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

A

• †Acanthichnus – tentative report
• Acila
  • †Acila chicotana
• Acmaea
  • †Acmaea genettae – type locality for species
• †Adocus
• †Albanerpeton
  • †Albanerpeton nexuosus
• †Albertosaurus – tentative report
• †Aletridelphys
  • †Aletridelphys hatcheri
• †Allantodiopsis
  • †Allantodiopsis erosa
  • †Allantodiopsis JC018 – informal
• 

  Life restoration of the Late Jurassic theropod dinosaur Allosaurus
  †Allosaurus – type locality for genus
  • †Allosaurus fragilis – type locality for species
  • †Allosaurus lucasi – type locality for species
• †Amblotherium – type locality for genus
  • †Amblotherium gracilis
• Amia
• †Amphicoelias – type locality for genus
  • †Amphicoelias altus – type locality for species
• 

  Fossilized skull of the Late Jurassic crocodile relative Amphicotylus
  †Amphicotylus
  • †Amphicotylus lucasii – type locality for species
• †Amplovalvata
  • †Amplovalvata scabrida
• †Anaklinoceras
  • †Anaklinoceras minutum – type locality for species
  • †Anaklinoceras reflexum
• †Anisoceras
  • †Anisoceras plicatilis
• †Anisomyon
  • †Anisomyon centrale
• †Anomia
  • †Anomia subquadrata
  • †Anomia tellinoides
• 

  Fossil (right) of the Early Jurassic dinosaur footprint ichnogenus Anomoepus
  †Anomoepus – tentative report
• †Apateodus
• †Apatopus
• †Apatosaurus – type locality for genus
  • †Apatosaurus ajax – type locality for species
  • †Apatosaurus laticollis – type locality for species. Junior synonym of A. louisae.
  • †Apatosaurus louisae
• †Arcellites
  • †Arcellites disciformis
• †Archaeolamna
  • †Archaeolamna kopingensis
• †Arenicolites
• Aspideretes
  • †Aspideretes vagans – type locality for species
• †Aspideretoides
• Astarte
• †Atlantosaurus
  • †Atlantosaurus immanis – type locality for species
• †Axonoceras
  • †Axonoceras compressum

B

• †Baculites
  • †Baculites aquilaensis
  • †Baculites asper
  • †Baculites clinolobatus – type locality for species
  • †Baculites codyensis
  • †Baculites compressus
  • †Baculites cuneatus
  • †Baculites grandis
  • †Baculites haresi
  • †Baculites mclearni
  • †Baculites meeki – type locality for species
  • †Baculites reesidei
• 

  Restoration of the Late Jurassic sauropod dinosaur Barosaurus rearing to defend itself against a pair of the theropod Allosaurus
  †Barosaurus
• †Basilemys
  • †Basilemys sinuosa – or unidentified comparable form
• †Behuninia
  • †Behuninia provoensis
• †Bellifusus
• †Bison
  • †Bison alticornis – type locality for species
• †Borealosuchus
  • †Borealosuchus sternbergii
• †Brachauchenius – or unidentified comparable form
• †Brachiosaurus – type locality for genus
  • †Brachiosaurus altithorax – type locality for species
• †Brachychampsa
  • †Brachychampsa montana
• †Brachychirotherium
• †Brachyphyllum
  • †Brachyphyllum rechtenii – type locality for species
• 

  Life restoration of a herd of the Late Jurassic sauropod dinosaur Brontosaurus
  †Brontosaurus
  • †Brontosaurus excelsus
  • †Brontosaurus yahnahpin

C

• †Calycoceras
  • †Calycoceras canitaurinum
  • †Calycoceras naviculare
• 

  Life restoration of a herd of the Late Jurassic sauropod dinosaur Camarasaurus
  †Camarasaurus – type locality for genus
  • †Camarasaurus agilis – type locality for species
  • †Camarasaurus grandis
  • †Camarasaurus lewisi
  • †Camarasaurus supremus – type locality for species
• †Camptosaurus – type locality for genus
  • †Camptosaurus dispar – type locality for species
• Carcharias
  • †Carcharias amonensis
  • †Carcharias saskatchewanensis
  • †Carcharias tenuiplicatus
• †Caririchnium
  • †Caririchnium leonardii – type locality for species
  • †Caririchnium leonaridii
• †Cataceramus
  • †Cataceramus gladbeckensis
• †Cedrobaena
  • †Cedrobaena brinkman
• †Ceratodus – type locality for genus
  • †Ceratodus felchi – type locality for species
  • †Ceratodus guentheri – type locality for species
• 

