List of the prehistoric life of South Dakota

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

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

Paleozoic

 * †Acrotreta
 * †Agnostogonus
 * †Agnostogonus incognitus – or unidentified comparable form
 * Agnostus pisiformis Kinnekulle 1 CRF.jpg †[[Agnostus]]
 * †Amiaspis
 * †Amiaspis erratica
 * †Ankoura
 * †Ankoura triangularis
 * †Ankoura triangularus
 * †Aphelaspis
 * †Aphelaspis haguei
 * †Arapahoia
 * †Arapahoia spathulata
 * †Arapahoia spatulata
 * †Arcifimbria
 * †Arcifimbria pahasapaensis
 * †Arcifimbrin
 * †Arcifimbrin pahasapaensis
 * †Arcuolimbus
 * †Arcuolimbus convexus
 * †Billingsella
 * †Billingsella wichitaensis
 * †Blountia
 * †Blountia arcuosa
 * †Blountia arion
 * †Blountia bristolensis
 * †Blountia eleanora
 * †Blountia janei
 * †Blountia nixonensis
 * †Blountiella
 * †Blountiella alberta
 * †Blountiella cordilleria
 * †Briscoia
 * †Briscoia angustilimba – or unidentified comparable form
 * †Briscoia dalyi
 * †Bynumia
 * †Bynumia eumus
 * †Bynumina
 * †Camaraspis
 * Caseodus cropped.png †[[Caseodus]]
 * †Caseodus eatoni – or unidentified related form
 * †Cedaria
 * †Cedarina
 * †Cedarina cordillerae
 * †Cedarina dakotaensis
 * †Cedarina dakotensis
 * †Cheilocephalus
 * †Cheilocephalus brevilobus
 * †Cladodus – or unidentified comparable form
 * †Clelandia
 * †Clelandia typicalis
 * †Coosella
 * †Coosella onusta
 * †Coosella perplexa
 * †Coosella prolifica
 * †Coosia
 * †Coosia albertensis
 * †Coosia alethes
 * †Coosina
 * †Coosina ariston
 * †Crepicephalus
 * †Crepicephalus auratus
 * †Crepicephalus buttsimontanaenis
 * †Crepicephalus buttsimontanaensis
 * †Crepicephalus buttsimotanaensis
 * †Crepicephalus deadwoodensis
 * †Crepicephalus rectus
 * †Crepicephalus snowyenis
 * †Crepicephalus snowyensis
 * †Cyrtogomphoceras
 * †Dartonaspis
 * †Dartonaspis wichitaensis
 * †Dartonaspis witchitaensis
 * †Deadwoodia
 * †Dicellomus
 * †Diestoceras
 * †Dikelocephalus
 * †Dikelocephalus minnesotensis
 * †Dresbachia
 * †Dresbachia amata
 * Edestus protopirata1DB.jpg †[[Edestus]]
 * †Ellipsocephaloides
 * †Ellipsocephaloides curtus
 * †Ellipsocephaloides monensis
 * †Ellipsocephaloides monsensis
 * †Endoceras
 * †Eoorthis
 * †Eoorthis indianola
 * †Eoorthis remnicha
 * †Ephippiorthoceras
 * †Glaphyraspis
 * †Glaphyraspis newtoni
 * †Glaphyraspis parva
 * †Hadragnostus
 * †Hadragnostus modestus
 * †Hardyoides
 * †Hardyoides tenerus
 * †Holmesella
 * †Holmesella quadrata
 * †Homagnostus
 * †Homagnostus obesus
 * Hyoliths01.JPG]] †Hyolithes''
 * †Hysteropleura
 * †Hysteropleura schucherti
 * †Idahoia
 * †Idahoia serapio
 * †Idahoia wisconsensis
 * †Idiomesus
 * †Idiomesus granti
 * †Idiomesus infimus
 * †Illaenurus
 * †Illaenurus priscus
 * Janassa bituminosa.jpg †[[Janassa]]
 * †Kingstonia
 * †Kingstonia bealesoides
 * †Kingstonia scrinium
 * †Kingstonia spicata
 * †Kingstonia spicta
 * †Kingstonia walcotti
 * †Kingstonia walcottia
 * †Komaspidella
 * †Komaspidella hata
 * †Komaspidella lata
 * †Kormagnostus
 * †Kormagnostus beltensis
 * †Kormagnostus seclusus
 * †Lambeoceras – tentative report
 * †Lingulella
 * †Lingulepis
