List of marine gastropod genera in the fossil record

This list of marine gastropod genera in the fossil record is an attempt to list all the genera of sea snails or marine gastropod mollusks which have been found in the fossil record. Nearly all of these are genera of shelled gastropods, since it is relatively rare for mollusks without a shell to leave recognizable traces.

Many of the genera on the list are still extant, are still living now. On the current version of this list, some extant genera are mistakenly marked as extinct, with a "†" next to the name, but this will slowly become more accurate over time as corrections are made.

The list consists of formal genera names in the class Gastropoda; it excludes purely vernacular names. It shows all commonly accepted genera, but it also includes genera which are now considered invalid or doubtful ("nomina dubia"), and names that were not formally published ("nomina nuda"), as well as junior synonyms of more established names.

The list also includes some genera which were first described as gastropods, but which are no longer considered to be gastropods, and which in many cases are not even considered to be mollusks.

Naming conventions and terminology follow the International Code of Zoological Nomenclature.
* Junior synonym: A name which describes the same taxon as a previously published name. If two or more genera are formally designated and the type specimens are later assigned to the same genus, the first to be published (in chronological order) is the senior synonym, and all other instances are junior synonyms. Senior synonyms are generally used, except by special decision of the ICZN, but junior synonyms cannot be used again, even if deprecated. Junior synonymy is often subjective, unless the genera described were both based on the same type specimen.
*"Nomen nudum" (Latin for "naked name"): A name that has appeared in print but has not yet been formally published by the standards of the ICZN. "Nomina nuda" (the plural form) are invalid, and are therefore not italicized as a proper generic name would be. If the name is later formally published, that name is no longer a "nomen nudum" and will be italicized on this list. Often, the formally published name will differ from any "nomina nuda" that describe the same specimen.
*"Nomen oblitum" (Latin for "forgotten name"): A name that has not been used in the scientific community for more than fifty years after its original proposal.
*Preoccupied name: A name that is formally published, but which has already been used for another taxon. This second use is invalid (as are all subsequent uses) and the name must be replaced. Preoccupied names are not valid generic names.
*"Nomen dubium" (Latin for "dubious name"): A name describing a fossil with no unique diagnostic features.

