# 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

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* D
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* F
* G
* H
* I
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* †Abra – tentative report
** †Abra longicalla
* Acanthodesia
** †Acanthodesia oblongula
** †Acanthodesia savartii
* †Acantodesia
** †Acantodesia oblongula
* Illustration of a living Acipenser sturgeon 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
* Fossilized skull of the Miocene baleen whale Aglaocetus †Aglaocetus
** †Aglaocetus patulus
* Alca
** †Alca torda – or unidentified comparable form
* Aligena
** †Aligena aequata
** †Aligena elevata
* †Ambystoma
** †Ambystoma maculatum
** †Ambystoma tigrinum
* Amia
* Life restoration of the Miocene-Pliocene beardog Amphicyon †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
* Restoration of an Arctodus, or short-faced bear, with a human to scale †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
* Shell of a modern Astarte 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
** Life restoration of the Miocene stargazer Astroscopus countermani †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
* Life restoration of the Miocene sperm whale Aulophyseter †Aulophyseter
** †Aulophyseter mediatlanticus – type locality for species

## B

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* F
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* Portrait of a living Balaenoptera baleen whale 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
** A living Blarina brevicauda, or northern short-tailed shrew †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
** A living Brevoortia tyrannus, or Atlantic menhaden †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

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* Cadulus
** †Cadulus bellulus
** †Cadulus newtonensis
** †Cadulus thallus
* Caecum
** †Caecum patuxentium
* †Calianassa
** †Calianassa atlantica
** †Calianassa matsoni – or unidentified comparable form
* Callinectes
** †Callinectes ornatus
** A living Callinectes sapidus, or Chesapeake blue crab †Callinectes sapidus
* Calliostoma
** †Calliostoma alphelium
** †Calliostoma aphelium
** †Calliostoma humile – or unidentified comparable form
** †Calliostoma philanthropus
** †Calliostoma philathropus
* Callista
** †Callista marylandica
* Callocardia
** †Callocardia catharia
* A living Calonectris shearwater Calonectris
* Calyptraea
** †Calyptraea aldrichi – type locality for species
** †Calyptraea centralis
* †Calyptraphorus
** †Calyptraphorus jacksoni
* Cancellaria
** †Cancellaria alternata
* Cancer
** †Cancer irroratus
* Canis
** Illustration in multiple views of a fossilized skull of the Pleistocene Canis armbrusteri, or Armbruster's wolf †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
** Fossilized tooth of the Miocene-Pliocene shark Cosmopolitodus hastalis, 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
* Life restoration of the Miocene-Pliocene whale Cetotherium †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
** Shells of the Pliocene scallop Chesapecten jeffersonius †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
** A living Chrysemys picta, or painted turtle †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
* Fossil of the Miocene-Pleistocene barnacle Concavus 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
* Shell of a Corbula basket clam 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
* Fossil of the Early Cretaceous-Eocene shark Cretolamna †Cretolamna
** †Cretolamna appendiculata
* Crotalus
** †Crotalus horridus
* Crucibulum
** †Crucibulum constrictum
** †Crucibulum costata
** †Crucibulum multilineatum
* A living Cryptobranchus alleganiensis, 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
** Shell in multiple views of a Cyrtopleura costata, or angel wing clam †Cyrtopleura costata
* Cythara
* †Cythereis
** †Cythereis tuberculata
* Cytheridea
** †Cytheridea punctillata
* †Cytheris
** †Cytheris tuberculata

## D

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* †Dallarca
** †Dallarca elevata
** †Dallarca elnia
** †Dallarca idonea
** †Dallarca staminea
** †Dallarca subrostrata
* A living Dasyatis stingray 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
* Underside of the reconstructed cranium of the Miocene baleen whale Diorocetus †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
* Fossil shell of the Cretaceous-modern marine venus clam Dosinia Dosinia
** †Dosinia acetabulum
* †Dosiniopsis
** †Dosiniopsis lenticularis

## E

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* †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
** Illustration of a fossilized shell of the Miocene murex sea snail Ecphora gardnerae †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
* Fossilized cranium in multiple views of the Paleocene-Eocene gavial relative Eosuchus †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
* Life restoration of the Pleistocene bovid Euceratherium, or the shrub ox. Robert Bruce Horsfall (1913). †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
* Life restoration of the Miocene whale Eurhinodelphis (above) †Eurhinodelphis
** †Eurhinodelphis longirostris
* Euspira
** †Euspira heros
** †Euspira marylandica
** †Euspira tuomeyi

## F

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* Felis
** †Felis couguar
* †Ficopsis
* Fissurella
** †Fissurella fluviamariana – type locality for species
* Living Fistulobalanus barnacles †Fistulobalanus
** †Fistulobalanus klemmi
* †Florilus
** †Florilus chesapeakensis
* †Florimetis
** †Florimetis biplicata
* †Fulgar
** †Fulgar coronatum

