# List of the Paleozoic life of Iowa

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

## A

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* †Abatocrinus
* †Acidaspis
* †Aclisina
* Fossilized calyx and partial stem of the Devonian-Permian crinoid ("sea lily") Actinocrinites †Actinocrinites
** †Actinocrinites gibsoni
** †Actinocrinites jugosus
** †Actinocrinites lowei
** †Actinocrinites pernodosus
** †Actinocrinites probolos
* †Actinopteria – tentative report
* †Actinostroma
** †Actinostroma clathratum
* †Acutatheca
** †Acutatheca propira
* †Adocetocystis
* †Adolfia
* †Aechmina
** †Aechmina cuspidata
** †Aechmina ionensis
** †Aechmina maquiketensis
** †Aechmina taurea
* †Agassizodus
** †Agassizodus variabilis
* †Agelacrinites
* †Aglaocrinus
** †Aglaocrinus compactus
* †Allanella
** †Allanella allani
** †Allanella annae
** †Allanella cardinalis
* †Allenella
** †Allenella allani
** †Allenella annae
* †Allocrinus
** †Allocrinus ornatus
** †Allocrinus subglobosus
* †Allorhynchus
** †Allorhynchus currei – or unidentified comparable form
* †Allozygocrinus
** †Allozygocrinus dubuquensis
* †Alveolites
* †Ambocoelia
** †Ambocoelia louisianaensis
** †Ambocoelia minuta
* †Ambonychia
* †Americoncha
** †Americoncha marginata
* †Amphicoelia
* †Amphicyrtoceras
* †Amphipora
** †Amphipora pervesiculata
* †Amplexus
* †Anartiocystis
* †Anastrophia
* †Anataphrus
* †Anematina
** †Anematina conica
* †Angyomphalus
** †Angyomphalus lens
** †Angyomphalus penelenticulata – type locality for species
* †Anisotrypa
* †Anomphalus
* †Anthracospirifer
** †Anthracospirifer pellaensis
* †Antiquatonia
* †Antirhynchonella
* †Antirotella
** †Antirotella kindlei – type locality for species
* †Aorocrinus
* †Aparchites
** †Aparchites barbatus
** †Aparchites carinatus
** †Aparchites chatfieldensis
** †Aparchites ellipticus
** †Aparchites fimbriatus
** †Aparchites macrus
** †Aparchites paratumida
* †Aphelecrinus
* †Apycnodiscus
* †Arabellites
* †Arachnophyllum
* †Archaeocalyptocrininus
** †Archaeocalyptocrininus iowensis
** †Archaeocalyptocrininus nodosus
* †Archaeocalyptocrinus
** †Archaeocalyptocrinus iowensis
** †Archaeocalyptocrinus nodosus
* †Archaeocrinus
** †Archaeocrinus obconicus
* †Archaeogastropod
* †Archinacella
** †Archinacella rotunda
* Fossil of the Silurian trilobite Arctinurus †Arctinurus
* †Arctomeristina
* †Arisaigia
* †Arrectocrinus
** †Arrectocrinus iowensis
* †Arthroxylon
* †Asphaltinella
* †Asterophyllites
** †Asterophyllites multifolia
* †Asthenophyllum
* †Astraeospongium
* †Astreptodictya
* †Astrocystites
** †Astrocystites ottawaensis – tentative report
* †Atelodictyon
** †Atelodictyon masoncityense – type locality for species
* †Athyris
** †Athyris cedarensis
** †Athyris crassicardinalis
** †Athyris fultonensis – or unidentified comparable form
** †Athyris simplex
** †Athyris spiriferiodes
** †Athyris vitatta
** †Athyris vittata
** †Athyris zonulata
* †Atribonium
** †Atribonium nora
** †Atribonium paupera
** †Atribonium prolifica
** †Atribonium subovata
** †Atribonium swallovi
* †Atrypa
** Fossilized shell of the Silurian-Late Devonian brachiopod Atrypa reticularis †Atrypa reticularis
** †Atrypa reticularus
* †Atryparia
** †Atryparia varicostata
* †Atrypoidea
* †Aulacella
* †Aulocopella
** †Aulocopella dactylos – type locality for species
** †Aulocopella probolos – type locality for species
** †Aulocopella scelidos – type locality for species
* †Aviculopecten
** †Aviculopecten marbuti – or unidentified comparable form

## B

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* Bairdia
* †Bairdiocypris
** †Bairdiocypris granti
* †Bairdocypris
** †Bairdocypris granti
* †Basseleratia
** †Basseleratia typa
* †Bassleratia
** †Bassleratia typa
* †Batostomella
* †Baylea
** †Baylea trifibra – type locality for species
* †Beecheria
** †Beecheria chouteauensis
* †Belemnocrinus
* Fossilized shell of the Silurian-Early Triassic mollusc Bellerophon †Bellerophon
** †Bellerophon blairi
** †Bellerophon panneus
** †Bellerophon patersoni
** †Bellerophon vinculatus
* †Bellornatia
** †Bellornatia tricollis
* †Belodina
** †Belodina compressa
* †Beloitoceras – tentative report
** †Beloitoceras discrepana
* †Bembexia
** †Bembexia minima
* †Bensbergia
** †Bensbergia pulchra – type locality for species
* †Beyrichia
** †Beyrichia irregularis
* †Bighornia
* †Blothrocrinus
* †Bobbodus
** †Bobbodus schaefferi
* †Bolicrinus
** †Bolicrinus deflatus
** †Bolicrinus globosus
* †Bollia
** †Bollia regularis
** †Bollia ruthae
** †Bollia subaequata
* Reconstructive diagram (left) of a fossil (right) of the Ordovician sea urchin Bothriocidaris. The short spines which were attached to the tubercles are not drawn. †Bothriocidaris
** †Bothriocidaris maquoketensis
* †Botryocrinus
** †Botryocrinus thomasi – type locality for species
* †Brachythyris
** †Brachythyris burlingtonensis – or unidentified comparable form
** †Brachythyris chouteauensis
** †Brachythyris peculiaris
* †Brachytomaria
** †Brachytomaria semele
* †Breviphillipsia
* †Brockocystis
** †Brockocystis nodosaria
* †Bromidella
** †Bromidella depressa
** †Bromidella rhomboides
* †Bryantodina
** †Bryantodina typicalis
* †Bucanella
** †Bucanella conradi
* †Bucanopsis
** †Bucanopsis lirata
* †Bullatekka
** †Bullatekka granilabiatus
* †Bullatella
** †Bullatella granilabiatus
* Life restoration of the Early Ordovician-Silurian trilobite Bumastus †Bumastus
* †Buranella
* †Buxtonia – tentative report
* †Byrsolopsina
** †Byrsolopsina centipunctata
** †Byrsolopsina normella
** †Byrsolopsina ovata
** †Byrsolopsina planilateralis
* Bythocypris
** †Bythocypris curta
** †Bythocypris furnishi

