# List of the Mesozoic life of Arizona

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

## A

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* †Acaenasuchus – type locality for genus
** †Acaenasuchus geoffreyi – type locality for species
* †Acallosuchus – type locality for genus
** †Acallosuchus rectori – type locality for species
* Fossilized shell of the Early Cretaceous ammonoid cephalopod Acanthohoplites †Acanthohoplites
** †Acanthohoplites berkeyi
** †Acanthohoplites erraticus
** †Acanthohoplites hesper
** †Acanthohoplites impetrabilis
** †Acanthohoplites schucherti
** †Acanthohoplites teres
* Acila
** †Acila schencki
* Acirsa
** †Acirsa kelseyi – type locality for species
* Acmaea
* †Acrodus
* †Acteon
** †Acteon propinguis
* †Actinastrea
* †Adamanasuchus – type locality for genus
** †Adamanasuchus eisenhardtae – type locality for species
* †Admetopsis
** †Admetopsis subfusiformis
* †Adocus
* Fossilized shell of the Late Cretaceous ammonoid cephalopod Allocrioceras †Allocrioceras
** †Allocrioceras annulatum
* †Alzadites
** †Alzadites incomptus
* †Ambrosea
** †Ambrosea nitida
* †Ammorhynchus – type locality for genus
** †Ammorhynchus navajoi – type locality for species
* †Anaschisma – report made of unidentified related form or using admittedly obsolete nomenclature
* †Anatimya
** †Anatimya virgata
* †Anchura
** †Anchura hopii – type locality for species
* Restoration of the Late Triassic phytosaur Angistorhinus †Angistorhinus – tentative report
* †Anisoceras
** †Anisoceras coloradoense
* †Anisodontosaurus – type locality for genus
** †Anisodontosaurus greeri – type locality for species
* †Anisomyon
** †Anisomyon spp.
* †Anomia
** †Anomia ponticulana
* †Antediplodon
** †Antediplodon dockumensis
* †Apachesaurus
** †Apachesaurus gregorii
* †Apatosaurus
* †Aphrodina
** †Aphrodina munda – or unidentified comparable form
* Petrified trunk segments of the Permian-Late Triassic conifer tree Araucarioxylon arizonicum. This species is the state fossil of Arizona †Araucarioxylon
** †Araucarioxylon arizonicum
* †Arca
* Arcopagia – or unidentified comparable form
** †Arcopagia A – informal
* Arctica
* †Arganodus
* †Aricycas
** †Aricycas paulae
* †Arizonasaurus – type locality for genus
** †Arizonasaurus babbitti – type locality for species
* Astarte
** †Astarte adkinsi
* †Australosomus – or unidentified comparable form

## B

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* Fossilized shell of the Late Cretaceous ammonoid cephalopod Baculites †Baculites
** †Baculites calamus
* Barbatia
** †Barbatia tramitensis
* †Barrancapus
* †Batrachopus
** †Batrachopus deweyi
* †Bellifusus
** †Bellifusus gracilistriatus
** †Bellifusus willistoni – or unidentified comparable form
* †Beudanticeras
** †Beudanticeras victoris
* Fossil slab and counterslab of the bony fish Boreosomus †Boreosomus – tentative report
* †Borissiakoceras
* †Borrissiakoceras
** †Borrissiakoceras orbiculatum
* Brachiodontes
** †Brachiodontes filisculptus
* †Brachychirotherium
* †Brasilichnium – or unidentified comparable form
* †Breviarca – tentative report
* †Burroceras
** †Burroceras clydense
** †Burroceras transitorium

