List of the prehistoric life of Colorado facts for kids

This list of the prehistoric life of Colorado contains the various prehistoric life-forms whose fossilized remains have been reported from within the US state of Colorado.

Precambrian

The Paleobiology Database records no known occurrences of Precambrian fossils in Colorado.

Paleozoic

Selected Paleozoic taxa of Colorado

• †Actinoceras
• †Aglaocrinus
• †Amorphognathus
• †Amplexus
• †Archaeocidaris
• 

  Life restoration of the Middle-Late Ordovician jawless fish Astraspis
  †Astraspis – type locality for genus
  • †Astraspis desiderata – type locality for species
• †Athyris
• †Aviculopecten
• †Calamites
  • †Calamites cistii
  • †Calamites cruciatus
• †Callipteris
  • †Callipteris lyratifolia – or unidentified comparable form
• †Camarotoechia
• †Caninia
• 

  Fossil of the Ordovician-Silurian tabulate coral Catenipora
  †Catenipora
• †Ceraurinus
• †Charactoceras – tentative report
• †Chirognathus
• †Composita
  • †Composita ovata
• †Conocardium
• †Cordaites
• †Cornulites
• †Crania
• †Ctenacanthus
  • †Ctenacanthus buttersi
  • †Ctenacanthus furcicarinatus
• †Cupressocrinites
• 

  Restoration of the Permian synapsid (mammal precursor) Cutleria
  †Cutleria – type locality for genus
  • †Cutleria wilmarthi – type locality for species
• †Cyclopteris
• †Cyrtogomphoceras
• †Cyrtospirifer
  • †Cyrtospirifer animasensis
  • †Cyrtospirifer whitneyi
• †Echinosphaerites – tentative report
• †Edestus
• †Endoceras
• †Eretmocrinus
• 

  Life restoration of the Carboniferous-Permian amphibian Eryops
  †Eryops
• †Euomphalus
• †Girvanella
• †Halysites
• †Isalaux – type locality for genus
• †Isonema
• †Kionoceras
• †Lambeoceras
• †Lepidodendron
• †Lepidostrobus
• †Limnoscelis
• †Lingula
• †Meristella
• †Neospirifer
  • †Neospirifer goreii
• †Neuropteris
  • †Neuropteris auriculata
  • †Neuropteris gigantea – tentative report
  • †Neuropteris heterophylla
• 

  Restoration of the Carboniferous-Permian synapsid (mammal precursor) Ophiacodon
  †Ophiacodon
• †Oradectes
• †Ormoceras
• †Orthoceras
• †Oulodus
• †Paladin – tentative report
• †Pecopteris
  • †Pecopteris arborescens
• †Plaesiomys
• †Platyceras
• 

  Life restoration of the Carboniferous-Permian sail-backed amphibian Platyhystrix
  †Platyhystrix
  • †Platyhystrix rugosus
• †Pugnax
• †Receptaculites
• †Samaropsis
• †Sandia
• †Seymouria
• †Sigillaria
  • †Sigillaria elegans – or unidentified comparable form
• †Sphenophyllum
• †Sphenopteris
• †Spirifer
  • †Spirifer centronatus
• Spirorbis
• †Spyroceras
• †Stigmaria
• †Strepsodiscus – type locality for genus
• †Strophomena
• †Syringopora
• 

  Fossil of the Silurian-Carboniferous crinoid ("sea lily") Taxocrinus (right)
  †Taxocrinus
• †Walchia
• †Westonoceras

Mesozoic

Selected Mesozoic taxa of Colorado

• Acmaea
• †Adocus
• †Albanerpeton
  • †Albanerpeton nexuosus
• †Albertosaurus – tentative report
• 

  Life restoration of the Late Jurassic theropod dinosaur Allosaurus
  †Allosaurus – type locality for genus
  • †Allosaurus fragilis – type locality for species
• †Amblotherium – type locality for genus
• Amia
• †Amphicoelias – type locality for genus
  • †Amphicoelias altus – type locality for species
• †Amphicotylus
  • †Amphicotylus lucasii – type locality for species
• †Anaklinoceras
• †Anisoceras
• †Anomia
• †Anomoepus – tentative report
• †Apateodus
• †Apatopus
• 

  Comparison of A. ajax (orange) and A. louisae (red) with a human (blue) and Brontosaurus parvus (green)
  †Apatosaurus – type locality for genus
  • †Apatosaurus ajax – type locality for species
  • †Apatosaurus louisae – type locality for species
• †Arenicolites
• Aspideretes
• Astarte
• †Atlantosaurus
  • †Atlantosaurus immanis – type locality for species
• †Axonoceras
• 

  Fossilized shell of the Late Cretaceous ammonoid cephalopod Baculites
  †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
• †Barosaurus
• 

  Fossilized skeleton of the Cretaceous turtle Basilemys
  †Basilemys
• †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
• †Brachyphyllum
• 

  Life restoration of a herd of the Late Jurassic sauropod dinosaur Brontosaurus
  †Brontosaurus
  • †Brontosaurus excelsus
  • †Brontosaurus yahnahpin
• †Calycoceras
• †Camarasaurus – type locality for genus
  • †Camarasaurus grandis
  • †Camarasaurus lewisi
  • †Camarasaurus supremus – type locality for species
• †Camptosaurus – type locality for genus
  • †Camptosaurus dispar – type locality for species
• Carcharias
• †Caririchnium
• †Cedrobaena
• †Ceratodus – type locality for genus
• 

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

  Life restoration of the face of the Late Cretaceous multituberculate mammal Cimolomys
  †Cimolomys
• †Cionodon – type locality for genus
  • †Cionodon arctatus – type locality for species
• †Cirroceras
• †Clidastes
• †Coelophysis – tentative report
• †Coelurus
  • †Coelurus fragilis
• †Compsemys
• †Coniasaurus
• Corbula
• †Crenella
• 