## C

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* †Caenanoplia
** †Caenanoplia logani
* †Calamocarpon
** †Calamocarpon insignis
* †Calceocrinus
** †Calceocrinus levorsoni
* †Calcisphaera
** †Calcisphaera laevis
* †Calliocrinus
** †Calliocrinus longispinus
* †Callocrinus
** †Callocrinus longispinus
* †Callocystites
* †Calvinaria
** †Calvinaria ambigua
** †Calvinaria bransoni
* †Calvustrigis – tentative report
* Fossil of the Early Ordovician-Early Devonian trilobite Calymene †Calymene
* †Camarophorella
** †Camarophorella lenticularis
* †Camarotoechia
** †Camarotoechia chemungensis
** †Camarotoechia chouteauensis
** †Camarotoechia crassiplicata
** †Camarotoechia perplexa
** †Camarotoechia quadricostatum
** †Camarotoechia saxatilis
** †Camarotoechia saxatillis
** †Camarotoechia tuta
* †Camerella
* †Carabocrinus
** †Carabocrinus radiatus
** †Carabocrinus slocomi
* †Cardiola
** †Cardiola lyoni
* †Carinatrypa
** †Carinatrypa dysmorphstrota
* †Cariniferella
** †Cariniferella iowensis
* †Carpocrinus
** †Carpocrinus bodei
* †Caryocrinites
* Fossil of the Ordovician-Silurian tabulate coral Catenipora †Catenipora
* †Ceratocephala
* †Ceratopsis
** †Ceratopsis humilinoda
** †Ceratopsis quadrifida
** †Ceratopsis trilobis
* †Ceraurus
* †Cerithioides
** †Cerithioides judiae
* †Characterophyllum
** †Characterophyllum nanum
* †Charactoceras
* †Charactophyllum
** †Charactophyllum nanum
* †Charionella
** †Charionella nortoni
* Fossil of the Cambrian-Middle Devonian trilobite Cheirurus †Cheirurus
* †Chomatodus
** †Chomatodus inconstans
* †Chonetes
** †Chonetes glenparkensis
** †Chonetes illinoisensis
** †Chonetes logani
** †Chonetes multicosta
** †Chonetes multicostata
** †Chonetes ornatus
* †Chonetina
* †Chonetinella
* †Chonetipustula
** †Chonetipustula concentrica
* †Chonopectus
** †Chonopectus fischeri
* †Chonophyllum
* †Clathrocoilona
** †Clathrocoilona involuta – type locality for species
* †Clathrodictyon
* †Cleiocrinus
** †Cleiocrinus regius
* †Cleiothyridina
** †Cleiothyridina crassicardinalis – or unidentified related form
** †Cleiothyridina glenparkensis – or unidentified comparable form
** †Cleiothyridina incrassata – or unidentified comparable form
** †Cleiothyridina sublamellosa
* †Climacoconus
** †Climacoconus pumilus
* Assemblage of fossils of the Cambrian graptolite Climacograptus †Climacograptus
** †Climacograptus pumilis
** †Climacograptus typicalis
* †Clinolithes
* †Clinopistha
* †Clintonella – tentative report
* †Clorinda
* †Cochliodus
** †Cochliodus occidentalis
* †Coelospira
* †Coeloterorhynchus
** †Coeloterorhynchus schucherti
** †Coeloterorhynchus subacuminata
** †Coeloterorhynchus subacuminatus
* †Coenites
* †Composita
** †Composita humilis – tentative report
** †Composita immatura – or unidentified comparable form
** †Composita trinuclea
* †Compsocrinus
* †Concavicaris
** †Concavicaris sinuata – or unidentified comparable form
* †Conocardium
* †Conotreta
* †Conularia
* †Coolinia
* Fossil of the Middle Ordovician-Carboniferous horn coral Cornulites †Cornulites
* †Costistricklandia
** †Costistricklandia castellana
** †Costistricklandia multilirata
* †Cotylacrina
** †Cotylacrina sandra
* †Cranaena
** †Cranaena amana
** †Cranaena arcuosa
** †Cranaena calvini
** †Cranaena depressa
** †Cranaena elia
** †Cranaena famelica
** †Cranaena inflata
** †Cranaena infrequens
** †Cranaena iowensis
** †Cranaena jacunda
** †Cranaena lata
** †Cranaena littleonensis
** †Cranaena littletonensis
** †Cranaena maculata
** †Cranaena marsii
** †Cranaena micula
** †Cranaena navicella
** †Cranaena occidentalis
** †Cranaena pachytesta
** †Cranaena parvirostra
** †Cranaena rhomboidialis
** †Cranaena rockfordensis
** †Cranaena romingeri
** †Cranaena seminula
** †Cranaena subcylindrica
** †Cranaena subglobosa
** †Cranaena subglossa
** †Cranaena subgobulosa
** †Cranaena subouata
** †Cranaena subovata
** †Cranaena thomasi
* †Cranaenella
* †Crania
** †Crania famelica
* †Crassiproetus
** †Crassiproetus arietinus
** †Crassiproetus bumastoides
** †Crassiproetus occidens
** †Crassiproetus searighti
* †Cremacrinus
** †Cremacrinus gerki
** †Cremacrinus guttenbergensis
** †Cremacrinus punctatus – or unidentified related form
** †Cremacrinus type locality for species – informal
* †Cribanocrinus
* †Crotalocrinintes
* Fossilized stem segments of the Silurian crinoid ("sea lily") Crotalocrinites †Crotalocrinites
* †Crurithyris
* †Cryptophyllus
** †Cryptophyllus oboloides
** †Cryptophyllus sulcatus
* †Ctenobolbina
** †Ctenobolbina emaciata
** †Ctenobolbina maquoketensis
* †Ctenodonta
** †Ctenodonta anatina
** †Ctenodonta calvini
* †Cupularostrum
** †Cupularostrum contracta
** †Cupularostrum saxatilis
** †Cupularostrum saxatillis
* †Cupulocorona
* †Cupulocrinus
** †Cupulocrinus angustatus
** †Cupulocrinus conjugans – or unidentified related form
** †Cupulocrinus crossmani
** †Cupulocrinus latibrachiatus – or unidentified related form
* †Curtognathus
* †Cusacrinus
* †Cyathaxonia
** †Cyathaxonia arcuatus
* Fossilized calyx and partial stem of the Silurian-Permian crinoid ("sea lily") Cyathocrinites †Cyathocrinites
* †Cyathocrintes
** †Cyathocrintes striatissimus – or unidentified comparable form
* †Cyathophyllum
* †Cyclocrinites
** †Cyclocrinites dactilioides
** †Cyclocrinites dactioloides
* †Cyclocystoides
* †Cyclonema
** †Cyclonema bilix
** †Cyclonema minuta
* †Cyclora
* †Cynopodius
* †Cyphaspis
* †Cypricardella
* †Cypricardinia
** †Cypricardinia sulcifera
* †Cyrtia
** †Cyrtia exporrecta
* †Cyrtina
** †Cyrtina inulta
** †Cyrtina iowaensis
** †Cyrtina triquetra
** †Cyrtina umbonata
* †Cyrtodonta
* †Cyrtolites
* †Cyrtospira
* Fossilized shells of the Middle-Late Devonian brachiopod Cyrtospirifer †Cyrtospirifer
** †Cyrtospirifer disjunctus
** †Cyrtospirifer whitneyi
* †Cystiphyllum
** †Cystiphyllum mundulum
* †Cystodictya
* †Cytocrinus

