * †Myalina postcarbonica
 * †Myledaphus
 * †Myledaphus bipartitus
 * Myophorella-1.jpg †[[Myophorella]]
 * †Myophorella yellowstonensis
 * Myrica
 * †Myrica bolanderi – tentative report
 * †Myrica nervosa
 * †Myrtophyllum
 * †Myrtophyllum torreyi
 * †Mytiloides
 * †Mytiloides stantoni
 * †Mytilus
 * †Mytilus whitei

N

 * †Nageiopsis
 * †Nageiopsis angustifolia
 * †Nageiopsis longifolia
 * †Nanocuris
 * †Nanocuris improvida
 * †Nanomyops
 * †Nanosaurus
 * †Nanosaurus rex
 * †Nanotyrannus – tentative report
 * †Naomichelys
 * †Naomichelys speciosa
 * American Lotus (Nelumbo lutea) 01.jpg †[[Nelumbo]]
 * †Nelumbo weymouthi – type locality for species
 * †Nelumbo weymouthii
 * †Nemocardium
 * †Nemocardium parahillanum
 * †Nemodon
 * †Nemodon eufalensis
 * †Nemodon grandis
 * †Neocardioceras
 * †Neocardioceras laevigatum – type locality for species
 * †Neocardioceras minutum – type locality for species
 * †Neocardioceras transiens
 * †Neocardioceras uptonense – type locality for species
 * †Neogastroplites
 * †Neogastroplites wyomingensis
 * †Neonereites – or unidentified comparable form
 * †Neonereites biserialis
 * †Neoplagiaulax
 * †Neoschizodus
 * †Neoschizodus laevigatus
 * †Nerinea – tentative report
 * †Neurankylus
 * †Neurankylus wyomingensis – type locality for species
 * †Nilsonia
 * †Nilsonia mehli
 * †Nilsonia nigricollensis
 * Nodosaria
 * Nodosaurus textilis.jpg †Nodosaurus – type locality for genus
 * †Nodosaurus textilis – type locality for species
 * †Nonactaeonina
 * †Nonactaeonina attenuata
 * †Normannites – tentative report
 * †Normannites crickmayi – or unidentified comparable form
 * †Nortedelphys
 * †Nortedelphys jasoni
 * †Nortedelphys magnus
 * †Nortedelphys minimus
 * Nuculidae - Nucula piacentina.jpg [[Nucula]]
 * †Nucula cancellata
 * †Nucula nacatochana
 * †Nucula planimarginata
 * Nuculana
 * †Nuculana bisulcata
 * †Nuculana corsicana
 * †Nuculana equilateralis – tentative report
 * †Nuculana evansi
 * †Nuculana pittensis
 * †Nymphaeites
 * †Nymphaeites dawsoni

O

 * †Obamadon
 * †Obamadon gracilis
 * †Obnixia – type locality for genus
 * †Obnixia thaynesiana
 * †Odaxosaurus – type locality for genus
 * †Odaxosaurus piger – type locality for species
 * Odontaspis ferox 3.jpg [[Odontaspis]]
 * †Odontaspis cheathami – type locality for species
 * †Odontaspis steineri – type locality for species
 * †Oklatheridium
 * †Oklatheridium wiblei
 * †Oligoptycha
 * †Oligoptycha concinna
 * †Omasaria
 * †Onoclea
 * †Onoclea minima
 * †Opertochasma
 * †Ophiopsis
 * †Ophthalmosaurus
 * †Ophthalmosaurus natans
 * †Opisthias
 * †Opisthias rarus – type locality for species
 * †Opisthotriton
 * †Opisthotriton kayi
 * Ornitholestes mount at Royal Tyrrell Museum.jpg †[[Ornitholestes]] – type locality for genus
 * †Ornitholestes hermanni – type locality for species
 * †Ornithomimus
 * †Ornithomimus minutus
 * †Ornithomimus sedens – type locality for species
 * †Ornithomimus velox – or unidentified comparable form
 * †Orthotrigonia
 * †Orthotrigonia sohli – tentative report
 * †Osmakasaurus – tentative report
 * †Osmakasaurus depressus
 * Fighting Othnielia.jpg]] Ostrea''
 * †Ostrea inornata
 * †Othnielia
 * †Othnielosaurus
 * †Othnielosaurus consors – type locality for species
 * †Oxybeloceras
 * †Oxybeloceras crassum
 * †Oxytoma
 * †Oxytoma nebrascana