  Restoration of the Late Jurassic ceratosaur Ceratosaurus
  †Ceratosaurus – type locality for genus
  • †Ceratosaurus nasicornis – type locality for species
• Cerithiopsis
• †Champsosaurus
• Chara
• †Chelonipus
• †Chinlea
  • †Chinlea sorenseni
• †Chinlestegophis – type locality for genus
  • †Chinlestegophis jenkinsi – type locality for species
• †Chirotherium
  • †Chirotherium lulli
• †Cimolichthys
  • †Cimolichthys nepaholica
• †Cimolodon – or unidentified comparable form
• 

  Life restoration of the face of the Late Cretaceous multituberculate mammal Cimolomys
  †Cimolomys
• †Cionichthys
  • †Cionichthys dunklei
• †Cionodon – type locality for genus
  • †Cionodon arctatus – type locality for species
• †Cirroceras
  • †Cirroceras conradi
• †Cladoceramus
  • †Cladoceramus undulatoplicatus
• †Clidastes
• †Clioscaphites
  • †Clioscaphites choteauensis
  • †Clioscaphites saxitonianus
  • †Clioscaphites vermiformis
• †Coahuilites
  • †Coahuilites sheltoni
• †Cochlichnus
• †Codellaster – type locality for genus
  • †Codellaster keepersae – type locality for species
• †Coelophysis – tentative report
• 

  Diagram illustrating the known fossil material of the Late Jurassic theropod dinosaur Coelurus
  †Coelurus
  • †Coelurus fragilis
• †Compsemys
  • †Compsemys victa
• †Coniasaurus
  • †Coniasaurus crassidens
• Corbula
• †Corydalites – type locality for genus
  • †Corydalites fecundum – type locality for species
• Crassatella
  • †Crassatella franzeseii
• †Cremnoceramus
  • †Cremnoceramus deformis
• †Crenella
• †Creonella
  • †Creonella triplicata
• †Cretodus
  • †Cretodus semiplicatus
• †Cretolamna
  • †Cretolamna appendiculata
• †Cretomanta
  • †Cretomanta canadensis
• 

  Restoration of the Late Cretaceous shark Cretoxyrhina, or the Ginsu shark
  †Cretoxyrhina
  • †Cretoxyrhina mantelli
• Cucullaea
  • †Cucullaea nebrascensis
• Cuspidaria
  • †Cuspidaria ventricosa
• †Czekanowskia
  • †Czekanowskia turneri – tentative report

D

• †Diablophis
  • †Diablophis gilmorei – type locality for species
• †Didymoceras
  • †Didymoceras aurarium – type locality for species
  • †Didymoceras cheyennense
  • †Didymoceras draconis
  • †Didymoceras stevensoni
• †Dinehichnus
  • †Dinehichnus socialis
• †Dinochelys
  • †Dinochelys whitei
• 

  Diagram illustrating the Late Jurassic sauropod dinosaurs Diplodocus carnegii (green) and D. hallorum (orange) with an anachronistic human to scale.
  †Diplodocus – type locality for genus
  • †Diplodocus lacustris – type locality for species
  • †Diplodocus longus – type locality for species
• Diplodonta
  • †Diplodonta davisi
• †Diplosaurus
  • †Diplosaurus felix – type locality for species
• Discinisca
• †Discoscaphites
  • †Discoscaphites conradi
• †Docodon
  • †Docodon apoxys – type locality for species
• †Dorsetisaurus
• 

  Fossilized skull of the Late Jurassic-Early Cretaceous turtle Dorsetochelys
  †Dorsetochelys
  • †Dorsetochelys buzzops – type locality for species
• †Drepanocheilus
  • †Drepanocheilus evansi
  • †Drepanocheilus nebrascensis
  • †Drepanocheilus obesus
• †Dryophyllum
  • †Dryophyllum tennesseensis
• †Dryosaurus
  • †Dryosaurus altus

