# List of the Paleozoic life of Utah

This list of the Paleozoic life of Utah contains the various prehistoric life-forms whose fossilized remains have been reported from within the US state of Utah and are between 538.8 and 252.17 million years of age.

## A

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* †Acanthopecten
** †Acanthopecten carboniferus
** †Acanthopecten coloradoensis
* †Achlysopsis
** †Achlysopsis liokata – or unidentified comparable form
** †Achlysopsis punctatum
* †Acidiphorus
** †Acidiphorus brevis – or unidentified comparable form
** †Acidiphorus brevus
** †Acidiphorus brighti
** †Acidiphorus pseudobathurus
** †Acidiphorus unicorna – type locality for species
** †Acidiphorus wahwahensis
** †Acidiphorus williamsi – type locality for species
* †Acinocricus
** †Acinocricus stichus
* †Acodus
** †Acodus similaris
* †Acontiodus
** †Acontiodus coniformis
* †Acrothele
** †Acrothele subsidua
* †Acrotreta
* †Adiantites
** †Adiantites tenuifolius
* †Aesiocrinus
** †Aesiocrinus secundus – type locality for species
* Assemblage of fossils of the Cambrian trilobite Agnostus †Agnostus
** †Agnostus neglectus
* †Allorisma
* †Allorynchus
* †Alokistocare
** †Alokistocare carnatum
** †Alokistocare harrisi
** †Alokistocare idahoense
** †Alokistocare normale
** †Alokistocare subcoronatum
* †Alokistocarella
** †Alokistocarella brighamensis
* †Altiocculus
** †Altiocculus concavus
** †Altiocculus drumensis
* †Amblycranium
** †Amblycranium cornutum
** †Amblycranium linearus – type locality for species
** †Amblycranium variabile
* †Amecephalus
** †Amecephalus laticudum
* †Ameura – tentative report
* †Ammagnostus
** †Ammagnostus beltensis
* †Amphiscapha
* †Amplexizaphrentis
** †Amplexizaphrentis paucicinctus
** †Amplexizaphrentis spinulosus
** †Amplexizaphrentis subcrassus
* †Amplexocarina
* †Amplexus
* †Anabarochilna
** †Anabarochilna australis – or unidentified comparable form
* †Ananias
** †Ananias nevadensis – or unidentified related form
* †Ancillotoechia
** †Ancillotoechia perryi – type locality for species
* †Anemonaria
** †Anemonaria delicatula
* †Angulotreta
* †Angyomphalus
** †Angyomphalus regularis
* †Anidanthus
** †Anidanthus echaris
* †Anisopyge
* †Anisotrypa
* †Annularia
** †Annularia stellata
* †Annulispongia – type locality for genus
** †Annulispongia interrupta – type locality for species
* Restorative model of the Cambrian arthropod Anomalocaris †Anomalocaris
** †Anomalocaris nathorsti
* †Anomalorthis
** †Anomalorthis lambda
** †Anomalorthis oklahomensis
** †Anomalorthis utahensis
* †Anomphalus
** †Anomphalus rotulus
* †Anthaspidella
* †Anthracospirifer
** †Anthracospirifer increbescens
** †Anthracospirifer leidyi
** †Anthracospirifer occiduus
* †Antiquatonia
** †Antiquatonia portlockianus
** †Antiquatonia sulcatus – or unidentified comparable form
* †Apachella
* †Apatognathus
* †Aphelaspis
** †Aphelaspis haguei
* †Aphelotoxon
** †Aphelotoxon acuminata
* †Apheoorthis
** †Apheoorthis melita – or unidentified comparable form
* †Apheorthis
** †Apheorthis meeki – or unidentified comparable form
* †Archaeocalamites
** †Archaeocalamites scrobiculatus
* †Archaeocothurnus – tentative report
** †Archaeocothurnus bifida – type locality for species
* †Archaeoscyphia
** †Archaeoscyphia rossi
* †Archeocalamites
** †Archeocalamites radiatus
* †Archeoschyphia
* Fossils of the Carboniferous-Permian bryozoan Archimedes †Archimedes
** †Archimedes macfarlani
** †Archimedes owenanus
* †Arcuolimbus
* †Arenicolites
* †Arroyocrinus
** †Arroyocrinus stokesi – type locality for species
* †Arthrophycus – tentative report
* †Artisia
* †Asaphelina
* †Asaphellus – tentative report
* Fossil of the Cambrian trilobite Asaphiscus †Asaphiscus
** †Asaphiscus wheeleri
* †Ascopora
** †Ascopora macellata
* †Astartella
** †Astartella subquadrata
* †Asterophyllites
** †Asterophyllites charaeformis
** †Asterophyllites equisetiformis
** †Asterophyllites longifolius
* †Athabaskia
** †Athabaskia bithus
** †Athabaskia wasatchensis
* †Athyridacid
* †Athyris
** †Athyris lamellosa
* Fossilized shell of the Late Ordovician-Carboniferous brachiopod Atrypa †Atrypa
** †Atrypa hedei
** †Atrypa parva – or unidentified comparable form
* †Atrypid
* †Aulacoparia – tentative report
** †Aulacoparia quadrata
** †Aulacoparia venta
* †Aulacotheca
** †Aulacotheca campbellii
** †Aulacotheca hemingwayi
* †Aulopora – tentative report
* †Aviculopecten
** †Aviculopecten girtyi
** †Aviculopecten kaibabensis – or unidentified comparable form
* †Aviculopinna
** †Aviculopinna peracuta – tentative report
* Fossil of the Cambrian velvet worm relative Aysheaia †Aysheaia

## B

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* †Babylonites
** †Babylonites conoideus
* †Bakevellia
* †Baltagnostus
** †Baltagnostus eurypyx
* †Barrandia – tentative report
* †Bathymyonia
** †Bathymyonia nevadensis
* †Bathyurellus
** †Bathyurellus feitleri
** †Bathyurellus pogonipensis
** †Bathyurellus pogonopensis
** †Bathyurellus teretus – type locality for species
* †Bathyuriscus
** †Bathyuriscus brighamensis
** †Bathyuriscus elegans
** †Bathyuriscus fimbriatus
** †Bathyuriscus wasatchensis
* †Bayfieldia
* †Bearriverops
** †Bearriverops alsacharovi – type locality for species
** †Bearriverops borderinnensis – type locality for species
** †Bearriverops deltaensis – type locality for species
** †Bearriverops ibexensis – type locality for species
** †Bearriverops loganensis
* †Beckwithia
** †Beckwithia typa
* †Belemnospongia
** †Belemnospongia neofascicularis – type locality for species
* †Bellazona
** †Bellazona bella
** †Bellazona polita – type locality for species
* †Bellefontia
** †Bellefontia acuminiferentis
** †Bellefontia chamberlaini
** †Bellefontia ibexensis
* †Benthamaspis
** †Benthamaspis diminutiva
** †Benthamaspis gibberula – type locality for species
** †Benthamaspis obrepta
* †Beyrichoceras
* †Bighornia
* †Billingsella
* †Biscoia
* †Blastoidocrinus
** †Blastoidocrinus carchariaedens – or unidentified comparable form
* †Blountia
* †Bolaspidella
** †Bolaspidella contracta
** †Bolaspidella housensis
** †Bolaspidella type locality for species – informal
** †Bolaspidella wellsvillensis
* †Bolbocephalus
* †Bollandoceras
** †Bollandoceras occidentale – type locality for species
* †Bonneterrina
* †Bourbonnella
** †Bourbonnella jocelynae – type locality for species
* †Bowmania
* †Brachyaspidion
** †Brachyaspidion microps
** †Brachyaspidion sulcatum
* †Brachyprion
** †Brachyprion geniculata
* †Brachythyris
* Life restoration of the mysterious Cambrian animal Branchiocaris †Branchiocaris
** †Branchiocaris pretiosa
* †Brassicicephalus
* †Breckwithia
** †Breckwithia typa
* †Brodioptera
** †Brodioptera stricklani – type locality for species
* †Bromella
* †Brooksella
* †Bucania
* †Bythicheilus
** †Bythicheilus typicum