## C

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* Cadulus
** †Cadulus praetenuis
* †Calamites
* †Calamophylliopsis
** †Calamophylliopsis sandbergeri
* †Calsoyasuchus – type locality for genus
** †Calsoyasuchus valliceps – type locality for species
* †Calycoceras
** †Calycoceras naviculare
* †Calyptosuchus
** †Calyptosuchus wellesi
* Restoration of the Late Triassic theropod dinosaur Camposaurus †Camposaurus – type locality for genus
** †Camposaurus arizonensis – type locality for species
* †Camptonectes
** †Camptonectes A – informal
** †Camptonectes B – informal
** †Camptonectes platessa
* †Caprina
* †Caprinuloidea
** †Caprinuloidea gracilis
* Carota
** †Carota dalli
* Caryocorbula
** †Caryocorbula nematophora
* Life restoration of the Late Triassic-Eocene lungfish Ceratodus †Ceratodus
* †Cerithioderma
** †Cerithioderma darcyi – type locality for species
** †Cerithioderma occidentalis
* Cerithiopsis
** †Cerithiopsis sohli – type locality for species
* Charonia – tentative report
** †Charonia kanabense
** †Charonia soozi – type locality for species
* †Chatterjeea
* †Chindesaurus – type locality for genus
** †Chindesaurus bryansmalli – type locality for species
* Restoration of the Late Triassic coelacanth fish Chinlea †Chinlea – tentative report
* †Chirotherium
** †Chirotherium barthii
** †Chirotherium rex – type locality for species
** †Chirotherium sickleri
* Chlamys
** †Chlamys thompsoni
* †Choffaticeras
** †Choffaticeras pavillieri – or unidentified comparable form
* †Chondrodonta
* †Cibolaites
** †Cibolaites molenaari
* †Cionichthyes
* †Cionichthys – or unidentified comparable form
* †Coalcomana
** †Coalcomana ramosa
* †Coelophysis
** Life restoration of Coelophysis kayentakatae †Coelophysis kayentakatae – type locality for species
* †Collignoniceras
** †Collignoniceras carolinum – or unidentified related form
** †Collignoniceras woollgari
* †Colognathus
** †Colognathus obscurus
* †Colombiceras – tentative report
** †Colombiceras brumale
* Corbula
** †Corbula kanabensis
* †Cosgriffius – type locality for genus
** †Cosgriffius campi – type locality for species
* †Craginia
** †Craginia turriformis
* †Craniscus
** †Craniscus hesperius – type locality for species
* Crassatella
* Fossilized shell of the Cretaceous-modern oyster Crassostrea Crassostrea
** †Crassostrea soleniscus
* †Crosbysaurus
** †Crosbysaurus harrisae
* Cucullaea
** †Cucullaea depressa
** †Cucullaea stephensoni
* †Cunningtoniceras
** †Cunningtoniceras novimexicanum
* Cuspidaria
** †Cuspidaria alaeformis
* †Cyclorisma
** †Cyclorisma orbiculata
* †Cyclothyris
** †Cyclothyris americana – type locality for species
* Cylichna
* †Cylinodrotruncatum
** †Cylinodrotruncatum spp.
* †Cymbophora
** †Cymbophora emmonsi
** †Cymbophora huerfanensis
** †Cymbophora utahensis
* †Cyprimeria
** †Cyprimeria cyprimeriformis

## D

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* †Dakotacorbula
** †Dakotacorbula senecta
* †Dechellyia
** †Dechellyia gormani – type locality for species
* †Dentalium
* †Deshayesites – tentative report
** †Deshayesites butleri
* †Desmatochelys
** †Desmatochelys lowi
* †Desmatosuchus
** †Desmatosuchus haplocerus
** †Desmatosuchus spurensis
* †Dilophosauripus – type locality for genus
** †Dilophosauripus williamsi – type locality for species
* Life restoration of the Early Jurassic theropod dinosaur Dilophosaurus resting †Dilophosaurus
** †Dilophosaurus wetherilli – type locality for species
* †Dinnebitodon – type locality for genus
** †Dinnebitodon amarali – type locality for species
* †Dinnetherium – type locality for genus
** †Dinnetherium nezorum – type locality for species
* Discinisca
* †Dolicholatirus – tentative report
* †Drepanocheilus
** †Drepanocheilus ruidium
* †Drepanochilus
** †Drepanochilus ruidium
* Restoration of the Late Triassic dinosaur relative Dromomeron †Dromomeron
** †Dromomeron gregorii
* †Dufrenoyia
** †Dufrenoyia compitalis
** †Dufrenoyia joserita
** †Dufrenoyia justinae