C

*†"Cabania"
*†"Cabestanna"
* "Caecum"
*†"Caesia"
*†"Calaurops"
*†"Calcarata"
*†"Calcitrapessa"
*†"Calicantharus"
*†"Caliendrum"
*†"Callianax"
*†"Calliobasis"
*†"Calliomphalus"
* "Calliostoma"
*†"Calliotectum"
*†"Calliotropis"
*†"Calliovarica"
*†"Callispira"
*†"Callistadia"
*†"Callistele"
*†"Callistocypraea"
*†"Callitomaria"
*†"Callolongchaeus"
*†"Callopoma"
*†"Callotrochus"
*†"Callusaria"
*†"Calodisculus"
*†"Calophos"
*†"Calorebama"
* "Calotrophon"
*†"Calpurna"
*†"Calthalotia"
*†"Calvadosiella"
*†"Calverturris"
* "Calyptraea"
*†"Calyptraphorus"
*†"Calyptroides"
*†"Calyptropsis"
*†"Camarnia"
*†"Cambodgia"
*†"Campanelle"
*†"Campanile"
*†"Campanilopa"
*†"Campbellospira"
*†"Campichia"
*†"Camponaxis"
*†"Camponeila"
*†"Camposcala"
*†"Camptoceratops"
*†"Campylacrum"
*†"Canaliscala"
*"Canarium" (synonym of "Strombus" (Canarium) )
*†"Cancellaria"
*†"Cancellariella"
*†"Cancelrana"
*†"Cancilla"
*†"Candinia"
*†"Canepina"
*"Cantharidella"
* "Cantharidus"
*†"Cantharulus"
* "Cantharus"
*†"Cantrainea"
*†"Capulacmaea"
*†"Capulus"
*†"Carboninia"
*†"Cardinalia"
*†"Careliopsis"
*†"Caribiella"
*†"Caricella"
*†"Carinacca"
*"Carinaria"
*†"Carinaropsis"
*†"Carinator"
*†"Carinodrillia"
*†"Carinomphalus"
*†"Carinotropsis"
*†"Carota"
*†"Caseyella"
*†"Casimiria"
* "Casmaria"
*†"Cassianastraea"
*†"Cassianaxis"
*†"Cassianebala"
*†"Cassianilda"
*†"Cassianocirrus"
*†"Cassianozyga"
*†"Cassidaria"
*†"Cassiope"
*†"Cassiopella"
*†"Cassipelia"
* "Cassis"
*†"Catantostoma"
*†"Cataschisma"
*†"Catazona"
*†"Catazone"
*†"Catenoscala"
*†"Catenotoma"
*†"Catilon"
*†"Caucasella"
*†"Cautotriphora"
*†"Caveola"
*†"Cavernisa"
*†"Cavilabium"
*†"Caviumbonia"
* "Cavolina"
*†"Celatoconus"
* "Cellana"
*†"Cenomanella"
*†"Centrifuga"
*†"Centrifugus"
*†"Cepatia"
*†"Ceratia"
*†"Ceratopea"
*†"Ceratostoma"
*†"Ceraunocochlis"
*†"Ceritella"
* "Cerithidea"
*†"Cerithideops"
*†"Cerithideopsilla"
*†"Cerithideopsis"
* "Cerithidium"
*†"Cerithiella"
*†"Cerithina"
*†"Cerithinella"
*†"Cerithioclava"
*†"Cerithiocyga"
*†"Cerithioderma"
*†"Cerithioides"
*†"Cerithiomorpha"
*†"Cerithiopsida"
*†"Cerithiopsidella"
* "Cerithiopsis"
*†"Cerithiscala"
* "Cerithium"
*†"Cerithopsina"
*†"Chalarostrepsis"
*†"Charadreum"
* "Charonia"
*†"Chartroniella"
*†"Chasmotheca"
*†"Chauvetia"
*†"Chavanicerithium"
*†"Chedevillia"
* "Cheilea"
*†"Cheilospicata"
*†"Cheilotomona"
*†"Chelotia"
*†"Chelyconus"
*†"Chemnitzia"
*†"Chepultapecia"
*†"Chesaclava"
*†"Chesasyrinx"
*†"Chesathais"
*†"Chesatrophon"
*†"Chevallieria"
* "Chicoreus"
*†"Chileutomia"
*†"Chilocyclus"
*†"Chilodonta"