## C

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* †Cactocrinus
** †Cactocrinus arnoldi
* Fossilized stems from the Carboniferous-Permian horsetail relative Calamites †Calamites
** †Calamites cistii – or unidentified comparable form
** †Calamites cistiiformis
** †Calamites gigas
** †Calamites hesperius
** †Calamites infractus
** †Calamites suckowii
* †Calamostachys – tentative report
* †Calathium
** †Calathium yersini – type locality for species
* †Callipteris – tentative report
* †Callocladia
** †Callocladia jensensis
* †Calycocoelia
* †Calygirtyoceras
** †Calygirtyoceras arcticum
** †Calygirtyoceras confusionense – type locality for species
* †Camarotoechia
* †Cambromedusa – type locality for genus
** †Cambromedusa furcula – type locality for species
* †Camerella
* †Campbelloceras – tentative report
* Life restoration of the Cambrian arthropod Canadaspis (left) †Canadaspis
** †Canadaspis perfecta – or unidentified comparable form
* †Canadia
* †Canadiphyllum
* †Cancrinella
** †Cancrinella phosphatica – or unidentified comparable form
* †Caninaphyllum
** †Caninaphyllum incrussatum
* †Caninia
** †Caninia torquia
* †Caninophyllum
* †Canthylotreta
** †Canthylotreta marjumensis
* †Cardiomorpha
* †Cardiopteris
** †Cardiopteris hirta – or unidentified comparable form
* †Carolinites
** †Carolinites ekphymosus
** †Carolinites genacinaca – type locality for species
** †Carolinites killarnyensis
** †Carolinites killaryensis
* †Castericystis
** †Castericystis sprinklei – type locality for species
** †Castericystis vali – type locality for species
* †Catoraphiceras
** †Catoraphiceras colon
* †Caulpsis
** †Caulpsis punctata
* †Cavusgnathus
** †Cavusgnathus regularis
** †Cavusgnathus unicornis
* Fossil of the Cambrian trilobite Cedaria †Cedaria
** †Cedaria minor
* †Cedarina – tentative report
* †Cenorhynchia
** †Cenorhynchia type locality for species A – informal
* †Cernuolimbus
** †Cernuolimbus granulosus
* †Chaenomya
* †Chaetetes
** †Chaetetes milleporaceous
* †Chancelloria
** †Chancelloria eros
** †Chancelloria pentacta – type locality for species
* †Chancia)
** †Chancia ebdome – or unidentified comparable form
* †Chanciaopsis – type locality for genus
** †Chanciaopsis heteromorphos – type locality for species
* †Chanciopsis
** †Chanciopsis heteromorphos
* †Cheilocephalus
* †Chilotrypa
* Life restoration of the Cambrian sponge Choia †Choia
** †Choia carteri
** †Choia hindei
** †Choia ridleyi
** †Choia utahensis
* †Chondrites
* †Chonetes
* †Chonetina
** †Chonetina flemingi
* †Choristites
** †Choristites fritschi – or unidentified comparable form
** †Choristites pavlovi – or unidentified comparable form
* Fossil of the Carboniferous tabulate coral Cladochonus †Cladochonus
* †Clathrospira – tentative report
* †Clavagnostus
** †Clavagnostus repandus
* †Cleiothyridina
** †Cleiothyridina type locality for species A – informal
** †Cleiothyridina type locality for species B – informal
* †Clelandia
** †Clelandia utahensis
* †Cliothyridina
** †Cliothyridina orbicularis
* †Clonograptus
* †Coelogasteroceras
* †Coenites
* †Colinispongia
** †Colinispongia regularis
* Fossilized shell of the Late Devonian-Permian brachiopod Composita †Composita
** †Composita argentea
** †Composita mira
** †Composita ovata
** †Composita parasulcata
** †Composita plana
** †Composita subtilita
** †Composita trilobata
** †Composita trinuclea
* †Condrathyris
** †Condrathyris perplexa
* †Conotreta
** †Conotreta millardensis
* †Coosella
* †Coosina
* †Cordaianthus
** †Cordaianthus pseudofluitans
* †Cordaicarpus
** †Cordaicarpus binutus – type locality for species
** †Cordaicarpus cordatus
** †Cordaicarpus elongatus
** †Cordaicarpus globosus – type locality for species
** †Cordaicarpus jayshulerii – type locality for species
** †Cordaicarpus manningcanensis – type locality for species
* Fossilized foliage of the Carboniferous-Permian conifer relative Cordaites †Cordaites
** †Cordaites angulosostriatus
** †Cordaites principalis
** †Cordaites Sp. A – informal
** †Cordaites Sp. B – informal
* †Cornucarpus
** †Cornucarpus longicaudatus – type locality for species
* †Corynepteris
** †Corynepteris angustissima
* †Costellarina
* †Cotalagnostus
* Crania
** †Crania rowleyi
* †Cravenoceras
* †Crepicephalus
* †Crossopteris – type locality for genus
** †Crossopteris mcknightii – type locality for species
** †Crossopteris undulata – type locality for species
** †Crossopteris utahensis – type locality for species
* †Crurithyris
** †Crurithyris arcuatus – or unidentified comparable form
** †Crurithyris expansa – tentative report
* †Cruziana
* †Ctenalosia
** †Ctenalosia fixata
* †Ctenocystis
** †Ctenocystis utahensis
* †Ctenospondylus
** †Ctenospondylus casei – or unidentified related form
* †Cyathaxonia
* †Cyathocarpus
** †Cyathocarpus arborescens
** †Cyathocarpus cyatheus
* †Cybeloides
* †Cybelopsis
** †Cybelopsis speciosa
* Fossilized foliage from the Carboniferous seed fern Cyclopteris †Cyclopteris
** †Cyclopteris dilatata
* †Cymatospira
** †Cymatospira montfortianus
* †Cymbiocrinus
** †Cymbiocrinus anatonus – type locality for species
** †Cymbiocrinus cuneatus – type locality for species
* †Cyperites
** †Cyperites bicarinatus
* †Cyrtia
* †Cyrtina
* †Cyrtorostra
* †Cystodictya
** †Cystodictya astrepta