E

• †Edmontonia
• 

  Skeletal reconstruction and restored soft tissue of the Late Cretaceous duck-billed dinosaur Edmontosaurus regalis with an anachronistic human to scale
  †Edmontosaurus
  • †Edmontosaurus regalis – type locality for species
• Eilenodon – type locality for genus
  • †Eilenodon robustus – type locality for species
• †Elopopsis
• †Enchodus
  • †Enchodus gladiolus – or unidentified comparable form
  • †Enchodus shumardi – or unidentified comparable form
• †Entolium
• †Eoacteon
  • †Eoacteon sublinearis
• †Eomunidopsis
  • †Eomunidopsis cobbani – type locality for species
• †Eosauropus
  • †Eosauropus cimarronensis
  • †Eosauropus cimmaronensis
• 

  A living Equisetum, or horsetail
  †Equisetum
  • †Equisetum burchardtii – or unidentified comparable form
• †Etea
  • †Etea peasei
• †Eubrontes
  • †Eubrontes giganteus
• †Eucalycoceras
  • †Eucalycoceras pentagonum
• †Euomphaloceras
  • †Euomphaloceras septemseriatum
• †Eutrephoceras
  • †Eutrephoceras dekayi
• †Eutretauranosuchus – type locality for genus
  • †Eutretauranosuchus delfsi – type locality for species
• †Exiteloceras
  • †Exiteloceras jenneyi
• †Exogyra
  • †Exogyra boveyensis – or unidentified related form

F

• 

  Fossilized shell of the Late Cretaceous ammonoid cephalopod Fagesia
  †Fagesia
• Ficus
  • †Ficus planicostata
• †Forresteria
  • †Forresteria hobsoni – type locality for species
• †Fruitachampsa – type locality for genus
  • †Fruitachampsa callisoni – type locality for species
• †Fruitadens – type locality for genus
  • †Fruitadens haagarorum – type locality for species
• †Fruitafossor – type locality for genus
  • †Fruitafossor windscheffeli – type locality for species

G

• 

  Fossilized skull of the Late Jurassic sauropod dinosaur Galeamopus
  †Galeamopus
  • †Galeamopus pabsti
• †Glirodon
  • †Glirodon grandis
• †Glyptops
  • †Glyptops plicatulus – type locality for species
• †Goniopholis
  • †Goniopholis felchi – type locality for species
• †Grallator
  • †Grallator cursorius
  • †Grallator tenuis
• †Gryphaeostrea
• †Gwyneddichnium
• †Gypsonictops
• †Gyroides

H

• 

  Restoration of the Late Jurassic crocodile relative Hallopus
  †Hallopus
  • †Hallopus victor – type locality for species
• †Haplocanthosaurus – type locality for genus
  • †Haplocanthosaurus delfsi – type locality for species
  • †Haplocanthosaurus priscus – type locality for species
• †Harduinia
  • †Harduinia stantoni
  • †Harduinia taylori
• †Haresiceras
  • †Haresiceras placentiforme
• †Helopanoplia
  • †Helopanoplia distincta – or unidentified comparable form
• †Hemicalypterus
• †Hermanophyton
• 

  Fossilized shell of the Late Cretaceous ammonoid cephalopod Herrickiceras
  †Herrickiceras
  • †Herrickiceras costatus
• †Holaster
  • †Holaster feralis – type locality for species
• †Homolopsis
• †Hoploscaphites^[1]
  • †Hoploscaphites birkelundae
  • †Hoploscaphites landesi
  • †Hoploscaphites macer^[1]
  • †Hoploscaphites nicolletii
• †Hulettia – report made of unidentified related form or using admittedly obsolete nomenclature
  • †Hulettia hawesi – type locality for species
• †Hypsirophus – type locality for genus
  • †Hypsirophus discurus – type locality for species

I

• †Ichthyodectes
• †Ignotornis – type locality for genus
  • †Ignotornis mcconnelli – type locality for species
• 

