List of the Cenozoic life of Maryland

This list of the Cenozoic life of Maryland contains the various prehistoric life-forms whose fossilized remains have been reported from within the US state of Maryland and are between 66 million and 10,000 years of age.

A

 * †Abra – tentative report
 * †Abra longicalla
 * Acanthodesia
 * †Acanthodesia oblongula
 * †Acanthodesia savartii
 * †Acantodesia
 * †Acantodesia oblongula
 * Sturgeon2.jpg [[Acipenser]]
 * †Acrocoelum
 * †Acrocoelum richardsi – type locality for species
 * Acropora
 * †Acropora palmata
 * Acteocina
 * †Acteocina canaliculata
 * Acteon
 * †Acteon danicus – type locality for species
 * †Acteon ovoides
 * †Adocus
 * †Aepycamelus – tentative report
 * Aetobatus
 * †Aetobatus arcuatus
 * †Aetobatus irregularis
 * †Aetobatus profundus – type locality for species
 * Aglaocetus moreni.jpg †[[Aglaocetus]]
 * †Aglaocetus patulus
 * Alca
 * †Alca torda – or unidentified comparable form
 * Aligena
 * †Aligena aequata
 * †Aligena elevata
 * †Ambystoma
 * †Ambystoma maculatum
 * †Ambystoma tigrinum
 * Amia
 * Amphicyon-ingens reconstruction.jpg †[[Amphicyon]]
 * Amyda
 * †Amyda cellulosa
 * Anachis
 * †Anachis avara
 * Anadara
 * †Anadara andrewsi
 * †Anadara ovalis
 * †Anadara subrostrata
 * †Anadara transversa
 * Anas
 * †Anas crecca
 * Ancilla – report made of unidentified related form or using admittedly obsolete nomenclature
 * Angulus
 * †Angulus agilis
 * Anomia
 * †Anomia aculeata
 * †Anomia marylandica
 * †Anomia multilineata
 * †Anomia simplex
 * Anticlimax – tentative report
 * †Anticlimax gardnerae – type locality for species
 * †Aphelops – tentative report
 * †Aporrhaid
 * †Aporrhaid gastropod
 * Aporrhais
 * †Aporrhais potomacensis
 * Aquila
 * †Aquila chrysaetos
 * †Araeodelphis – type locality for genus
 * †Araeodelphis natator – type locality for species
 * †Araloselachus
 * †Araloselachus cuspidata
 * Arca
 * †Arca callipleura
 * †Arca improcera
 * †Archaeohippus
 * Architectonica
 * †Architectonica form A informal
 * †Architectonica form B informal
 * ArctodusSimusReconstruct.jpg †[[Arctodus]]
 * †Arctodus pristinus
 * Argopecten
 * †Argopecten irradians
 * †Armatobalanus
 * †Armatobalanus calvertensis
 * Arossia
 * †Arossia bohaska – type locality for species
 * †Arossia cummembrana – type locality for species
 * †Arossia newmani
 * †Asaphis
 * †Asaphis centenaria
 * †Aspideretoides
 * †Aspideretoides virginianus
 * Astarte elliptica 2008-09-07-4.jpg bivalve]] Astarte''
 * †Astarte cuneiformis
 * †Astarte exaltata
 * †Astarte marylandica
 * †Astarte obruta
 * †Astarte perplana
 * †Astarte thisphila
 * †Astarte thomasi
 * †Astarte undata
 * Asterias
 * †Asterias forbesi – or unidentified comparable form
 * Astrangia
 * †Astrangia danae
 * †Astrehelia
 * †Astrehelia palmata
 * †Astrhelia
 * †Astrhelia plamata
 * †Astroscopus
 * Astroscopus countermani.jpg †[[Astroscopus countermani]] – type locality for species
 * Astyris
 * †Astyris communis
 * †Astyris lunata
 * Ataphrus
 * †Ataphrus glandula
 * Athleta
 * †Athleta limopsis
 * †Athleta tuomeyi
 * †Atopomys
 * †Atopomys texensis
 * Atrina
 * †Atrina harrisi
 * †Atrina harrisii
 * Aulophyseter BW.jpg †[[Aulophyseter]]
 * †Aulophyseter mediatlanticus – type locality for species

B

 * LMazzuca Fin Whale.jpg [[Balaenoptera]]
 * †Balaenoptera cephalus
 * †Balaenoptera pusilla – type locality for species
 * Balanus
 * †Balanus concabvus
 * †Balanus concava
 * †Balanus crenatus
 * †Balanus imitator
 * †Balanus vulcanellus – type locality for species
 * Bankia
 * †Bankia gouldi
 * Barnea
 * †Barnea costata
 * Bathytormus
 * †Bathytormus alaeformis
 * †Batiacasphaera
 * †Batiacasphaera sphaerica
 * †Belosphys
 * Bicorbula
 * †Bicorbula idonea
 * Blarina
 * Blarina brevicauda.jpg †[[Blarina brevicauda]]
 * †Blarina carolinensis
 * †Bolis – or unidentified comparable form
 * Bonasa
 * †Bonasa umbellus
 * Boreotrophon
 * †Boreotrophon harasewychi – type locality for species
 * Brachidontes
 * †Brachidontes potomacensis
 * †Brachyprotoma
 * †Brachyprotoma obtusata
 * †Brevirostrodelphis
 * †Brevirostrodelphis dividum – type locality for species
 * †Brevoortia
 * Brevoortia tyrannus1.jpg †[[Brevoortia tyrannus]] – or unidentified comparable form
 * Buccinofusus
 * †Buccinofusus chesapeakensis
 * †Buccinofusus parilis
 * Bufo
 * †Bufo americanus
 * †Bufo woodhousei
 * †Bulliopsis
 * †Bulliopsis marylandica
 * †Bulliopsis quadrata
 * Busycon – type locality for genus
 * †Busycon carica
 * †Busycon fusiforme
 * †Busycon fusiformis
 * †Busycotyphus
 * †Busycotyphus coronatum
 * †Busycotyphus rugosum
 * Busycotypus
 * †Busycotypus alveatum
 * †Busycotypus asheri – type locality for species
 * †Busycotypus canaliculatus
 * †Busycotypus coronatum
 * †Busycotypus rugosum