## E

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* †Edentosuchus – tentative report
** †Edentosuchus undescribed species – informal
** †Edentosuchus undescribed species 1 – informal
** †Edentosuchus undescribed species 2 – informal
* Elliptio
* †Entolium
** †Entolium gregarium
* †Eoacteon – tentative report
* †Eocaecilia – type locality for genus
** †Eocaecilia micropodia – type locality for species
* Restoration of the Middle Triassic amphibian Eocyclotosaurus †Eocyclotosaurus
** †Eocyclotosaurus wellesi – type locality for species
* †Eopneumatosuchus – type locality for genus
** †Eopneumatosuchus colberti – type locality for species
* †Eucalycoceras
** †Eucalycoceras pentagonum
* †Eulima – tentative report
** †Eulima funicula
* †Eunaticina
** †Eunaticina textilis
* †Euomphaloceras
** †Euomphaloceras irregulare
** †Euomphaloceras septemseriatum
* †Euspira
** †Euspira concinna
** †Euspira stantoni – type locality for species
* †Exogyra
** †Exogyra acroumbonata
** †Exogyra lancha
** †Exogyra levis
** †Exogyra olisiponensis

## F

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* Fossilized shell of the Late Cretaceous ammonoid cephalopod Fagesia †Fagesia
** †Fagesia catinus
* †Felixigyra
* †Flemingostrea
** †Flemingostrea prudentia
* †Fulpia
** †Fulpia pinguis

## G

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* †Gemmarcula
** †Gemmarcula arizonensis – type locality for species
** †Gemmarcula menardi
* Fossilized shell of the Carboniferous-Eocene bivalve Gervillia †Gervillia
** †Gervillia cholla
** †Gervillia heinemani
** †Gervillia navajovus – type locality for species
** †Gervillia rasori
* Ginkgo
* †Grallator
** †Grallator cursorius
* †Granocardium
** †Granocardium trite
* †Graphidula
** †Graphidula walcotti
* †Gregania – tentative report
* Interior and exterior of a fossilized shell of the Late Triassic-Eocene marine bivalve Gryphaea †Gryphaea
* †Gryphaeostrea
** †Gryphaeostrea elderi – type locality for species
** †Gryphaeostrea nationsi – type locality for species
* Gyrodes
** †Gyrodes conradi
** †Gyrodes depressa
** †Gyrodes tramitensis – or unidentified comparable form
* †Gyrolepis
* †Gyrotropis
** †Gyrotropis nationsi – type locality for species

## H

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* Fossilized skull of the Middle Triassic amphibian Hadrokkosaurus †Hadrokkosaurus – type locality for genus
** †Hadrokkosaurus bradyi – type locality for species
* †Hamites
** †Hamites simplex
* †Hamulus
* Hemiaster
** †Hemiaster jacksoni – or unidentified comparable form
* †Hesperosuchus – type locality for genus
** †Hesperosuchus agilis – type locality for species
* Homarus
* †Hopiichnus – type locality for genus
** †Hopiichnus shingi – type locality for species
* †Hybodus

## I

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* †Immunitoceras
** †Immunitoceras immunitum
* Fossilized shell of the Early Jurassic-Late Cretaceous marine bivalve Inoceramus with a human indicating its size †Inoceramus
** †Inoceramus corpulentas
** †Inoceramus dimidius – or unidentified comparable form
** †Inoceramus flavus
** †Inoceramus heinzi – or unidentified related form
** †Inoceramus lamarcki
** †Inoceramus nodai
** †Inoceramus pictus
** †Inoceramus tenuistriatus – tentative report
* †Isochirotherium
** †Isochirotherium coltoni – type locality for species
** †Isochirotherium marshalli