*†"Chilodontoidea"
*†"Chingua"
*†"Chippewaella"
*†"Chiralithes"
*†"Chiraluta"
*†"Chlathrus"
* "Chlorostoma"
*†"Chlupacispira"
*†"Chondrocerithium"
*†"Chorus"
*†"Christitys"
*†"Chrysallida"
*†"Chrysame"
*†"Chrysostoma"
*†"Cibecuia"
*†"Cidarina"
*†"Cigelirina"
*†"Cilara"
*†"Cimoliocentrum"
*†"Cimolithium"
*†"Cinclidonema"
*†"Cinctiscala"
* "Cingula"
*"Cingulina"
*†"Cinguliturris"
*†"Cinulia"
*†"Circulopsis"
*†"Circuloscala"
*†"Circulus"
*†"Cirillia"
*†"Cirrus"
*†"Cirsocerithium"
*†"Cirsochilus"
*†"Cirsomphalus"
*"Cirsonella"
*†"Cirsope"
*†"Cirsostylus"
*"Cirsotrema"
* "Cittarium"
*†"Claibornia"
*†"Clanculopsis"
* "Clanculus"
*†"Clathrobaculus"
* "Clathrodrillia"
* "Clathromangelia"
*†"Clathronema"
*†"Clathroscala"
*†"Clathrospira"
*†"Clathrus"
*†"Clathurella"
*†"Clava"
*†"Clavatula"
*†"Clavellofusus"
*†"Clavidrupa"
*†"Clavilithes"
*†"Claviscala"
*†"Clavocerithium"
*†"Clavstoma"
*†"Clavus"
*†"Cleobula"
*†"Cleotrivia"
*†"Clifdenia"
*†"Climacina"
*†"Climacopoma"
*†"Clinopegma"
*†"Clinura"
*†"Clinurella"
*†"Clinuropsis"
* "Clio"
*†"Clivuloturris"
*†"Closia"
*†"Closteriscus"
*†"Closteroides"
*†"Cloughtonia"
*†"Clypeola"
*†"Clypeolum"
*†"Clypeomorus"
*†"Clypidina"
*†"Coalingodea"
*†"Coanollonia"
*†"Coccopigya"
*†"Cocculina"
*†"Cocculinella"
*†"Cochiolepis"
*†"Cochleochilus"
* "Cochlespira"
*†"Cochlespirella"
*†"Cochlespiropsis"
*†"Cochliconus"
*†"Codinella"
*†"Codonocheilus"
*†"Coelobolma"
*†"Coelocaulus"
*†"Coelocentrus"
*†"Coelochrysalis"
*†"Coelocyclus"
*†"Coelodiscus"
*†"Coeloscapha"
*†"Coelostylina"
*†"Coelotrochus"
*†"Coelozone"
*†"Coemansia"
*†"Colina"
*†"Collabrina"
*†"Colliculus"
*†"Collina"
* "Collisella"
*†"Collonia"
*†"Collonista"
*†"Colostracon"
*†"Colpites"
*†"Colpomphalus"
*†"Colposigma"
*†"Colpospira"
*†"Colpostomia"
* "Colubraria"
*†"Colubrella"
*†"Colubrellina"
* "Columbarium"
* "Columbella"
*†"Columbellaria"
*†"Columbellina"
*†"Columbellisipho"
*†"Columbellopsis"
* "Colus"
*†"Coluzea"
*†"Colwellia"
*†"Comarmondia"
*†"Cominella"
*†"Cominista"
*†"Cominula"
*†"Comitas"
*†"Commonozonispira"
* "Compsodrillia"
*†"Compsonema"
*†"Conactaeon"
*"Concholepas"
*†"Conchothyra"
*†"Concinnispira"
*†"Condonella"
*†"Confusiscala"
*†"Coninoda"
*†"Coniscala"
* "Conjectura"
*†"Conocerithium"
*†"Conoidacmaea"
*†"Conolithes"
*†"Conominolia"
*†"Conomitra"
*†"Conomurex"
*†"Conorbis"
*†"Conorhytis"
*†"Conotoma"
*†"Conotomaria"
*†"Consobrinella"
*†"Contemniscala"
*†"Contortella"
*†"Conuber"
*"Conus"
*†"Cookia"
*†"Cophocara"
*†"Copidocatomus"
*†"Coptochetus"
*†"Coptosipho"
*†"Coptostoma"