C

 * Cadulus
 * †Cadulus bellulus
 * †Cadulus newtonensis
 * †Cadulus thallus
 * Caecum
 * †Caecum patuxentium
 * †Calianassa
 * †Calianassa atlantica
 * †Calianassa matsoni – or unidentified comparable form
 * Callinectes
 * †Callinectes ornatus
 * The Childrens Museum of Indianapolis - Atlantic blue crab.jpg †[[Callinectes sapidus]]
 * Calliostoma
 * †Calliostoma alphelium
 * †Calliostoma aphelium
 * †Calliostoma humile – or unidentified comparable form
 * †Calliostoma philanthropus
 * †Calliostoma philathropus
 * Callista
 * †Callista marylandica
 * Callocardia
 * †Callocardia catharia
 * CorysShearwaterBottom.jpg [[Calonectris]]
 * Calyptraea
 * †Calyptraea aldrichi – type locality for species
 * †Calyptraea centralis
 * †Calyptraphorus
 * †Calyptraphorus jacksoni
 * Cancellaria
 * †Cancellaria alternata
 * Cancer
 * †Cancer irroratus
 * Canis
 * Canis ambrusteri skull.png †[[Canis armbrusteri]] – type locality for species
 * †Canis latrans
 * †Canis rufus – or unidentified comparable form
 * Cantharus
 * †Cantharus marylandicus
 * †Carassatellites
 * †Carassatellites turgidulus
 * Carcharhinus
 * †Carcharhinus egertoni
 * Carcharias
 * †Carcharias collata – type locality for species
 * Carcharodon
 * †Carcharodon auriculatus
 * Isurus hastalis labiale cm.JPG, or broad-toothed mako]] †Carcharodon hastalis''
 * Cardita
 * †Cardita protracta
 * †Caricella
 * Carphophis
 * †Carphophis amoenus
 * Caryocorbula
 * †Caryocorbula cuneata
 * †Caryocorbula inaqualis
 * Cassis
 * Castor
 * †Castor canadensis
 * Catapleura
 * †Catapleura repanda – type locality for species
 * †Cephalotropis – type locality for genus
 * †Cephalotropis coronatus – type locality for species
 * Cerastoderma
 * †Cerastoderma leptopleurum
 * Cervus
 * †Cetophis – type locality for genus
 * †Cetophis heteroclitus – type locality for species
 * Cetorhinus
 * Cetotherium BW.jpg †[[Cetotherium]]
 * †Cetotherium megalophysum
 * †Cetotherium parvum – type locality for species
 * Chama
 * †Chama corticosa
 * Chelone
 * Chelydra
 * †Chelydra serpentina
 * †Chesacardium
 * †Chesacardium craticuloides
 * †Chesacardium laqueatum
 * †Chesaclava – type locality for genus
 * †Chesaclava dissimilis
 * †Chesaclava quarlesi – type locality for species
 * †Chesaconavus
 * †Chesaconavus chesapeakensis
 * †Chesaconavus rossi
 * †Chesaconcavus
 * †Chesaconcavus chesapeakensis
 * †Chesaconcavus myosulcatus
 * †Chesaconcavus proteus
 * †Chesaconcavus rossi
 * †Chesaconcavus santamaria
 * †Chesapecten
 * †Chesapecten coccymelus
 * †Chesapecten coccymeus
 * †Chesapecten covepointensis
 * Chesapecten Jeffersonius Outside.jpg †[[Chesapecten jeffersonius]]
 * †Chesapecten madisonius
 * †Chesapecten monicae
 * †Chesapecten nefrens
 * †Chesapecten santamaria
 * †Chesasyrinx – type locality for genus
 * †Chesasyrinx rotifera
 * †Chesatrophon – type locality for genus
 * †Chesatrophon chesapeakeanus – type locality for species
 * Chlamys
 * †Chlamys choctavensis
 * †Chlamys sheldonae
 * †Chloridella
 * †Chloridella empusa
 * Chrysemys
 * Painted Turtle (14541060047).jpg †[[Chrysemys picta]]
 * †Cimomia
 * †Cimomia marylandensis – type locality for species
 * Circulus – report made of unidentified related form or using admittedly obsolete nomenclature
 * †Circulus form A informal
 * Cirsotrema
 * †Cirsotrema form A informal
 * †Cirsotrema from B informal
 * Clavus
 * †Cleistophaeridium
 * †Cleistophaeridium placacanthum
 * Clementia
 * †Clementia inoceriformis
 * Clethrionomys
 * †Clethrionomys gapperi – or unidentified comparable form
 * Cliona
 * †Cliona sulphurea
 * †Clionia
 * †Clionia sulphurea
 * Coluber
 * †Coluber constrictor
 * Balanidae - Concavus concavus.JPG [[Concavus]]
 * †Concavus concavus
 * †Concavus crassostricola
 * Condylura
 * †Condylura cristata
 * Conopeum
 * †Conopeum germanum
 * Conus
 * †Conus deluvianus
 * †Conus diluvianus
 * †Conus sanctaemariae – type locality for species
 * Coralliophaga
 * †Coralliophaga bryani
 * Corbula modesta 002.jpg [[Corbula]]
 * †Corbula elevata
 * †Corbula inaequalis
 * †Corbula pectorosa – type locality for species
 * †Coronia
 * Crassatella
 * †Crassatella aquiana
 * †Crassatella marylandica
 * †Crassatella melinus
 * Crassostrea
 * †Crassostrea virginica
 * Crenilabium – or unidentified comparable form
 * †Crenilabium elatum
 * †Creonella
 * †Creonella obscuriplica – type locality for species
 * Crepidula
 * †Crepidula fornicata
 * †Crepidula plana
 * Shark fossil.jpg †[[Cretolamna]]
 * †Cretolamna appendiculata
 * Crotalus
 * †Crotalus horridus
 * Crucibulum
 * †Crucibulum constrictum
 * †Crucibulum costata
 * †Crucibulum multilineatum
 * Hellbender.jpg, or hellbender salamander]] Cryptobranchus''
 * †Cryptobranchus guildayi – type locality for species
 * Cucullaea
 * †Cucullaea gigantea
 * †Cucullaea transversa
 * Cumingia
 * †Cumingia tellinoides
 * †Cybium
 * Cyclocardia
 * †Cyclocardia granulata
 * †Cyclopsiella
 * †Cyclopsiella lusatica
 * Cyclostremiscus
 * †Cyclostremiscus sohli – type locality for species
 * Cylichna
 * †Cylichna venusta – type locality for species
 * Cymatosyrinx
 * †Cymatosyrinx mariana – type locality for species
 * †Cynarctus
 * †Cynarctus marylandica – type locality for species
 * †Cynarctus wangi – type locality for species
 * †Cynorca – tentative report
 * Cypraea
 * Cyrtopleura
 * Cyrtopleura costata 13a.jpg †[[Cyrtopleura costata]]
 * Cythara
 * †Cythereis
 * †Cythereis tuberculata
 * Cytheridea
 * †Cytheridea punctillata
 * †Cytheris
 * †Cytheris tuberculata