 * †Linnarssonella
 * Listracanthus hystrix.JPG †[[Listracanthus]]
 * †Listracanthus hystrix
 * †Litagnostus
 * †Litagnostus paralis
 * †Llanoaspis
 * †Llanoaspis undulata
 * †Meniscocorypphe
 * †Meniscocorypphe platycephala
 * †Menomonia
 * †Menomonia prooculis
 * †Meteoraspis
 * †Meteoraspis keeganensis
 * †Meteoraspis metra
 * †Meteoraspis robusta
 * †Modocia
 * †Modocia centralis
 * †Modocia oweni
 * †Monocheilus
 * †Monocheilus micros
 * †Monocheilus truncatus
 * †Nahannagnostus
 * †Nahannagnostus nganasanicus
 * †Nahannagnostus nganasanious
 * †Parabolinoides
 * †Parabolinoides contractus
 * †Parabolinoides granulosus
 * †Pemphigaspis
 * †Pemphigaspis bullata
 * †Petrodus
 * †Petrodus patelliformis
 * †Plethopeltis
 * †Prosaukia
 * †Prosaukia misa
 * †Pseudagnostus
 * †Pseudagnostus douvillei
 * †Pseudagnostus josephus
 * †Ptchaspis
 * †Ptchaspis striata
 * †Ptychaspis
 * †Ptychaspis bullasa
 * †Ptychaspis miniscaensis
 * †Ptychopleurites
 * †Ptychopleurites spinosa
 * †Pugionicauda
 * †Pugionicauda paradoxa
 * †Rasettia
 * †Rasettia capax
 * †Rasettia magna
 * †Saukiella
 * †Saukiella pyrene
 * †Spyroceras
 * †Syspacheilus
 * †Taenicephalus
 * †Taenicephalus nasutus
 * †Taenicephalus shumardi
 * †Terranovella
 * †Terranovella dorsalis
 * Tricrepicephalus texanus CRF.jpg †[[Tricrepicephalus]]
 * †Tricrepicephalus conia
 * †Tricrepicephalus coria
 * †Tricrepicephalus metra
 * †Tricrepicephalus tripunctatus
 * †Tripteroceras
 * †Uncaspis
 * †Uncaspis limbata
 * †Uncaspis unca
 * †Welleraspis
 * †Welleraspis group – informal
 * †Welleraspis group – informal
 * †Westonoceras
 * †Wilsonoceras
 * †Winnipegoceras

Selected Mesozoic taxa of South Dakota

 * Acipenser – or unidentified comparable form
 * †Actinocamax
 * †Adocus
 * †Agerostrea
 * Allosaurus Revised.jpg †[[Allosaurus]]
 * †Alphadon
 * †Alphadon marshi
 * †Anatotitan
 * †Anatotitan copei
 * †Anomia
 * †Anzu – type locality for genus
 * †Anzu wyliei – type locality for species
 * †Apatosaurus
 * †Araucarioxylon
 * Archelon skeleton.jpg †[[Archelon]] – type locality for genus
 * †Archelon ischyros – type locality for species
 * †Artocarpus – report made of unidentified related form or using admittedly obsolete nomenclature
 * Aspideretes
 * †Asplenium
 * †Baculites
 * †Baculites clinolobatus
 * †Baculites compressus
 * †Baculites grandis
 * †Baculites larsoni
 * †Baculites ovatus
 * †Baculites yokoyamai
 * †Bananogmius
 * †Baptornis
 * †Baptornis varneri – type locality for species
 * Barosaurus lentus1.jpg †[[Barosaurus]] – type locality for genus
 * †Barosaurus lentus – type locality for species
 * †Basilemys
 * †Belemnitella
 * †Belemnitella bulbosa
 * Beryx – or unidentified related form
 * †Bolodon
 * †Bolodon hydei – type locality for species
 * †Borealosuchus
 * †Borealosuchus sternbergii
 * Brachidontes
 * †Brachychampsa
 * †Brachychampsa montana
 * †Brodavis
 * †Brodavis baileyi – type locality for species
 * †Caenagnathus
 * †Calycoceras
 * †Calycoceras boreale – type locality for species
 * †Calycoceras dromense – or unidentified comparable form
 * Camarasaurs1.jpg †[[Camarasaurus]]
 * Campeloma
 * †Caturus
 * †Champsosaurus