## G

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* A living Galeocerdo cuvier, or tiger shark Galeocerdo
** †Galeocerdo aduncus
** †Galeocerdo appendiculatus
** †Galeocerdo contortus
** †Galeocerdo latidens
* Galeodea
* Gari
** †Gari gubernatoria
* Gastrochaena
* Gavia
** †Gavia immer
* Fossilized skull of the Miocene crocodile relative Gavialosuchus †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
* A living Glaucomys, or New World flying squirrel 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
* Mounted fossilized skeleton of the Miocene-Pleistocene elephant relative Gomphotherium †Gomphotherium
** †Gomphotherium obscurum – type locality for species
* †Gryphaeostrea
** †Gryphaeostrea vomer
* Gulo
** †Gulo gulo
* Gyrinophilus
** †Gyrinophilus porphyriticus – or unidentified comparable form

## H

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* †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
* Shells in differing orientations of Hastula augur sea snails 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
** Fossilized teeth of the Miocene weasel shark Hemipristis serra †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
* Mounted fossilized skeleton of the Miocene-Pliocene horse Hippotherium †Hippotherium
* Hyla
** †Hyla crucifer
* Hyotissa
** †Hyotissa haitensis
* Hysteroconcha
** †Hysteroconcha marylandica
** †Hysteroconcha staminaea
* †Hystrichosphaeropsis
** †Hystrichosphaeropsis obscura

## I

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* Ictalurus
* Ilyanassa
** †Ilyanassa obsoleta
** †Ilyanassa trivittata
* Ischadium
** †Ischadium recurvum
* Fossilized skeleton of the Middle Jurassic-Miocene Chimaera relative Ischyodus †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

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

## K

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* Kalolophus
** †Kalolophus antillarum
* †Kapalmerella
** †Kapalmerella mortoni
* Life restoration of the Oligocene-Miocene dolphin Kentriodon †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

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* †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
* A modern Lamna mackerel shark 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
** A living Lepus americanus, or snowshoe hare †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
** Pair of living Lontra canadensis, or North American river otter †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

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* Macoma
** Shell of a Limecola balthica, 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
** Life restorations of a Mammut americanum, 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
** 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
* Mounted fossilized skeleton of the Miocene-Pleistocene ground sloth Megalonyx †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
** Collection of Mercenaria mercenaria, also known as hard clams or quahogs †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
* Mounted fossilized skeleton of the Miocene-Pleistocene manatee relative Metaxytherium †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
* Restoration of the Pliocene-Pleistocene Miracinonyx, or American cheetah †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
** A living Neovison vison, 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
* Fossilized skeleton of the Pliocene-Holocene peccary Mylohyus †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

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* †Nanosiren – tentative report
* Napaeozapus
** †Napaeozapus insignis
* Narona
** †Narona potomacensis
* Nassa
* A living Nassarius, or nassa mud snail Nassarius
** †Nassarius peralta
** †Nassarius vibex
* Nemocardium
** †Nemocardium lene
* Neofiber
* Neotoma – type locality for genus
** †Neotoma floridana
** †Neotoma spelaea – type locality for species
* Nerodia
** A living Nerodia sipedon, or northern water snake †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
** Close-up portrait of a living Notorynchus cepedianus, or broadnose sevengill shark †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

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* Ochotona
** †Ochotona princeps – or unidentified comparable form
* Odocoileus
** †Odocoileus virginianus
* A living Odontaspis sand shark 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
* Life restoration of the Miocene sperm whale Orycterocetus †Orycterocetus
** †Orycterocetus crocodilinus
* †Osteopygis
** †Osteopygis roundsi
* Ostrea
** †Ostrea alepidota
** †Ostrea carolinensis
** †Ostrea trachydiscus – type locality for species
* †Otodus
** †Otodus angustidens – tentative report
** Diagram illustrating the largest (grey) and most conservative (red) size estimates of the Miocene-Pliocene shark Carcharocles megalodon (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