*†"Coptostomella"
*†"Coraeophos"
*†"Coralliophila"
*†"Cordieria"
*†"Cordispira"
*†"Coriandria"
*†"Cornulina"
*†"Coronatica"
*†"Coronia"
*†"Coroniopsis"
*†"Coroniscala"
*†"Coronopsis"
*†"Corsania"
*†"Cortinella"
*†"Cosmasyrinx"
*†"Cosmetalepas"
*†"Cosmocerithium"
*†"Cosmolithes"
*†"Cosmophiline"
*†"Cossmannea"
*†"Cossmannia"
*†"Cossmannica"
*†"Costaella"
* "Costellaria"
*†"Costoanachis"
*†"Costosyrnola"
*†"Cotonopsis"
*†"Cottonia"
*†"Couthouyia"
*†"Cowlitzia"
*†"Craginia"
*†"Cranopsis"
*†"Craspedostoma"
*†"Crassilabrum"
*†"Crassimarginata"
*†"Crassimurex"
*†"Crassiscala"
* "Crassispira"
*†"Crassispirella"
*†"Crassopleura"
*†"Crawfordina"
*†"Crebriscala"
*†"Cremides"
*†"Crenaturricula"
*†"Crenetocerithium"
*†"Crenilabium"
*†"Crenilunula"
*†"Crenistriella"
*†"Crenisutura"
*†"Creniturbo"
*†"Crenulazone"
*†"Creonella"
*†"Crepidula"
*†"Crepipatella"
*†"Creseis"
*†"Cretaceomurex"
*†"Cribraria"
*†"Crimella"
*†"Crisposcala"
*†"Cristalloella"
*†"Crommium"
*†"Cronia"
*†"Crossata"
*†"Crossea"
*†"Crosseola"
*†"Crossoceras"
*†"Crossostoma"
*†"Crossotrema"
* "Crucibulum"
*†"Cruziturricula"
*†"Cryoturris"
*†"Cryptaulax"
*†"Cryptoborsonia"
*†"Cryptobranchia"
*†"Cryptochorda"
*†"Cryptoconus"
*†"Cryptocordieria"
*†"Cryptomella"
*†"Cryptonatica"
*†"Cryptonerita"
*†"Cryptoplocus"
*†"Cryptoptyxis"
*†"Cryptorhytis"
*†"Cryptospira"
*†"Ctenilyria"
*†"Ctenocolpus"
*†"Cubestana"
*†"Culmia"
*†"Cupaniella"
*†"Cuphosolenus"
*†"Cuphotifer"
*†"Cupidoliva"
*†"Curetia"
*†"Cuvierina"
*†"Cyclites"
*†"Cyclobathmus"
*†"Cyclodostomia"
*†"Cyclomolops"
*†"Cyclonema"
*†"Cyclope"
*†"Cycloscala"
*†"Cycloscena"
*†"Cyclospongia"
*†"Cyclostomaria"
*†"Cyclostrema"
*†"Cyclostremela"
* "Cyclostremiscus"
*†"Cyclostromella"
*†"Cyclotheca"
*†"Cyclothyca"
*†"Cycloturbo"
*†"Cyclozyga"
*"Cylichna"
*†"Cylichnania"
*†"Cylichnatys"
* "Cylichnella"
*†"Cylichnina"
*†"Cylichnopsis"
*†"Cylicioscapha"
*†"Cylinder"
*†"Cylindriscala"
*†"Cylindritella"
*†"Cylindrites"
*†"Cylindritopsis"
*†"Cylindrobullina"
*†"Cylindromitra"
*†"Cylindrotruncatum"
*†"Cyllene"
*†"Cyllenina"
*†"Cymakra"
*†"Cymatiella"
* "Cymatium"
*†"Cymatophos"
*†"Cymatospira"
*†"Cymatosyrinx"
* "Cymbiola"
*†"Cymbium"
*†"Cymbularia"
*†"Cymenorhytis"
*†"Cymia"
*†"Cynisca"
*†"Cyniscella"
* "Cyphoma"
*†"Cyphonochelus"
* "Cypraea"
* "Cypraecassis"
*†"Cypraedia"
*†"Cypraeerato"
*†"Cypraeogemmula"
*†"Cypraeopsis"
*†"Cypraeorbis"
*†"Cypraeotrivia"
*†"Cyproglobina"
*†"Cypropterina"
*†"Cyrbasia"
*†"Cyrtochetus"
*†"Cyrtospira"
*†"Cyrtostropha"
*†"Cyrtulotibia"
*†"Cythara"
*†"Cytharella"