D

 * †Dallarca
 * †Dallarca elevata
 * †Dallarca elnia
 * †Dallarca idonea
 * †Dallarca staminea
 * †Dallarca subrostrata
 * Common stingray tynemouth.jpg [[Dasyatis]]
 * †Dasyatis centrourus – or unidentified comparable form
 * †Delphinodon
 * †Delphinodon leidyi
 * Dentalium
 * †Dentalium attenuatum
 * †Desmathyus
 * Diadophis
 * †Diadophis punctatus
 * Diodora
 * †Diodora griscomi
 * †Diodora marlboroensis
 * †Diodora marylandica
 * †Diodora marylandicus
 * †Diodora nassula
 * †Diodora redimicula
 * Buttercup Diorocetus.jpg †[[Diorocetus]] – type locality for genus
 * †Diorocetus hiatus – type locality for species
 * Diplodonta
 * †Diplodonta marlboroensis
 * †Diplodonta subvexa
 * †Dipoides
 * Discinisca
 * †Discinisca lugubris
 * †Discinisca lugubrius
 * Divalinga
 * †Divalinga quadrisulcata
 * †Dolicholatirus
 * Veneridae - Dosinia orbicularis.JPG [[Dosinia]]
 * †Dosinia acetabulum
 * †Dosiniopsis
 * †Dosiniopsis lenticularis

E

 * †Eburneopecten
 * †Eburneopecten cerinus – type locality for species
 * †Eburneopecten dalli
 * Echinocardium
 * †Echinocardium marylandiense – type locality for species
 * Echinophoria – type locality for genus
 * †Echinophoria caelatura
 * †Ecphora
 * †Ecphora chesapeakensis – type locality for species
 * Ecphora quadricostata.jpg †[[Ecphora gardnerae]]
 * †Ecphora meganae
 * †Ecphora quadricostata
 * †Ecphora scientistensis
 * †Ecphora tampaensis
 * †Ecphora tricostata
 * †Ecphora turneri
 * †Ectoganus
 * †Ectoganus gliriformis – or unidentified comparable form
 * †Ectopistes
 * †Ectopistes migratorius
 * Elaphe
 * †Elaphe vulpina
 * Electra
 * †Electra monostachys
 * Elphidium
 * †Elphidium discoidale
 * †Elphidium incertum
 * †Elphidium latispatium
 * Ensis
 * †Ensis directus
 * †Ensis ensiformis
 * †Entobia
 * Entosolenia
 * †Entosolenia globosa
 * †Entosolenia lucida
 * Eontia
 * †Eontia palmerae
 * †Eontia ponderosa
 * †Eopleurotoma – or unidentified comparable form
 * †Eopleurotoma harrisi
 * †Eopleurotoma potomacensis
 * Eosuchus cropped.jpg †[[Eosuchus]]
 * †Eosuchus minor
 * †Eosurcula – or unidentified comparable form
 * †Eosurcula ducateli
 * Epitonium
 * †Epitonium angulatum
 * †Epitonium chancellorensis – type locality for species
 * †Epitonium denticulatum
 * †Epitonium humphreysii
 * †Epitonium multistriatum
 * †Epitonium rupicola
 * †Epitonium sayanum
 * Eponides
 * †Eponides frigida
 * Eptesicus
 * †Eptesicus fuscus – or unidentified comparable form
 * Equus
 * †Equus complicatus
 * †Equus giganteus
 * Erethizon
 * †Erethizon dorsatum
 * Euceratherium cropped.png †[[Euceratherium]]
 * †Euceratherium collinum
 * †Euclastes – tentative report
 * Eucrassatella
 * †Eucrassatella melinus
 * Eulima
 * †Eulima brightseatensis – type locality for species
 * †Eulima form A informal
 * Eumeces
 * †Eumeces fasciatus – or unidentified comparable form
 * Eupleura
 * †Eupleura caudata
 * Macrodelphinus_kelloggi.jpg †[[Eurhinodelphis]]
 * †Eurhinodelphis longirostris
 * Euspira
 * †Euspira heros
 * †Euspira marylandica
 * †Euspira tuomeyi

F

 * Felis
 * †Felis couguar
 * †Ficopsis
 * Fissurella
 * †Fissurella fluviamariana – type locality for species
 * Thoracida Sessilia Balanina 20090305.jpg †[[Fistulobalanus]]
 * †Fistulobalanus klemmi
 * †Florilus
 * †Florilus chesapeakensis
 * †Florimetis
 * †Florimetis biplicata
 * †Fulgar
 * †Fulgar coronatum