## D

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* †Dalmanellida
* †Deiracephalus
* †Delaria
** †Delaria sevilloidia
* †Delocrinus
** †Delocrinus subhemisphericus
* †Deltina – type locality for genus
** †Deltina limba – type locality for species
* Dentalium
* †Derbyia
** †Derbyia bennetti
** †Derbyia crassa
** †Derbyia sulca
** †Derbyia wabashensis
* †Desmoinesia
** †Desmoinesia muricatina
* †Diacanthaspis
** †Diacanthaspis trispineus – type locality for species
* Life restoration of the Permian reptile relative Diadectes †Diadectes
* †Diagoniella
** †Diagoniella cyathiformis
** †Diagoniella hindei
** †Diagoniella magna – type locality for species
** †Diagoniella robisoni – type locality for species
* †Diaphragmus
** †Diaphragmus cestriensis
* †Dicanthopyge
** †Dicanthopyge convergens
* †Dicranocaris
** †Dicranocaris guntherorum
* †Dictyoclostus
** †Dictyoclostus burlingtonensis
** †Dictyoclostus inflatus
* †Dictyonema
** †Dictyonema flabelliforme – or unidentified comparable form
* Fossil of the Middle Ordovician graptolite Didymograptus †Didymograptus
** †Didymograptus artus
** †Didymograptus bifidus
** †Didymograptus nitidus – or unidentified comparable form
* †Dielasma
** †Dielasma formosum
** †Dielasma phosphoriense
** †Dielasma spatulatum
* †Dimegelasma
* †Dimeropygiella
** †Dimeropygiella blanda
** †Dimeropygiella caudanodosa – type locality for species
** †Dimeropygiella fillmorensis
** †Dimeropygiella mccormicki
** †Dimeropygiella ovata
* †Dimorphoceras
** †Dimorphoceras rileyi – type locality for species
** †Dimorphoceras worki – type locality for species
* †Dioxycaris
** †Dioxycaris argenta
* †Diparalasma
* †Diparelasma
** †Diparelasma pogonipensis – or unidentified comparable form
** †Diparelasma rowelli
** †Diparelasma transversum – or unidentified comparable form
* †Diphyphyllum
* †Diplagnostus
** †Diplagnostus planicauda
* †Diplorrhina
** †Diplorrhina depressa
* †Diplothmema
** †Diplothmema arnoldi
** †Diplothmema obtusiloba
** †Diplothmema trifoliolata
* †Diplotrypa – tentative report
* †Ditomopyge
* †Dolerorthis – tentative report
** †Dolerorthis flabellites
* †Donaldina
* †Dorypyge
** †Dorypyge swasii
** †Dorypyge wellsvillensis
* †Drepanodus
** †Drepanodus homocurvatus
* †Dresbachia
** †Dresbachia amata
* †Duartea
** †Duartea bruntoni
* †Dunbarinella – tentative report
* †Dunderbergia
** †Dunderbergia anyta
** †Dunderbergia bigranulosa – tentative report
* †Dyoros
** †Dyoros type locality for species A – informal
* †Dysoristus
* †Dytremacephalus
* †Dzhaprakoceras

## E

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* †Echinalosia
** †Echinalosia type locality for species A – informal
* †Echinaria
** †Echinaria semipunctata – or unidentified related form
* †Echinauris – or unidentified comparable form
** †Echinauris subhorrida
* †Echinoconchus
** †Echinoconchus elegans
** †Echinoconchus semipunctatus
* †Echinocrinus
* †Ectenonotus
** †Ectenonotus progenitor
** †Ectenonotus whittingtoni
* Life restoration of the Permian lobe-finned fish Ectosteorhachis †Ectosteorhachis – or unidentified related form
** †Ectosteorhachis nitidus
* †Edmondia
* †Ehmaniella
** †Ehmaniella quadrans – tentative report
* †Ekvasophyllum
** †Ekvasophyllum inclinatum
* †Elburgia
** †Elburgia granulosa
** †Elburgia intermedia
* †Eldonia
** †Eldonia ludwigi
* †Eleutherocentrus
** †Eleutherocentrus petersoni
* †Elrathella
* Fossils at different stages of development of the Cambrian trilobite Elrathia †Elrathia
** †Elrathia kingi
* †Elrathiella
** †Elrathiella dugwayensa – type locality for species
* †Elrathina
** †Elrathina spencei
* †Elvinia
* †Emeraldella
* †Endelocrinus
** †Endelocrinus matheri
* †Endoceras
* †Entogonites
** †Entogonites acus
** †Entogonites borealis
** †Entogonites burbankensis – type locality for species
* †Eoastarte
** †Eoastarte subcircularis
* †Eofletcheria
* †Eoorthis
* †Eriaster – type locality for genus
** †Eriaster ibexensis – type locality for species
* †Eridopora
* †Eridotrypa
** †Eridotrypa hindsi
** †Eridotrypa subtilis
* †Erixanium
** †Erixanium carinatum
* Life restoration of the Carboniferous-Permian amphibian Eryops †Eryops
* †Euconospira
* †Eukrinaster – type locality for genus
** †Eukrinaster ibexensis – type locality for species
* †Eukteanochiton – type locality for genus
** †Eukteanochiton milleri – type locality for species
* †Euloma – report made of unidentified related form or using admittedly obsolete nomenclature
** †Euloma cordilleri
* †Eumetria
** †Eumetria acuticosta
** †Eumetria costata
* †Euphemites
** †Euphemites carbonarius
* †Euphemitopsis
** †Euphemitopsis subpapillosa – type locality for species
* †Euptychaspis
* †Eurekia
* †Eurytreta
** †Eurytreta bisecta – or unidentified comparable form
** †Eurytreta fillmorensis – type locality for species

## F

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* †Faberophyllum
* †Falcatamacaris – type locality for genus
** †Falcatamacaris bellua – type locality for species
* †Fenestella
** †Fenestella acarinata
** †Fenestella crockfordae
** †Fenestella dissepinodaria
** †Fenestella hamithensis
** †Fenestella incipiens
** †Fenestella parallela
** †Fenestella rarinodosa
** †Fenestella regalis
** †Fenestella serratula
** †Fenestella tooelensis
** †Fenestella trifurcata
** †Fenestella utahensis
* †Fenestralia
** †Fenestralia sanctiludovici
* †Fenestrellina
* †Fistulipora
* †Forteyops
** †Forteyops sexapugia – type locality for species
* †Fusulinella