  Fossil of the Early Cretaceous-Eocene shark Cretolamna
  †Cretolamna
  • †Cretolamna appendiculata
• †Cretoxyrhina
  • †Cretoxyrhina mantelli
• Cucullaea
• Cuspidaria
• †Didymoceras
  • †Didymoceras cheyennense
  • †Didymoceras stevensoni
• †Dinehichnus
• †Dinochelys
• 

  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
• †Diplosaurus
• Discinisca
• †Discoscaphites
  • †Discoscaphites conradi
• †Docodon
• †Dorsetisaurus
• †Dorsetochelys
• †Dryosaurus
  • †Dryosaurus altus
• †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
• †Elopopsis
• †Enchodus
  • †Enchodus gladiolus – or unidentified comparable form
  • †Enchodus shumardi – or unidentified comparable form
• †Equisetum
• †Eubrontes
  • †Eubrontes giganteus
• †Eucalycoceras
• †Euomphaloceras
• †Eutrephoceras
• †Eutretauranosuchus – type locality for genus
  • †Eutretauranosuchus delfsi – type locality for species
• †Exiteloceras
• †Exogyra
• 

  Fossilized shell of the Late Cretaceous ammonoid cephalopod Fagesia
  †Fagesia
• Ficus
• †Forresteria
• †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
• †Galeamopus
  • †Galeamopus pabsti
• †Glirodon
  • †Glirodon grandis
• †Glyptops
• 

  Restoration of the Late Jurassic-Early Cretaceous crocodile relative Goniopholis
  †Goniopholis
• †Grallator
• †Hallopus
  • †Hallopus victor – type locality for species
• †Haplocanthosaurus – type locality for genus
  • †Haplocanthosaurus delfsi – type locality for species
  • †Haplocanthosaurus priscus – type locality for species
• †Hemicalypterus
• †Herrickiceras
• †Hoploscaphites
  • †Hoploscaphites birkelundae
  • †Hoploscaphites nicolletii
• †Hulettia – report made of unidentified related form or using admittedly obsolete nomenclature
• †Hypsirophus – type locality for genus
• †Ichthyodectes
• †Ignotornis – type locality for genus
• 

  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
• 

  Fossilized shell of the Late Cretaceous ammonoid cephalopod Jeletzkytes
  †Jeletzkytes
  • †Jeletzkytes brevis
  • †Jeletzkytes dorfi
  • †Jeletzkytes nodosus
• †Kepodactylus – type locality for genus
  • †Kepodactylus insperatus – type locality for species
• †Laosaurus – report made of unidentified related form or using admittedly obsolete nomenclature
• Lepisosteus – tentative report
• †Leptalestes – tentative report
  • †Leptalestes cooki
• †Leptolepis – or unidentified comparable form
• Lima
• †Lingula
• †Lioestheria
• †Lisserpeton
  • †Lisserpeton bairdi
• †Lonchidion
• †Lucina
• †Macelognathus
• †Magnoavipes
• †Marshosaurus – or unidentified comparable form
• 

  Fossilized skull of the Late Cretaceous multituberculate mammal Meniscoessus
  †Meniscoessus
  • †Meniscoessus collomensis – type locality for species
  • †Meniscoessus robustus – or unidentified comparable form
• †Mesadactylus – type locality for genus
  • †Mesadactylus ornithosphyos – type locality for species
• †Mesodma
  • †Mesodma formosa – or unidentified comparable form
• †Mesojassoides – type locality for genus
  • †Mesojassoides gigantea – type locality for species
• †Metoicoceras
  • †Metoicoceras geslinianum
• †Micropycnodon
• †Modiolus
• †Morosaurus
• †Morrolepis
• †Myledaphus
  • †Myledaphus bipartitus
• 

  Fossilized skeleton of the Late Jurassic armored dinosaur Mymoorapelta
  †Mymoorapelta – type locality for genus
  • †Mymoorapelta maysi – type locality for species
• Myrica
• †Nanosaurus – type locality for genus
  • †Nanosaurus agilis – type locality for species
  • †Nanosaurus rex
• Natica
• †Neocardioceras
  • †Neocardioceras densicostatum – type locality for species
  • †Neocardioceras juddii
  • †Neocardioceras laevigatum
  • †Neocardioceras minutum
  • †Neocardioceras uptonense
• †Neoptychites
• 

  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
• †Odaxosaurus
  • †Odaxosaurus piger
• †Opisthias
• †Opisthotriton
• †Ornitholestes – tentative report
• †Ornithomimipus
• †Ornithomimus – type locality for genus
  • †Ornithomimus velox – type locality for species
• Ostrea
• †Othnielia – tentative report
• †Othnielosaurus
  • †Othnielosaurus consors
• †Oxytoma
• 

  Fossilized skull of the Late Cretaceous dome-headed dinosaur Pachycephalosaurus
  †Pachycephalosaurus
• †Pachyrhizodus
  • †Pachyrhizodus minimus
• †Palaeobalistum
• †Palaeopteryx – type locality for genus
• †Parabrontopodus – type locality for genus
• †Paramacellodus
• †Paressonodon – type locality for genus
• †Parikimys – type locality for genus
• †Parviraptor
• †Pentaceratops
  • †Pentaceratops sternbergii
• †Pinna
• †Placenticeras
  • †Placenticeras meeki
• 

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

  Fossilized skull of the Late Cretaceous mosasaur Prognathodon
  †Prognathodon
  • †Prognathodon overtoni
  • †Prognathodon stadtmani – type locality for species
• Propeamussium
• †Protocardia
• †Protosphyraena
• Prunus
• †Pseudoperna
  • †Pseudoperna congesta
• †Pseudotetrasauropus – tentative report
• †Pteraichnus
• †Ptychodus
  • †Ptychodus anonymus
  • †Ptychodus decurrens
  • †Ptychodus occidentalis
  • †Ptychodus whipplei
• Pycnodonte
  • †Pycnodonte newberryi
• Rhinobatos
  • †Rhinobatos incertus
• †Rosselia
• †Saurillodon
• †Scapherpeton
• 