F

*†"Fadaiella"
*†"Faloriella"
*†"Falsicolus"
*†"Falsifusus"
*†"Falsostyliola"
*†"Falsostyliola"
*†"Faluniella"
* "Fartulum"
* "Fasciolaria"
*†"Fascioplex"
*†"Fascivelvata"
*†"Fastigiella"
*"Fautor"
* "Favartia"
*†"Favria"
*†"Favriella"
*†"Fax"
*†"Faxxia"
*†"Feneoniana"
*†"Fenestrosyrinx"
*†"Fenolignum"
*†"Fibula"
*†"Fibulella"
*†"Fibuloptygmatis"
*†"Fibuloptyxis"
*†"Ficopsis"
*†"Fictoacteon"
*†"Fictonoba"
*†"Ficulomorpha"
*†"Ficulopsis"
* "Ficus"
*†"Filodrilla"
*†"Fimbriatella"
*†"Finlayola"
*†"Fischeriella"
* "Fissurella"
*†"Fissurellidea"
*†"Fissurisepta"
*†"Flacilla"
*†"Flemmingia"
*†"Fletcherviewia"
*†"Flexopteron"
*†"Floribella"
*†"Floripatella"
*†"Floyda"
*†"Folina"
*†"Foratiscala"
* "Forreria"
*†"Forsia"
*†"Forskaelena"
*†"Fossacypraea"
*†"Fossariopsis"
* "Fossarius"
*†"Fossatrivia"
*†"Fredenia"
*†"Friginatica"
*†"Frombachia"
*†"Fujispira"
*†"Fulgerca"
* "Fulgoraria"
*†"Fulguroficus"
*†"Fulgurofusus"
*†"Funis"
* "Funiscala"
*†"Fuscibuccinum"
*†"Fuscoscala"
*†"Fusiaphera"
*†"Fusiguraleus"
*†"Fusimilis"
*†"Fusimitra"
* "Fusinus"
*†"Fusiptyxis"
*†"Fusispira"
*†"Fusitoma"
* "Fusitriton"
*†"Fusitron"
*†"Fusiturricula"
*†"Fusiturris"
*†"Fusoficula"
*†"Fusoidella"
*†"Fusoterebra"
*†"Fusus"
*†"Futhystylus"
*†"Fyfea"

I

*†"Ianthinopsis"
*†"Iddingsia"
*†"Idioraphe"
*†"Ihungia"
*†"Ilanga"
*†"Iljinella"
* "Illyanassa"
*†"Imbricaria"
*†"Incilaster"
*†"Incisilabium"
*†"Indocerithium"
*†"Indovoluta"
*†"Infracoronia"
*†"Infundibulops"
*†"Inglisella"
*†"Inquisitor"
*†"Insolentia"
*†"Involuta"
*†"Iolaea"
*†"Iothia"
*†"Iphiana"
*†"Iravadia"
* "Iredalina"
*"Iredalula"
*†"Isanda"
*†"Ischnoptygma"
* "Iselica"
*†"Isfarispira"
*†"Ishnula"
*†"Islipia"
*†"Isonema"
*†"Isospira"
*†"Ispharina"
*†"Isselia"
*†"Italoptygmatis"
*†"Ithycythara"
*†"Itia"
*†"Itieria"
*†"Itomelania"
*†"Itruvia"
*†"Ivara"
*†"Ividella"