## G

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* †Gattendorfia
* †Genalaticurus
** †Genalaticurus genalatus
* Fossil of the Cambrian trilobite Genevievella †Genevievella
** †Genevievella granulatus
* †Girtyella – tentative report
* †Girtyoceras
** †Girtyoceras gordoni – type locality for species
** †Girtyoceras hamiltonense
** †Girtyoceras primum – type locality for species
* †Girtypecten
* †Girtyspira
* †Girvanella
* †Glabrocingulum
** †Glabrocingulum coronatum
** †Glabrocingulum granulosum – type locality for species
** †Glabrocingulum mephitifontis – type locality for species
* †Glaphyrites
** †Glaphyrites nevadensis
* †Globocrinus
** †Globocrinus bulbus – type locality for species
* †Glochinomorpha – type locality for genus
** †Glochinomorpha stifeli – type locality for species
* †Glosopleura
* †Glossopleura
** †Glossopleura boccar
** †Glossopleura gigantea
** †Glossopleura producta
** †Glossopleura prona
** †Glossopleura punctatum
* †Glyphaspis
** †Glyphaspis concavus – type locality for species
* †Glyptospira
* †Gnathodus
** †Gnathodus texanus
* †Gnetopsis
** †Gnetopsis anglica
* Fossil of the Cambrian echinoderm Gogia †Gogia
** †Gogia granulosa
** †Gogia guntheri
** †Gogia kitchnerensis
** †Gogia spiralis
* †Goleocrinus
** †Goleocrinus vadosus – type locality for species
** †Goleocrinus vedosus
* †Goniasma
* †Goniatites
** †Goniatites americanus
** †Goniatites deceptus – type locality for species
** †Goniatites eganensis
** †Goniatites sowerbyi
* †Goniophrys
** †Goniophrys prima
* †Goniotelena
** †Goniotelena ensifer
* †Goniotelina
** †Goniotelina ensifer
** †Goniotelina plicolabeonus – type locality for species
* †Goniotelus – tentative report
** †Goniotelus ludificatus
* †Gonitelina
* †Gothodus
** †Gothodus communis
* †Grammatodon
** †Grammatodon politus
* †Grandaurispina – or unidentified comparable form
** †Grandaurispina type locality for species A – informal
* †Gruntia – tentative report
* †Guizhoupecten – tentative report
** †Guizhoupecten tubicostata – or unidentified comparable form
* †Gujocardita
** †Gujocardita parviradiatus – type locality for species
* †Gunterichthys – type locality for genus
** †Gunterichthys lehiensis – type locality for species

## H

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* †Haimacystis
** †Haimacystis rozhnovi
* †Hammatocyclus
** †Hammatocyclus brazerensis – type locality for species
* †Hamptonia
** †Hamptonia bowerbanki
** †Hamptonia parva – type locality for species
* †Haplistion
** †Haplistion sphaericum
* Life restoration of the Cambrian brachiopod relative Haplophrentis †Haplophrentis
** †Haplophrentis carinatus
** †Haplophrentis reesei
* †Hardyoides
* †Hazelia
** †Hazelia palmata
* †Heckethornia
** †Heckethornia alticapitis – type locality for species
** †Heckethornia ballionae – type locality for species
** †Heckethornia bowiei – type locality for species
** †Heckethornia hyndeae
** †Heckethornia morrisseyi – type locality for species
** †Heckethornia numani
** †Heckethornia smithi – type locality for species
* †Heintzella
** †Heintzella whitneyi
* Life restoration of the Permian Chimaera relative Helicoprion †Helicoprion
* †Helicospira
* †Hematites
** †Hematites barbarae – type locality for species
** †Hematites burbankensis – type locality for species
* †Hemiptychina
** †Hemiptychina quadricostata
* †Hemirhodon
** †Hemirhodon amplipyge
* †Hemitrypa
** †Hemitrypa reticulata
* †Hesperonomia
** †Hesperonomia dinorthoides
** †Hesperonomia fontinalis
** †Hesperonomia frontinalis
* †Hesperonomiella
** †Hesperonomiella minor
* †Heteralosia
* †Heteropecten
** †Heteropecten vanvleeti – or unidentified comparable form
* †Hillyardina
** †Hillyardina marginauctum
** †Hillyardina semicylindrica – or unidentified comparable form
* †Hindia
** †Hindia sphaeroidalus
* †Hintzecurus
** †Hintzecurus paragenalatus
* †Hintzeia
** †Hintzeia aemula
** †Hintzeia celsaora
** †Hintzeia firmimarginis
* †Hintzespongia – type locality for genus
** †Hintzespongia bilamina – type locality for species
* †Holcospermum
* †Homagnostus
* †Homalophyllites
* †Hormotoma – tentative report
* †Housia
* †Howellella
* †Hudsonospongia – tentative report
* †Huronia
** †Huronia vertebralis
* †Hustedia
** †Hustedia elongata
** †Hustedia mormoni – type locality for species
* †Hyattidina – tentative report
* †Hyolithellus
†Hyolithes
** †Hyolithes comptus
* †Hypagnostus
** †Hypagnostus parvifrons
* Hyperammina
* †Hyperbolochilus
* †Hypselocrinus
** †Hypselocrinus cavus – type locality for species
** †Hypselocrinus defendus – type locality for species
** †Hypselocrinus secundus
** †Hypselocrinus superus – type locality for species
* †Hystriculina
** †Hystriculina fragilis
** †Hystriculina wabashensis
* †Hystricurus
** †Hystricurus contractus
** †Hystricurus oculilunatus
** †Hystricurus robusta

## I

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* †Ianthinopsis
* †Ibexella
** †Ibexella multidiaphragmata
* †Ibexicurus
** †Ibexicurus parsonsi – type locality for species
* †Iddingsia
* †Idiognathodus
* †Idiomesus
* †Illaenurus
* Fossil of the Middle Ordovician trilobite Illaenus †Illaenus
** †Illaenus utahensis
* †Inflatia
** †Inflatia bilobata
* †Iphidella
* †Irvingella
** †Irvingella flohri – tentative report
** †Irvingella major
* †Ischyrotoma
** †Ischyrotoma juabensis
** †Ischyrotoma wahwahensis
* †Isorthis
* †Isoteloides
** †Isoteloides flexus
** †Isoteloides polaris
* †Isoxyes

## J

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* †Jeffersonia
* †Jenkinsonia
** †Jenkinsonia varga
* †Juresania
** †Juresania nebraskensis

## K

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* †Kainella
* †Kanoshia
** †Kanoshia depressus – type locality for species
** †Kanoshia kanoshensis
** †Kanoshia reticulata
* †Kanoshopora
** †Kanoshopora droserae
* †Kawina
** †Kawina webbi
** †Kawina wilsoni
* †Kazakhoceras
** †Kazakhoceras bylundi – type locality for species
* †Kindbladia
** †Kindbladia affinis
* †Kingstonia
* †Kirkella
** †Kirkella fillmorensis
* †Kiwetinokia
** †Kiwetinokia utahensis
* †Kochina
** †Kochina vestita
* †Kochiproductus
* †Komia
* †Komiella
** †Komiella ostiolata
* Fossil of the Cambrian trilobite Kootenia †Kootenia
** †Kootenia acicularis
** †Kootenia mendosa
** †Kootenia quadriceps
** †Kootenia spencei
* †Kootina
** †Kootina pectenoides
* †Kormagnostella
** †Kormagnostella advena
** †Kormagnostella insolita
* †Kormagnostus
* †Kozlowskia
** †Kozlowskia capaci – or unidentified related form
* †Kutorginella
** †Kutorginella lasallensis
* †Kuvelousia
** †Kuvelousia leptosa