 * †Cimexomys
 * †Cimolodon
 * †Cimolodon nitidus
 * †Cimolomys
 * †Cimolomys gracilis
 * †Claosaurus
 * †Claosaurus affinis – type locality for species
 * †Clidastes
 * †Clidastes propython
 * †Cocculus
 * Gasteropods - Ammonites - Collignoniceras woolgari.JPG †[[Collignoniceras]]
 * †Collignoniceras collisniger – type locality for species
 * †Collignoniceras jorgenseni – type locality for species
 * †Collignoniceras percarinatum
 * †Collignoniceras praecox
 * †Collignoniceras vermilionense
 * †Collignoniceras woolgari
 * †Collignoniceras woollgari
 * †Compsemys
 * Corbula
 * †Corbulamella
 * †Crenella
 * †Crenella elegantula
 * †Cretolamna
 * †Cretolamna appendiculata
 * †Cteniogenys
 * Cucullaea
 * †Cuspidaria
 * Cycadeoidea fossil cropped.png †[[Cycadeoidea]]
 * †Cycadeoidea aspera – type locality for species
 * †Cycadeoidea cicatricula – type locality for species
 * †Cycadeoidea colei – type locality for species
 * †Cycadeoidea colossalis – type locality for species
 * †Cycadeoidea dacotensis
 * †Cycadeoidea excelsa – type locality for species
 * †Cycadeoidea formosa – type locality for species
 * †Cycadeoidea furcata – type locality for species
 * †Cycadeoidea ingens – type locality for species
 * †Cycadeoidea insolita – type locality for species
 * †Cycadeoidea jenneyana
 * †Cycadeoidea Jenneyana
 * †Cycadeoidea marshiana – type locality for species
 * †Cycadeoidea mcbridei – type locality for species
 * †Cycadeoidea McBridei – type locality for species
 * †Cycadeoidea minnekahtensis – type locality for species
 * †Cycadeoidea nana – type locality for species
 * †Cycadeoidea occidentalis – type locality for species
 * †Cycadeoidea paynei – type locality for species
 * †Cycadeoidea pulcherrima – type locality for species
 * †Cycadeoidea stillwelli – type locality for species
 * †Cycadeoidea turrita – type locality for species
 * †Cycadeoidea Wellsii – type locality for species
 * †Dakotadon
 * †Dakotadon lakotaensis
 * †Dakotaraptor – type locality for genus
 * †Dakotaraptor steini – type locality for species
 * †Desmatochelys
 * †Didelphodon
 * †Diplodocus
 * †Discoscaphites
 * †Discoscaphites conradi
 * †Discoscaphites gulosus
 * †Discoscaphites rossi – type locality for species
 * †Dolichorhynchops
 * †Dolichorhynchops osborni
 * †Edmontonia
 * †Edmontonia longiceps
 * Anatotitan BW.jpg]] †Edmontosaurus''
 * †Elasmosaurus
 * †Elasmosaurus intermedius – type locality for species
 * †Enchodus
 * †Eubostrychoceras
 * †Eucalycoceras
 * †Eutrephoceras
 * †Geosternbergia
 * †Geosternbergia maiseyi – type locality for species
 * Gleichenia
 * †Globidens
 * †Globidens alabamensis
 * †Globidens dakotensis – type locality for species
 * †Globidens schurmanni – type locality for species
 * †Glyptops
 * Glyptostrobus
 * †Glyptostrobus europaeus
 * †Gorgosaurus
 * †Hainosaurus
 * †Hamites
 * Hesperornis BW.jpg †[[Hesperornis]]
 * †Hesperornis regalis – or unidentified comparable form
 * Hiatella – tentative report
 * †Hoplitosaurus
 * †Hoplitosaurus marshi – type locality for species
 * †Hoploparia
 * †Hoploscaphites
 * †Hoploscaphites comprimus
 * †Hoploscaphites melloi – type locality for species