## D

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* †Dalejina
* †Dalmanella
** †Dalmanella edgewoodensis – or unidentified comparable form
* Fossil of the Late Ordovician-Middle Devonian trilobite Dalmanites †Dalmanites
* †Dapsilodus
** †Dapsilodus mutatus
* †Dawsonoceras
* †Decadocrinus
** †Decadocrinus crassidactylus – type locality for species
** †Decadocrinus pachydactylus – type locality for species
** †Decadocrinus spinulifer – type locality for species
* †Decaschisma
* †Dechenella
** †Dechenella haldemani – or unidentified comparable form
** †Dechenella nortoni
** †Dechenella prouti
** †Dechenella rowi – or unidentified comparable form
* Life restoration of two species of the Silurian trilobite Deiphon †Deiphon
* †Delocrinus
** †Delocrinus vulgatus
* †Deltaherpeton – type locality for genus
** †Deltaherpeton hiemstrae – type locality for species
* †Delthyris – tentative report
* †Deltodus
** †Deltodus spatulatus
* †Dendrocrinus
** †Dendrocrinus casei
** †Dendrocrinus curvijunctus – or unidentified related form
** †Dendrocrinus oswegoensis
* Shell of a Dentalium tusk shell †Dentalium
** †Dentalium grandaevum
* †Derbyia
* †Desquamatia
** †Desquamatia brandonensis
** †Desquamatia independensis
** †Desquamatia randalia
** †Desquamatia rotunda
** †Desquamatia rusica
** †Desquamatia scutiformis
** †Desquamatia waterlooensis
* †Devonatrypa
** †Devonatrypa brandonensis
** †Devonatrypa pronis
** †Devonatrypa trowbridgei
** †Devonatrypa waterlooensis
* †Devonochonetes
** †Devonochonetes calivini
* †Devonoproductus
** †Devonoproductus reticulocostus
** †Devonoproductus vulgaris
** †Devonoproductus walcotti
* †Diamphidiocystis
* †Diceromyonia
* †Dichacaenia
** †Dichacaenia harberti
* †Dichocrinus
* †Dicoelosia
* †Dicranella
** †Dicranella bicornis
** †Dicranella marginata
** †Dicranella simplex
** †Dicranella spinosa
** †Dicranella typa
* †Dicranopeltis
* †Dictyoclostus
* †Dictyotomaria
** †Dictyotomaria quasicapillaria – type locality for species
* †Dielasma
** †Dielasma burlingtonensis
** †Dielasma chouteauensis
** †Dielasma formosum
* †Dimerocrinites
** †Dimerocrinites hopkintonensis
** †Dimerocrinites pentangularis
** †Dimerocrinites sculptus
* †Dinobolus
* †Dinolobus
* †Dinorthis
* †Diopatraites
* †Diphyphyllum
* †Diploblastus
** †Diploblastus glaber
* Cambrian graptolite Diplograptus †Diplograptus
** †Diplograptus modestus – or unidentified comparable form
* †Diplophyllum
* †Diplosphaerina
** †Diplosphaerina inaequalis
* †Discosorus
* †Disphyllum
** †Disphyllum conjugans – type locality for species
** †Disphyllum dispassum
** †Disphyllum floydense
** †Disphyllum iowensis – type locality for species
** †Disphyllum tubiforme
* †Dolerorthis
* †Donaldina – tentative report
* †Dorycrinus
** †Dorycrinus gouldi
** †Dorycrinus mississippiensis
* †Douvillina
** †Douvillina arcuata
** †Douvillina cayuta
** †Douvillina delicata
** †Douvillina distans
** †Douvillina maxima
** †Douvillina navicula
** †Douvillina oxycostratum
** †Douvillina variabilis
* †Douvillinaria
** †Douvillinaria delicata
** †Douvillinaria perversa
** †Douvillinaria variabilis
** †Douvillinaria variablis
* †Drepanoistodus
** †Drepanoistodus suberectus
* †Dudleyaspis
* †Dvorakia
** †Dvorakia chattertoni – type locality for species

## E

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* †Earlandia
* †Ecclimadictyon
** †Ecclimadictyon fastigiatum
* †Echinocoelia
** †Echinocoelia halli
* †Echinoconchus
* †Ectenocrinus
** †Ectenocrinus raymondi
** †Ectenocrinus simplex
* †Ectodemites
** †Ectodemites primus
* †Ectogrammysia
** †Ectogrammysia hannibalensis
* Life restoration of the Late Devonian-Carboniferous Chimaera relative Edestus †Edestus
** †Edestus crenulata
** †Edestus mirus – type locality for species
* †Edmondia
** †Edmondia jejunus
* †Eldredgeops
** †Eldredgeops rana
* †Eleutherokomma
** †Eleutherokomma jasperensis
* †Elita
** †Elita diversa
** †Elita inconsueta
** †Elita johnsonensis
** †Elita minor
** †Elita subundifera
** †Elita urbana
* †Ellesmeria
** †Ellesmeria scobeyi
* †Ellesmeroceras
** †Ellesmeroceras luthei
** †Ellesmeroceras thomasi
* †Emanuella
** †Emanuella ii – report made of unidentified related form or using admittedly obsolete nomenclature
** †Emanuella meristoides
** †Emanuella sublineata
* †Emphereaster
** †Emphereaster missouriensis
* †Encrinurus
* Fossilized shells and restored appearances of the Middle-Late Ordovician nautiloid cephalopod Endoceras †Endoceras
* †Endostaffella
** †Endostaffella discoidea
* †Endothyra
** †Endothyra obsoleta – tentative report
* †Endothyranella
* †Enoploura
** †Enoploura wetherbyi
* †Enteletes
* †Entelophyllum
* Eocaudina
** †Eocaudina septaforaminalis – type locality for species
* †Eochonetes
** †Eochonetes aspera
** †Eochonetes dignata – type locality for species
** †Eochonetes recedens
* †Eodictyonella
* †Eolissochonetes
* †Eomartiniopsis
** †Eomartiniopsis rostrata
* †Eoparisocrinus
** †Eoparisocrinus crossmani
* †Eophacops
* †Eoplectodonta
* †Eoschmidtella
** †Eoschmidtella umbonata
* †Eospirifer
** †Eospirifer radiatus
* †Eospirigerina
** †Eospirigerina putilla – or unidentified comparable form
* †Eostrophalosia
** †Eostrophalosia independensis
** †Eostrophalosia inexpectans
** †Eostrophalosia rockfordensis
* †Eosyringothyris
** †Eosyringothyris aspera
** †Eosyringothyris occidentalis
** †Eosyringothyris thomasi
** †Eosyringothyris triangularis
* †Ephippiorthoceras
* †Eridoconcha
** †Eridoconcha gibbera
** †Eridoconcha punctata
* †Eridotrypa
* †Erismacanthus
** †Erismacanthus barbatus
* †Erismodus
** †Erismodus radicans
* †Escharopora
* Fossilized calyx of the Silurian-Middle Devonian crinoid ("sea lily") Eucalyptocrinites †Eucalyptocrinites
** †Eucalyptocrinites depressus
** †Eucalyptocrinites inornatus
** †Eucalyptocrinites ornatus – or unidentified comparable form
** †Eucalyptocrinites proboscidalis
* †Eukloedenella
** †Eukloedenella richmondensis
* †Eumetria
** †Eumetria iowensis
** †Eumetria osagensis
* †Eumorphocystis
* †Eunema
** †Eunema quadrisulcata
* Fossilized shell of the Silurian-Permian sea snail Euomphalus †Euomphalus
** †Euomphalus angularis
** †Euomphalus obtusus
* †Euphemites
** †Euphemites lentiformis
** †Euphemites urei
* †Euprimitia
** †Euprimitia celata
** †Euprimitia flores
** †Euprimitia labiosa
** †Euprimitia linepunctata
** †Euprimitia minuta
** †Euprimitia sanctipauli
* †Euptychocrinus
** †Euptychocrinus skopaios
* †Eurychilina
** †Eurychilina incurva
** †Eurychilina minutifoveata
** †Eurychilina partifimbriata
** †Eurychilina reticulata
** †Eurychilina subradiata
** †Eurychilina ventrosa
* †Eutaxocrinus
** †Eutaxocrinus gracilis
* †Exocrinus
** †Exocrinus multirami