## L

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* †Lachnostoma
** †Lachnostoma latucelsum – type locality for species
* †Lagenospermum
** †Lagenospermum discissium – type locality for species
* †Lamellispira
* †Lavadamia
** †Lavadamia joplinae – type locality for species
* †Leanchoila
** †Leanchoila protogonia
** †Leanchoila superlata
* Life restoration in multiple views of the Cambrian arthropod Leanchoilia †Leanchoilia
** †Leanchoilia hanceyi
** †Leanchoilia superlata
* †Lecanospira
* †Leiorhynchoidea
* †Leiorhynchus
* †Leiostegium
** †Leiostegium formosa
** †Leiostegium manitouense – or unidentified comparable form
** †Leiostegium manitouensis
* †Lejopyge
** †Lejopyge calva
* †Leperditia
** †Leperditia bivia
* †Lepidocarpon
** †Lepidocarpon linearifolium
* Life restoration of the Carboniferous tree-sized club moss relative Lepidodendron †Lepidodendron
** †Lepidodendron aculeatum
** †Lepidodendron obovatum
** †Lepidodendron volkmannianum
* †Lepidophylloides
* †Lepidophyllum
** †Lepidophyllum longifolium
* †Lepidostrobophyllum
** †Lepidostrobophyllum majus
* †Lepidostrobus
** †Lepidostrobus obovatus
** †Lepidostrobus variabilis
* †Leptaena
* †Leptalosia
** †Leptalosia scintilla – or unidentified comparable form
* †Leptanena
* †Leptomitella
** †Leptomitella metta – type locality for species
* †Leptomitus
* †Lesuerilla – tentative report
* †Licnocephala
** †Licnocephala bicornuta – tentative report
** †Licnocephala cavigladius
* Lima
* †Limapecten
* Limatula
* †Limipecten
* †Linevitus
** †Linevitus billingsi
* Lingula
** †Lingula carbonaria
* Illustration of a fossilized shell of the Cambrian-Late Ordovician brachiopod Lingulella †Lingulella
** †Lingulella incurvata
** †Lingulella pogonipensis – or unidentified comparable form
* †Linipalus
** †Linipalus magnispinus
* †Linnarssonella
* †Linnarssonia
** †Linnarssonia bellatula
** †Linnarssonia ophirensis
* †Linoproductus
** †Linoproductus meniscus
** †Linoproductus ovatus
** †Linoproductus planiventralis – tentative report
** †Linoproductus prattenians
** †Linoproductus prattenianus
* †Lissocoelia
** †Lissocoelia cylindrica
* †Lithostrontionella
* †Lithostrotionella
** †Lithostrotionella americana – or unidentified comparable form
* †Llanoaspis
* †Lobatospongia – type locality for genus
** †Lobatospongia nodensis – type locality for species
* †Lochriea
** †Lochriea commutata
* †Lonchocephalus
* †Lophophyllidium
** †Lophophyllidium profundum
* †Loxonema
* †Loxoplocus
* †Lunulazona
** †Lunulazona costata
** †Lunulazona nodomarginata
* †Lyracystis
** †Lyracystis reesei

## M

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* †Macluritella
* †Maclurites
* †Macronotella
* †Madaraspis
** †Madaraspis magnifica
* Restoration of the mysterious Cambrian life-form Margaretia †Margaretia
** †Margaretia dorus
* †Marginifera
* †Marginovatia
** †Marginovatia catinulus
* †Mariopteris
** †Mariopteris muricata
* †Marjumicystis
** †Marjumicystis mettae – type locality for species
* †Marpolia
* †Matherella
* †Matthevia
** †Matthevia variabilis
** †Matthevia wahwahensis – type locality for species
* †Meekopora
* †Meekospira
* †Menomonia
** †Menomonia semele
* †Menoparia
** †Menoparia genalunata
* †Metabowmania
** †Metabowmania braggi – type locality for species
** †Metabowmania morgani
* Fossilized shell of the Carboniferous-Permian nautiloid cephalopod Metacoceras †Metacoceras
* †Metadimorphoceras
** †Metadimorphoceras mangeri – type locality for species
** †Metadimorphoceras richardsi
* †Meteoaspis – tentative report
* †Meteoraspis
* †Michelinia
* †Microcardinalia
* †Micromitra
** †Micromitra pannula
* †Millardicurus
** †Millardicurus housensis – type locality for species
** †Millardicurus millardensis
** †Millardicurus paramillardensis – type locality for species
* †Modiolopsis
* Modiolus – report made of unidentified related form or using admittedly obsolete nomenclature
* †Modocia
** †Modocia brevispina
** †Modocia laevinucha
** †Modocia typicalis
** †Modocia weeksensis – type locality for species
* †Mollisonia
** †Mollisonia symmetrica
* †Morania
** †Morania fragmenta
* †Mourlonia
** †Mourlonia venusta – type locality for species
* †Myalina

## N

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* †Nanorthis
** †Nanorthis hamburgensis
** †Nanorthis multicostata
* Restoration of the Cambrian-Silurian arthropod Naraoia †Naraoia
** †Naraoia compacta
* †Narynella
** †Narynella sulcata
* †Naticopis
** †Naticopis altonensis – tentative report
* †Naticopsis
* †Natiria
* †Neochonetes
** †Neochonetes granulifer
* †Neolenus
** †Neolenus inflatus – type locality for species
** †Neolenus intermedius – type locality for species
** †Neolenus superbus
* †Neoprioniodus
** †Neoprioniodus scitulus
** †Neoprioniodus varians
* Fossilized shell of the Carboniferous-Permian brachiopod Neospirifer †Neospirifer
** †Neospirifer cameratus
** †Neospirifer kansasensis
** †Neospirifer triplicatus
* †Neozaphrentis – tentative report
* †Nephalicephalus – type locality for genus
** †Nephalicephalus beebei – type locality for species
* †Nettapezoura
** †Nettapezoura basilika
* †Neuralethopteris
** †Neuralethopteris pocahontas – or unidentified comparable form
* Fronds of the Carboniferous seed fern Neuropteris †Neuropteris
** †Neuropteris ampelina – type locality for species
** †Neuropteris gigantea
** †Neuropteris heterophylla
* †Nieszkowskia – tentative report
* †Niobe – tentative report
* †Nisusia
* †Norwoodia
** †Norwoodia bellaspina
* †Nothorthis
* †Nuculavus
* †Nuculopsis
* †Nuia
* †Nunnacrinus
** †Nunnacrinus olsoni – type locality for species