 * †Hoploscaphites nicolletii
 * †Hulettia
 * †Hypsilophodon
 * †Hypsilophodon wielandi – type locality for species
 * †Ichthyodectes
 * Inoceramus steenstrup, world's largest fossil mollusk.jpg †[[Inoceramus]]
 * †Inoceramus apicalis
 * †Inoceramus ginterensis
 * †Inoceramus tenuis – or unidentified related form
 * †Inoceramus tenuistriatus – tentative report
 * †Ischyodus
 * †Ischyodus rayhaasi
 * Isurus
 * †Jeletzkytes
 * †Jeletzkytes dorfi
 * †Jeletzkytes nebrascensis
 * †Jeletzkytes spedeni – type locality for species
 * Lamna
 * [[File:Leidyosuchus canadensis, Dinosaur Provincial Park, Alberta, Canada, Late Cretaceous - Royal Ontario Museum - DSC00090.JPG|thumb|upright|Fossilized skull of the Late Cretaceous alligator relative Leidyosuchus]] †[[Leidyosuchus]]
 * †Lemnaceae
 * †Lepidotes – tentative report
 * Lepisosteus
 * †Leptalestes
 * †Leptalestes cooki
 * †Leptalestes krejcii
 * †Lucina – tentative report
 * †Martinectes
 * †Martinectes bonneri
 * †Melvius
 * †Meniscoessus
 * †Meniscoessus robustus
 * †Mesodma
 * †Mesodma formosa
 * †Mesodma hensleighi
 * †Mesodma thompsoni
 * †Modiolus
 * Mosasaurus BW.jpg †[[Mosasaurus]]
 * †Mosasaurus missouriensis – type locality for species
 * †Myledaphus
 * †Myledaphus bipartitus
 * †Nelumbo
 * †Neocardioceras
 * †Neocardioceras transiens – type locality for species
 * Nucula
 * †Nucula percrassa
 * †Ophiomorpha
 * †Ornithomimus
 * †Osmakasaurus
 * †Osmakasaurus depressus – type locality for species
 * Ostrea
 * †Otoscaphites
 * †Oxytoma
 * Pachycephalosaurus wyomingensis dinosaur (Upper Cretaceous; Montana, USA).jpg †[[Pachycephalosaurus]] – type locality for genus
 * †Pachycephalosaurus wyomingensis – type locality for species
 * †Pachyrhizodus
 * †Pahasapasaurus – type locality for genus
 * †Pahasapasaurus haasi – type locality for species
 * †Palmoxylon
 * Panopea
 * †Paronychodon
 * †Paronychodon lacustris
 * Pholadomya
 * †Pistia – report made of unidentified related form or using admittedly obsolete nomenclature
 * †Placenticeras
 * †Placenticeras pseudoplacenta
 * Platanus
 * Platecarpus2010.jpg †[[Platecarpus]]
 * †Platecarpus somenensis – or unidentified comparable form
 * †Platecarpus tympaniticus
 * †Plesiobaena
 * †Plioplatecarpus
 * †Plioplatecarpus primaevus – type locality for species
 * †Prognathodon
 * †Prognathodon overtoni – type locality for species
 * †Proplacenticeras
 * †Protocardia
 * †Protosphyraena
 * †Protostega
 * Pteranodon longiceps mmartyniuk wiki.png †[[Pteranodon]]
 * †Pteranodon longiceps
 * †Ptychodus
 * †Ptychodus occidentalis
 * Quercus
 * †Rhamnus
 * †Richardoestesia
 * †Richardoestesia isosceles
 * Sassafras
 * †Scaphites
 * †Sequoia
 * Solemya
 * Sphaerium
 * †Sphenobaiera
 * †Sphenodiscus
 * †Sphenodiscus beecheri – tentative report
 * †Sphenodiscus lobatus
 * †Sphenodiscus pleurisepta
 * Squalicorax
 * †Squalicorax falcatus
 * Squalus
 * Styxocycle by johnson mortimer-dafh0ce.gif †[[Styxosaurus]]
 * †Styxosaurus browni
 * †Styxosaurus snowii – type locality for species
 * †Tatankaceratops – type locality for genus
 * †Tatankaceratops sacrisonorum – type locality for species
 * Taxodium