G

 * Tiger shark.jpg, or tiger shark]] Galeocerdo''
 * †Galeocerdo aduncus
 * †Galeocerdo appendiculatus
 * †Galeocerdo contortus
 * †Galeocerdo latidens
 * Galeodea
 * Gari
 * †Gari gubernatoria
 * Gastrochaena
 * Gavia
 * †Gavia immer
 * Gavialosuchus americanus Expominer 07.jpg †[[Gavialosuchus]]
 * †Gavialosuchus antiquus
 * Gegania
 * †Gegania marylandica
 * Gemma
 * †Gemma gemma
 * Genota – or unidentified comparable form
 * †Genota bellistriata
 * Geukensia
 * †Geukensia demissa
 * Gibbula – tentative report
 * †Gibbula glandula
 * †Gilbertina
 * †Gilbertina texana
 * Glaucomys volans.jpg [[Glaucomys]]
 * Globigerina
 * †Globigerina praebulloides
 * Globigerinoides
 * †Globigerinoides altiaperturus
 * †Globigerinoides sicanus
 * †Globoquadrina
 * †Globoquadrina altispira
 * Glossus
 * †Glossus fraterna
 * †Glossus ignolea – or unidentified comparable form
 * †Glossus markoei
 * †Glossus markoii
 * †Glossus marylandica
 * †Glossus mazlea
 * †Glossus santamaria
 * Glycimeris
 * †Glycimeris parilis
 * Glycymeris
 * †Glycymeris americana
 * †Glycymeris idonea
 * †Glycymeris lentiformis
 * †Glycymeris parilis
 * Glyptemys
 * †Glyptemys muhlenbergii
 * Gomphotherium productum.jpg †[[Gomphotherium]]
 * †Gomphotherium obscurum – type locality for species
 * †Gryphaeostrea
 * †Gryphaeostrea vomer
 * Gulo
 * †Gulo gulo
 * Gyrinophilus
 * †Gyrinophilus porphyriticus – or unidentified comparable form

H

 * †Habibacysta
 * †Habibacysta tectata
 * †Hadrodelphis – type locality for genus
 * †Hadrodelphis calvertense – type locality for species
 * †Halicetus – type locality for genus
 * †Halicetus ignotus – type locality for species
 * Haminoea
 * †Haminoea solitaria
 * Hastula solida 001.jpg [[Hastula]]
 * †Hastula inornata
 * †Hastula simplex
 * Haustator
 * †Haustator form A informal
 * †Haustator gnoma – type locality for species
 * †Haustator premortoni – type locality for species
 * †Heliadornis – type locality for genus
 * †Heliadornis ashbyi – type locality for species
 * Hemimactra
 * †Hemimactra solidissima
 * †Hemimactra subparilis
 * Hemipristis
 * Hemipristis serra snaggettoth shark teeth 007.jpg †[[Hemipristis serra]]
 * †Hercoglossa
 * †Hercoglossa tuomeyi – type locality for species
 * †Hesperhys
 * Heterodon
 * †Heterodon platyrhinos – or unidentified comparable form
 * Hiatella
 * †Hiatella arctica
 * †Hiatella artica
 * Hippoporidra
 * †Hippoporidra edax
 * Hipparion.JPG †[[Hippotherium]]
 * Hyla
 * †Hyla crucifer
 * Hyotissa
 * †Hyotissa haitensis
 * Hysteroconcha
 * †Hysteroconcha marylandica
 * †Hysteroconcha staminaea
 * †Hystrichosphaeropsis
 * †Hystrichosphaeropsis obscura

I

 * Ictalurus
 * Ilyanassa
 * †Ilyanassa obsoleta
 * †Ilyanassa trivittata
 * Ischadium
 * †Ischadium recurvum
 * Ischyodus avitus .jpg †[[Ischyodus]]
 * †Ischyodus williamsae – type locality for species
 * Isognomon
 * †Isognomon maxillata
 * †Isognomon tortum
 * Isurus
 * †Ixacanthus – type locality for genus
 * †Ixacanthus coelospondylus – type locality for species

J

 * †Judithemys
 * †Judithemys kranzi – type locality for species

K

 * Kalolophus
 * †Kalolophus antillarum
 * †Kapalmerella
 * †Kapalmerella mortoni
 * Kentriodon BW.jpg †[[Kentriodon]] – type locality for genus
 * †Kentriodon pernix – type locality for species
 * †Kummelia
 * †Kummelia americana
 * Kuphus – report made of unidentified related form or using admittedly obsolete nomenclature
 * Kurtziella
 * †Kurtziella cerina

L

 * †Labyrinthodinium
 * †Labyrinthodinium truncatum
 * †Lacinia
 * †Lacinia pygmaea – type locality for species
 * Lacuna
 * †Lacuna feorra – type locality for species
 * †Laevihastula – type locality for genus
 * †Laevihastula marylandica – type locality for species
 * †Laevihastula simplex
 * †Lagodon
 * Lamna nasus noaa.jpg [[Lamna]]
 * †Lamna denticulata
 * †Lamna obliqua
 * †Lamna vincenti
 * Lampropeltis
 * †Lampropeltis triangulum
 * Lasiopodomys
 * †Lasiopodomys deceitensis
 * Lenticulina
 * †Lenticulina rotulata
 * Lepisosteus
 * †Leptomactra
 * †Leptomactra delumbis
 * †Leptomactra marylandica
 * †Leptophoca – type locality for genus
 * †Leptophoca lenis – type locality for species
 * †Leptophoca proxima – or unidentified comparable form
 * Lepus
 * Lepus americanus 5459 cropped.jpg †[[Lepus americanus]]
 * †Levifusus
 * †Levifusus trabeatus
 * Libinia
 * †Libinia dubia
 * †Lingulodinium
 * †Lingulodinium macherophorum
 * Lirophora
 * †Lirophora alevata
 * †Lirophora alveata
 * †Lirophora latilirata
 * †Lirophora parkeria
 * Lithophaga – or unidentified comparable form
 * †Lithophaga marylandica
 * Littoraria
 * †Littoraria irrorata
 * Lontra
 * LutraCanadensis fullres.jpg †[[Lontra canadensis]]
 * †Lophocetus
 * †Lophocetus calvertensis – type locality for species
 * †Lophocetus pappus – type locality for species
 * †Lophochelys – tentative report
 * Lopholatilus
 * Loxoconcha
 * †Loxoconcha impressa
 * Lucina – report made of unidentified related form or using admittedly obsolete nomenclature
 * Lucina
 * †Lucina dartoni
 * †Lucina whitei
 * Lucinoma
 * †Lucinoma contracta
 * †Lucinoma filosa
 * Lunatia
 * †Lunatia catenoides
 * Lyonsia
 * †Lyonsia hyalina