## O

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* †Obolus
** †Obolus ella
* †Odontopteris
** †Odontopteris osmundaeformis – or unidentified comparable form
** †Odontopteris subcrenulata – or unidentified comparable form
* †Odontospirifer
** †Odontospirifer type locality for species A – informal
* †Oepikodus
** †Oepikodus quadratus
* Fossil of the Cambrian trilobite Ogygopsis †Ogygopsis
** †Ogygopsis typicalis
* †Oistodus
** †Oistodus lanceolatus
** †Oistodus linguatus
** †Oistodus longiramis
** †Oistodus multicorrugatus – or unidentified related form
** †Oistodus parallelus
* †Olenellus
** †Olenellus gilberti
* †Olenoides
** †Olenoides expansus
** †Olenoides nevadensis
** †Olenoides serratus
** †Olenoides spencei
** †Olenoides tricephalus
* Life restoration of the Carboniferous-Permian synapsid (mammal precursor) Ophiacodon †Ophiacodon
** †Ophiacodon navajovicus
* †Ophileta
* †Opsioryctocephalus
** †Opsioryctocephalus opsis
* †Orbiculoidea
** †Orbiculoidea capuliformis
** †Orbiculoidea missouriensis
** †Orbiculoidea utahensis – type locality for species
* †Orbipora
** †Orbipora utahensis
* †Orthambonites
** †Orthambonites eucharis – or unidentified comparable form
** †Orthambonites michaelis
** †Orthambonites subulata
* †Orthis
** †Orthis subalata – or unidentified comparable form
** †Orthis subulata
** †Orthis swanensis
* †Orthonema
** †Orthonema socorroense – or unidentified comparable form
* †Orthotetes
** †Orthotetes kaskaskiensis
* †Orthriochiton – type locality for genus
** †Orthriochiton utahensis – type locality for species
* †Oryctocare
** †Oryctocare geikei
* †Oryctocephalus
** †Oryctocephalus walcotti
* †Ottenbyella
** †Ottenbyella ibexiana – type locality for species
* Life restoration of the Cambrian priapulid worm relative Ottoia †Ottoia
** †Ottoia prolifica
* †Ovatia
** †Ovatia muralis
* †Owenella
* †Ozarkodina

## P

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* †Pachycranium
** †Pachycranium faciclunis
* Fossil of the Cambrian trilobite Pagetia †Pagetia
** †Pagetia fossula – or unidentified comparable form
* †Paladin
* †Palaeacis
* Palaeoaplysina
** †Palaeoaplysina laminaeformis
* †Palaeobotryllus
* †Palaeoneilo
** †Palaeoneilo parvaradiatus
* †Palaeoscolex
** †Palaeoscolex ratcliffei
* †Paleococrinus
* †Palmerocrinus
** †Palmerocrinus profundus
* †Paltodus
** †Paltodus jeffersonensis
* †Parabellefontia
** †Parabellefontia concinna
* †Parabolinoides
* †Paracosmetocrinus
** †Paracosmetocrinus lundi – type locality for species
* †Parahystricurus
** †Parahystricurus bispicatus
** †Parahystricurus fraudator
* †Parajuresania
** †Parajuresania nebrascensis
* †Parallelodon
* †Parapilekia – tentative report
* †Paraplethopeltis
** †Paraplethopeltis genacurvus
** †Paraplethopeltis genarectus
* †Parkaspis
** †Parkaspis drumensis
* †Peelerophon – tentative report
* †Pelagiella
* †Peniculauris
** †Peniculauris bassi
** †Peniculauris ivesi
* †Penniretepora
* †Pentameroides
* †Pentamerus
* †Pericyclus
* †Permophorus
** †Permophorus albequus
** †Permophorus occidentalis
* Assemblage of fossils of the Cambrian trilobite Itagnostus interstrictus, until recently known as Peronopsis interstricta †Peronopsis
** †Peronopsis acadica
** †Peronopsis amplaxis
** †Peronopsis bonnerensis
** †Peronopsis brighamensis
** †Peronopsis fallax
** †Peronopsis interstricata
** †Peronopsis interstricta
** †Peronopsis montis
** †Peronopsis scutalis
** †Peronopsis segmenta
** †Peronopsis sermenta
* †Perspicaris
** †Perspicaris ellipsopelta
* †Petasmatherus
** †Petasmatherus type locality for species A – informal
* †Petigurus
** †Petigurus inexpectatus
* †Pharkidonotus
** †Pharkidonotus percarinatus
* †Phillipsia
* †Phosphannulus
* †Phrenophoria
** †Phrenophoria type locality for species A – informal
* †Phricodothyris
* †Phyllograptus
* †Pilekia
** †Pilekia trio – tentative report
* Pinna – report made of unidentified related form or using admittedly obsolete nomenclature
* †Plagioglypta
* †Platycrinites
* †Platycrinus
** †Platycrinus graphicus – or unidentified comparable form
* Life restoration of the Carboniferous-Permian sail-backed amphibian Platyhystrix †Platyhystrix – or unidentified comparable form
** †Platyhystrix rugosus
* †Platyworthenia
* †Plectelasma
** †Plectelasma type locality for species A – informal
** †Plectelasma type locality for species B – informal
* †Plethospira
* †Pleurosiphonella
** †Pleurosiphonella virginica
* †Pliomerops
** †Pliomerops insolita
* †Polidevcia
** †Polidevcia bellistriata
** †Polidevcia obesa
* †Politicurus
** †Politicurus politus
* †Polypora
** †Polypora cestriensis
** †Polypora debilis
** †Polypora micronodosa
** †Polypora stansburyensis
* †Ponticulocarpus – type locality for genus
** †Ponticulocarpus robisoni – type locality for species
* †Praedaraelites
** †Praedaraelites loeblichi
* †Prehousia
** †Prehousia alata
** †Prehousia diverta
* †Presbynileus
** †Presbynileus elongatus
** †Presbynileus ibexensis
** †Presbynileus utahensis
* †Probolionia
* †Prodentalium
** †Prodentalium canna
* †Productella
* †Productus – report made of unidentified related form or using admittedly obsolete nomenclature
* †Proehmaniella
** †Proehmaniella basilica
* †Prohedinia
** †Prohedinia spencei
* †Prolecanites – tentative report
** †Prolecanites lyoni
* †Prosaukia
* †Protoblechnum
** †Protoblechnum bradyi – type locality for species
* †Protopliomerella
** †Protopliomerella contracta
* †Protopliomerops
** †Protopliomerops quattuor – type locality for species
* †Protopresbynileus
** †Protopresbynileus willdeni
* †Protoretepora
* †Protospongia
** †Protospongia elongata
* †Prototreta
* †Protowentzelella
** †Protowentzelella cystosa
* †Psalikilus
** †Psalikilus likum
** †Psalikilus paraspinosum
** †Psalikilus spinosum
** †Psalikilus typicum
* †Psephosthenaspis
** †Psephosthenaspis glabrior
** †Psephosthenaspis microspinosa
** †Psephosthenaspis pseudobathyurus
* †Pseudagnostus
* †Pseudoarctolepis
** †Pseudoarctolepis sharpi
* †Pseudoarctolepsis
** †Pseudoarctolepsis sharpi
* †Pseudoclelandia
** †Pseudoclelandia fluxafissura – or unidentified related form
* †Pseudocybele
** †Pseudocybele altinasuta
** †Pseudocybele lemurei
** †Pseudocybele nasuta – type locality for species
* †Pseudodoriodotis
* †Pseudohystricurus
* †Pseudokainella – tentative report
** †Pseudokainella armatus
* †Pseudomera
** †Pseudomera arachnopyge
** †Pseudomera barrandei – or unidentified comparable form
** †Pseudomera insolita
* †Pseudomonotis
** †Pseudomonotis equistriata
* †Pseudomphalotrochus
** †Pseudomphalotrochus incrustatus
* †Pseudoolenoides
** †Pseudoolenoides acicaudus
** †Pseudoolenoides aspinosus
** †Pseudoolenoides dilectus
* †Pseudopermophorus
** †Pseudopermophorus annettae
* †Pseudoperonopsis
* †Pseudorthoceras
* †Pseudosaratogia – tentative report
* †Pseudoschwagerina
* †Pterocephalia
* †Pteronites
* †Ptychagnostus
** †Ptychagnostus aculeatus
** Fossil of the Cambrian trilobite Ptychagnostus atavus †Ptychagnostus atavus
** †Ptychagnostus cassis
** †Ptychagnostus germanus
** †Ptychagnostus intermedius
** †Ptychagnostus occultatus
** †Ptychagnostus punctuosus
** †Ptychagnostus richmondensis
** †Ptychagnostus seminula
* †Ptychomphalus
* †Ptychoparella
* †Ptylopora
** †Ptylopora condrai
** †Ptylopora eliasi
* †Ptyocephalus
** †Ptyocephalus accliva
** †Ptyocephalus declevita – type locality for species
** †Ptyocephalus declivita
** †Ptyocephalus versini
** †Ptyocephalus vigilans
* †Pugnax
** †Pugnax utah – type locality for species
* †Pugnoides
* †Punctospirifer
** †Punctospirifer campestris
** †Punctospirifer kentuckensis
* †Punka
** †Punka nitida – or unidentified comparable form