  Fossilized shell of the Early Jurassic-Late Cretaceous marine bivalve Inoceramus with a human indicating its size
  †Inoceramus
  • †Inoceramus altus
  • †Inoceramus altusiformis
  • †Inoceramus anomalus
  • †Inoceramus arnoldi
  • †Inoceramus balticus
  • †Inoceramus brancoiformis
  • †Inoceramus bueltenensis
  • †Inoceramus cordiformis
  • †Inoceramus crippsi – or unidentified related form
  • †Inoceramus deformis
  • †Inoceramus erectus
  • †Inoceramus flavus
  • †Inoceramus grandis
  • †Inoceramus longealatus
  • †Inoceramus muelleri - or unidentified loosely related form
  • †Inoceramus oblongus
  • †Inoceramus pictus
  • †Inoceramus prefragilis
  • †Inoceramus rutherfordi – or unidentified comparable form
  • †Inoceramus tenuistriatus – tentative report
• †Ischyrhiza
  • †Ischyrhiza avonicola – or unidentified comparable form

J

• 

  Fossilized shell of the Late Cretaceous ammonoid cephalopod Jeletzkytes
  †Jeletzkytes
  • †Jeletzkytes brevis
  • †Jeletzkytes dorfi
  • †Jeletzkytes nodosus
• †Jensensispermum
  • †Jensensispermum redmondii
• Jupiteria
  • †Jupiteria scitula

K

• †Kepodactylus – type locality for genus
  • †Kepodactylus insperatus – type locality for species

L

• †Laosaurus – report made of unidentified related form or using admittedly obsolete nomenclature
• Laternula
• Lepisosteus – tentative report
  • †Lepisosteus occidentalis
• †Leptalestes – tentative report
  • †Leptalestes cooki
• 

  Restoration of a school of the Middle Triassic-Early Cretaceous bony fish Leptolepis
  †Leptolepis – or unidentified comparable form
• †Lewyites
  • †Lewyites oronensis
• Lima
  • †Lima janetae – type locality for species
• †Lingula
• †Lioestheria
  • †Lioestheria tendagurensis – or unidentified comparable form
• †Lisserpeton
  • †Lisserpeton bairdi
• †Lonchidion
  • †Lonchidion selachos
• †Lucina
• †Lyropecten

M

• 

  Diagram illustrating the known fossil material of two specimens of the Late Jurassic crocodile relative Macelognathus
  †Macelognathus
  • †Macelognathus vagans
• †Magadiceramus
  • †Magadiceramus complicatus
  • †Magadiceramus crenelatus
  • †Magadiceramus soukupi - or unidentified loosely related form
  • †Magadiceramus subquadratus
• †Magnoavipes
  • †Magnoavipes caneeri – type locality for species
• †Marmarthia – or unidentified comparable form
  • †Marmarthia pearsonii
• †Marshosaurus – or unidentified comparable form
• 

  Fossilized skull of the Late Cretaceous multituberculate mammal Meniscoessus
  †Meniscoessus
  • †Meniscoessus collomensis – type locality for species
  • †Meniscoessus conquistus
  • †Meniscoessus robustus – or unidentified comparable form
• †Mesadactylus – type locality for genus
  • †Mesadactylus ornithosphyos – type locality for species
• †Mesembrioxylon
  • †Mesembrioxylon carterii – type locality for species
• †Mesodma
  • †Mesodma formosa – or unidentified comparable form
• †Mesojassoides – type locality for genus
  • †Mesojassoides gigantea – type locality for species
• †Mesolanistes
  • †Mesolanistes reesidei
• †Metengonoceras
  • †Metengonoceras dumbli
• †Metoicoceras
  • †Metoicoceras geslinianum
• †Micrabacia
  • †Micrabacia radiata
• †Micropycnodon
  • †Micropycnodon kansasensis
• †Modiolus
  • †Modiolus kremmlingensis – type locality for species
  • †Modiolus meeki
• †Moremanoceras
  • †Moremanoceras scotti
• †Morosaurus
  • †Morosaurus laticollis – type locality for species
• †Morrolepis
  • †Morrolepis schaefferi – type locality for species
• †Myledaphus
  • †Myledaphus bipartitus
• 