P

 * Pachycephalosaurus wyomingensis dinosaur (Upper Cretaceous; Montana, USA).jpg †[[Pachycephalosaurus]]
 * †Pachycephalosaurus wyomingensis – type locality for species
 * †Pachyrhizodus
 * †Pachyteuthis
 * †Pachyteuthis densus
 * †Palaeoaster
 * †Palaeoaster inquirenda
 * †Palaeobatrachus
 * †Palaeobatrachus occidentalis – type locality for species
 * †Palaeocypraea
 * †Palaeocypraea squyeri – type locality for species
 * †Palaeosaniwa – type locality for genus
 * †Palaeosaniwa canadensis – type locality for species
 * †Paleoaster
 * †Paleoaster inquirenda
 * †Paleopsephurus
 * †Paleopsephurus wilsoni
 * †Paleorhinus
 * †Paleorhinus parvus – type locality for species
 * †Paliurus
 * †Paliurus minimus
 * †Paliurus zizyphoides – tentative report
 * †Pantosaurus – type locality for genus
 * †Pantosaurus striatus – type locality for species
 * †Parachondroceras
 * †Parachondroceras andrewsi
 * †Parachondroceras filicostatum
 * †Paracimexomys
 * †Paracimexomys priscus
 * †Paracredneria
 * †Paracredneria cretacea – type locality for species
 * †Paraderma – type locality for genus
 * †Paraderma bogerti – type locality for species
 * †Paradiscoglossus – type locality for genus
 * †Paradiscoglossus americanus – type locality for species
 * †Paralbula
 * †Paralbula casei
 * †Paramacellodus
 * †Paramacellodus keebleri
 * †Paranymphaea
 * †Paranymphaea hastata
 * †Parasaniwa – type locality for genus
 * †Parasaniwa wyomingensis – type locality for species
 * †Parastomechinus
 * †Parastomechinus brightoni
 * Paleorhinus.jpg †[[Parasuchus]]
 * †Parasuchus bransoni – type locality for species
 * †Paressonodon
 * †Paressonodon nelsoni
 * †Pariguana – type locality for genus
 * †Pariguana lancensis – type locality for species
 * †Parikimys
 * †Parikimys carpenteri
 * †Parmicorbula
 * †Parmicorbula bisulcata
 * †Paronychodon
 * †Paronychodon lacustris – type locality for species
 * †Parvodus
 * †Paurodon – type locality for genus
 * †Paurodon valens – type locality for species
 * †Pecopteris
 * †Pecopteris borealis
 * †Pecopteris Geyleriana
 * Pecten
 * †Pecten nebrascensis
 * Pectinodon.png †[[Pectinodon]] – type locality for genus
 * †Pectinodon bakkeri – type locality for species
 * †Pediomys
 * †Pediomys elegans – type locality for species
 * †Pentacrinus
 * †Permophorus
 * †Permophorus triassicus – type locality for species
 * Persea – report made of unidentified related form or using admittedly obsolete nomenclature
 * †Persea hayana
 * †Petalolepis – tentative report
 * †Petalolepis fibrillatus
 * †Phlycticrioceras
 * †Phlycticrioceras trinodosus
 * †Phoenicites – or unidentified comparable form
 * Pholadomyidae - Pholadomya scutata.JPG [[Pholadomya]]
 * †Pholadomya inaequiplicata
 * †Pholadomya kingi
 * †Phragmites
 * †Phragmites falcata
 * †Phyllites
 * †Phyllites crassipes
 * †Phyllites cretaceous
 * †Phyllites dentata
 * †Phyllites ficifolius
 * †Phyllites grandifolius-cretaceous
 * Phyllodus
 * †Phyllodus toliapicus
 * Physa marmorata.png]] Physa'' – or unidentified comparable form
 * †Piceoerpeton
 * †Piceoerpeton naylori
 * Pinna
 * †Pinna kingi
 * Pinus
 * †Pinus susquaensis
 * Pistacia
 * †Pistacia eriensis
 * †Pistia
 * †Pistia corrugata
 * Placenticeras meeki.jpg †[[Placenticeras]]
 * †Placenticeras intercalare
 * †Placenticeras meeki
 * †Placenticeras pseudoplacenta
 * †Plagiostoma
 * †Plagiostoma occidentalis
 * Planorbis
 * †Plastomenus
 * †Platacodon – type locality for genus
 * †Platacodon nanus – type locality for species
 * †Platanites
 * †Platanites marginata
 * †Platanophyllum
 * †Platanophyllum montanum
 * †Platanophyllum platanoides
 * Platanus
 * †Platanus primaeva