## Q

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* †Quadratia
* †Quadrisonia – tentative report
** †Quadrisonia lavadamensis
* †Quadrochonetes
** †Quadrochonetes type locality for species A – informal

## R

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* †Ramiporalia
* †Raphistoma – tentative report
* †Raphistomina
* †Ratcliffespongia – type locality for genus
** †Ratcliffespongia perforata – type locality for species
** †Ratcliffespongia sheeleri
** †Ratcliffespongia wheeleri – type locality for species
* †Rayonnoceras
** †Rayonnoceras solidiorme
* Fossil of the Early Ordovician-Permian benthic alga Receptaculites †Receptaculites
** †Receptaculites elongatus
** †Receptaculites mammilaris
** †Receptaculites mammillaris
* †Rectifenestella
** †Rectifenestella tenax
* †Regispongia
** †Regispongia contorta
* †Remopleuridiella
** †Remopleuridiella angularis – type locality for species
** †Remopleuridiella caudalimbata
* †Reticulatia
** †Reticulatia americana
* †Retispira
** †Retispira cincta – type locality for species
** †Retispira textilis – or unidentified comparable form
* †Rhabdomeson
** †Rhabdomeson artum
* †Rhipidomella
** †Rhipidomella missouriensis
* Shell of a Rhodea land snail †Rhodea
** †Rhodea vespertina
* †Rhombopora
** †Rhombopora tenuirama
* †Rhynchopora
* †Ribeiria
** †Ribeiria lucan
* †Rigbyocarpus – type locality for genus
** †Rigbyocarpus ebracteatus – type locality for species
* †Rodea
** †Rodea vespertina – or unidentified comparable form
* †Rossaspis
** †Rossaspis superciliosa
* †Rossicurus
** †Rossicurus lepidus
* †Rugatia
** †Rugatia occidentalis
* †Rugosochonetes
** †Rugosochonetes loganensis
* Fossil of the arthropod burrow ichnogenus Rusophycus †Rusophycus
* †Rylstonia – tentative report

## S

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* †Saffordotaxis
* †Sanguinolites
** †Sanguinolites elongatus – type locality for species
* †Saukia
* Fossil of the Cambrian-Ordovician trilobite Saukiella †Saukiella
* †Scandodus
** †Scandodus furnishi
* †Scaphellina – tentative report
* †Scenella
** †Scenella radians
* †Schizambon
** †Schizambon obtusus – type locality for species
* †Schizodus
** †Schizodus bifidus
** †Schizodus subovatus – type locality for species
* †Schizophoria
* †Schmalenseeia
* †Schuchertella
** †Schuchertella lens
* †Schwagerina
* †Scolicia
* †Scolopodus
** †Scolopodus gracilis
** †Scolopodus pseudoquadratus
** †Scolopodus quadraplicatus
** †Scolopodus rex
* †Seelyia
* †Selenocoryphe – type locality for genus
** †Selenocoryphe platyura – type locality for species
* Fossil of the Cambrian priapulid worm Selkirkia †Selkirkia
** †Selkirkia columbia – or unidentified comparable form
** †Selkirkia spencei
** †Selkirkia willoughby
* †Sentinelia – tentative report
** †Sentinelia draco – or unidentified comparable form
* †Septimyalina
** †Septimyalina burmai – tentative report
* †Septopora
** †Septopora ulrichi
* †Shoshonorthis
** †Shoshonorthis michaelis
** †Shoshonorthis swanensis
* †Shumardia
** †Shumardia exopthalmus
* Restorative model of the Cambrian arthropod Sidneyia †Sidneyia
* †Sigillaria
** †Sigillaria brardii
* †Sinuella – tentative report
* †Siphonobolus – tentative report
* †Spathognathus
** †Spathognathus cristulus
** †Spathognathus scitulus
* †Spencella
** †Spencella utahensa – type locality for species
** †Spencella utahensis
* Life restoration of the Carboniferous-Permian synapsid (mammal precursor) Sphenacodon Sphenacodon
** †Sphenacodon ferocior – or unidentified comparable form
* †Sphenophyllostachys – tentative report
* †Sphenophyllum
** †Sphenophyllum angustifolium
** †Sphenophyllum verticillatum
* †Sphenopteridium
** †Sphenopteridium dissectum
** †Sphenopteridium zaitzeffii – type locality for species
* †Sphenopteris
** †Sphenopteris diphlebia – type locality for species
* †Sphenosteges
** †Sphenosteges hispidus
* †Spinilingula
** †Spinilingula prisca – type locality for species
* †Spinofacia – type locality for genus
** †Spinofacia pectinatus – type locality for species
* Fossilized shell of the Late Ordovician-Late Triassic brachiopod Spirifer †Spirifer
** †Spirifer centronatus
** †Spirifer opimus
** †Spirifer rockymountanus
* †Spiriferina
* †Spirinella
** †Spirinella pauciplicata
* Spirorbis
* †Squamaria
* †Squamularia – report made of unidentified related form or using admittedly obsolete nomenclature
* †Stenolobulites
** †Stenolobulites simulator
** †Stenolobulites sinuosus
* †Stenopora
** †Stenopora confusionensis
* †Stenoporella
** †Stenoporella mineriensis
* †Stenorhachis – tentative report
** †Stenorhachis genalticurvatus
* †Stibaraster – type locality for genus
** †Stibaraster ratcliffei – type locality for species
* Fossil preserved in situ of a Carboniferous tree-like club moss relative with attached Stigmaria rhizome system †Stigmaria
** †Stigmaria ficoides
* †Stigmariopsis
** †Stigmariopsis anglica
* †Stolodus – or unidentified related form
** †Stolodus stola
* †Straparollus
* †Streblochondria
* †Strebloplax
** †Strebloplax pertusa
* †Streblopteria
** †Streblopteria montpelierensis
* †Streblotrypa
** †Streblotrypa angulatum
* †Streptelasma
* †Striatifera
** †Striatifera brazeriana
* †Strigambitus
** †Strigambitus utahensis
* †Strobeus – or unidentified related form
* †Sulcoretepora
* †Supaia
** †Supaia rigida
* †Symphysurina
** †Symphysurina cleora – or unidentified comparable form
** †Symphysurina globocapitella
** †Symphysurina illaenoides
** †Symphysurina spicata – or unidentified comparable form
** †Symphysurina uncaspicata
** †Symphysurina walcotti
* †Symphysurus – tentative report
* †Synarmocrinus
** †Synarmocrinus depressus – type locality for species
* †Syntrophina
** †Syntrophina campbelli – or unidentified comparable form
** †Syntrophina carinifera
* †Syntrophopsis
** †Syntrophopsis polita
** †Syntrophopsis transversa
* Fossil of the Devonian tabulate coral Syringopora †Syringopora
** †Syringopora aculeata
** †Syringopora surcularia
* †Syringothyris
** †Syringothyris textus