L

*†"Labiostrombus"
*†"Labridens"
*†"Labrocuspis"
*†"Laccinum"
*†"Lachryma"
*†"Lacinia"
*†"Lacriforma"
* "Lacuna"
*†"Lacunaria"
*†"Lacunella"
*†"Lacunina"
*†"Lacunospira"
*†"Lacurnaria"
*†"Ladinotrochus"
*†"Ladinula"
*†"Laetifautor"
*†"Laevella"
*†"Laevibaculus"
*†"Laevibuccinum"
*†"Laeviconulus"
*†"Laevihastula"
*†"Laevinerinea"
*†"Laeviselica"
*†"Laevistrombus"
*†"Laeviterebrum"
*†"Laevitomaria"
*†"Laevityphis"
*†"Lagunitus"
*†"Laiocochlis"
* "Lambis"
* "Lamellaria"
*†"Lamelliphorus"
*†"Lamellospira"
*†"Lampanella"
*†"Lampasopsis"
*†"Lamprodoma"
*†"Lamprodomina"
*†"Lampusia"
*†"Lancedellia"
*†"Lapparia"
*†"Lathyrulus"
*†"Latiala"
* "Latiaxis"
*†"Latifusus"
*†"Latirolagena"
* "Latirus"
*†"Latisipho"
*†"Latitaenia"
*†"Laubella"
*†"Lautoconus"
*†"Laxispira"
*†"Leaella"
*†"Lecanospira"
*†"Leiopyrga"
*†"Leiorhinus"
*†"Leiostraca"
*†"Leiotrochus"
*†"Lemintina"
*†"Lemniscolittorina"
*†"Lenitrophon"
*†"Lenticularis"
*†"Lentigo"
* "Lepeta"
*†"Lepetella"
*†"Lepetopsis"
*†"Lepicythara"
*†"Lepidotrochus"
*†"Leporemax"
*†"Leporicypraea"
*"Lepsiella"
*†"Lepsithais"
*†"Leptadrillia"
*†"Leptegauana"
*†"Leptocolpus"
*†"Leptoconus"
*†"Leptomaria"
*†"Leptomphalus"
*†"Leptomurex"
*†"Leptoptygma"
*†"Leptorima"
*†"Leptoscapha"
*†"Leptosurcula"
*†"Leptothyra"
*†"Leptothyropsis"
*†"Leptozone"
*†"Leptozyga"
*†"Lesperonia"
*†"Lesueurilla"
*†"Leucorhynchia"
* "Leucosyrinx"
* "Leucozonia"
*†"Leufroyia"
*†"Levella"
*†"Levenia"
*†"Leviathania"
*†"Levifusus"
*†"Lewinskia"
*†"Lewisiella"
*†"Liaohenia"
*†"Libycerithium"
*†"Lienardia"
*†"Ligatella"
*†"Lilax"
*†"Liljevallospira"
*"Liloa"
*"Limacina"
*†"Limneria"
*"Limulatys"
*†"Linatella"
*†"Linemera"
*†"Linglingella"
*†"Liniaxis"
*†"Linopyrga"
*†"Linsleyella"
*†"Liocarenus"
*†"Liocerithium"
*†"Liochlamys"
*†"Liocium"
*†"Lioglyphostoma"
*†"Liomesus"
*†"Liopeplum"
*†"Liospira"
*†"Liotella"
* "Liotia"
*†"Liotina"
*†"Lippistes"
*†"Liracassis"
*†"Liracraea"
*†"Lirastrombina"
*†"Lirasyrinx"
*†"Liratilia"
*†"Liratomina"
*†"Lirobittium"
*†"Lirocingula"
*†"Lirofusus"
*†"Lironoba"
*†"Lirosoma"
*†"Lirularia"
*†"Lisbonia"
*†"Lischkeia"
*†"Lispodesthes"
*†"Lissapiopsis"
*†"Lissochilus"
*†"Lissomuricopsis"
*†"Lissospira"
* "Lissotesta"
* "Lissotestella"
*†"Lithoconus"
*†"Lithophysema"
* "Lithopoma"
*†"Lithotrochus"
* "Litiopa"
* "Littoraria"
* "Littorina"
*†"Littorinides"
*†"Littorinolacuna"
*†"Littorinopsis"
*†"Littorniscala"
* "Livonia"
*†"Lodanaria"
* "Lodderena"
*†"Lodderia"
*†"Lomia"
*†"Lomirosa"
*†"Longchaeus"
*†"Longicerithium"
*†"Longoconcha"
*†"Longstaffia"
*†"Lophioturris"
*†"Lophocochlias"
*†"Lophonema"
*†"Lophospira"
* "Lottia"
*†"Lowenstamia"
*†"Loxisonia"
*†"Loxobidens"
*†"Loxonema"
*†"Loxoplocus"
*†"Loxoptyxis"
*†"Loxotaphrus"
*†"Loxotoma"
* "Lucapina"
* "Lucapinella"
*†"Lucerapex"
*†"Lucidestea"
*†"Luciella"
*†"Luciellina"
* "Lunatia"
*†"Lunatica"
*†"Lunella"
*†"Lunulazona"
*†"Lupira"
*†"Luponovula"
*†"Luria"
*†"Lutema"
*†"Lutima"
*†"Lydiphnis"
*†"Lyncina"
*†"Lyosoma"
*†"Lyria"
*†"Lyrianella"
*†"Lyrischapa"
*†"Lyromangelia"
*†"Lyropurpura"
*†"Lyrosurcula"
*†"Lyrotyphis"
*†"Lysiogyrus"
*†"Lysis"
*†"Lytospira"