 * Platecarpus2010.jpg †[[Platecarpus]]
 * †Platecarpus brachycephalus
 * †Platecarpus tympaniticus
 * †Platymya
 * †Platymya rockymontana
 * †Platypterygius
 * †Platypterygius americanus – type locality for species
 * †Plesiacanthoceras
 * †Plesiacanthoceras bellsanum – or unidentified comparable form
 * †Plesiacanthoceras wyomingense
 * †Plesiobaena
 * †Plesiobaena antiqua
 * Plesiopleurodon2DB.jpg †[[Plesiopleurodon]] – type locality for genus
 * †Plesiopleurodon wellesi – type locality for species
 * †Plesiosaurus
 * †Plesiosaurus shirleyensis – type locality for species
 * †Pleuromya
 * †Pleuromya haydeniana – type locality for species
 * †Pleuromya subcompressa
 * †Plicatolamna
 * †Plicatolamna arcuata
 * Plicatula
 * Polinices
 * †Polinices concinna – or unidentified related form
 * †Polyacrodus
 * †Polyacrodus parvidens – or unidentified comparable form
 * †Polycotylus
 * Poposaurus gracilis (1).jpg †[[Poposaurus]] – type locality for genus
 * †Poposaurus gracilis – type locality for species
 * Populus
 * †Populus aspens
 * †Populus aspensis – type locality for species
 * †Porosoma
 * †Porosoma reesidei – type locality for species
 * †Portheus
 * †Postligata
 * †Postligata crenata
 * †Potamoceratodus
 * †Potamornis – type locality for genus
 * †Potamornis skutchi – type locality for species
 * †Powellia – type locality for genus
 * †Powellia oblongata – type locality for species
 * †Priacodon
 * †Priacodon ferox – type locality for species
 * †Priacodon grandaevus – type locality for species
 * †Priacodon lulli – type locality for species
 * †Priacodon robustus – type locality for species
 * †Prionocyclus
 * †Prionocyclus germari
 * †Prionocyclus hyatti
 * †Prionocyclus novimexicanus
 * †Prodesmodon – type locality for genus
 * †Prodesmodon copei – type locality for species
 * †Prodiplocynodon – type locality for genus
 * †Prodiplocynodon langi – type locality for species
 * †Promyalina
 * †Promyalina putiatinensis
 * †Promyalina spathi
 * †Pronoella
 * †Pronoella cinnabarensis
 * †Pronoella iddingsi – or unidentified comparable form
 * †Pronoella uintahensis
 * †Prorokia
 * †Prorokia fontenellensis
 * †Protalphadon
 * †Protalphadon lulli – type locality for species
 * †Protexanites
 * †Protexanites bourgeoisianus
 * †Protocardia
 * †Protocardia rara
 * †Protocardia schucherti – or unidentified comparable form
 * †Protolambda
 * †Protolambda florencae – type locality for species
 * †Protolambda hatcheri
 * †Protophyllocladus
 * †Protophyllocladus subintegrifolius
 * †Protophyllum
 * †Protoplatyrhina
 * †Protoplatyrhina renae
 * Protungulatum donnae cropped.jpg †[[Protungulatum]] – tentative report
 * Prunus
 * †Prunus aspensis – type locality for species
 * †Psalodon
 * †Psalodon fortis – type locality for species
 * †Psalodon marshi – type locality for species
 * †Psalodon potens – type locality for species
 * †Pseudoctenis
 * †Pseudoctenis AF013 – informal
 * †Pseudodontaspis – type locality for genus
 * †Pseudodontaspis herbsti – type locality for species
 * †Pseudoperna
 * †Pseudoperna congesta
 * †Pteraichnus
 * †Pteraichnus stokesi – type locality for species
 * Pteranodon longiceps mmartyniuk wiki.png †[[Pteranodon]]
 * †Pteranodon longiceps
 * †Pteria
 * †Pteria gastrodes
 * †Pteria linguaeformis
 * †Pteria linguiformis
 * †Pteria lingulaeformis
 * †Pteria ussurica – or unidentified comparable form
 * †Pterodactylus
 * †Pterodactylus montanus – type locality for species
 * †Ptilotodon
 * †Ptilotodon wilsoni
 * †Ptychodous
 * †Ptychotrygon
 * †Ptychotrygon boothi – type locality for species
 * †Ptychotrygon ellae – type locality for species
 * †Ptychotrygon greybullensis – type locality for species