M

 * Macoma
 * Macoma balthica (habitus).jpg, or Baltic clam]] †Macoma balthica''
 * †Macoma calcarea
 * Macrocallista
 * †Macrocallista marylandica
 * †Macrocallista subimpressa
 * †Macrokentriodon – type locality for genus
 * †Macrokentriodon morani – type locality for species
 * Mactrodesma
 * †Mactrodesma subponderosa
 * †Mactrodesma subponderosum
 * †Mammut
 * †Mammut americanum
 * †Mammuthus
 * †Mammuthus columbi
 * MammothVsMastodon.jpg, or American mastodon (right), and a Mammuthus primigenius, or wooly mammoth (left)]] †Mammuthus primigenius''
 * Marginella
 * †Marginella minuta
 * †Mariacolpus – type locality for genus
 * †Mariacolpus plebeia
 * †Mariadrillia – type locality for genus
 * †Mariadrillia parvoidea
 * †Mariafusus – type locality for genus
 * †Mariafusus marylandica
 * †Marianarona – type locality for genus
 * †Marianarona asheri – type locality for species
 * †Marianarona marylandica – type locality for species
 * †Mariasalpinx – type locality for genus
 * †Mariasalpinx emilyae – type locality for species
 * †Mariasveltia – type locality for genus
 * †Mariasveltia lunata
 * †Mariaturricula – type locality for genus
 * †Mariaturricula biscatenaria
 * Marmota
 * [[File:Groundhog - Marmota monax, Leesylvania State Park, Woodbridge, Virginia cropped.jpg|thumb|upright|A living Marmota monax, or groundhog]] †[[Marmota monax]]
 * Martesia
 * †Martesia cuneiformis
 * †Martesia ovalis
 * †Marvacrassatella
 * †Marvacrassatella marylandica
 * †Marvacrassatella melina
 * †Marvacrassatella turgidula
 * Massilina
 * †Massilina marylandica
 * Mathilda
 * †Mathilda crebricosta – type locality for species
 * †Mathilda form A informal
 * †Mathilda form B informal
 * †Mathilda form C informal
 * †Mathilda kauffmani – type locality for species
 * †Mathilda marylandensis – type locality for species
 * †Medoriopsis
 * †Medoriopsis marylandica
 * Megalonyx wheatleyi - AMNH - DSC06327.JPG †[[Megalonyx]]
 * Megaptera
 * †Megaptera expansa – type locality for species
 * Melampus
 * †Melampus bidentatus
 * Melanitta
 * †Melanitta deglandi
 * Meleagris
 * †Meleagris gallopavo
 * †Melosia
 * †Melosia staminea
 * Membranipora
 * †Membranipora flabellata
 * Menestho
 * †Menestho form A informal
 * Mephitis
 * †Mephitis mephitis
 * Mercenaria
 * †Mercenaria blakei
 * †Mercenaria campechiensis
 * †Mercenaria cuneata – type locality for species
 * †Mercenaria ducatelli – tentative report
 * LittleNeck clams USDA96c1862.jpg †[[Mercenaria mercenaria]]
 * †Mercenaria plena
 * †Mercenaria staminea
 * †Mercenaria subcuneata
 * †Mercenaria tetrica
 * Meretrix
 * †Meretrix subimpressa
 * †Merychippus
 * †Mesocetus
 * †Mesocetus siphunculus
 * †Mesorhytis – tentative report
 * †Mesorhytis pomonkensis
 * †Mesorhytis potomacensis
 * †Messapicetus
 * †Messapicetus longirostris
 * Metaxytherium floridanum.jpg †[[Metaxytherium]]
 * †Metaxytherium crataegense – type locality for species
 * †Micropogon
 * †Micropogon undulatus
 * Microtus
 * †Microtus chrotorrhinus – or unidentified comparable form
 * †Microtus guildayi
 * †Microtus involutus – or unidentified comparable form
 * †Microtus pennsylvanicus
 * Mictomys
 * †Mictomys borealis
 * Miltha
 * †Miltha aquiana
 * †Miocepphus
 * †Miocepphus bohaskai – type locality for species
 * †Miocepphus mcclungi
 * Miracinonyx inexpectatus.jpg †[[Miracinonyx]]
 * †Miracinonyx inexpectatus
 * Mitra
 * †Mitra marylandica
 * Modiolus
 * †Modiolus dalli
 * †Modiolus ducatelli
 * †Modiolus ducatellii
 * †Modiolus modiolus
 * †Modiolus potomacensis – type locality for species
 * †Moira – tentative report
 * †Moira atropos
 * †Monotherium
 * †Monotherium affine
 * Morus
 * †Morus avitus – type locality for species
 * Mulinia
 * †Mulinia lateralis
 * Mustela
 * MinkforWiki.jpg, or American mink]] †Mustela vison'' – or unidentified comparable form
 * †Mya
 * †Mya arenaria
 * Myliobatis
 * †Myliobatis dixoni – type locality for species
 * †Myliobatis frangens – type locality for species
 * †Myliobatis fremenvillii – or unidentified comparable form
 * †Myliobatis gigas
 * †Myliobatis pachyodon
 * †Myliobatis vicomicanus
 * Mylohyus nasutus.jpg †[[Mylohyus]]
 * †Mylohyus fossilis – type locality for species
 * †Mylohyus obtusidens
 * Myotis
 * †Myotis grisescens – or unidentified comparable form
 * Myrtea – tentative report
 * †Myrtea astartiformis
 * †Myrtea uhleri
 * Mysella
 * †Mysella planulata
 * Mytilus
 * †Mytilus incurvus

N

 * †Nanosiren – tentative report
 * Napaeozapus
 * †Napaeozapus insignis
 * Narona
 * †Narona potomacensis
 * Nassa
 * Nassarius tiarula.jpg [[Nassarius]]
 * †Nassarius peralta
 * †Nassarius vibex
 * Nemocardium
 * †Nemocardium lene
 * Neofiber
 * Neotoma – type locality for genus
 * †Neotoma floridana
 * †Neotoma spelaea – type locality for species
 * Nerodia
 * Nerodia sipedonPCSL02111B1.jpg †[[Nerodia sipedon]]
 * Neverita
 * †Neverita asheri – type locality for species
 * †Neverita cliftonensis
 * †Neverita discula – type locality for species
 * †Neverita duplicatus
 * †Neverita potomacensis – type locality for species
 * †Nodisurculina – type locality for genus
 * †Nodisurculina engonata
 * Noetia
 * †Noetia carolinensis
 * Nonion
 * †Nonion calvertensis
 * †Nonion pompilioides
 * †Nonion sloanii
 * Notidanus
 * †Notidanus primigeneus
 * †Notidanus primigenius
 * Notophthalmus
 * †Notophthalmus viridescens – or unidentified comparable form
 * Notorynchus
 * 170121-Sevengill-02 DSC0627 (1).jpg †[[Notorynchus cepedianus]] – type locality for species
 * Novocrania
 * †Novocrania lububris
 * Nucula
 * †Nucula potomacensis
 * †Nucula proxima
 * †Nucula prunicola
 * †Nucula taphria
 * Nuculana
 * †Nuculana acuta
 * †Nuculana cliftonensis
 * †Nuculana cultelliformis
 * †Nuculana improcera
 * †Nuculana liciata
 * †Nuculana luciata
 * †Nuculana parilis
 * †Nuculana tysoni