  Mounted fossilized skeleton of the Late Jurassic armored dinosaur Mymoorapelta
  †Mymoorapelta – type locality for genus
  • †Mymoorapelta maysi – type locality for species
• Myrica
  • †Myrica torreyi
• †Mytiloides
  • †Mytiloides duplicostatus – or unidentified related form
  • †Mytiloides latus – or unidentified comparable form
  • †Mytiloides mytiloides
  • †Mytiloides opalensis
  • †Mytiloides stantoni – or unidentified comparable form
  • †Mytiloides submytiloides – or unidentified related form

N

• †Nanosaurus – type locality for genus
  • †Nanosaurus agilis – type locality for species
  • †Nanosaurus rex
• 

  Multiple views of a fossilized shell belonging to a Natica moon snail
  Natica
• †Nemodon
  • †Nemodon adkinsi
  • †Nemodon harriesi – type locality for species
• †Neocardioceras
  • †Neocardioceras densicostatum – type locality for species
  • †Neocardioceras juddii
  • †Neocardioceras laevigatum
  • †Neocardioceras minutum
  • †Neocardioceras uptonense
• †Neocrioceras
• †Neoptychites
  • †Neoptychites cephalotus
• †Neurankylus
• †Nigericeras
  • †Nigericeras scotti – type locality for species
• †Nonactaeonina
  • †Nonactaeonina deflexa
  • †Nonactaeonina triticea
• †Nortedelphys
  • †Nortedelphys jasoni
• 

  Restoration of several species of the Late Cretaceous ammonoid cephalopod Nostoceras
  †Nostoceras
  • †Nostoceras approximans – or unidentified comparable form
  • †Nostoceras larimerense – type locality for species
  • †Nostoceras monotuberculatum
  • †Nostoceras obtusum – or unidentified comparable form
  • †Nostoceras splendidum – or unidentified comparable form
• Nucula
  • †Nucula percrassa
• Nuculana
• †Nymphalucina
  • †Nymphalucina bourni – type locality for species
  • †Nymphalucina cleburni

O

• †Octopodichnus
• †Odaxosaurus
  • †Odaxosaurus piger
• †Oligoptycha
  • †Oligoptycha concinna
• †Opertochasma
  • †Opertochasma cuneatum
• †Opisthias
• †Opisthotriton
  • †Opisthotriton kayi
• †Ornitholestes – tentative report
• †Ornithomimipus
  • †Ornithomimipus angustus – or unidentified comparable form
• 

  Fossilized skeleton of the Late Cretaceous ostrich dinosaur Ornithomimus
  †Ornithomimus – type locality for genus
  • †Ornithomimus velox – type locality for species
• Ostrea
  • †Ostrea beloiti
  • †Ostrea subradiata
• †Othnielia – tentative report
• †Othnielosaurus
  • †Othnielosaurus consors
• †Oxybeloceras
  • †Oxybeloceras crassum
• †Oxytoma

P

• 

  Fossilized skull of the Late Cretaceous dome-headed dinosaur Pachycephalosaurus
  †Pachycephalosaurus
• †Pachyrhizodus
  • †Pachyrhizodus minimus
• †Palaeobalistum
• †Palaeopteryx – type locality for genus
• †Paleonelumbo
  • †Paleonelumbo macroloba
• †Parabrontopodus – type locality for genus
  • †Parabrontopodus mcintoshi – type locality for species
• †Parallelodon
• †Paramacellodus
• †Parapleurites
  • †Parapleurites morrisonensis – type locality for species
• †Paressonodon – type locality for genus
  • †Paressonodon nelsoni – type locality for species
• †Parikimys – type locality for genus
  • †Parikimys carpenteri – type locality for species
• †Parviraptor
• 