Q

 * †Quenstedtia
 * †Quenstedtia sublevis
 * Eiche bei Schönderling, 2.jpg, or oak tree]] †Quenstedtia sublewis''
 * †Quercophyllum
 * †Quercophyllum gardneri
 * †Quercophyllum wyomingense – type locality for species
 * Quercus
 * †Quercus ellisiana
 * †Quercus stantoni
 * †Quercus stantonii
 * †Quercus viburnifolia
 * †Quereuxia
 * †Quereuxia angulata

R

 * †Raninella
 * †Reesidella
 * †Retinovena – type locality for genus
 * †Retinovena fluvialis – type locality for species
 * †Retispira
 * †Retispira bittneri
 * Rhabdocolpus – tentative report
 * †Rhaeboceras
 * †Rhaeboceras halli
 * †Rhaeboceras subglobosum
 * †Rhamnus
 * Richardoestesia.png]] †Rhamnus hirsuta''
 * †Rhamnus minutus
 * Rhinobatos
 * †Rhinobatos casieri
 * †Rhizocorallium
 * †Rhynchosauroides – type locality for genus
 * †Rhynchosauroides palmatus – type locality for species
 * †Richardoestesia
 * †Richardoestesia isosceles
 * †Ropalonaria
 * †Ropalonaria arachne
 * Rostellaria – tentative report
 * †Rotodactylus – or unidentified comparable form