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
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* T
* U
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* W
* X
* Y
* Z
* Pagurus
** †Pagurus pollicaris
* †Palaeocarcharodon
** †Palaeocarcharodon orientalis
* †Palaeocystodinium
** †Palaeocystodinium golzowense
* Restoration of the Cretaceous-Eocene sea snake Palaeophis †Palaeophis
** †Palaeophis grandis
* †Pamicellaria
** †Pamicellaria convoluta
* Pandora
** †Pandora gouldiana
* Panopea
** †Panopea americana
** †Panopea elongata
** †Panopea goldfussi
** †Panopea goldfussii
** †Panopea whitfieldi
* Panopeus
** †Panopeus herbstii
* Panthera
** A living Panthera leo, or lion †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
** A living Perisoreus canadensis, or grey jay †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
* Life restoration of the Paleocene-Eocene ungulate Phenacodus. Charles R. Knight (1898). †Phenacodus – tentative report
* †Phenacomya
** †Phenacomya petrosa
* Phenacomys
* †Phocageneus
** †Phocageneus venustus
* Pholadomya
** †Pholadomya marylandica
* †Physeterula
* Physodon
** †Physodon triqueter
* Pinna
* Pipistrellus
* Shell of a Pitar venus clam 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
* Restoration of a herd of alarmed Miocene-Pleistocene peccaries 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
** A living Pogonias cromis, or black drum †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
* Life restoration of the Paleocene-Eocene waterfowl Presbyornis †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
** A living Pseudacris triseriata, or western chorus frog †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
* A living Puffinus shearwater Puffinus
** †Puffinus conradi – type locality for species
* Pycnodonte
** †Pycnodonte percrassa
* †Pyropsis – tentative report

## Q

* A
* B
* C
* D
* E
* F
* G
* H
* I
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* L
* M
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* Z
* Shell of a Quinqueloculina foraminiferan Quinqueloculina
** †Quinqueloculina flexuosa
** †Quinqueloculina seminula

## R

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
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* L
* M
* N
* O
* P
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* T
* U
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* W
* X
* Y
* Z
* †Rana
** A living Lithobates clamitans (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
** A living Morone saxatilis (formerly Roccus saxatilis), or striped bass †Roccus saxatilis
* †Rotalia
** †Rotalia beccardi
** †Rotalia beccarii

## S

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* Saccella
** †Saccella parva
* Salamandra
** †Salamandra opaca
* †Sangamona
** †Sangamona fugitiva
* †Scala
** †Scala marylandica
* Fossilized teeth of the Neogene sperm whale Scaldicetus †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
* Fossilized skull of the Miocene toothed whale Schizodelphis †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
* Life restoration of the Pleistocene-Holocene saber-tooth cat Smilodon †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
** A living Sorex cinereus, or cinereus shrew †Sorex cinereus
** †Sorex fumeus
* Spermophilus
** †Spermophilus tridecemlineatus
* †Sphaerula
** †Sphaerula subvexa
* Sphenia – tentative report
* †Sphyraenodus
** †Sphyraenodus speciosus
* A living Sphyrna hammerhead shark 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
* Life restoration of the Oligocene-Miocene shark-toothed dolphin Squalodon †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
** Illustration of a living Squilla empusa mantis shrimp †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
** A living Synaptomys cooperi, or southern bog lemming †Synaptomys cooperi
* †Synechodus
** †Synechodus clarki
** †Synechodus clarkia
* Syrnola
** †Syrnola toulmini – type locality for species

## T

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* Tagelus
** †Tagelus plebeius
* Tamias
** †Tamias striatus
* Tamiasciurus
** †Tamiasciurus hudsonicus
* †Taphrosphys
** †Taphrosphys miocenica – type locality for species
* †Tapiravus
** †Tapiravus validus – or unidentified comparable form
* A living Tapirus, or tapir 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
* Fossilized skeleton of the Oligocene-Miocene gavial relative Thecachampsa †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
* A living Tremarctos, or spectacled bear 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
* Fossilized shells of the Late Jurassic-modern tower snail Turritella Turritella
** †Turritella alticostata
** †Turritella exaltata
** †Turritella humerosa
** †Turritella indenta
** †Turritella indentata
** †Turritella plebeius
** †Turritella plebeua
** †Turritella potomacensis
** †Turritella subponderosa
** †Turritella subvariabilis
** †Turritella terebriformis
* A living Tursiops, or bottlenose dolphin Tursiops
* Typhis
** †Typhis acuticosta

## U

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* Umbraculum – tentative report
* Urosalpinx
** †Urosalpinx cinerea
** †Urosalpinx subrusticus
* Ursus
** A living Ursus americanus, or American black bear †Ursus americanus

## V

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* Venericardia
** †Venericardia ascia
** †Venericardia potapacoensis
** †Venericardia regia
* A living Vespertilio bat 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

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* Xestoleberis
* Fossilized skeleton of the Miocene whale Xiphiacetus †Xiphiacetus
** †Xiphiacetus bossi – type locality for species
** †Xiphiacetus cristatus – type locality for species
* Xiphias
** †Xiphias radiata – tentative report

## Y

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
* Yoldia
** †Yoldia laevis
** Illustration of the shell of a Yoldia limatula, or file yoldia †Yoldia limatula
** †Yoldia potomacensis
* †Yolida

## Z

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* 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