  Life restoration of the Late Cretaceous horned dinosaur Pentaceratops
  †Pentaceratops
  • †Pentaceratops sternbergii
• †Pentasauropus
• †Petropteron – type locality for genus
  • †Petropteron mirandum – type locality for species
• †Phelopteria
  • †Phelopteria linguaeformis
  • †Phelopteria ruppii – type locality for species
• †Phlycticrioceras
  • †Phlycticrioceras trinodosus
• †Pinna
• †Placenticeras
  • †Placenticeras meeki
  • †Placenticeras placentum
  • †Placenticeras syrtale
• †Plastomenus – tentative report
  • †Plastomenus insignis – type locality for species
  • †Plastomenus punctulatus – type locality for species
• †Platanites
  • †Platanites marginata
• 

  Fossilized shell of the Cretaceous marine bivalve Platyceramus
  †Platyceramus
  • †Platyceramus ahsenensis
  • †Platyceramus cycloides
  • †Platyceramus mantelli - or unidentified loosely related form
  • †Platyceramus platinus
• †Platyognathus
• †Plesiobaena
  • †Plesiobaena antiqua – or unidentified comparable form
• †Polyonax – type locality for genus
  • †Polyonax mortuarius – type locality for species
• †Preprismatoolithus
  • †Preprismatoolithus coloradensis
• †Priacodon
  • †Priacodon fruitaensis – type locality for species
• †Prionocyclus
• †Probaena
  • †Probaena sculpta – type locality for species
• 

  Fossilized skull of the Late Cretaceous mosasaur Prognathodon
  †Prognathodon
  • †Prognathodon overtoni
  • †Prognathodon stadtmani – type locality for species
• Propeamussium
  • †Propeamussium simplicus
• †Protalphadon
• †Protexanites
  • †Protexanites shoshonensis
• †Protocardia
  • †Protocardia barneyi – type locality for species
• †Protocupressinoxylon
  • †Protocupressinoxylon medlynii – type locality for species
• 

  Life restoration of the Late Cretaceous bony fish Protosphyraena
  †Protosphyraena
• Prunus
  • †Prunus corrugis
• †Pseudaspidoceras
  • †Pseudaspidoceras collignoni
• †Pseudobaculites
• †Pseudocalycoceras
  • †Pseudocalycoceras angolaense
  • †Pseudocalycoceras dentonense
• †Pseudoisurus
  • †Pseudoisurus tomosus – or unidentified comparable form
• †Pseudoperna
  • †Pseudoperna bentonensis
  • †Pseudoperna congesta
  • †Pseudoperna inflatum – type locality for species
• †Pseudotetrasauropus – tentative report
• †Pteraichnus
• †Ptychodus
  • †Ptychodus anonymus
  • †Ptychodus decurrens
  • †Ptychodus occidentalis
  • †Ptychodus whipplei
• †Puebloites
  • †Puebloites spiralis
• Pycnodonte
  • †Pycnodonte newberryi

R

• †Rhaeboceras
  • †Rhaeboceras coloradoense – type locality for species
  • †Rhaeboceras halli
  • †Rhaeboceras subglobosum
• 

  A living Rhinobatos guitar fish
  Rhinobatos
  • †Rhinobatos incertus
• †Rhynchosauroides
• †Rosselia
• †Rotodactylus

S

• †Sabalites
  • †Sabalites JC016 – informal
  • †Sabalites LA042 – informal
• †Saurillodon
• †Scapherpeton
  • †Scapherpeton tectum
• 

  Fossilized shell of the Late Cretaceous ammonoid cephalopod Scaphites
  †Scaphites
  • †Scaphites binneyi
  • †Scaphites depressus
  • †Scaphites hippocrepis – or unidentified comparable form
  • †Scaphites nodosus
• †Schadipes – type locality for genus
  • †Schadipes crypticus – type locality for species
• †Sciponoceras
  • †Sciponoceras gracile
• †Scoyenia
• †Selaginella
  • †Selaginella JC023 – informal
• 

  Fossilized skeleton of the Late Triassic-Early Jurassic bony fish Semionotus
  †Semionotus
• †Solenoceras
  • †Solenoceras larimerense
  • †Solenoceras reesidei – or unidentified comparable form
  • †Solenoceras texanum
• †Sphenodiscus
  • †Sphenodiscus pleurisepta
• †Spiroxybeloceras
  • †Spiroxybeloceras meekanum
• Squalicorax
  • †Squalicorax curvatus
  • †Squalicorax falcatus
  • †Squalicorax pristodontus
• †Squatirhina
  • †Squatirhina americana
• 