O

 * Ochotona
 * †Ochotona princeps – or unidentified comparable form
 * Odocoileus
 * †Odocoileus virginianus
 * Odontaspis ferox 3.jpg [[Odontaspis]]
 * †Odontaspis actutissima
 * †Odontaspis acutissima
 * †Odontaspis hopei
 * †Odontaspis littoralis
 * †Odontaspis macrota
 * †Odontaspis verticalis
 * †Odontaspis winkleri
 * †Odontopolys
 * Odostomia
 * †Odostomia insignifica
 * †Ogivalina
 * †Ogivalina parvula
 * Ondatra
 * †Ondatra annectens
 * †Ondatra zibethicus
 * †Operculodinium
 * †Operculodinium centrocarpum
 * †Operculodinium piaseckii
 * Opheodrys
 * †Opheodrys vernalis
 * Ophiura
 * †Ophiura marylandica
 * Brygmophyseter2.jpg †[[Orycterocetus]]
 * †Orycterocetus crocodilinus
 * †Osteopygis
 * †Osteopygis roundsi
 * Ostrea
 * †Ostrea alepidota
 * †Ostrea carolinensis
 * †Ostrea trachydiscus – type locality for species
 * †Otodus
 * †Otodus angustidens – tentative report
 * Megalodon scale.svg (sometimes Carcharodon or Otodus megalodon) with a whale shark (violet), great white shark (green), and anachronistic human (black) to scale]] †Otodus megalodon''
 * Otus
 * †Otus guildayi – type locality for species
 * †Oxyrhina
 * †Oxyrhina cuspidata
 * †Oxyrhina desorii
 * †Oxyrhina elegans
 * †Oxyrhina retroflexa
 * †Oxyrhina sillimani

P

 * Pagurus
 * †Pagurus pollicaris
 * †Palaeocarcharodon
 * †Palaeocarcharodon orientalis
 * †Palaeocystodinium
 * †Palaeocystodinium golzowense
 * Palaeophis maghrebianus life restoration cropped.jpg †[[Palaeophis]]
 * †Palaeophis grandis
 * †Pamicellaria
 * †Pamicellaria convoluta
 * Pandora
 * †Pandora gouldiana
 * Panopea
 * †Panopea americana
 * †Panopea elongata
 * †Panopea goldfussi
 * †Panopea goldfussii
 * †Panopea whitfieldi
 * Panopeus
 * †Panopeus herbstii
 * Panthera
 * Lion (Panthera leo) (30941994012) cropped.jpg †[[Panthera leo]]
 * †Panthera onca
 * Paraconcavus
 * †Paraconcavus rooseveltensis
 * †Paramya
 * †Paramya subovata
 * Parascalops
 * †Parascalops breweri
 * †Parietobalaena – type locality for genus
 * †Parietobalaena palmeri – type locality for species
 * Parvilucina
 * †Parvilucina crenulata
 * †Parvilucina multistriata
 * †Pasitheola
 * †Pasitheola marylandensis – type locality for species
 * Pecten
 * †Pecten humphreysii
 * †Pecten marylandica
 * Pekania
 * †Pekania diluviana – type locality for species
 * †Pelocetus – type locality for genus
 * †Pelocetus calvertensis – type locality for species
 * †Pelodelphis – type locality for genus
 * †Pelodelphis gracilis – type locality for species
 * †Pentadinium
 * †Pentadinium latincinctum – or unidentified comparable form
 * Periploma – tentative report
 * Perisoreus
 * Perisoreus canadensis mercier2.jpg †[[Perisoreus canadensis]]
 * Peromyscus
 * †Peromyscus cumberlandensis
 * †Peromyscus leucopus – or unidentified comparable form
 * †Petauristodon
 * †Petauristodon alpinus – or unidentified comparable form
 * Petricola
 * †Petricola calvertensis
 * †Petricola pholadiformis
 * Phacoides
 * †Phacoides anodonata
 * †Phacoides contractus
 * Knight Phenacodus.jpg †[[Phenacodus]] – tentative report
 * †Phenacomya
 * †Phenacomya petrosa
 * Phenacomys
 * †Phocageneus
 * †Phocageneus venustus
 * Pholadomya
 * †Pholadomya marylandica
 * †Physeterula
 * Physodon
 * †Physodon triqueter
 * Pinna
 * Pipistrellus
 * Veneridae - Pitar lupanaria.JPG [[Pitar]]
 * †Pitar morrhuanus
 * †Pitar ovatus
 * †Pitar pyga
 * †Pitar subnasuta
 * Pitymys
 * †Pitymys cumberlandensis
 * Placopecten
 * †Placopecten clintonius
 * †Placopecten marylandica
 * †Placopecten virginiana
 * Platidia
 * †Platidia marylandica – type locality for species
 * Platygonus leptorhinus cropped.png of the genus Platygonus. Charles R. Knight (1922).]] †Platygonus
 * †Platygonus cumberlandensis
 * †Platygonus intermedius – type locality for species
 * †Platygonus tetragonus
 * †Platygonus vetus
 * Plecotus
 * †Plecotus alleganiensis – type locality for species
 * Plethodon
 * †Plethodon gultinosus
 * Pleurotomella
 * †Pleurotomella bellistriata – type locality for species
 * †Pliorhytis
 * †Pliorhytis centenaria
 * Pogonias
 * Pogonias Cromis 2010-05-28.jpg †[[Pogonias cromis]] – or unidentified comparable form
 * †Poliniciella – type locality for genus
 * †Poliniciella marylandica – type locality for species
 * Polydora
 * Polystira
 * †Polystira barretti
 * †Polystira communis
 * Poromya
 * †Poromya subovata
 * †Praeorbulina
 * †Praeorbulina glomerosa
 * Presbyornis Enhancement.jpg †[[Presbyornis]]
 * †Presbyornis isoni – type locality for species
 * †Prionodon
 * †Prionodon egertoni
 * Prionotus
 * †Prionotus evolans – or unidentified related form
 * †Priscodelphinus
 * †Priscodelphinus acutidens – type locality for species
 * †Priscodelphinus atropius – type locality for species
 * †Priscodelphinus conradi
 * †Priscodelphinus stenus – type locality for species
 * †Priscodelphinus uraeus
 * †Priscoficus
 * †Priscoficus arguta
 * Propebela
 * †Propebela marylandica – type locality for species
 * †Propebela parva
 * Prophaethon – tentative report
 * †Prosthennops
 * †Prosthennops niobrarensis
 * †Prosthennops xiphodonticus
 * †Protocardia
 * †Protocardia virginiana
 * Pseudacris
 * Pseudacris triseriata.jpg †[[Pseudacris triseriata]]
 * †Pseudoaptyxis
 * †Pseudoaptyxis sanctaemariae – type locality for species
 * †Pseudocepphus – type locality for genus
 * †Pseudocepphus teres – type locality for species
 * Pseudoliva
 * †Pseudoliva longicostata – type locality for species
 * †Pseudoliva tuberculifera
 * Pseudomalaxis – or unidentified comparable form
 * †Pseudomalaxis ripleyana
 * †Pseudophorus
 * †Pseudophorus calvertensis – type locality for species
 * †Pseudotrition
 * †Pseudotrition ruber
 * Pteria
 * †Ptychosalpinx
 * †Ptychosalpinx altilis
 * †Ptychosalpinx multirugata
 * †Ptychosalpinx pustulosus – type locality for species
 * Puffinus gavia - SE Tasmania.jpg [[Puffinus]]
 * †Puffinus conradi – type locality for species
 * Pycnodonte
 * †Pycnodonte percrassa
 * †Pyropsis – tentative report