## F

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* Y
* Z
* †Fardenia – tentative report
* †Favosites
* †Fenestella
* †Fenestrellina
* †Ferganella
* †Fistulipora
* †Flabellitesia
** †Flabellitesia flabellites
* Front (left) and right side (right) views of an enrolled fossil of the Middle Ordovician-Silurian trilobite Flexicalymene †Flexicalymene
* †Floweria
** †Floweria altirostris
** †Floweria orthoplicata
** †Floweria prava
* †Floyda
** †Floyda concentrica
* †Fourstonella

## 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
* †Galateacrinus
** †Galateacrinus gossameri
* †Gilmocrinus
* †Girtyella
** †Girtyella indianse
* †Glabrocingulum
** †Glabrocingulum angulosa – type locality for species
** †Glabrocingulum minutum – type locality for species
* †Glaphyrites
* †Glossites
* †Glyptorthis
** †Glyptorthis pulchra – type locality for species
** †Glyptorthis subcircularis – type locality for species
* †Gomphocystites
* Fossilized shell of the Late Devonian-Late Triassic ammonoid cephalopod Goniatites †Goniatites
* †Goniocrinus
* †Goniophyllum
** †Goniophyllum pyramidale
* †Gorgonophontes
** †Gorgonophontes peleron
* †Graffhamicrinus
** †Graffhamicrinus magnijkus
** †Graffhamicrinus subcoronatus
* †Grammysia
** †Grammysia amygdalinus
* †Gravicalymene
* †Greenops
** †Greenops barrisi
** †Greenops fitzpatricki
* Multiple views of a fossil of the Ordovician horn coral Grewingkia †Grewingkia
* †Gypidula
** †Gypidula cornuta
** †Gypidula munda
** †Gypidula occidentalis
** †Gypidula papyracea
** †Gypidula parva
* †Gypidulina
* †Gyroceras

## 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
* †Hadrorhynchia
** †Hadrorhynchia solon
* †Haeretocrinus
** †Haeretocrinus missouriensis
* †Hagnocrinus
* †Hallatia
** †Hallatia convexa
** †Hallatia duplicata
** †Hallatia particylincrica
** †Hallatia particylindrica
* †Hallicystis
* †Halliella
** †Halliella magnipunctata
* Fossil of the Ordovician bryozoan ("moss animal") Hallopora †Hallopora
* †Halysiocrinus
** †Halysiocrinus barrisi
** †Halysiocrinus elephantinus – type locality for species
* †Halysites
* †Hammatostroma
** †Hammatostroma albertense
* †Harpidella – tentative report
** †Harpidella brandonensis
* †Harpidium
** †Harpidium luckeyensis – or unidentified related form
** †Harpidium maquoketa
* †Hedeina
* †Heliolites
* Fossil of the Middle Devonian horn coral Heliophyllum †Heliophyllum
** †Heliophyllum solidum
* †Helliella
** †Helliella magnipunctata
* †Hemicystites
* †Hemiphragma
* †Hemiplethorhynchus
** †Hemiplethorhynchus subovatum
* †Hermatostroma
** †Hermatostroma polymorphum
* †Hernodia
* †Hesperidella
** †Hesperidella initialis
* Fossil of the Devonian colonial rugose coral Hexagonaria, also known as a Petoskey stone †Hexagonaria
** †Hexagonaria bassleri
** †Hexagonaria inequalis
** †Hexagonaria oweni
** †Hexagonaria whitfieldi
* †Hibbardella
** †Hibbardella subacoda
* †Hindella
* †Hindia
** †Hindia parva – tentative report
** †Hindia sphaeroidalis
* †Holcocrinus
* Fossilized shells of the Ordovician-Carboniferous sea snail Holopea †Holopea
** †Holopea iowaensis
* †Homacanthus
** †Homacanthus delicatulus
* †Homoeospira
* †Homotrypella
* †Hormotoma
** †Hormotoma gracilis
* †Howellella
* †Hudsonaster
* †Huronia
* †Hustedia
* †Hyattidina
* †Hybocrinus
** †Hybocrinus conicus
†Hyolithes
** †Hyolithes parviusculus
* †Hypergonia
** †Hypergonia percarinata
* †Hypothyridina
** †Hypothyridina emmonsi
** †Hypothyridina intermedia
** †Hypothyridina magister
* †Hypselocrinus
* †Hypsitycha
** †Hypsitycha hybrida
* †Hysitycha
** †Hysitycha neenah
* †Hystriculina

## 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
** †Ianthinopsis pinguis – type locality for species
* †Icriodus
** †Icriodus calvini – type locality for species
** †Icriodus latericrescens
** †Icriodus nodosus
** †Icriodus orri – type locality for species
** †Icriodus subterminus
* †Icthyocrinus
* †Idiognathodus
** †Idiognathodus attenuatus – type locality for species
** †Idiognathodus claviformis
** †Idiognathodus iowaensis – type locality for species
* †Ignoceras
** †Ignoceras undata
* †Indospirifer
** †Indospirifer orestes
* Life restoration of the Carboniferous Chimaera relative Iniopteryx †Iniopteryx
** †Iniopteryx rushlaui
** †Iniopteryx tedwhitei
* †Iocrinus
* †Iowacystis
** †Iowacystis sagittaria
* †Iowaphyllum
** †Iowaphyllum johanni
* †Iowatrypa
** †Iowatrypa americana
** †Iowatrypa owenensis
* †Ischadites
* †Isorthis
* †Isorthoceras
** †Isorthoceras sociale
* Fossil of the Middle-Late Ordovician giant trilobite Isotelus. †Isotelus

## 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
* †Juresania

## 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
* †Kaskia
* †Kayoceras
* †Kiesowia
** †Kiesowia binoda
** †Kiesowia insolens
* †Kinocrinus
** †Kinocrinus inflatus
* Fossilized shells of the Middle Ordovician-Permian nautiloid cephalopod Kionoceras †Kionoceras
** †Kionoceras decorahense – type locality for species
* †Kirkidium
* †Kitikamispira – tentative report
** †Kitikamispira perstrialis – type locality for species
* †Knightella
** †Knightella shumardiana – type locality for species
* †Kosovopeltis
** †Kosovopeltis acamas
* †Krausella
** †Krausella arcuata
** †Krausella curtispina
** †Krausella inaequalis
* †Krinocrinus
** †Krinocrinus inflatus