  Fossilized shell of the Late Cretaceous ammonoid cephalopod Scaphites
  †Scaphites
  • †Scaphites binneyi
  • †Scaphites depressus
  • †Scaphites hippocrepis – or unidentified comparable form
  • †Scaphites nodosus
• †Scoyenia
• †Selaginella
• †Semionotus
• †Sphenodiscus
  • †Sphenodiscus pleurisepta
• 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
• †Stenomyti – type locality for genus
  • †Stenomyti huangae – type locality for species
• †Stokesosaurus – or unidentified comparable form
• †Supersaurus – type locality for genus
  • †Supersaurus vivianae – type locality for species
• Tellina
• †Tenea
• Teredo
• †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
• †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
• †Treptichnus
• †Triceratops
  • †Triceratops galeus – type locality for species
  • †Triceratops horridus
• †Trinacromerum – or unidentified comparable form
• Turritella
• †Tylosaurus
  • †Tylosaurus proriger
• 

  Fossilized skeleton of the Late Cretaceous tyrannosaur Tyrannosaurus
  †Tyrannosaurus
  • †Tyrannosaurus rex
• †Vascoceras
• Viviparus
• †Volviceramus
• †Walteria – type locality for genus
• †Watinoceras
  • †Watinoceras coloradoense – type locality for species
• †Websteria
• †Xiphactinus
  • †Xiphactinus audax

Cenozoic

Selected Cenozoic taxa of Colorado

• 

  A living Abies, or fir tree
  Abies
• †Absyrtus
• †Acalles
• Abies
• †Absyrtus
• †Acalles
• Acer
• †Acilius
• Acris
• †Acrostichum
• †Adalia
• †Adelopsyche – type locality for genus
• †Adocus
• Aegialia
• †Aelurodon
• 

  Life restoration of the Miocene camel Aepycamelus, or the long-necked camel. Heinrich Harder (1920).
  †Aepycamelus
  • †Aepycamelus giraffinus
• †Aeshna
• Agabus
• †Agallia
• †Agathemera
• Agelaius
• †Agnotocastor
• Agrilus
• Agriotes
• †Agromyza
• †Agulla
  • †Agulla protomaculata – type locality for species
• 

  Foliage and fruits of an Ailanthus tree
  †Ailanthus
• †Aletodon
• Aleurites
• †Alforjas – tentative report
• †Allognathosuchus
• †Allophylus
• Altica
• †Alysia
• Amara
• †Amauropilio
• †Amblycorypha – tentative report
• †Amblyteles
• †Ambystoma
  • †Ambystoma tigrinum
• 

  Life restoration of the Miocene elephant relative Amebelodon. Margret Flinsch (1932).
  †Amebelodon
• Amelanchier
• Amia
• †Ammophila
• †Ampelopsis
• †Amphechinus
• †Amphicerus
• †Amphicyon
  • †Amphicyon galushai
  • †Amphicyon ingens
• 

  Fossilized skull of the Miocene saber-toothed cat Amphimachairodus
  †Amphimachairodus
• †Anabrus
• Anas
• †Anasa
• †Anatis
• †Anchitherium
• Andrena
• †Andrias
• †Andricus
• †Anelaphus
• †Anemia
• †Angustidens
• Anisotoma
• †Anobium
• †Anomala
• †Anomalon
• Anser
• †Antas
• Anthaxia
• †Antherophagus
• 

  A living Anthidium, or carder bee
  †Anthidium
  • †Anthidium exhumatum – type locality for species
  • †Anthidium scudderi – type locality for species
• †Anthomyia
• Anthonomus
• †Anthophora
• Antilocapra
  • †Antilocapra americana
• †Antocha
• Aphaenogaster
  • †Aphaenogaster donisthorpei – type locality for species
  • †Aphaenogaster mayri – type locality for species
• †Aphelops
• Aphodius
• Aphrophora
• Apion
• †Apolysis
• Aquila
  • †Aquila chysaetos
• Araneus
• †Archaeotherium
• †Archimyrmex – type locality for genus
  • †Archimyrmex rostratus – type locality for species
• †Archiponera – type locality for genus
  • †Archiponera wheeleri – type locality for species
• 

  Life restoration of the Paleocene mammal Arctocyon
  †Arctocyon
• †Argia
• †Arhopalus
• †Aristolochia
• †Artocarpus
• †Asimina
• Asio
• †Asplenium
• †Aster
• †Astronium
• Ataenius
• †Athalia
• 

  A living Athous click beetle
  †Athous
• †Athyana
• †Attagenus
• †Auraria – type locality for genus
• Aythya
  • †Aythya affinis
  • †Aythya americana
• †Aztlanolagus
• †Baena
• †Baris
• 

  Life restoration of the Paleocene-Eocene pantodont mammal Barylambda
  †Barylambda
• †Bassus
• †Bathornis – type locality for genus
  • †Bathornis veredus – type locality for species
• †Bathygenys
• †Bathyopsis
• †Belyta
• Bembidion
  • †Bembidion constricticolle
• †Bembidium
• †Beris
• Betula
• Bibio
• †Bibiodes
• †Bidessus
• Bison
  • †Bison antiquus – or unidentified comparable form
  • 

    Mounted fossilized skeleton of the Pleistocene Bison latifrons, or long-horned bison
    †Bison latifrons
• †Blechnum
• Bledius
• Boletina
• †Borealosuchus
• †Borophagus
  • †Borophagus pugnator
• †Brachinus
• †Brachycrus
• Brachylagus
• †Brachyprotoma
  • †Brachyprotoma obtusata
• †Brachypsalis
• 