S

 * †Sabalites
 * †Sabalites eocenica
 * †Sabalites montana
 * †Saccoloma – report made of unidentified related form or using admittedly obsolete nomenclature
 * †Saccoloma gardneri
 * †Saliciphyllum
 * †Saliciphyllum wyomingensis
 * Salix alba Morton.jpg [[Salix]]
 * †Salix cumberlandensis
 * †Salix frontierensis
 * †Salix lancensis
 * †Salpichlaena
 * †Salpichlaena AF003 – informal
 * †Sapindopsis
 * †Sapindopsis belviderensis
 * †Sapindopsis magnifolia
 * †Sapindopsis schultzi – type locality for species
 * †Sapindopsis schultzii
 * †Sapindopsis variabilis
 * †Sarjeantopodus – type locality for genus
 * †Sarjeantopodus semipalmatus – type locality for species
 * Sassafras7.jpg [[Sassafras]]
 * †Sassafras bradleyi – type locality for species
 * †Sassafras bradleyii
 * †Sassafras thermale
 * †Saurexallopus – type locality for genus
 * †Saurexallopus lovei – type locality for species
 * †Saurexallopus zerbsti – type locality for species
 * †Saurocephalus
 * †Saurolophus
 * †Sauropelta
 * †Sauropelta edwardsorum
 * Sauroposeidon Scale Diagram Steveoc86.svg †[[Sauroposeidon]]
 * †Sauroposeidon proteles
 * †Saurornithoides – or unidentified comparable form
 * †Saurornitholestes
 * †Sauvagesia
 * †Sauvagesia austinensis – or unidentified comparable form
 * †Scapanorhynchus
 * †Scapanorhynchus texanus
 * †Scapherpeton
 * †Scapherpeton tectum
 * SmallScaphites.jpg †[[Scaphites]]
 * †Scaphites aquilaensis
 * †Scaphites binneyi
 * †Scaphites hippocrepis
 * †Scaphites stantoni
 * †Scaphites ventricosus
 * †Scaphites whitfieldi
 * †Scleropteris
 * †Scleropteris distantifolia – type locality for species
 * †Scleropteris rotundifolia – type locality for species
 * †Scotiophryne
 * †Scotiophryne pustulosa
 * Scyliorhinus
 * †Scyliorhinus tensleepensis – type locality for species
 * †Selaginella
 * †Selaginella falcata – tentative report
 * †Semiungula – type locality for genus
 * †Semiungula assymetrica – type locality for species
 * Del Norte Titan 230 cropped.jpg [[Sequoia (genus)|Sequoia]]
 * †Sequoia cuneata
 * †Sequoia dakotensis
 * †Sequoia gracilia
 * †Sequoia gracilis
 * †Sequoia langsdorfii
 * †Sequoia reichenbachi
 * †Sequoia Reichenbachi
 * †Serrifusus
 * †Serrifusus dakotensis
 * †Skolithos
 * †Smilax
 * †Smilax coloradensis – tentative report
 * †Socognathus
 * †Socognathus brachyodon – type locality for species
 * †Sohlites
 * †Sohlites spinosus
 * †Sokophyllum – type locality for genus
 * †Sokophyllum dentatum – type locality for species
 * Solemya elarraichensis holotype.jpg [[Solemya]]
 * †Solemya bilix
 * †Solemya obscura
 * †Solenoceras
 * †Solyma
 * †Sparganium
 * †Sparganium aspens
 * †Sparganium aspensis – type locality for species
 * Sphaerium – or unidentified comparable form
 * †Sphenodiscus
 * †Sphenodiscus lobatus – or unidentified comparable form
 * †Sphenodiscus pleurisepta
 * †Sphenolepidium
 * †Sphenolepidium Kurrianum
 * †Sphenolepidium parceramosum
 * †Sphenopteris
 * †Sphenopteris plurinervia
 * †Spiroceras
 * †Spiroceras orbignyi – or unidentified comparable form
 * Squalicorax pristodontus Agassiz, 1843 1.jpg [[Squalicorax]]
 * †Squalicorax kaupi
 * †Squalicorax pristodontus
 * †Squatirhina
 * †Squatirhina americana – type locality for species
 * †Squatirhina roessingi – type locality for species
 * †Staphylea
 * †Staphylea fremonti
 * †Staphylea fremontii
 * †Stegopelta – type locality for genus
 * †Stegopelta landerensis – type locality for species
 * Stegosaurus stenops sophie wiki martyniuk.png †[[Stegosaurus]] – type locality for genus
 * †Stegosaurus affinis – type locality for species
 * †Stegosaurus armatus – type locality for species
 * †Stegosaurus longispinus – type locality for species
 * †Stegosaurus stenops
 * †Stegosaurus sulcatus – type locality for species
 * †Stegosaurus ungulatus – type locality for species
 * †Steinichnus
 * †Stemmatoceras
 * †Stemmatoceras albertense – or unidentified related form
 * Sterculia
 * †Sterculia mucronata
 * †Sterculia towneri
 * †Stokesosaurus – tentative report
 * †Stokesosaurus clevelandi
 * †Struthiomimus – or unidentified comparable form
 * Supersaurus NT crop.png with an anachronistic human to scale]] †Stygiochelys''
 * †Styxosaurus
 * †Styxosaurus browni – type locality for species
 * †Supersaurus
 * †Supersaurus vivianae
 * †Syncyclonema
 * †Syncyclonema rigida
 * †Synechodus
 * †Synechodus turneri – type locality for species