## 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
* †Laccoprimitia
** †Laccoprimitia elegantula
** †Laccoprimitia fillmorensis
* †Lacertasterias – type locality for genus
** †Lacertasterias elegans – type locality for species
* †Laddella
** †Laddella insueta
* †Ladogioides
** †Ladogioides solon
* Laevidentalium
* †Lamottia
** †Lamottia heroensis
* †Lampterocrinus
* †Lanecrinus – tentative report
* †Leangella
* †Lecanocrinus
* †Lecathylus
** †Lecathylus gregarius
* †Lechritochoceras
* †Leioclema
** †Leioclema occidens
* †Leiorhynchus
** †Leiorhynchus argenteum
** †Leiorhynchus gosseleti
** †Leiorhynchus iris
* †Leperditella
** †Leperditella dorsicornis
** †Leperditella fryei
** †Leperditella macra
** †Leperditella millepunctata
** †Leperditella persimilis
** †Leperditella sacceliformis
* †Leperditia
* †Lepidocyclus
* †Lepidoleptaena – or unidentified related form
* †Leptaena
** †Leptaena rhomboidalis
* †Leptagonia
** †Leptagonia analoga
* †Leptellina
* †Leptobolus
** †Leptobolus occidentalis
* †Leptodesma
** †Leptodesma acutilaris
** †Leptodesma subovata
* †Leptopora
** †Leptopora typa
* †Leptoptygma
** †Leptoptygma oligospira – type locality for species
* †Leptostrophia – tentative report
* †Leptotrypella
* †Lichenalia
* †Lichenocrinus
* Shell of the Cambrian-modern brachiopod Lingula †Lingula
** †Lingula changi
** †Lingula cuneata
** †Lingula fragila
** †Lingula milwaukeensis – or unidentified comparable form
** †Lingula milwaukiensis
* †Lingulodiscina
** †Lingulodiscina marginalis
* †Linocrinus
* †Linoporella
* †Linoproductus
** †Linoproductus ovatus
* †Liospira
** †Liospira micula
** †Liospira spicula – or unidentified comparable form
* †Litostrobus
** †Litostrobus iowensis
** †Litostrobus paulus
* †Lonchodus – tentative report
* †Lophophyllidium
* †Lophospira
** †Lophospira depauperata
* †Lorangerella
** †Lorangerella gregaria
* †Loxonema
* †Lumbriconereites
* †Luxocrinus
** †Luxocrinus simplex
* †Lyonicrinus
* †Lyriocrinus
* †Lysocystites
** †Lysocystites nodosus
* †Lytospira

## 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
* †Macgeea
** †Macgeea camplanulata – type locality for species
** †Macgeea concinnula – type locality for species
** †Macgeea culmula
** †Macgeea solitaria
* †Macrocrinus
** †Macrocrinus mundulus
* Macrocypris
** †Macrocypris kayi
* †Macrocyproides
** †Macrocyproides clermontensis
* †Macronotella
** †Macronotella arcta
** †Macronotella scofeldi
** †Macronotella scofieldi
* †Macropotamorhynchus
** †Macropotamorhynchus tuta
* †Macrostylocrinus
** †Macrostylocrinus compressus
** †Macrostylocrinus obpyramidalis – or unidentified comparable form
** †Macrostylocrinus vermiculatus
* †Manicrinus
* Fossilized shell of the Devonian ammonoid cephalopod Manticoceras †Manticoceras
** †Manticoceras regulare
* †Manticrinus
* †Maquoketacrinus
** †Maquoketacrinus ornatus
* †Maratia
** †Maratia mara
** †Maratia micula
* †Marsupiocrinus
** †Marsupiocrinus primaevus
* †Mediospirifer
* †Megalomoidea
* †Megamyonia
** †Megamyonia unicostata
* †Megastrophia
** †Megastrophia profunda
* †Megistocrinus
** †Megistocrinus pernodosus
* †Melocrinites
* †Merista
* Illustration (lower right, entry 15) of a fossilized shell in front and side views of the Silurian-Late Devonian brachiopod Meristella †Meristella
** †Meristella parva
* †Meristina
* †Merocrinus
* †Mesoblastus – or unidentified comparable form
* †Mesolobus
* †Metaconularia
* †Metalonchodina
** †Metalonchodina deflecta – type locality for species
* †Michelia
* †Michelinoceras
* †Microcardinalia
* †Milleratia
** †Milleratia cincinnatiensis
** †Milleratia cincinnattiensis
* †Mirifusella – type locality for genus
** †Mirifusella fortunata – type locality for species
* †Modiomorpha
* †Monomerella
* †Murchisonia
* †Myalina
* †Mycterops
** †Mycterops whitei – type locality for species
* †Myeinocystites
* †Myelodactylus
* †Mystrocephala
** †Mystrocephala pulchra – or unidentified comparable form
** †Mystrocephala raripustulosus
* †Mytilarca

## 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
* †Nactocrinus
* †Nalivkinia – tentative report
* †Nataliana – type locality for genus
** †Nataliana sinuata – type locality for species
* Fossilized shell of the Early Devonian – Triassic sea snail Naticopsis †Naticopsis
** †Naticopsis depressa – type locality for species
* †Neopanderodus
* †Neospirifer
* †Neozaphrentis
** †Neozaphrentis pellaensis
* †Nervostrophia
** †Nervostrophia calvini
** †Nervostrophia canace
** †Nervostrophia contaderoensis
** †Nervostrophia extensa
** †Nervostrophia multinervosa
** †Nervostrophia rockfordensis
** †Nervostrophia solida
** †Nervostrophia thomasi
* †Newberria
** †Newberria cordiforme
** †Newberria johanni
* †Ningulella
** †Ningulella paucisulcata
* †Nodambichilina
** †Nodambichilina symmetrica
* †Nucellangium
** †Nucellangium glabrum
* †Nucleospira
** †Nucleospira barrisi
* Interior of a fossilized shell of the Early Ordovician-modern marine bivalve Nucula Nucula
** †Nucula glanparkensis
** †Nucula iowensis
* Nuculana
** †Nuculana sacata
* †Nuculites
** †Nuculites neglectus
* †Nuculopsis

## 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
* †Odontopleura
* †Oepikina
* †Oistodus
** †Oistodus venustus
* †Onniella
** †Onniella quadrata
* Life restoration of the Middle-Late Devonian lobe-finned fish Onychodus †Onychodus
* †Opikatia
** †Opikatia emaciata
** †Opikatia rotunda
* †Opoa
* †Orbiculoidea
** †Orbiculoidea telleri
** †Orbiculoidea varsoviensis
** †Orbiculoidea wardi
* †Orecopia
** †Orecopia circinatus – type locality for species
* †Oriostoma
* †Orthoceras
** †Orthoceras indianense
* †Orthodesma
* †Orthograptus
** †Orthograptus eucharis
** †Orthograptus truncatus
* †Orthonychia
** †Orthonychia vomerium
* †Orthospirifer
** †Orthospirifer capax
** †Orthospirifer euruteines
** †Orthospirifer iowensis
** †Orthospirifer parryanus
* †Orthotetes
** †Orthotetes kaskaskiensis
* †Otarion – tentative report
* †Oulodus
** †Oulodus abbreviata – type locality for species
** †Oulodus serratus
* †Ovatia
** †Ovatia laevicostata
** †Ovatia ovata
* †Ozarkodina
** †Ozarkodina campbelli – type locality for species
** †Ozarkodina delicatula
** †Ozarkodina raaschi