O

*†"Oamaruia"
*†"Obex"
*†"Obexomia"
*†"Obornella"
* "Obtortio"
*†"Obtusella"
* "Ocenebra"
*†"Ochetochilus"
*†"Ochetoclava"
*†"Ocinebrellus"
*†"Ocinebrina"
*†"Odetta"
*†"Odoardia"
*†"Odontobasis"
*†"Odontofusus"
*†"Odontomaria"
*†"Odontopolys"
*†"Odontopurpura"
*†"Odontoturbo"
*†"Odostomella"
* "Odostomia"
*†"Odostomidea"
*†"Oehlertia"
* "Oenopota"
*†"Offleya"
*†"Offlyeotrochus"
*†"Ogivia"
*†"Okinawavoluta"
*†"Olequahia"
*†"Oligoptycha"
*†"Oligoptyxis"
* "Oliva"
*†"Olivancillaria"
* "Olivella"
*†"Olivia"
*†"Olivula"
*†"Olssonella"
*†"Omalaxis"
* "Omalogyra"
*†"Omanimaria"
*†"Omogymna"
*†"Omospira"
*†"Omphalius"
*†"Omphalonema"
*†"Omphaloptycha"
*†"Omphalotrochus"
*"Omphalotropis"
*†"Oncochilus"
*†"Ongleya"
*†"Oniscidia"
*†"Onkospira"
*†"Onoba"
* "Oocorys"
*†"Ooliticia"
*†"Oonia"
*†"Oostrombus"
*†"Ootomaria"
*†"Ootomella"
* "Opalia"
*†"Opaliopsis"
*†"Opella"
*†"Ophileta"
*†"Ophiletina"
* "Ophiodermella"
*†"Opimilda"
*†"Opisthonema"
*†"Optoturris"
* "Orbitestella"
*†"Orecopia"
*†"Orectospira"
*†"Orinella"
*†"Ormastralium"
*†"Ornamentaria"
*†"Ornatoptygmatis"
*†"Ornatospira"
*†"Ornopsis"
*†"Orospira"
*†"Orthaulax"
*†"Orthochetus"
*†"Orthochilus"
*†"Orthonema"
*†"Orthonychia"
*†"Orthoptyxis"
*†"Orthostomia"
*†"Orthosurcula"
*†"Osilinus"
*†"Ossiania"
*†"Ostioma"
*†"Otatara"
*†"Otollonia"
*†"Otomphalus"
*†"Otopleura"
*†"Otostoma"
*†"Ottoino"
*"Otukaia"
*†"Ovactaeonina"
*†"Ovatipsa"
*†"Ovilia"
*†"Ovinotis"
*†"Ovirissoa"
*†"Ovulactaeon"
*†"Ovulopsis"
*†"Owenella"
*†"Oxyacrum"
*†"Oxycypraea"
*†"Oxygyrus"
*†"Oxymeris"
*†"Oxyspira"
*†"Oxystele"
*†"Ozarkina"
*†"Ozarkispira"
*†"Ozodochilus"