  Skeletal reconstruction of the Eocene-Oligocene bear-dog Brachyrhynchocyon
  †Brachyrhynchocyon
• †Brachyspathus – type locality for genus
• Bracon
• †Bruchus
• Bubo
  • †Bubo virginianus
• Bufo
  • †Bufo cognatus
  • †Bufo woodhousei
• †Buprestis
• †Bursera
• 

  A living Buteo hawk
  Buteo
• †Caesalpinia
• †Calcarius
  • †Calcarius lapponicus
  • †Calcarius ornatus
• †Calippus
• †Caliroa
• †Callimoxys
• †Callomyia – tentative report
• Calosoma
• †Calyptapis – type locality for genus
  • †Calyptapis florissantensis – type locality for species
• 

  Life restoration of the Pliocene-Holocene camel Camelops
  †Camelops
  • †Camelops hesternus
• Camponotus
• Canis
  • †Canis edwardii – or unidentified comparable form
  • †Canis latrans
• †Cantius
  • †Cantius abditus
  • †Cantius frugivorus
  • †Cantius mckennai
  • †Cantius ralstoni
• †Capnobotes
• †Capsus
• 

  A living Carabus ground beetle
  Carabus
• †Cardiophorus
• †Cardiospermum
• †Carpocyon
• Carpodacus
  • †Carpodacus cassinii
• †Carpophilus
• Carya
• Castanea
• †Catopsalis
  • †Catopsalis alexanderi – type locality for species
• †Cecidomyia – tentative report
• Cedrela
• †Celastrus
• Celtis
• †Centron – type locality for genus
• †Ceratina
• 

  Life restoration of the Paleocene-Eocene crocodilian Ceratosuchus
  †Ceratosuchus – type locality for genus
  • †Ceratosuchus burdoshi – type locality for species
• †Ceraturgus
• Cercidiphyllum
• Cercis
• †Cercocarpus
• †Cercopis
• Cervus
  • †Cervus elaphus
• Ceutorhynchus
• Chaetodipus
  • †Chaetodipus hispidus
• †Chalcis
• †Chalybion
• †Chamaecyparis
• 

  A stand of living Chamaedorea palms
  †Chamaedorea
• Charina
• †Chauliognathus
• Cheilosia
• †Chelonus
• †Chilocorus
• †Chionaemopsis – type locality for genus
• Chironomus
• Chondestes
  • †Chondestes grammacus
• †Chriacus
• †Chrysis
• †Chrysobothris
• †Chrysogaster
• Chrysomela
• †Cicada
• †Cicadella
• †Cimbex
• †Cimexomys
  • †Cimexomys arapahoensis – type locality for species
  • †Cimexomys minor
• 

  A living Cinnamomum, or cinnamon tree
  Cinnamomum
• Cissus
• †Cixius – tentative report
• †Cladius
• †Cladura
• †Clastoptera
• †Cleonus
• †Closterocoris
  • †Closterocoris elegans – type locality for species
• †Clubiona
• †Clytus
• †Coccinella
• †Coeliodes
• Colaptes
  • 

    A living Colaptes auratus, or northern flicker
    †Colaptes auratus
• †Colaspis
• †Collops
• †Colopterus
• †Colubrina
• †Compsemys
• †Coniatus
• Conotelus
  • †Conotelus obscurus
• †Conotrachelus
• †Conzattia
• †Copecion
• †Copelemur
• †Copidita
• Corixa
• †Corizus
• †Cormocyon
• †Cormohipparion
• Cornus
• Corticaria
• Corvus
  • †Corvus brachyrhynchos
  • †Corvus corax
• †Corylus
• 

  Life restoration of the Paleocene-Eocene pantodont mammal Coryphodon. Heinrich Harder (1920).
  †Coryphodon
• Cossonus
• †Cotinus
• †Crabro
• †Cratacanthus
• Crataegus
• Crotalus
  • †Crotalus viridis
• †Croton
• †Cryptocephalus
• †Cryptocheilus
• Cryptophagus
• Cryptorhynchus
• †Cryptus
• 

  A living Culex mosquito
  Culex
• †Curculio
• †Cuterebra
• †Cyclotrachelus
• †Cydamus
• †Cylindrotoma
• †Cynarctoides
  • †Cynarctoides acridens
• †Cynelos
• Cynomys
• †Cyphomyia
• †Cypris
• †Daphne
• Daphnia
• 

  Life restoration of the Eocene-Miocene bear dog Daphoenus
  †Daphoenus
• †Davidia
• †Denaeaspis – type locality for genus
  • †Denaeaspis chelonopsis – type locality for species
• †Dennstaedtia
• †Dermatobia
• †Dermestes
• †Diabrotica
• †Diacodexis
• †Dialysis
• Diamesa
• †Dianthidium
• †Diceratherium
• †Dicerca
• Dicranomyia
• †Dicranota
• †Dictyla
• †Didymictis
• †Didymosphaeria
• †Dilophodon
• 

  Life restoration of the Eocene-Miocene false saber-toothed cat Dinictis. Robert Bruce Horsfall (1913).
  †Dinictis
• †Dinohippus
• †Dioctria
• Dioscorea
• †Diploptera
• Diplotaxis – tentative report
• Diplotaxis
• Dipodomys
  • †Dipodomys ordii
• Dipteronia
• †Dissacus
• †Docimus – type locality for genus
• Dodonaea
• 

  Preserved Dolichoderus ant
  Dolichoderus
  • †Dolichoderus antiquus – type locality for species
  • †Dolichoderus kohlsi – type locality for species
  • †Dolichoderus rohweri – type locality for species
• †Dominickus – type locality for genus
  • †Dominickus castnioides – type locality for species
• †Domnina
• Donacia
• Dorytomus
• †Doxocopa
• †Drassonax
• 