## 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
* †Pachyphyllum
** †Pachyphyllum crassicostatum
** †Pachyphyllum dumonti – type locality for species
** †Pachyphyllum gregarium
** †Pachyphyllum minutissimum
** †Pachyphyllum websteri
** †Pachyphyllum woodmani
* †Paladin
** †Paladin wilsoni
* †Palaeocapulus
** †Palaeocapulus equilateralis
* †Palaeoconcha
* †Palaeocyclus
* †Palaeoneilo
** †Palaeoneilo barrisi
** †Palaeoneilo fecunda
* †Palaeostachys
** †Palaeostachys andrewsii
* †Palaeozygopleura
** †Palaeozygopleura difficile
* †Palmatolepis
** †Palmatolepis foliacea
** †Palmatolepis semichatovae
* †Panderous
** †Panderous gracilis
** †Panderous panderi
* †Parabolbina
** †Parabolbina antecedans
** †Parabolbina carinifera
** †Parabolbina staufferi
* †Paracosmetocrinus
* †Paracyclas
** †Paracyclas dubia
** †Paracyclas dubius
** †Paracyclas elliptica
** †Paracyclas parvula
** †Paracyclas paucipleura
** †Paracyclas proavia
** †Paracyclas sabini
** †Paracyclas validalinea
** †Paracyclas validelinea
* †Paraphorhynchus
** †Paraphorhynchus elongatum
** †Paraphorhynchus striatocostatum
* †Paraschmidtella
** †Paraschmidtella irregularis
** †Paraschmidtella uphami
* †Parenthatia
** †Parenthatia camerata
** †Parenthatia punctata
* †Patellilabia
** †Patellilabia scriptiferus
* †Paucicrura
** †Paucicrura corpulenta
* †Paupospira
* Fossil of the Carboniferous crustacean Peachocaris †Peachocaris
** †Peachocaris acanthouraea – type locality for species
* †Pedomphalella
** †Pedomphalella intermedia
** †Pedomphalella subovata
* †Pentamerella
** †Pentamerella dubia
** †Pentamerella laeviscula
** †Pentamerella laeviuscula
** †Pentamerella magna
** †Pentamerella multicostella
** †Pentamerella obsolescens
** †Pentamerella rugosa
** †Pentamerella subarata
* †Pentameroides
** †Pentameroides corrugatus
** †Pentameroides subrectus
* Fossilized shell of the Silurian-Middle Devonian brachiopod Pentamerus †Pentamerus
** †Pentamerus oblongus
* †Pentlandina
* †Pentremites
** †Pentremites pulchellus
* †Perditocardinia
** †Perditocardinia iowensis – type locality for species
* †Periechocrinus
* †Pernopecten
** †Pernopecten cooperensis
* †Petalocrinus
** †Petalocrinus mirabilis
* Fossilized tooth of the Carboniferous-Permian shark Petalodus †Petalodus
** †Petalodus allegheniensis
* †Petalotrypa
** †Petalotrypa formosa
* †Petrocrania
** †Petrocrania famelica
** †Petrocrania familica
* †Petrodus
** †Petrodus patelliformis
* †Phacops
** †Phacops iowensis
* †Phanerotrema
* †Philhedra
** †Philhedra sheldoni
* †Phillipsia
* †Phoebodus
** †Phoebodus densneptuni – type locality for species
* †Pholidostrophia
** †Pholidostrophia iowensis
* †Phragmoceras
* †Phragmodus
** †Phragmodus cognitus
** †Phragmodus undatus
* †Phricodothyris
* †Phymatopleura
* †Physonemus
** †Physonemus hamuspiscatorius
** †Physonemus pandatus
* †Piloricilla
** †Piloricilla sedaliensis
* †Pinnocaris
** †Pinnocaris americana – type locality for species
* †Pisocrinus
* Fossilized shell of the Ordovician brachiopod Plaesiomys †Plaesiomys
** †Plaesiomys subquadrata
* †Plagioglypta
** †Plagioglypta iowaensis
* †Planalvus – type locality for genus
** †Planalvus gibberosa – type locality for species
* †Plasmopora
* †Platyceras
** †Platyceras antiquum
** †Platyceras insolitum
** †Platyceras irrasum
** †Platyceras latum – tentative report
** †Platyceras nasutum
** †Platyceras paralium
* Three fossilized calyces of the Devonian-Permian crinoid ("sea lily") Platycrinites †Platycrinites
* †Platycrinus
* †Platylichas
* †Platyrachella
** †Platyrachella ballardi
** †Platyrachella macbridei
* †Platyschisma
** †Platyschisma barrisi
** †Platyschisma depressa
** †Platyschisma laudoni – type locality for species
* †Platystrophia
** †Platystrophia biforata
* †Plectatrypa
* †Plectodina
** †Plectodina aculeata
* †Plectodonta
** †Plectodonta produla
* Fossil of the Late Ordovician cystoid echinoderm Pleurocystites †Pleurocystites
** †Pleurocystites beckeri
** †Pleurocystites filitextus – tentative report
** †Pleurocystites strimplei
* Pleurotomaria – tentative report
** †Pleurotomaria verticillata
* †Plicochonetes
* †Plicostricklandia
* †Podolithus
* †Poleumita
* †Polusocrinus
** †Polusocrinus rosa
* Various conodont elements of Polygnathus †Polygnathus
** †Polygnathus decorosus
** †Polygnathus intermedius
** †Polygnathus parawebbi
** †Polygnathus xylus
* †Polyplacognathus
** †Polyplacognathus ramosus
* †Polytryphocycloides
* †Polytylites
** †Polytylites wilsoni
* †Porcellia
** †Porcellia crassinoda
** †Porcellia obliquinoda
** †Porcellia rectinoda – type locality for species
* †Porocrinus
** †Porocrinus crassus
** †Porocrinus fayettensis
** †Porocrinus pentagonius
* †Porpites
* †Posidonia
* †Praecupulocrinus
** †Praecupulocrinus conjugans
* †Praenucula – tentative report
* †Praewaagenoconcha
** †Praewaagenoconcha speciosa
* †Prasopora
* †Prasoporina
* †Pregazacrinus
** †Pregazacrinus hemisphericus
* †Primitia
** †Primitia gibbera
** †Primitia spinata
* †Primitiella
** †Primitiella bellevuensis
** †Primitiella carlei
** †Primitiella constricta
** †Primitiella milleri
** †Primitiella plattevillensis
* †Primitiopsis – tentative report
** †Primitiopsis bella
* †Primitopsis – tentative report
** †Primitopsis bella
* †Priscella
* †Probillingsites
* †Productella
** †Productella belanskii
** †Productella camerata
** †Productella fragilis
** †Productella iowa
** †Productella linnensis
** †Productella perplana
** †Productella rugatula
** †Productella sericea
** †Productella subaculeata
** †Productella subalata
** †Productella thomasi
* †Productus
** †Productus arcuatus
** †Productus ovatus
** †Productus sedaliensis
* †Proetides
** †Proetides insignis
* Restoration of the Silurian trilobite Proetus †Proetus
** †Proetus channahonensis – or unidentified comparable form
* †Promexyele
** †Promexyele peyeri
* †Prospira
** †Prospira greenockensis – or unidentified related form
** †Prospira legrandensis
* †Protacrocrinus
* †Protatrypa
* †Protaxocrinus
* †Protoleptostrophia
** †Protoleptostrophia fragilis
* †Protomegastrophia
* †Protometgastrophia
* †Protoniella
** †Protoniella parva
* †Protoscolex
* †Pseudoammodiscus
* †Pseudoatrypa
** †Pseudoatrypa bentonensis
** †Pseudoatrypa blackhawkensis
** †Pseudoatrypa boyeri – or unidentified comparable form
** †Pseudoatrypa bremerensis
** †Pseudoatrypa devoniana
** †Pseudoatrypa minor
** †Pseudoatrypa percrassa
** †Pseudoatrypa rotunda
** †Pseudoatrypa rugatula
* †Pseudobelodina – tentative report
* †Pseudoconocardium
* †Pseudoglomospira
* †Pseudopalmula
** †Pseudopalmula palmuloides
* †Pseudoplagiothyra
** †Pseudoplagiothyra praecursor
* †Pseudozygopleura
* †Pseudulrichia
** †Pseudulrichia simplex
* †Pterinea
* †Ptychophyllum
* †Ptychopleurella
** †Ptychopleurella bouchardi – or unidentified comparable form
* †Ptychopteria
** †Ptychopteria chemungensis
* †Ptyctodopsis – type locality for genus
** †Ptyctodopsis menzeli – type locality for species
* Life restoration of the Late Devonian placoderm fish Ptyctodus †Ptyctodus
* †Pugnoides
** †Pugnoides calvini
** †Pugnoides ottumwa
* †Punctaparchites
** †Punctaparchites rugosus
** †Punctaparchites splendens
* †Punctospirifer
** †Punctospirifer solidirostris
* †Pycnostylus
* †Pyramiblastus
** †Pyramiblastus fusiformis – type locality for species
* †Pyrgocystis