Q

 * QuinqueloculinaDonegalBay.jpg [[Quinqueloculina]]
 * †Quinqueloculina flexuosa
 * †Quinqueloculina seminula

R

 * †Rana
 * Male Green Frog - Hunterdon County, NJ.jpg (sometimes Rana clamitans), or green frog]] †Rana clamitans''
 * †Rana pipiens
 * †Rana sylvatica
 * Rangia
 * †Rangia cuneata
 * Ranzania
 * †Reticulatosphaera
 * †Reticulatosphaera actinocoronata
 * Retusa
 * †Retusa conulus
 * †Retusa marylandica
 * †Retusa sylvaerupis
 * †Rhabdosteus – type locality for genus
 * †Rhabdosteus latiradix – type locality for species
 * Rhinoptera
 * Rhynchobatus
 * †Rhynchobatus pristinus
 * †Roccus
 * Morone saxatilis SI2.jpg (formerly Roccus saxatilis), or striped bass]] †Roccus saxatilis''
 * †Rotalia
 * †Rotalia beccardi
 * †Rotalia beccarii

S

 * Saccella
 * †Saccella parva
 * Salamandra
 * †Salamandra opaca
 * †Sangamona
 * †Sangamona fugitiva
 * †Scala
 * †Scala marylandica
 * Scaldicetus grandis cropped.jpg †[[Scaldicetus]]
 * †Scapanorhynchus
 * †Scapanorhynchus subulatus – tentative report
 * Scaphander
 * †Scaphander potomacensis – type locality for species
 * Scaphella – type locality for genus
 * †Scaphella solitaria
 * †Scaphella virginiana
 * Sceloporus
 * †Sceloporus undulatus – or unidentified comparable form
 * Cyrtodelphis sulcatus.JPG †[[Schizodelphis]]
 * †Schizodelphis barnesi
 * †Schizodelphis sulcatus
 * Schizoporella
 * †Schizoporella unicornis
 * Sciaenops
 * †Sciaenops eastmani
 * Sciuropterus
 * †Sciuropterus volans
 * Sciurus
 * †Sciurus carolinensis
 * †Scutella
 * †Scutella aberti
 * †Sediliopsis – type locality for genus
 * †Sediliopsis gracilis
 * Seila
 * †Seila adamsii
 * Semele – tentative report
 * Semele
 * †Semele carinata
 * †Semele subovata
 * Serpulorbis
 * †Serpulorbis granifera
 * †Serpulorbis graniferus
 * †Sigmesalia
 * †Sigmesalia palmerae – type locality for species
 * Siphonalia
 * †Siphonalia devexus
 * †Siphonalia potomacensis – type locality for species
 * †Siphonocetus
 * †Siphonocetus clarkianus
 * †Siphonocetus priscus
 * Smilodon fatalis.jpg †[[Smilodon]]
 * †Smilodon fatalis
 * †Smilodontopis
 * †Smilodontopis mooreheadi
 * Solariorbis
 * †Solariorbis form A informal
 * †Solariorbis laurelae – type locality for species
 * †Solariorbis lipara
 * †Solarium
 * †Solarium trilineatum
 * Solecardia
 * †Solecardia cossmani
 * Solen
 * Sorex
 * MaskedShrew23.jpg †[[Sorex cinereus]]
 * †Sorex fumeus
 * Spermophilus
 * †Spermophilus tridecemlineatus
 * †Sphaerula
 * †Sphaerula subvexa
 * Sphenia – tentative report
 * †Sphyraenodus
 * †Sphyraenodus speciosus
 * Hammerhead shark.jpg [[Sphyrna]]
 * †Sphyrna laevissima – type locality for species
 * †Sphyrna magna
 * †Sphyrna prisca
 * Spilogale
 * †Spilogale putorius – type locality for species
 * †Spiniferites
 * †Spiniferites mirabilis
 * Spiroplectammina
 * †Spiroplectammina spinosa
 * Spisula
 * †Spisula subcuneata
 * Squalodon BW.jpg †[[Squalodon]]
 * †Squalodon atlanticus
 * †Squalodon calvertensis – type locality for species
 * †Squalodon mento – type locality for species
 * †Squalodon protervus
 * †Squalodon whitmorei
 * †Squalodon wymanii – type locality for species
 * Squatina
 * †Squatina occidentalis – type locality for species
 * Squilla
 * Squilla empusa.jpg †[[Squilla empusa]]
 * †Stenasodelphis – type locality for genus
 * †Stenasodelphis russellae – type locality for species
 * Stewartia
 * †Stewartia anodonta
 * †Stewartia foremani
 * Sthenorytis
 * †Sthenorytis pachypleura
 * Stramonita
 * †Stramonita haemostoma
 * †Strepsidura
 * Strioterebrum
 * †Strioterebrum dislocatum
 * Stylopoma
 * †Stylopoma spongites
 * †Sumatradinium
 * †Sumatradinium druggii
 * †Syllomus
 * †Syllomus aegyptiacus – type locality for species
 * Sylvilagus
 * †Sylvilagus floridanus
 * Synaptomys
 * Synaptomys cooperi.jpg †[[Synaptomys cooperi]]
 * †Synechodus
 * †Synechodus clarki
 * †Synechodus clarkia
 * Syrnola
 * †Syrnola toulmini – type locality for species