  Fossilized horns, jaws, and limb bones of the Miocene deer relative Dromomeryx
  †Dromomeryx
  • †Dromomeryx borealis – type locality for species
• †Dryobius
• Dryopteris
• Dyschirius
• †Dysdercus
• †Echmatemys
• †Ectobius
• †Ectocion
• †Ectoconus
• †Elaeomyrmex – type locality for genus
  • †Elaeomyrmex coloradensis – type locality for species
  • †Elaeomyrmex gracilis – type locality for species
• †Elaphidion
• Elaphropus
• †Elater
• Eleodes
• †Emiliana – type locality for genus
  • †Emiliana alexandri – type locality for species
• †Empis
• †Enallagma
• Engelhardtia
• Enochrus
• †Entimus
• 

  Life restoration of a pair of the Eocene uintathere mammal Eobasileus. Charles R. Knight (1890s).
  †Eobasileus
  • †Eobasileus cornutus
• †Eocuculus – type locality for genus
• †Eogryllus
• †Eohippus
  • †Eohippus angustidens
• †Eosacantha – type locality for genus
  • †Eosacantha delocranioides – type locality for species
• †Eotitanops
• Ephedra
• †Ephemera
• †Epicaerus
• Epicauta
• †Epicyon
  • †Epicyon haydeni
• †Epihippus
• Epuraea
• †Epyris
• †Equisetum
• Equus
  • †Equus conversidens
  • †Equus francisci
  • 

    Restoration of the Pliocene-Holocene horse Equus scotti, or Scott's horse
    †Equus scotti – or unidentified comparable form
  • †Equus simplicidens
• Eremophila
  • †Eremophila alpestris
• Erethizon
• Eriocampa
• †Eriophyes – tentative report
• †Eristalis
• †Ernobius
• †Ethmia
• †Eubazus
• †Eucnemis
• †Eucommia
• Eugenia
• 

  Fossil of the Eocene ant Eulithomyrmex
  †Eulithomyrmex – type locality for genus
  • †Eulithomyrmex rugosus – type locality for species
  • †Eulithomyrmex striatus – type locality for species
• †Euparius
• Euphorbia
• †Eurytoma
• Eutamias
  • †Eutamias minimus – or unidentified comparable form
• †Exochus
• Fagus
• Falcipennis
• Falco
  • †Falco sparverius
• Ficus
• 

  Fossilized flower of the Eocene-Oligocene mallow relative Florissantia
  †Florissantia – type locality for genus
  • †Florissantoraphidia funerata – type locality for species
• Formica
• †Fornax
• †Fraxinus
• †Fulgora
• †Fulica
  • †Fulica americana
• †Gaurotes
• †Geocoris
• Geomys
  • †Geomys bursarius
• †Geron – tentative report
• Gerris
• †Gigantocamelus
• †Glossina – type locality for genus
• Glyptostrobus
• Gnophomyia
• †Gomphocerus
• 

  Mounted fossilized skeleton of the Miocene-Pleistocene elephant relative Gomphotherium
  †Gomphotherium
• †Gorytes
• †Grammoptera
• †Gyaclavator – type locality for genus
  • †Gyaclavator kohlsi – type locality for species
• †Gymnopternus
• †Gymnorhinus
• †Hadrianus
• Halesia
• †Hapalodectes
• †Haplolambda
• Harpalus
• †Helaletes
• †Helichus
• †Hellwigia
• Helophorus
• †Hemiauchenia
  • †Hemiauchenia macrocephala
• 

  Life restoration of the Eocene tapir relative Heptodon
  †Heptodon
• †Heriades
• †Herpetotherium
  • †Herpetotherium fugax
  • †Herpetotherium knighti
• Hersiliola
• †Hesperocyon
• Heterodon
  • †Heterodon nasicus
• †Hexerites – type locality for genus
  • †Hexerites primalis – type locality for species
• †Heyderia
• Holbrookia
  • †Holbrookia maculata
• †Holcorpa – type locality for genus
  • †Holcorpa maculosa – type locality for species
• †Homogalax
• †Hoplia
• †Hoplocampa
• †Hoplochelys
• †Humulus
• 

  Life restoration of the Eocene-Miocene creodont mammal Hyaenodon
  †Hyaenodon
  • †Hyaenodon crucians
  • †Hyaenodon horridus
  • †Hyaenodon mustelinus
• †Hydnobius
• Hydrangea
• Hydriomena
• †Hydriomena? protrita – tentative report
• Hydrobius
  • †Hydrobius fuscipes
• †Hydromystria
• Hydrophilus
• Hydroporus
• Hydropsyche
• †Hydroptila
• 

  A living Hygrotus predaceous diving beetle
  Hygrotus
• †Hylobius
• †Hymenophyllum
• †Hyopsodus
• †Hypertragulus
• †Hypisodus
• †Hypohippus
• †Hypolagus
• †Hyporhina
  • †Hyporhina galbreathi – type locality for species
• †Hyrachyus
• 

  Life restoration of the Eocene-Oligocene odd-toed ungulate Hyracodon. Charles R. Knight (1896).
  †Hyracodon
• †Hyracotherium
  • †Hyracotherium vasacciense
• †Ichneumon
• Ilex
• †Indusia
• †Iridomyrmex
  • †Iridomyrmex florissantius – type locality for species
  • †Iridomyrmex obscurans – type locality for species
• †Ischyromys
• †Isomira
• †Isothea – type locality for genus
• †Isotrilophus
• †Iulus
• †Jadera
• †Janus
• Jassus – tentative report. Lapsus calami of Iassus.
• †Judolia
  • †Judolia antecurrens – type locality for species
• 

  A living Juglans, or walnut tree
  Juglans
• Junco
  • †Junco hyemalis
• †Juncus
• †Kalmia
• †Kimbetohia
• Koelreuteria
• †Lacon
• †Lagopus
  • †Lagopus leucurus
• †Lambdotherium
• †Lapton
• 