  Restoration of the Late Jurassic stegosaur Stegosaurus
  †Stegosaurus – type locality for genus
  • †Stegosaurus armatus – type locality for species
  • †Stegosaurus stenops – type locality for species
  • †Stegosaurus ungulatus
• †Steinerocaulis
  • †Steinerocaulis radiatus
• †Stenomyti – type locality for genus
  • †Stenomyti huangae – type locality for species
• †Stokesosaurus – or unidentified comparable form
• †Stramentum
  • †Stramentum haworthi
• Sulcoretusa
  • †Sulcoretusa dominici – type locality for species
• †Sumitomoceras
  • †Sumitomoceras bentonianum
  • †Sumitomoceras conlini
• 

  Restoration in multiple views of the Late Jurassic sauropod dinosaur Supersaurus with an anachronistic human to scale
  †Supersaurus – type locality for genus
  • †Supersaurus vivianae – type locality for species
• †Syncyclonema
  • †Syncyclonema travisanus
• †Synorichthys – type locality for genus
  • †Synorichthys stewarti – type locality for species

T

• †Tanaocrossus – type locality for genus
  • †Tanaocrossus kalliokoskii – type locality for species
• †Tanocrossus
• Tellina
• †Tenea
  • †Tenea parilis
• Teredo
  • †Teredo irregularis
• †Texanites
  • †Texanites americanus
• 

  Fossilized skeleton of the Late Cretaceous plesiosaur Thalassomedon
  †Thalassomedon – type locality for genus
  • †Thalassomedon hanningtoni – type locality for species
• †Theiophytalia – type locality for genus
  • †Theiophytalia kerri – type locality for species
• †Therangospodus – or unidentified comparable form
• †Thescelosaurus
• †Tibiaporrhais
  • †Tibiaporrhais cooperensis
• †Titanosaurus
  • †Titanosaurus montanus – type locality for species
• 

  Fossilized skulls of the Late Cretaceous horned dinosaurs Torosaurus (A) and Triceratops (B) to scale
  †Torosaurus
  • †Torosaurus latus
• †Torvosaurus – type locality for genus
  • †Torvosaurus tanneri – type locality for species
• †Trachybaculites
  • †Trachybaculites columna – or unidentified comparable form
• †Treptichnus
• †Triceratops
  • †Triceratops galeus – type locality for species
  • †Triceratops horridus
• †Trinacromerum – or unidentified comparable form
• Trochocyathus
  • †Trochocyathus egerius
• †Turbinopsis
• Turritella
• †Turseodus
  • †Turseodus dolorensis – type locality for species
• †Tylosaurus
  • †Tylosaurus proriger
• 

  Fossilized skeleton of the Late Cretaceous tyrannosaur Tyrannosaurus
  †Tyrannosaurus
  • †Tyrannosaurus rex

V

• †Vanikoropsis
  • †Vanikoropsis nebrascensis
• 

  Fossilized shell of the Late Cretaceous ammonoid cephalopod Vascoceras
  †Vascoceras
  • †Vascoceras birchbyi
• Viviparus
  • †Viviparus reesidei
• †Volviceramus
  • †Volviceramus grandis
  • †Volviceramus involutus
• †Voysa

W

• †Walteria – type locality for genus
  • †Walteria jeffersonensis – type locality for species
  • †Walteria jeffersoni – type locality for species
• †Watinoceras
  • †Watinoceras coloradoense – type locality for species
• †Websteria
  • †Websteria cretacea
• †Worthoceras

X

• †Xenoxylon
  • †Xenoxylon moorei – type locality for species
• 

  Life restoration of the Cretaceous bony fish Xiphactinus
  †Xiphactinus
  • †Xiphactinus audax

Z

• †Zyziphus
  • †Zyziphus fibrillosus
  • †Zyziphus LA007 – informal
  • †Zyziphus LA032 – informal

References

• Various Contributors to the Paleobiology Database. "Fossilworks: Gateway to the Paleobiology Database". Retrieved 17 December 2021.