T

 * †Tancredia
 * †Tancredia transversa
 * Tanycolagreus topwilsoni.jpg †[[Tanycolagreus]] – type locality for genus
 * †Tanycolagreus topwilsoni – type locality for species
 * Tapeinidium
 * Tapeinidium undulatum – tentative report
 * †Tarrantoceras
 * †Tarrantoceras exile – type locality for species
 * †Tarrantoceras flexicostatum – type locality for species
 * †Tarrantoceras sellardsi
 * †Tatenectes
 * †Tatenectes laramiensis – type locality for species
 * †Tathiodon – type locality for genus
 * †Tathiodon agilis – type locality for species
 * †Telacodon
 * †Telacodon laevis – type locality for species
 * †Tenea
 * †Tenea circularis
 * Tenontosaurus BW.jpg †[[Tenontosaurus]]
 * †Tenontosaurus tilletti
 * Teredo
 * †Thalassinoides
 * †Theatonius – type locality for genus
 * †Theatonius lancensis – type locality for species
 * †Theretairus – type locality for genus
 * †Theretairus antiquus – type locality for species
 * Thescelosaurus filamented.jpg †[[Thescelosaurus]] – type locality for genus
 * †Thescelosaurus neglectus – type locality for species
 * †Thescelus
 * †Thescelus insiliens – type locality for species
 * †Thoracosaurus – or unidentified comparable form
 * Thracia
 * †Thracia weedi
 * Thyasira
 * Thyrsopteris elegans kz.jpg †[[Thyrsopteris]]
 * †Thyrsopteris brevifolia
 * †Thyrsopteris brevipennis
 * †Thyrsopteris crassinervis
 * †Thyrsopteris dentifolia – type locality for species
 * †Thyrsopteris elliptica
 * †Thyrsopteris pecopteroides
 * †Thyrsopteris pinnatifida
 * †Tinodon – type locality for genus
 * †Tinodon bellus – type locality for species
 * †Torosaurus – type locality for genus
 * †Torosaurus latus – type locality for species
 * †Torotix – type locality for genus
 * †Torotix clemensi – type locality for species
 * Museum AL dinosaur.jpg †[[Torvosaurus]] – type locality for genus
 * †Torvosaurus tanneri – type locality for species
 * †Trachodon
 * †Trachyscaphites
 * †Trachyscaphites redbirdensis
 * †Trachytriton
 * †Trachytriton vinculum
 * †Tragodesmoceras
 * †Tragodesmoceras carlilense
 * †Trapa
 * †Trapa microphylla
 * LA-Triceratops mount-2.jpg †[[Triceratops]] – type locality for genus
 * †Triceratops horridus – type locality for species
 * †Triceratops ingens – type locality for species
 * †Triceratops prorsus – type locality for species
 * †Triceratops sulcatus – type locality for species
 * †Trigonia
 * †Trigonia americana
 * †Trigonia elegantissima
 * †Trigonia montanaensis
 * †Trigonia quadrangularis
 * †Trioracodon
 * †Trioracodon bisulcus – type locality for species
 * Tyrannosaurus Rex Holotype.jpg]] Trochocyathus'' – tentative report
 * †Trochodendroides
 * †Troodon
 * †Troodon formosus
 * †Turgidodon
 * †Turgidodon rhaister – type locality for species
 * †Turgidodon russelli
 * Typha
 * †Tyrannosaurus – type locality for genus
 * †Tyrannosaurus rex – type locality for species

U

 * †Ulmiphyllum
 * †Ulmiphyllum densinerve – type locality for species
 * †Uluops – type locality for genus
 * †Uluops uluops – type locality for species
 * Unio
 * †Unionites
 * †Unionites fassaensis

V

 * Vanikoro
 * †Vanikoro ambigua
 * †Vanikoropsis
 * †Vanikoropsis nebrascensis
 * †Vaugonia
 * Vitis californica with grapes.jpg, or grapevine]] †Vaugonia conradi''
 * †Veniella
 * †Veniella mortoni
 * †Viburnum
 * †Viburnum marginatum
 * †Viburnum montanum
 * †Viburnum rotundifolium
 * Vitis
 * †"Vitis" stantoni
 * Viviparus – or unidentified comparable form
 * †Volutoderma

W



 * †Weediaphyllum – type locality for genus
 * †Weediaphyllum parkensis – type locality for species
 * †Weichselia
 * †Weichselia reticulata
 * †Williamsonia – tentative report
 * †Williamsonia phoenicopsoides – type locality for species
 * †Woodwardia
 * †Woodwardia crenata

X



 * †Xenocephalites
 * †Xenoxylon
 * †Xiphactinus
 * †Xiphactinus vetus

Y

 * Yoldia
 * †Yoldia scitula – or unidentified related form
 * †Yoldia ventricosa

Z



 * †Zamites
 * †Zamites arcticus
 * †Zamites borealis
 * †Zamites brevipennis
 * †Zapsalis – or unidentified comparable form
 * †Zephyrosaurus – or unidentified comparable form
 * †Zofiabaatar – type locality for genus
 * †Zofiabaatar pulcher – type locality for species