  A living Larus gull
  Larus
• Lasiopodomys
• Lasius
• Lathrobium
• Laurus
• †Lebia
• †Leia
• †Lema
• Lemmiscus
  • †Lemmiscus curtatus
• Lepisosteus
• †Leptauchenia
• †Leptis
• †Leptocyon
• 

  Life restoration of the Eocene-Oligocene even-toed ungulate Leptomeryx
  †Leptomeryx
• †Leptomorphus
• Leptophloeus
• †Leptostylus
• †Leptura
• Lepus
  • †Lepus townsendii
• †Leucosticte
  • †Leucosticte atrata
  • †Leucosticte tephrocotis
• †Leucozona
• †Ligyrocoris
• †Ligyrus
• 

  A living Limnephilus caddisfly
  †Limnephilus
• †Limnobium
• †Limnophila
• †Limonius
• Lindera
• †Linnaea – type locality for genus
• †Linyphia
• †Liometopum
  • †Liometopum miocenicum – type locality for species
  • †Liometopum scudderi – type locality for species
• †Lithocharis
• 

  Life restoration of the Eocene butterfly Lithodryas
  †Lithodryas – type locality for genus
  • †Lithodryas styx – type locality for species
• †Locusta
• Lomatia
• Longitarsus
• Lontra
  • †Lontra canadensis – or unidentified comparable form
• †Lucanus
• †Lycosa
• †Lygaeus
• Lygodium
• Lynx
  • †Lynx rufus
• Lytta
• 

  Life restoration of the Eocene mammal Macrocranion
  Macrocranion
• †Macrodactylus
• †Macrophya
• †Macrorhoptus
• Magdalis
• Magnolia
• Mahonia
• †Maiorana
• †Malachius
• †Malus
• †Mammuthus
  • 

    Life restoration of a herd of Mammuthus columbi, or Columbian mammoths. The extent of the fur depicted is hypothetical. Charles R. Knight (1909).
    †Mammuthus columbi
• Marmota
  • †Marmota flaviventris
• Martes
• †Megacerops
• Megachile
• †Megacyllene
• †Megahippus
• †Megalictis
• †Megapenthes
• †Megatylopus
• †Melanactes
• †Melanophila
• †Melieria
• †Melittomma
• †Mellinus
• Melospiza
  • †Melospiza lincolnii
• †Meniscotherium
• 

  Life restoration of the Miocene rhinoceros Menoceras
  †Menoceras
• Mephitis
  • †Mephitis mephitis
• †Merychippus
  • †Merychippus sejunctus
• †Merychyus
• †Merycochoerus
• †Merycodus
• †Merycoidodon – type locality for genus
• †Mesatirhinus
• †Mesochorus
• †Mesocyon
• †Mesodma
  • †Mesodma hensleighi
• †Mesohippus
• †Mesoleptus
• †Mesonyx
  • †Mesonyx obtusidens
• †Mesostenus
• Messor
• 

  Life restoration of the Eocene pangolin relative Metacheiromys
  †Metacheiromys
• Metachroma
• †Metarhinus
• Metasequoia
  • †Metasequoia occidentalis
• †Miacis
• Miagrammopes
• †Michenia
• †Microplitis
• †Microsyops
• †Microtomarctus
• Microtus
  • 

    A living Microtus californicus, or California vole
    †Microtus californicus – or unidentified comparable form
  • †Microtus longicaudus
  • †Microtus ochrogaster
• †Mimoperadectes
• †Mindarus – type locality for genus
• †Miniochoerus
• †Miodytiscus – type locality for genus
• †Miohippus
• †Miomyrmex
  • †Miomyrmex impactus – type locality for species
  • †Miomyrmex striatus – type locality for species
• 

  Restoration of the Pliocene-Pleistocene Miracinonyx, or American cheetah
  †Miracinonyx
  • †Miracinonyx inexpectatus – or unidentified comparable form
  • †Miracinonyx studeri
• †Monosaulax
• Mordella
  • †Mordella atrata – or unidentified comparable form
  • †Mordella lapidicola – type locality for species
  • †Mordella priscula – type locality for species
  • †Mordella stygia – type locality for species
• Mordellistena
  • †Mordellistena florissantensis – type locality for species
  • †Mordellistena nearctica – type locality for species
  • †Mordellistena scudderiana – type locality for species
  • †Mordellistena smithiana – type locality for species
• †Moropus
• Morus
• Musca
• Mustela
  • †Mustela richardsonii
  • †Mustela nigripes
• †Myas
• †Mycetophagus
• Mycetoporus
• Myrica
• Myrmica
• Nebria
• †Nemognatha
• †Neoliotomus
  • †Neoliotomus conventus
  • †Neoliotomus ultimus
• Neogale
  • Neogale frenata
  • Neogale vison
• Neotoma
  • †Neotoma cinerea
• †Nepa
• †Nephila
• †Netelia
• †Nicocles
• 

  Mounted fossilized skeleton of the Eocene primate Notharctus
  †Notharctus
  • †Notharctus robustior
• Notonecta
• Numenius
  • †Numenius madagascariensis
• †Numitor – type locality for genus
• †Nyctea
  • †Nyctea scandiaca
• Nymphaea
• Nysius
• †Nyssa
• Ochotona
  • †Ochotona princeps
• †Odaxosaurus – or unidentified comparable form
  • †Odaxosaurus piger
• Odocoileus
  • 

    Living male (right) and female (left) Odocoileus hemionus, or mule deer.
    †Odocoileus hemionus
• †Odynerus
• †Oedipoda
• †Ogygoptynx – type locality for genus
• †Oligoaeschna – type locality for genus
• †Oligomerus
• †Oligotricha
• Omalium
• Omus
• Ondatra
• †Oodectes
• Ophisaurus
• Ophryastes
• †Ophyra
• †Opisthotriton
• †Orchelimum
• Orchestes
• Oreamnos – or unidentified comparable form
  • 