## K

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* †Kamerunoceras
** †Kamerunoceras turoniense
* Restoration of the Early Jurassic turtle Kayentachelys †Kayentachelys – type locality for genus
** †Kayentachelys aprix – type locality for species
* †Kayentapus – type locality for genus
** †Kayentapus hopii – type locality for species
* †Kayentasuchus – type locality for genus
** †Kayentasuchus walkeri – type locality for species
* †Kayentatherium – type locality for genus
** †Kayentatherium wellesi – type locality for species
* Life restoration of the Early Jurassic theropod dinosaur Kayentavenator †Kayentavenator – type locality for genus
** †Kayentavenator elysiae – type locality for species
* †Kazanskyella
** †Kazanskyella arizonica
* †Koskinonodon
** †Koskinonodon perfectus
* †Koupichnium – probable lapsus calami of Kouphichnium
* †Kraterokheirodon – type locality for genus
** †Kraterokheirodon colberti – type locality for species
* †Kummelonautilus

## L

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* †Lasalichthys – or unidentified comparable form
* Laternula
** †Laternula lineata
* †Legumen
** †Legumen ligula – or unidentified comparable form
* Lepisosteus
* Fossilized skull of the Late Triassic phytosaur Leptosuchus †Leptosuchus
** †Leptosuchus crosbiensis
* †Levicerithium
** †Levicerithium basicostae
** †Levicerithium micronema – tentative report
** †Levicerithium timberanum – or unidentified comparable form
* Lima
** †Lima cholla
** †Lima espinal
** †Lima muralensis
** †Lima utahensis
* Limatula
** †Limatula kochi
* †Linearis
** †Linearis striatimarginata
** †Linearis whitei
* †Lingula
** †Lingula subspatula
* †Liopistha
** †Liopistha meeki
* Electron micrograph of fossilized teeth from the Early Jurassic-Early Cretaceous freshwater shark Lissodus †Lissodus – tentative report
* †Lithocodium
* Lithophaga
* †Lonchidion
** †Lonchidion humblei
* †Longitubus
* Lopha
** †Lopha bellaplicata
** †Lopha staufferi
* †Lucina
** †Lucina subundata
* A living Lunatia moon sea snail Lunatia – tentative report
* †Lutema
** †Lutema hitzi

## M

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* Fossilized skull of the Late Triassic phytosaur Machaeroprosopus †Machaeroprosopus – type locality for genus
** †Machaeroprosopus buceros
** †Machaeroprosopus jablonskiae – type locality for species
** †Machaeroprosopus mccauleyi – type locality for species
** †Machaeroprosopus pristinus – type locality for species
** †Machaeroprosopus tenuis – type locality for species
** †Machaeroprosopus validus – type locality for species
* †Mammillopora
** †Mammillopora encrusta – type locality for species
* †Mammites
** †Mammites nodosoides
* †Masculostrobus
** †Masculostrobus clathratus – type locality for species
* †Mathilia – tentative report
** †Mathilia ripleyana
* †Meekia
* †Megalosauripus
* †Melvius
* Membranipora – or unidentified comparable form
* †Mesolanites
* †Mesostoma
* †Metaptychoceras
** †Metaptychoceras reesidei
* †Metoicoceras
** †Metoicoceras geslinianum
** †Metoicoceras mosbyense
* Life restoration of the Late Triassic amphibian Metoposaurus with an anachronistic human to scale †Metoposaurus
** †Metoposaurus fraasi – type locality for species
* †Microsolena
** †Microsolena texana
* †Modiolus
** †Modiolus attenuatus – or unidentified comparable form
** †Modiolus coloradoensis
** †Modiolus perryi – type locality for species
* †Moenkopia – type locality for genus
** †Moenkopia wellesi – type locality for species
* †Monopleura
** †Monopleura marcida – or unidentified comparable form
* †Moremanoceras
** †Moremanoceras scotti
* Life restoration of the Late Triassic-Middle Jurassic synapsid (mammal precursor) Morganucodon †Morganucodon
* †Morrowites
* †Mytiloides
** †Mytiloides columbianus
** †Mytiloides duplicostasus – or unidentified related form
** †Mytiloides hercynicus
** †Mytiloides kossmati
** †Mytiloides labiatus
** †Mytiloides latus – or unidentified comparable form
** †Mytiloides mytiloides
** †Mytiloides opalensis
** †Mytiloides submytiloides
* †Mytilus – tentative report