## T

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* †Tabulipora
** †Tabulipora atacta
** †Tabulipora carbonaria
** †Tabulipora ricta
** †Tabulipora sarcinula
** †Tabulipora stragula
* †Taeniopteris
* †Talpaspongia
** †Talpaspongia clavata
* Fossil of the feeding trace ichnogenus Teichichnus †Teichichnus – tentative report
* †Telangium
** †Telangium affine
* †Terranovella
* †Tesselacauda
** †Tesselacauda depressa – or unidentified comparable form
* †Testiispongia – type locality for genus
** †Testiispongia venula – type locality for species
* †Testispongia
** †Testispongia venula
* †Tetragraptus
** †Tetragraptus quadribrachiatus – or unidentified comparable form
* Fossils of the burrow ichnogenus Thalassinoides †Thalassinoides – tentative report
* †Thamniscus
** †Thamniscus raribifurcatus
* †Thamnosia – or unidentified comparable form
** †Thamnosia arctica – tentative report
* †Timania
* †Timaniella
** †Timaniella pseudocamerata
* †Tingia
** †Tingia placida – type locality for species
* †Tomagnostella
** †Tomagnostella exsculpta
* †Tonkinella
** †Tonkinella breviceps
** †Tonkinella valida
* †Torynifer
* †Totiglobus – tentative report
** †Totiglobus lloydi
* †Trace
** †Trace fossil
* †Trachycheilus
** †Trachycheilus granulosus
** †Trachycheilus whirlwindensis
* †Trematorthis – tentative report
* †Tricitictes
* †Tricrepicephalus
** †Tricrepicephalus teres
* †Trigonocarpus
** †Trigonocarpus noeggerathii
* †Trigonocerca
** †Trigonocerca typica
* †Trigonocercella
** †Trigonocercella acuta
* Illustration of a fossil of the Cambrian trilobite Trinodus †Trinodus
* †Triplagnostus
** †Triplagnostus gibbus
* †Triplophylites
** †Triplophylites compressus
** †Triplophylites ellipticus
** †Triplophylites subcrassus
* †Triticites
* †Tritoechia
** †Tritoechia loganensis
** †Tritoechia sinuata
* †Trocholites
* †Trochophyllum – tentative report
* †Trymataspis
** †Trymataspis depressa
* Restoration of the Permian reptile relative Tseajaia †Tseajaia
** †Tseajaia campi – type locality for species
* †Tulepyge
** †Tulepyge tulensis – type locality for species
* †Tumicephalus
** †Tumicephalus depressus
* †Tuzoia
** †Tuzoia argenta
** †Tuzoia guntheri
** †Tuzoia retifera
* †Tympanuella
** †Tympanuella transversa

## U

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* †Ufimia
* †Ulrichodina – tentative report
* †Uromystrum
** †Uromystrum validum – or unidentified comparable form
* †Utagnostus
** †Utagnostus trispinulus
* †Utahacanthus – type locality for genus
** †Utahacanthus guntheri – type locality for species
* †Utahcaris
** †Utahcaris orion
* Life restoration of the Carboniferous amphibian Utaherpeton †Utaherpeton – type locality for genus
** †Utaherpeton franklini – type locality for species
* †Utaspis
** †Utaspis marjumensis

## V

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* †Valospongia
** †Valospongia gigantis – type locality for species
** †Valospongia gigantus
* Fossil of the Cambrian-Silurian sponge Vauxia †Vauxia
** †Vauxia bellula
** †Vauxia gracilenta
** †Vauxia magna – type locality for species
* †Verkhotomia
** †Verkhotomia plenoides – or unidentified comparable form
* †Vesiculophyllum
* †Virgiana
** †Virgiana utahensis – type locality for species
* †Vnigripecten
** †Vnigripecten phosphaticus – or unidentified comparable form
* †Vorticina
** †Vorticina vortex – type locality for species

## W

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* †Waagenites
** †Waagenites type locality for species A – informal
* †Waagenoconcha
* †Wahwahlingula
** †Wahwahlingula sevierensis – type locality for species
* †Walcottoceras – tentative report
** †Walcottoceras monsense
* Restoration of the Cambrian arthropod Waptia †Waptia
** †Waptia fieldensis – or unidentified comparable form
* †Warthia – tentative report
* †Weeksina
** †Weeksina unispina
* †Wellerella
** †Wellerella osagensis
** †Wellerella tetrahedra
* †Wewokella
** †Wewokella solida
* †Wilkingia
* †Wimanella
* Life restoration of the Cambrian possible mollusc Wiwaxia †Wiwaxia
** †Wiwaxia corrugata
* †Worthenia

## X

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* Restoration of the Late Devonian–Triassic freshwater shark Xenacanthus †Xenacanthus – or unidentified related form
** †Xenacanthus texensis
* †Xenostegium
** †Xenostegium acuminferentis – or unidentified comparable form
** †Xenostegium franklinense
* †Xestotrema
** †Xestotrema pulchrum
* †Xystocrania – tentative report
** †Xystocrania perforator

## Y

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* †Yakia – tentative report
* †Yakovlevia
** †Yakovlevia multistriata
* †Yuknessaspis
** †Yuknessaspis benningtonis – type locality for species
* †Yuknessia
** †Yuknessia simplex
* †Yunnania

## Z

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* †Zacanthoides
** †Zacanthoides divergens
** †Zacanthoides divergensis
** †Zacanthoides fronslicinus
** †Zacanthoides grabaui
** †Zacanthoides idahoensis
** †Zacanthoides prolixis
* †Zaphrentites
* †Zhanatella
** †Zhanatella utahensis
* †Zittelella
** †Zittelella clarae – or unidentified comparable form
* †Zittelloceras