## 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
* †Quasibollia
** †Quasibollia ridicula
* †Quienquecaudex
** †Quienquecaudex springeri

## 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
* †Raphistomina
* †Raymondatia
** †Raymondatia goniglypta
** †Raymondatia gonigplyta
* †Raymondiata
** †Raymondiata goniglypta
* †Resserella
* †Retichonetes
** †Retichonetes brandonensis
* †Reticularia
** †Reticularia cooperensis
* †Retispira
** †Retispira bilabiatus
** †Retispira deflectus
** †Retispira exilis
** †Retispira perelegans
** †Retispira type locality for species Kues & Batten 2001 – informal
* †Rhaphanocrinus
* †Rhaphistomina
* †Rhineoderma
** †Rhineoderma dinglensis
* †Rhipidium
* †Rhipidomella
** †Rhipidomella cuneata
** †Rhipidomella dalyana – or unidentified comparable form
** †Rhipidomella tenuicostata
** †Rhipidomella thiemei
* †Rhodocrinites
* †Rhombopora
* †Rhynchodus
* †Rhynchopora
** †Rhynchopora pustulosa
** †Rhynchopora rowleyi
* †Rhynchotrema
* †Rhynchotreta
* †Rhyssochonetes
** †Rhyssochonetes bellarugosis
* †Rigidella
* †Ripidiorhynchus
** †Ripidiorhynchus cedarensis
* †Rugosochonetes
** †Rugosochonetes multicastatus

## 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
* †Saccelatia
** †Saccelatia angularis
** †Saccelatia arcuamuralis
** †Saccelatia arrecta
** †Saccelatia bullata
** †Saccelatia cletifera
* †Sanguinolites
* †Scaphelasma
* †Schellwienella
** †Schellwienella crenulicostata
** †Schellwienella inaequalis
** †Schellwienella inflata
** †Schellwienella planumbona
* †Schizoblastus
** †Schizoblastus roemeri
* †Schizodus
** †Schizodus sedaliensis
** †Schizodus trigonalis
* †Schizophoria
** †Schizophoria amanaensis
** †Schizophoria athabaskensis – or unidentified related form
** †Schizophoria athabaskiensis – or unidentified related form
** †Schizophoria chouteauensis
** †Schizophoria dorsata
** †Schizophoria floydensis
** †Schizophoria floydia
** †Schizophoria impressa
** †Schizophoria iowensis
** †Schizophoria landoni
** †Schizophoria lata
** †Schizophoria laudoni
** †Schizophoria macfarlanei
** †Schizophoria macfarlanii
** †Schizophoria minor
** †Schizophoria multistriata
** †Schizophoria subelliptica
* †Schmidtella
** †Schmidtella affinis
** †Schmidtella brevis
** †Schmidtella lacunosa
** †Schmidtella latimarginata
* †Schuchertella
** †Schuchertella acutistriata
** †Schuchertella altirostris
** †Schuchertella humboldtensis
** †Schuchertella iowensis
** †Schuchertella nodocostata
** †Schuchertella parva
** †Schuchertella pectiniformis
* †Scofielda
** †Scofielda bilateralis
* †Scofieldia
** †Scofieldia bilateralis
* †Scutellum
** †Scutellum depressum
** †Scutellum thomasi
* Fossilized calyx of the Carboniferous crinoid ("sea lily") Scytalocrinus †Scytalocrinus
* †Selenella
** †Selenella pediculus
* †Semitextularia
** †Semitextularia thomasi
* †Septemchiton
** †Septemchiton iowaensis
** †Septemchiton iowensis
* †Septopora
* †Serpulospira
** †Serpulospira paradoxus – type locality for species
* †Setigerites
* †Shumardella
* †Sieberella – tentative report
** †Sieberella insolita
* †Sievertsia
* †Sigournea – type locality for genus
** †Sigournea multidentata – type locality for species
* †Similodonta
** †Similodonta obliqua
* †Simulodonta
** †Simulodonta obliqua
* †Sinuites
** †Sinuites subcompressa
* †Siphonocrinus
** †Siphonocrinus nobilis
* †Skenidioides – tentative report
* †Skenidium
** †Skenidium independense
* †Smithiphyllum
** †Smithiphyllum belanskii
* †Sowerbyella
* †Spathella
* †Sphaerirhynchia
* Fossilized holdfast of the Cambrian-Carboniferous conulariid Sphenothallus †Sphenothallus
* †Spinatrypa
** †Spinatrypa aspera
** †Spinatrypa augusticostata – or unidentified comparable form
** †Spinatrypa bellula
** †Spinatrypa borealis
** †Spinatrypa hystrix
** †Spinatrypa mascula
** †Spinatrypa occidentalis
** †Spinatrypa planosulcata
** †Spinatrypa rockfordensis
** †Spinatrypa trulla
* †Spinatrypina
** †Spinatrypina angusticostata – or unidentified comparable form
** †Spinatrypina edmundsi
* †Spinocarinifera
** †Spinocarinifera arcuata
** †Spinocarinifera arcuatus
* †Spinocyrtia
** †Spinocyrtia alta
** †Spinocyrtia ballardi
** †Spinocyrtia capax
** †Spinocyrtia cedarensis
** †Spinocyrtia corvirostra
** †Spinocyrtia curvirostra
** †Spinocyrtia cyrtiformis
** †Spinocyrtia cyrtinaformis
** †Spinocyrtia iowensis
** †Spinocyrtia macbridei
** †Spinocyrtia pulchra
** †Spinocyrtia westerensis
* †Spinulicosta
** †Spinulicosta spinulicosta
* Fossilized shell of the Late Ordovician-Late Triassic brachiopod Spirifer †Spirifer
** †Spirifer biplicoides
** †Spirifer forbesi
** †Spirifer gregeri
** †Spirifer legrandensis
** †Spirifer louisianensis
** †Spirifer marshallensis
** †Spirifer missouriensis
** †Spirifer orestes
** †Spirifer platynotus
** †Spirifer stratiformis
* †Spiriferina
** †Spiriferina solidirostris
** †Spiriferina solidirostrus
** †Spiriferina subtexta
* †Spirinella
* Spirorbis
* †Spyroceras
* †Stachyodes
** †Stachyodes costulata
* †Stainbrookia
** †Stainbrookia infera
* †Staufferella
** †Staufferella falcata
* †Stegocoelia
** †Stegocoelia quadricincta – type locality for species
* †Stenopareia
** †Stenopareia slocomi – or unidentified comparable form
* †Stenopareiea
* †Stephanocrinus
* †Stereostylus
** †Stereostylus aages – type locality for species
* Life restorations of a male (foreground) and female (background) of the Late Devonian-Carboniferous Chimaera relative Stethacanthus †Stethacanthus
** †Stethacanthus depressus
** †Stethacanthus erectus
* †Stictopora
* †Stictostroma
** †Stictostroma ordinarium
* †Straparollus
** †Straparollus ammon
** †Straparollus argutus – type locality for species
** †Straparollus cyclostomus
** †Straparollus macromphalus
* †Streptelasma
** †Streptelasma trilobatum – or unidentified comparable form
* †Streptis
* †Streptognathodus
** †Streptognathodus delicatulus – type locality for species
** †Streptognathodus symmetricus – type locality for species
* †Streptorhynchus
** †Streptorhynchus tenuicostatum
* †Striatochonetes
** †Striatochonetes buchananensis
** †Striatochonetes schucherti
* †Striatopora
** †Striatopora iowensis
* †Stricklandia
** †Stricklandia laevis
** †Stricklandia lens
* †Striispirifer
* †Strimplecrinus
* †Strobilocystites
* †Stromatopora
* †Strophalosia
* †Strophodonta
** †Strophodonta umbonata
* †Stropholosia
** †Stropholosia littletonensis
* Fossilized shell of the Ordovician-Silurian brachiopod Strophomena †Strophomena
** †Strophomena abnormalis
** †Strophomena biplacata
** †Strophomena cedarensis
** †Strophomena cicatricosa
** †Strophomena costata
** †Strophomena dorsata
** †Strophomena erratica
** †Strophomena halli
** †Strophomena iowensis
** †Strophomena linderi
** †Strophomena littleonensis
** †Strophomena littletonensis
** †Strophomena masonensis
** †Strophomena mineolaensis
** †Strophomena nortoni
** †Strophomena parva
** †Strophomena perarcuata
** †Strophomena planodorsata
** †Strophomena plicata
** †Strophomena quadratella
** †Strophomena randalia
** †Strophomena reticulata
** †Strophomena scottensis
** †Strophomena solonensis
** †Strophomena subdemissa
** †Strophomena thomasi
** †Strophomena trilobata – type locality for species
** †Strophomena unbonata
** †Strophomena vera
* †Strophonella
* †Strophonelloides
** †Strophonelloides reversa
* †Strophostylus
** †Strophostylus bivolve
* †Stylonema – tentative report
* †Sublobalocrinus
** †Sublobalocrinus kasseri
* †Sulcatostrophia
** †Sulcatostrophia camerata
** †Sulcatostrophia euglyphea
* †Sygcaulocrinus
** †Sygcaulocrinus typus
* Fossil of the Devonian tabulate coral Syringopora †Syringopora
* †Syringostroma – tentative report
** †Syringostroma confertum
* †Syringothyris
** †Syringothyris halli
** †Syringothyris hannibalensis
** †Syringothyris newarkensis