## N

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* †Nannometoicoceras
** †Nannometoicoceras acceleratum
* †Navahopus – type locality for genus
** †Navahopus falcipollex – type locality for species
* †Neithea
** †Neithea vicinalis
* †Nemodon
* †Neocardioceras
** †Neocardioceras juddii
** †Neocardioceras minutum
* †Neoptychites
** †Neoptychites cephalotus
* Fossilized shell of the Jurassic-Cretaceous sea snail Nerinea †Nerinea
* Nerita
** †Nerita spp.
* Neritina
** †Neritina spp.
* †Nigericeras
** †Nigericeras ogojaense – or unidentified comparable form
* Nucula
** †Nucula coloradoensis
* Nuculana
** †Nuculana mutuata

## O

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* †Obnixia – type locality for genus
** †Obnixia thaynesiana
* Restoration of the Late Triassic–Early Jurassic synapsid (mammal precursor) Oligokyphus †Oligokyphus
* †Opis
** †Opis elevata
* †Orbitolina
** †Orbitolina texana
* Ostrea
** †Ostrea anomioides
** †Ostrea edwilsoni
* †Oxytoma
** †Oxytoma arizonensis – type locality for species

## P

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* †Pachyrhizodus – or unidentified comparable form
* †Paleopsephea
** †Paleopsephea arizonensis – type locality for species
* †Paracanthohoplites
** †Paracanthohoplites meridionalis
* †Parasimilia
** †Parasimilia spp.
* Life restoration of the Late Triassic phytosaur Parasuchus †Parasuchus
* †Paratypothorax
* †Parmicorbula
* †Parrishea
* †Parrishia – type locality for genus
** †Parrishia mccreai – type locality for species
* Parvilucina
** †Parvilucina juvenis
* †Pecten
** †Pecten peregrina
* †Perissoptera
** †Perissoptera prolabiata
* †Permocalculus
* Petrophyllia
** †Petrophyllia dartoni
* †Pharodina
** †Pharodina ferrana
* †Phelopteria
** †Phelopteria A – informal
** †Phelopteria B – informal
** †Phelopteria C – informal
** †Phelopteria dalli
** †Phelopteria E – informal
** †Phelopteria F – informal
** †Phelopteria gastrodes
** †Phelopteria minuta
* †Phoebodus
* Pholadomya
** †Pholadomya coloradoensis
* Physa
** †Physa reesidei – or unidentified comparable form
* †Pinna
** †Pinna kauffmani – type locality for species
** †Pinna petrina
* †Pirsilia
* †Placenticeras
** †Placenticeras cumminsi
* Restoration of the Late Triassic synapsid (mammal precursor) Placerias with an anachronistic human to scale †Placerias – type locality for genus
** †Placerias hesternus – type locality for species
* †Plastomenus
* †Pleisiopinna – tentative report
* †Pleisopinna – tentative report
* †Pleuriocardia
** †Pleuriocardia pauperculum
* Plicatula
** †Plicatula ferryi
** †Plicatula hydrotheca
* †Pollex – tentative report
* Polydora – tentative report
* †Polystrata
** †Polystrata alba
* †Polytremacis
* Restoration of the Late Triassic crocodile relative Poposaurus with an anachronistic human to scale †Poposaurus
** †Poposaurus gracilis
* Poromya
** †Poromya lohaliensis – type locality for species
* †Postosuchus
** †Postosuchus kirkpatricki
* †Pravusuchus
** †Pravusuchus hortus
* †Prionocyclus
** †Prionocyclus hyatti
** †Prionocyclus percarinatus
* †Procolophonichnium
* Life restoration of the Early Jurassic frog Prosalirus †Prosalirus – type locality for genus
** †Prosalirus bitis – type locality for species
* †Protelliptio – tentative report
* †Protome – type locality for genus
** †Protome batalaria – type locality for species
* †Protosuchus – type locality for genus
** †Protosuchus richardsoni – type locality for species
* †Pseudaspidoceras
** †Pseudaspidoceras flexuosum
** †Pseudaspidoceras pseudonodosoides
* †Pseudocalycoceras
** †Pseudocalycoceras angolaense
* †Pseudoperna
** †Pseudoperna bentonense
** †Pseudoperna bentonensis
* †Pseudopetalodontia
** †Pseudopetalodontia felixi
* †Pseudoptera
** †Pseudoptera propleura
* †Psilomya
** †Psilomya concentrica
** †Psilomya elongata
** †Psilomya meeki
* †Psilothyris
** †Psilothyris occidentalis
* †Pteraichnus – type locality for genus
** †Pteraichnus saltwashensis – type locality for species
* †Puebloites
** †Puebloites greenhornensis
** †Puebloites spiralis
* Pycnodonte
** †Pycnodonte kansasense – tentative report
** †Pycnodonte kellumi – or unidentified related form
** †Pycnodonte newberryi
* †Pyktes
** †Pyktes fusiformis
* †Pyncnodonte
** †Pyncnodonte kellumi – or unidentified related form
** †Pyncnodonte newberryi
* †Pyrgulifera
** †Pyrgulifera ornata
* †Pyropsis
** †Pyropsis coloradoensis – or unidentified comparable form
** †Pyropsis kochi – type locality for species