    A living Oreamnos harringtoni, or Harrington's mountain goat
    †Oreamnos harringtoni
• †Oreopanax
• †Orohippus
• †Orontium
• †Orphilus
• †Orthocentrus
• †Osmanthus
• †Osmunda
  • †Osmunda greenlandica
• †Otiorhynchus
• Ovis
  • †Ovis canadensis
• †Oxyacodon
• 

  Restoration of the Paleocene-Eocene creodont mammal Oxyaena
  †Oxyaena
• †Oxycera
• †Oxyomus
• †Pachyaena
• †Paederus
• †Palaeogale
• †Palaeolagus
• †Palaeonictis
• †Palaeosinopa
  • †Palaeospiza bella
• 

  Restorative model and fossilized skull of the Eocene brontothere mammal Palaeosyops
  †Palaeosyops – type locality for genus
• †Palaeovespa – type locality for genus
  • †Palaeovespa florissantia – type locality for species
  • †Palaeovespa gillettei – type locality for species
  • †Palaeovespa relecta – type locality for species
  • †Palaeovespa scudderi – type locality for species
  • †Palaeovespa wilsoni – type locality for species
• †Palatobaena
• †Panax
• †Panorpa
• †Paracynarctus
• †Parahippus
  • †Parahippus leonensis – or unidentified comparable form
• 

  Fossilized skeleton of the Pliocene-Pleistocene ground sloth Paramylodon
  †Paramylodon
  • †Paramylodon harlani
• †Paramys
• †Parandra
• †Paratylopus
• †Parectypodus
  • †Parectypodus lunatus
• †Parictis
• †Parthenocissus
• †Passaloecus
• †Patriofelis
• Pediacus
• Pekania
• †Pellea
• 

  Fossilized skull of the Eocene-Oligocene lizard Peltosaurus
  †Peltosaurus
  • †Peltosaurus granulosus – type locality for species
• †Pelycodus
  • †Pelycodus danielsae
  • †Pelycodus jarrovii
• Penthetria – type locality for genus
• †Pepsis
• †Peraceras
• †Peratherium
• Peromyscus
  • †Peromyscus maniculatus
• Persea
• 

  Fossil of the Oligocene ant Petraeomyrmex
  †Petraeomyrmex – type locality for genus
  • †Petraeomyrmex minimus – type locality for species
• †Phaca
• Phalacrocorax
• Phalaropus
  • †Phalaropus lobatus
• †Phasmagyps – type locality for genus
• Pheidole
• †Phenacodus
• Phenacomys
  • †Phenacomys intermedius
• Philadelphus
• †Philanthus
• 

  Illustration of a fossilized skull in multiple views of the Oligocene-Miocene bone-crushing dog Phlaocyon
  †Phlaocyon
• Phloeosinus
• †Phora
• Phryganea
• Phrynosoma
  • †Phrynosoma douglassi
• †Phylledestes – type locality for genus
  • †Phylledestes vorax – type locality for species
• †Phyllobaenus
• Phyllobius
• †Phyllophaga
• †Phymatodes
• Pica
  • †Pica hudsonia
• Picea
• Picoides
  • †Picoides villosus
• †Pidonia
• †Pimpla
• Pinus
• †Pipiza
• †Pison
• Pituophis
  • †Pituophis melanoleucus
• Platanus
• Plateumaris
• †Platycheirus
• Platydema
• 

  Life restoration of a herd of alarmed Miocene-Pleistocene peccaries of the genus Platygonus. Charles R. Knight (1922).
  †Platygonus
• Platynus
• Platystethus
• Plecia
• †Plesiadapis
• †Plesiobaena
• †Pliohippus
• †Plochionus
• †Poabromylus
• Podabrus
• Podiceps
• Podilymbus
  • †Podilymbus podiceps
• 

  Life restoration of the Eocene-Oligocene camel Poebrotherium
  †Poebrotherium
• †Poecilocapsus
• †Poecilognathus – type locality for genus
• †Pogonomyrmex
  • †Pogonomyrmex fossilis – type locality for species
• †Polysphincta
• Populus
• Porzana
  • †Porzana carolina
• †Potamogeton
• †Praepapilio – type locality for genus
  • †Praepapilio colorado – type locality for species
  • †Praepapilio gracilis – type locality for species
• †Priabona
• †Pristichampsus
• †Probathyopsis
• †Procas
• 

  Illustration of a fossil of the Eocene butterfly Prodryas
  †Prodryas – type locality for genus
  • †Prodryas persephone – type locality for species
• †Proiridomyrmex – type locality for genus
  • †Proiridomyrmex vetulus – type locality for species
• †Prolimnocyon
• †Proscalops
• Prosopis
• †Protazteca – type locality for genus
  • †Protazteca capitata – type locality for species
  • †Protazteca elongata – type locality for species
  • †Protazteca hendersoni – type locality for species
  • †Protazteca quadrata – type locality for species
• †Protohippus
• †Protolabis
• †Protomarctus
• 

  Protorohippus
  †Protorohippus
• †Protostephanus – type locality for genus
  • †Protostephanus ashmeadi – type locality for species
• †Protungulatum
  • †Protungulatum donnae
• Prunus
  • †Prunus gracilis
• †Psephenus
• Pseudacris
  • †Pseudacris triseriata
• 

  Restoration of the Miocene cat Pseudaelurus
  †Pseudaelurus
• †Pseudhipparion
• Pseudomyrmex
• †Pseudoprotoceras
• †Psittacotherium
• Ptelea
• Pterocarya
• †Pteromalus
• Pterostichus
• †Ptilodus
  • †Ptilodus kummae
• †Ptosima
• Quedius
• Quercus
• Rallus
  • †Rallus limicola
• †Ramoceros
• †Rallus
  • †Rallus limicola
• 