 * †Thescelosaurus
 * †Thescelosaurus neglectus
 * †Thespesius – type locality for genus
 * †Thespesius occidentalis – type locality for species
 * †Torosaurus
 * †Torosaurus latus
 * †Toxochelys
 * †Toxochelys latiremis
 * †Trachodon
 * †Tragodesmoceras
 * †Tragodesmoceras carlilense
 * †Tragodesmoceras carlilensis
 * †Triceratops
 * †Triceratops horridus
 * †Tylosaurus
 * †Tylosaurus proriger
 * Tyrannosaurus Rex Holotype.jpg †[[Tyrannosaurus]]
 * †Tyrannosaurus rex
 * Viviparus
 * †Yezoites
 * Yoldia
 * Ziziphus

Selected Cenozoic taxa of South Dakota

 * †Aelurodon
 * †Aepycamelus
 * †Agnotocastor
 * †Agriochoerus
 * Alligator
 * †Alligator prenasalis – type locality for species
 * †Ambystoma
 * †Ambystoma tigrinum
 * Amebelodon fricki.jpg †[[Amebelodon]]
 * †Ampelopsis
 * †Amphechinus
 * †Anchitherium
 * Antilocapra
 * †Antilocapra americana
 * Apalone
 * †Aphelops
 * †Archaeocyon
 * †Archaeohippus
 * †Archaeotherium
 * †Arctodus
 * †Arctodus simus
 * †Arctonasua
 * Azolla
 * †Barbourofelis
 * †Barbourofelis whitfordi
 * †Bathornis
 * †Bathornis veredus
 * Bison
 * Bison latifrons fossil buffalo (Pleistocene; North America) 1 (15257877377).jpg †[[Bison latifrons]]
 * Blarina
 * †Blarina carolinensis – or unidentified comparable form
 * †Bothriodon
 * †Brachypsalis
 * †Brachyrhynchocyon
 * †Brontops
 * Bufo
 * †Bufo woodhousei
 * Buteo
 * †Calippus
 * †Camelops
 * Canis
 * Canis lupus & Aenocyon dirus.jpg, the grey wolf, to scale with a fossilized skeleton of the Pleistocene wolf Canis dirus, or dire wolf]] †Canis dirus'' – or unidentified comparable form
 * †Canis latrans
 * †Canis lupus
 * †Carpocyon
 * Castor
 * †Castor canadensis – or unidentified comparable form
 * †Catostomus
 * Celtis
 * Cercidiphyllum
 * Charina
 * Chrysemys
 * Cnemidophorus
 * †Colodon
 * †Cormocyon
 * †Cormohipparion
 * Cosoryx fossil cropped.png †[[Cosoryx]]
 * †Cosoryx furcatus
 * †Cranioceras
 * Crotalus
 * †Cynarctoides
 * †Cynarctoides acridens
 * †Cynarctoides lemur
 * †Cynarctoides roii
 * †Cynarctus
 * †Cynodesmus
 * Cynomys
 * †Daphoenus
 * †Desmatippus
 * †Desmatochoerus
 * †Desmocyon
 * †Diceratherium
 * ExtmDinictis1921-029-11.jpg †[[Dinictis]]
 * †Dinohyus
 * †Dipoides
 * †Domnina
 * †Duchesnehippus
 * †Duchesneodus
 * †Ectopocynus
 * †Ekgmowechashala
 * †Ekgmowechashala philotau – type locality for species
 * Elaphe
 * †Elaphe vulpina
 * †Elomeryx
 * †Enhydrocyon
 * †Entelodon
 * †Eopelobates
 * †Epicyon
 * Equus
 * †Equus francisci
 * †Equus giganteus – or unidentified comparable form
 * †Etheostoma
 * Eubelodon cropped.jpg †[[Eubelodon]]
 * †Eucastor
 * †Eucommia
 * Eumeces
 * †Eumeces septentrionalis
 * †Eusmilus
 * Ficus
 * Geomys
 * †Gigantocamelus
 * Glyptostrobus
 * †Gomphotherium
 * Graptemys
 * Fossil maxilla Hemiauchenia Boulle.png relative Hemiauchenia]] †Hemiauchenia
 * †Hemicyon
 * †Herpetotherium
 * †Herpetotherium fugax
 * †Hesperocyon
 * †Hesperotestudo
 * Heterodon
 * †Heteromeryx
 * †Hipparion
 * †Hippotherium
 * †Homotherium – or unidentified comparable form
 * †Hoplophoneus
 * Hyaenodon NT small.jpg †[[Hyaenodon]]
 * †Hyaenodon crucians
 * †Hyaenodon horridus