## Q

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* †Quasicyclotosaurus – type locality for genus
** †Quasicyclotosaurus campi – type locality for species
* †Quitmaniceras
** †Quitmaniceras reaseri – or unidentified comparable form

## R

* A
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* †Radiolites
* Ramphonotus – or unidentified comparable form
* †Rectithyris
** †Rectithyris vespertina – type locality for species
* †Reticulodus – type locality for genus
** †Reticulodus synergus – type locality for species
* Life restoration of the Late Triassic crocodile relative Revueltosaurus †Revueltosaurus
** †Revueltosaurus callenderi
** †Revueltosaurus hunti
* †Rhadalognathus – type locality for genus
** †Rhadalognathus boweni – type locality for species
* †Rhamphinion – type locality for genus
** †Rhamphinion jenkinsi – type locality for species
* †Rhombopsis – tentative report
** †Rhombopsis huerfanensis
* †Rhynchosauroides
** †Rhynchosauroides schochardti
* †Rhynchostreon
** †Rhynchostreon levis
* A living Ringicula sea snail Ringicula
** †Ringicula codellana
* †Rioarribasuchus
** †Rioarribasuchus chamaensis
* Rostellaria
** †Rostellaria venenatus – tentative report
* †Rotodactylus – type locality for genus
** †Rotodactylus bradyi – type locality for species
** †Rotodactylus cursorius – type locality for species
* †Rubroceras
** †Rubroceras rotundum
* Fossilized skeleton of the Late Triassic phytosaur Rutiodon †Rutiodon

## S

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* Illustration in multiple views of the fossilized skull of the Early Jurassic sauropodomorph dinosaur Sarahsaurus †Sarahsaurus – type locality for genus
** †Sarahsaurus aurifontanalis – type locality for species
* Scalpellum – tentative report
* †Scaphites
** †Scaphites larvaeformis
* †Sciponoceras
** †Sciponoceras gracile
* †Scutarx – type locality for genus
** †Scutarx deltatylus – type locality for species
* †Scutellosaurus – type locality for genus
** †Scutellosaurus lawleri – type locality for species
* †Segisaurus – type locality for genus
** †Segisaurus halli – type locality for species
* †Selaginella
** †Selaginella anasazia – type locality for species
* Fossilized skeleton of the Late Triassic-Early Jurassic bony fish Semionotus †Semionotus – or unidentified comparable form
* †Senis
** †Senis elongatus
* †Sergipia
** †Sergipia hartti – tentative report
* Serpula
** †Serpula implicata
** †Serpula intrica
** †Serpula large
* †Shuvosaurus
** †Shuvosaurus inexpectatus
* †Sinzowiella
** †Sinzowiella spathi
* †Smilosuchus – type locality for genus
** †Smilosuchus adamanensis – type locality for species
** †Smilosuchus gregorii – type locality for species
** †Smilosuchus lithodendrorum – type locality for species
* Solemya
** †Solemya obscura
* Life restoration of the Early-Late Cretaceous brachiosaur Sonorasaurus †Sonorasaurus – type locality for genus
** †Sonorasaurus thompsoni – type locality for species
* †Spathites
** †Spathites puercoensis
* Spirorbis
* Squilla – tentative report
* †Stagonolepis
* †Stanocephalosaurus – type locality for genus
** †Stanocephalosaurus birdi – type locality for species
** †Stanocephalosaurus new species – informal
* †Stoliczkaia
** †Stoliczkaia scotti
* †Stomohamites
* †Stylocyathus
* †Sumitomoceras
** †Sumitomoceras conlini
* †Synaptichnium
** †Synaptichnium cameronensis – type locality for species
** †Synaptichnium diabloensis – type locality for species
* †Syncyclonema
** †Syncyclonema spp.
* †Syntarsus