## 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
* †Tabulophyllum
** †Tabulophyllum buccinum – type locality for species
** †Tabulophyllum curtum – type locality for species
** †Tabulophyllum ehlersi
** †Tabulophyllum ellipticum
** †Tabulophyllum expansum
** †Tabulophyllum levorsoni – type locality for species
** †Tabulophyllum longum
** †Tabulophyllum magnum
** †Tabulophyllum mutabile – type locality for species
** †Tabulophyllum ponderosum
** †Tabulophyllum rectum
** †Tabulophyllum robustum
** †Tabulophyllum rotundum
** †Tabulophyllum solidum
* †Tanaocystis
** †Tanaocystis type locality for species – informal
* †Tarphyphyllum
** †Tarphyphyllum cylindricum – type locality for species
* Fossil of the Silurian-Carboniferous crinoid ("sea lily") Taxocrinus (right) †Taxocrinus
* †Tecnocyrtina
** †Tecnocyrtina curvilineata
** †Tecnocyrtina missouriensis
* †Tenticospirifer
** †Tenticospirifer cyrtinaeformis
** †Tenticospirifer cyrtinaformis
** †Tenticospirifer shellrockensis
* †Tetradella
** †Tetradella carinata
** †Tetradella ellipsilira
** †Tetradella septinoda
** †Tetradella subquadrans
** †Tetradella ulrichi
* †Teutonophon
** †Teutonophon tangentialis
* †Thaerodonta
** †Thaerodonta recedens
* †Thalamocrinus
* †Theleproktocrinus
** †Theleproktocrinus davidsoni
* †Theodissa
** †Theodissa hungerfordi
* †Theodossia
** †Theodossia hungerfordi
* †Thomasaria
** †Thomasaria altumbona
* †Thomasatia
** †Thomasatia falcicosta
* †Thomasocrinus
** †Thomasocrinus cylindrica
* †Timeischytes
* †Torynifer
* †Trachydomia
** †Trachydomia variata
* †Tranodis
* †Trapezophyllum
* †Tremanotus
* †Trichinocrinus
* †Trigeria
* †Trimerella
* †Triplesia
* †Trochonema
* †Tropidodiscus
* †Trupetustroma
** †Trupetustroma bassleri
** †Trupetustroma hayense
* †Tubisalebra
* †Turbonopsis
** †Turbonopsis hackberryensis
** †Turbonopsis spiculatus – type locality for species
* †Tylothyris
** †Tylothyris bimesialis
** †Tylothyris inultilis
** †Tylothyris megista
** †Tylothyris mesacostalis
** †Tylothyris rockfordensis
** †Tylothyris subattenuatta
** †Tylothyris subvaricosa
** †Tylothyris sulcocostata

## 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
* †Ulocrinus
* †Ulrichia
** †Ulrichia saccula
* †Unispirifer
** †Unispirifer minnewankensis – or unidentified comparable form
** †Unispirifer platynotus

## 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
* †Variatrypa
** †Variatrypa arctica
** †Variatrypa lineata
** †Variatrypa rugatula
* †Verkhotomia – tentative report
** †Verkhotomia calvini

## 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
* †Waagenella
** †Waagenella sowerbyi – tentative report
* †Warrenella
** †Warrenella extensa
* †Warthia
* †Wellerella
* †Westerna
** †Westerna gigantea
* †Whatcheeria – type locality for genus
** †Whatcheeria deltae – type locality for species
* †Whidbornella
** †Whidbornella lachrymosa
* †Whitfieldella
* †Winchellatia
** †Winchellatia lansingensis
** †Winchellatia longispina
** †Winchellatia minnesotensis
* †Worthenia

## 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
* †Youngia

## 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
* †Zaphrenthis
** †Zaphrenthis calceola
** †Zaphrenthis cliffordana
* †Zygobolboides
** †Zygobolboides calvini
** †Zygobolboides grafensis
** †Zygobolboides iowensis
** †Zygobolboides thomasi
* †Zygospira
** †Zygospira resupinata