 * †Hyaenodon montanus – or unidentified comparable form
 * †Hyaenodon mustelinus – type locality for species
 * Hyla
 * †Hypertragulus
 * †Hypisodus
 * †Hypohippus
 * †Hypolagus
 * †Hyporhina – type locality for genus
 * †Hyporhina antiqua – type locality for species
 * †Hyracodon
 * Ictalurus
 * †Ischyrocyon
 * †Ischyromys
 * †Lambdoceras
 * Lampropeltis
 * Lepisosteus
 * Lepomis
 * †Leptauchenia
 * †Leptictis
 * Leptocyon gregorii holotype AMNH 12879.jpg †[[Leptocyon]]
 * †Leptomeryx
 * Lepus
 * †Lepus americanus – or unidentified comparable form
 * †Longirostromeryx
 * †Macrorhineura – type locality for genus
 * †Macrorhineura skinneri – type locality for species
 * †Mammacyon
 * †Mammuthus
 * Columbian mammoth cropped.png †[[Mammuthus columbi]]
 * Martes
 * †Megacerops
 * †Megachoerus – tentative report
 * †Megaleptictis
 * †Megaleptictis altidens
 * †Megalictis
 * †Megalictis ferox – type locality for species
 * †Megalonyx
 * †Megalonyx leptostomus
 * †Megalonyx wheatleyi
 * †Megapaloelodus – type locality for genus
 * †Menoceras
 * †Menops
 * †Merychippus
 * Merychyus cropped.png †[[Merychyus]]
 * †Merycochoerus
 * †Merycodus
 * †Merycoides
 * †Merycoidodon
 * †Mesocyon
 * †Mesohippus
 * †Mesoreodon
 * †Metamynodon
 * †Metamynodon planifrons
 * †Michenia
 * Microtus
 * †Miniochoerus
 * †Miohippus
 * †Miohippus grandis
 * †Monosaulax
 * †Moropus
 * Mustela
 * †Mylagaulus
 * †Nannippus
 * †Nanotragulus
 * †Neohipparion – type locality for genus
 * Neotoma
 * Nerodia
 * †Nerodia sipedon
 * †Nexuotapirus
 * †Niglarodon
 * †Nimravus
 * Notophthalmus
 * †Nototamias
 * †Notropis
 * †Noturus – tentative report
 * Ondatra
 * Onychomys
 * †Oreodontoides
 * Ortalis
 * †Osbornodon
 * †Otarocyon
 * †Oxetocyon
 * †Oxydactylus
 * Palaeocastor.jpg †[[Palaeocastor]]
 * †Palaeogale
 * †Palaeolagus
 * †Paracrax
 * †Paradaphoenus
 * †Paraenhydrocyon
 * †Parahippus
 * †Paramys
 * †Paratomarctus
 * †Paratylopus
 * †Parictis
 * †Peltosaurus
 * †Peltosaurus granulosus
 * †Peraceras
 * Perognathus
 * Peromyscus
 * †Philotrox
 * †Philotrox condoni
 * †Phlaocyon
 * †Phlaocyon minor
 * Phrynosoma
 * †Phrynosoma douglassi
 * †Planera
 * †Platygonus
 * †Pliauchenia
 * †Pliohippus
 * Poebrotherium.jpg †[[Poebrotherium]]
 * †Pogonodon
 * †Procamelus
 * †Procastoroides
 * †Promartes
 * †Promerycochoerus
 * †Proscalops
 * †Protapirus
 * †Proterix
 * †Protoceras
 * †Protohippus
 * †Protolabis
 * Pseudacris
 * Pseudaelurus cropped.png †[[Pseudaelurus]]
 * †Pseudhipparion
 * †Pseudoprotoceras
 * Querquedula
 * †Rana
 * †Rana catesbeiana
 * †Rana pipiens
 * Reithrodontomys
 * Rhineura
 * Salvadora
 * Scaphiopus
 * †Sespia
 * Sorex
 * †Sorex cinereus
 * Spea
 * Spermophilus
 * Stegomastodon mirificus - Smithsonian.JPG †[[Stegomastodon]]
 * †Stegomastodon mirificus
 * †Steneofiber
 * Strix
 * †Stylemys
 * †Subhyracodon
 * †Sunkahetanka
 * †Sunkahetanka geringensis
 * Sylvilagus
 * †Sylvilagus floridanus
 * Tapirus
 * Teleoceras Horsfall cropped.jpg †[[Teleoceras]]
 * †Teleoceras major
 * Thamnophis
 * †Thamnophis sirtalis
 * Thomomys
 * †Titanotylopus
 * †Trigenicus
 * †Trigonias
 * Tympanuchus
 * †Ursavus
 * †Ustatochoerus
 * Zapus
 * Zelkova