  Life restoration of the Miocene-Pliocene pronghorn Ramoceros and Cosoryx. Robert Bruce Horsfall (1913).
  †Ramoceros
• †Rana
  • †Rana catesbeiana
• †Raphidia
• Reithrodontomys
• Reticulitermes
• Rhabdomastix
• †Rhagio
• Rhagonycha
• †Rhamnus
• †Rhamphomyia
• 

  A living Rhineura floridana, or North American worm lizard
  Rhineura
• †Rhingia
• Rhizophagus
• Rhus
• †Rhyssa
• †Ribes
• †Robinia
• †Rogas
• Rosa
• †Rothschildia
• Rubus
• Sabal
• †Saccoloma
• Salix
• †Sambucus
• 

  Fossilized skeleton of the Eocene monitor lizard Saniwa
  †Saniwa
• †Saperda
  • †Saperda florissantensis – type locality for species
• †Sapindus
• †Sapromyza
• Sassafras
  • †Sassafras hesperia
• Scaphinotus
• Sceloporus
  • †Sceloporus undulatus
• Sciara
• †Sciophila
• Sciurus
• Scolytus
• †Segestria
• †Selaginella
• †Semanotus
• Sequoia
  • 

    Fossilized branch fragment from a Sequoia affinis
    †Sequoia affinis
• Serica
• †Sespia
• †Sialia
• †Sibinia
• †Sifrhippus
• Sigmodon
• †Silpha
• †Silvius
• †Sinonyx – or unidentified comparable form
• Sitona
• †Sitones
• Sitta
  • †Sitta carolinensis
• †Smilax
• 

  Mounted fossilized skeleton of the Eocene primate Smilodectes
  †Smilodectes
  • †Smilodectes gracilis
  • †Smilodectes mcgrewi
• Sonoma
• Sorex
  • †Sorex arcticus
  • †Sorex hoyi
• †Sparganium
• Spea
  • †Spea bombifrons
• †Spermophagus
• Spermophilus
  • †Spermophilus elegans – or unidentified comparable form
  • †Spermophilus lateralis
  • †Spermophilus richardsonii
  • †Spermophilus tridecemlineatus
• †Sphegina
• 

  Life restoration of the Eocene brontothere mammal Sphenocoelus
  †Sphenocoelus
• Spilogale
  • †Spilogale putorius
• Spizella
  • †Spizella breweri
• †Staphylea
• Staphylinus
• †Stenolophus
• †Stenosphenus
• Stenus
• Sterculia
• Stilbus
• †Stipa
• †Strategus
• †Stylinodon
• 

  Life restoration of the Eocene-Oligocene cow-sized rhinoceros Subhyracodon. Charles R. Knight (1890s).
  †Subhyracodon
• Sylvilagus
  • †Sylvilagus audubonii
• †Symphoromyia
• Syrphus
• †Systena
• †Tabanus
• Tachycineta
  • †Tachycineta bicolor
• Tachyporus
• †Tachys
• Tamiasciurus
  • †Tamiasciurus hudsonicus
  • †Tanysphyrus lemnae
• Tapirus
• Taxidea
  • †Taxidea taxus
• †Teilhardina
• 

  Restoration of the Miocene-Pliocene rhinoceros Teleoceras
  †Teleoceras
• †Tenor – type locality for genus
• †Tenthredo
• †Tetragnatha
• †Tetraonyx
• †Tetraopes
  • †Tetraopes submersus – type locality for species
• †Tetrapus
• Thamnophis
  • 

    A living Thamnophis elegans, or western terrestrial garter snake
    †Thamnophis elegans
  • †Thamnophis sirtalis
• †Thanasimus
• †Themira
• †Thomisus
• Thomomys
  • †Thomomys talpoides
• †Thouinia
• †Thuja
• †Ticholeptus
• Tilia
• †Tingis
• Tipula – type locality for genus
• †Titanoeca
• 

  Life restoration of the Paleocene pantodont mammal Titanoides
  †Titanoides
  • †Titanoides looki
  • †Titanoides primaevus
• †Tomarctus
  • †Tomarctus brevirostris – type locality for species
• †Tomoxia
  • †Tomoxia inundata – type locality for species
• †Torreya
• †Tortricites
• †Tortrix
  • †Tortrix florissantana – type locality for species
• †Torymus
• Trechus
• †Trichilia
• †Triga
• †Trigonias
• †Trigonoscuta
• †Triplax
• †Tritemnodon
• †Triumfetta
• †Trixoscelis
• †Trogosus
• Trogoxylon
• †Trogus
• †Tropisternus
• Trox
• †Trypherus
• †Tryphon
• †Tychius
• Typha
• †Uintacyon
• †Uintascorpio – type locality for genus
• Ulmus
• †Ulus
• Urocyon
  • 

    A living Urocyon cinereoargenteus, or gray fox
    †Urocyon cinereoargenteus
• †Ursavus
• Ursus
  • †Ursus americanus
• †Ustatochoerus
• †Vanessa
• †Vauquelinia
• †Viburnum
• †Vicia
• †Villa – type locality for genus
• Vitis
• †Viverravus
• †Vrilletta
• 

  Mounted fossilized skeleton of the Eocene mammal Vulpavus
  †Vulpavus
• Vulpes
  • †Vulpes velox
  • †Vulpes vulpes
• †Weinmannia
• †Woodwardia
• †Xantholinus
• †Xestobium
• †Xylocopa
• †Xylomya
• †Xyronomys
• †Yumaceras
• †Zamia
• Zelkova
• Zizyphus
• Zonotrichia
  • †Zonotrichia leucophrys
• †Zootermopsis
• 

  Known material diagram depicting the Miocene-Pleistocene mastodon relative Zygolophodon with a human to scale
  †Zygolophodon