T

 * Tagelus
 * †Tagelus plebeius
 * Tamias
 * †Tamias striatus
 * Tamiasciurus
 * †Tamiasciurus hudsonicus
 * †Taphrosphys
 * †Taphrosphys miocenica – type locality for species
 * †Tapiravus
 * †Tapiravus validus – or unidentified comparable form
 * South American tapir (Tapirus terrestris).JPG [[Tapirus]]
 * †Tapirus haysii – or unidentified comparable form
 * †Tasbacka
 * †Tasbacka ruhoffi – type locality for species
 * Taxidea
 * †Taxidea taxus – type locality for species
 * †Tectatodinium
 * †Tectatodinium pellitum
 * Teinostoma
 * †Teinostoma barryi
 * †Teinostoma umbilicatum
 * Tellina
 * †Tellina virginiana
 * †Tellina williamsi
 * Terebra
 * †Terebra curvilirata
 * †Terebra inornata
 * Terebratula
 * †Terebratula marylandica – type locality for species
 * Teredo
 * †Teredo virginiana
 * Terrapene
 * †Terrapene carolina
 * Testudo
 * †Testudo ducateli – type locality for species
 * Textularia
 * †Textularia ultimainflata
 * Thamnophis
 * Thecachampsa carolinensis cropped.jpg †[[Thecachampsa]]
 * †Thecachampsa antiqua
 * †Thecachampsa marylandica – type locality for species
 * †Thinocetus
 * †Thinocetus arthritus
 * Thomomys – type locality for genus
 * †Thomomys potomacensis – type locality for species
 * Thracia
 * †Thracia conradi
 * Torcula
 * †Torcula variabilis
 * †Tornatellaea
 * †Tornatellaea texana
 * Torquesia
 * †Torquesia prehumerosa – type locality for species
 * Spectacled Bear - Houston Zoo.jpg [[Tremarctos]]
 * †Tremarctos floridanus
 * †Tretosphys
 * †Tretosphys lacertosus – type locality for species
 * †Tretosphys ruschenbergeri – type locality for species
 * Triloculina
 * †Triloculina rotunda
 * Trionyx – report made of unidentified related form or using admittedly obsolete nomenclature
 * †Trionyx halophilus
 * Triphora
 * †Triphora tricincta
 * Tritonium
 * †Tritonium centrosum – type locality for species
 * Trochita
 * †Trochita aperta
 * †Trygon
 * †Trygon dux
 * †Tuba – tentative report
 * †Tuberculodinium
 * †Tuberculodinium vancampoae
 * Tudicla – or unidentified comparable form
 * Turricula – report made of unidentified related form or using admittedly obsolete nomenclature
 * †Turrifulgur – type locality for genus
 * †Turrifulgur turriculus – type locality for species
 * Turris – report made of unidentified related form or using admittedly obsolete nomenclature
 * †Turris piscatavensis
 * †Turris tysoni
 * Turritellatricarinata.jpg [[Turritella]]
 * †Turritella alticostata
 * †Turritella exaltata
 * †Turritella humerosa
 * †Turritella indenta
 * †Turritella indentata
 * †Turritella plebeius
 * †Turritella plebeua
 * †Turritella potomacensis
 * †Turritella subponderosa
 * †Turritella subvariabilis
 * †Turritella terebriformis
 * Bottlenose Dolphin KSC04pd0178.jpg [[Tursiops]]
 * Typhis
 * †Typhis acuticosta

U

 * Umbraculum – tentative report
 * Urosalpinx
 * †Urosalpinx cinerea
 * †Urosalpinx subrusticus
 * Ursus
 * 01 Schwarzbär cropped.jpg †[[Ursus americanus]]

V

 * Venericardia
 * †Venericardia ascia
 * †Venericardia potapacoensis
 * †Venericardia regia
 * Vespertilio murinus 2.jpg [[Vespertilio]]
 * †Vespertilio grandis
 * Vitrinella
 * †Vitrinella clarkmartini – type locality for species
 * Volutifusus
 * †Volutifusus acus – type locality for species
 * †Volutifusus asheri – type locality for species
 * †Volutifusus marylandicus – type locality for species
 * †Volutifusus meganucleus – type locality for species
 * †Volutifusus mutabilis
 * Volvulella
 * Vulpes

X

 * Xestoleberis
 * Xiphiacetus sp.jpg †[[Xiphiacetus]]
 * †Xiphiacetus bossi – type locality for species
 * †Xiphiacetus cristatus – type locality for species
 * Xiphias
 * †Xiphias radiata – tentative report

Y

 * Yoldia
 * †Yoldia laevis
 * Yoldia limatula illustration.png †[[Yoldia limatula]]
 * †Yoldia potomacensis
 * †Yolida

Z

 * †Zarhachis – type locality for genus
 * †Zarhachis crassangulum – type locality for species
 * †Zarhachis flagellator – type locality for species
 * †Zarhachis tysonii – type locality for species
 * †Zikkuratia
 * †Zikkuratia danica – type locality for species
 * †Zizyphinus
 * †Zizyphinus bryanii – type locality for species