## T

* A
* B
* C
* D
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* F
* G
* H
* I
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* M
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* †Tanytrachelos
* †Tecovasaurus
** †Tecovasaurus murryi
* †Tecovasuchus
** †Tecovasuchus chatterjeei
* †Tectaplica – tentative report
** †Tectaplica utahensis
* Tellina
** †Tellina carlilana – type locality for species
* †Tenea
* Life restoration of the Early Cretaceous Iguanodon relative Tenontosaurus †Tenontosaurus
* †Terebrimya
* Teredolithus
* †Therapsipus – type locality for genus
** †Therapsipus cumminsi – type locality for species
* †Thomasites
** †Thomasites gongilensis – or unidentified comparable form
* †Toucasia
** †Toucasia hancockensis
* †Tragodesmoceras
** †Tragodesmoceras bassi
** †Tragodesmoceras socorroense
* †Triasamnicola – or unidentified comparable form
** †Triasamnicola pilsbryi
* †Trigonia
** †Trigonia aliformis - or unidentified loosely related form
** †Trigonia cragini
** †Trigonia guildi
** †Trigonia kitchini
** †Trigonia mearnsi
** †Trigonia reesidei
** †Trigonia resoluta
** †Trigonia saavedra
** †Trigonia stolleyi
** †Trigonia weaveri
* Restoration of the Late Triassic reptile Trilophosaurus with an anachronistic human to scale †Trilophosaurus
** †Trilophosaurus buettneri
** †Trilophosaurus jacobsi – type locality for species
* †Triodus
** †Triodus moorei
* Trochocyathus
* Turritella
** †Turritella A – informal
** †Turritella B – informal
** †Turritella cobbani – type locality for species
** †Turritella codellana – type locality for species
** †Turritella kauffmani – type locality for species
** †Turritella whitei
* †Turseodus
** †Turseodus dolorensis – or unidentified comparable form
* Restoration of a pair of the Late Triassic aetosaur Typothorax †Typothorax
** †Typothorax coccinarum

## U

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* †Uatchitodon
** †Uatchitodon schneideri
* †Unicardium
* Unio

## V

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* Life restoration of the Late Triassic reptile Vancleavea †Vancleavea – type locality for genus
** †Vancleavea campi – type locality for species
* †Vascoceras
** †Vascoceras diartianum
* †Veniella
** †Veniella goniophora
** †Veniella mortoni
* †Vigilius
** †Vigilius wellesi
* Viviparus
* †Voysa
** †Voysa varia
* Vulsella

## W

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* †Watinoceras
** †Watinoceras coloradoense
** †Watinoceras devonense
** †Watinoceras hattini
** †Watinoceras praecursor – or unidentified comparable form
** †Watinoceras spp.
* †Weeksia
* †Wellesaurus
** †Wellesaurus peabodyi – type locality for species
* †Worthoceras
** †Worthoceras gibbosum
** †Worthoceras vermiculum

## Y

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* †Yezoites
** †Yezoites delicatulus