R

*†"Rabicea"
*†"Radinista"
*†"Raha"
*†"Raincourtia"
*†"Ramina"
* "Ranella"
*†"Ranellina"
*†"Rangimata"
*†"Ranularia"
* "Rapana"
*†"Raphischisma"
*†"Raphispira"
*†"Raphistoma"
*†"Raphistomina"
*†"Raphitoma"
*†"Rapopsis"
*†"Ratifusus"
*†"Raulinia"
*†"Ravitrona"
*†"Ravnostomia"
*†"Rectiplanes"
*†"Recurvina"
*†"Redocla"
*†"Remera"
*†"Remnita"
*"Renea"
*†"Reticulacella"
*†"Reticuloturris"
*†"Retiopustula"
*†"Retipirula"
*†"Retispira"
*†"Retizafra"
* "Retusa"
*†"Reymentella"
*†"Rhabdocolpus"
*†"Rhabdoconcha"
*†"Rhabdotocochlis"
*†"Rhaphischisma"
*†"Rhaphistomella"
* "Rhinoclavus"
*†"Rhinoderma"
*†"Rhizorus"
*†"Rhombella"
*†"Rhomboidestoma"
*†"Rhombopsis"
*†"Rhombostoma"
*†"Rhopalites"
*†"Rhynchocerithium"
*†"Rhynchocypraea"
*†"Rhytidopilus"
*†"Ricinella"
* "Rictaxis"
*†"Rigauxia"
*†"Rimella"
*†"Rimosodaphnella"
* "Rimula"
*†"Rimulopsis"
*†"Rinaldoconchus"
*†"Rinaldomphalus"
* "Ringicula"
*†"Ringiculella"
*†"Ringiculina"
*†"Ringiculocosta"
*†"Ringiculopsis"
*†"Ringiculoptycha"
*†"Ringiculospongia"
*†"Ringinella"
*†"Ripleyella"
*†"Risella"
*†"Risellopsis"
*†"Risselloidea"
* "Rissoa"
*†"Rissocerithium"
* "Rissoina"
*†"Rissolina"
*†"Rissomangelia"
*†"Rissopsetia"
*†"Ritena"
*†"Riuguhdrillia"
*†"Robus"
*†"Rochia"
*†"Rolandomphalus"
*†"Rollandiana"
* "Roperia"
*†"Rossiteria"
*†"Rostellaca"
*†"Rostellana"
*†"Rostellaria"
*†"Rostellinda"
*†"Rostreulima"
*†"Rostrocerithium"
*†"Rotadiscoides"
*†"Rothpeltzia"
*†"Rothpletzella"
*†"Rousseauspira"
*†"Roxania"
*†"Roxaniella"
* "Roya"
*†"Ruedemannia"
*†"Rufilla"
*†"Rugatiscala"
*†"Rugiferia"
*†"Rugobela"
*†"Rugotyphis"
*†"Rugulina"
*†"Rumerloella"

U

*†"Uberella"
*†"Uchauxia"
*†"Ulfa"
*†"Ulrichospira"
*†"Umbilia"
*†"Umbonellina"
* "Umbonium"
*†"Umbospira"
*†"Umbotrochus"
*†"Umbotropis"
* "Umbraculum"
*†"Umpquaia"
*†"Undiscala"
*†"Undulabucania"
*†"Undularia"
*†"Unedogemmula"
*†"Unicarinata"
*"Unitas"
*†"Upella"
*†"Urceolabrum"
*†"Urgonella"
*†"Urkutitoma"
*†"Uromitra"
* "Urosalpinx"
*†"Uttleya"
*†"Uvanilla"
*†"Uxia"
*†"Uzita"

X

* "Xancus"
*†"Xanthochorus"
*†"Xenogalea"
*†"Xenophalium"
* "Xenophora"
* "Xenotrophon"
*†"Xenuroturris"
*†"Xestosurcula"
*†"Xizangospira"
*†"Xuwenospira"
*†"Xymene"
*†"Xymenella"
*†"Xystrella"

References

*Sepkoski, J.J., Jr. (2002). A compendium of fossil marine animal genera. "Bulletins of American Paleontology" 364, 560 p.
* [http://strata.geology.wisc.edu/jack/ Sepkoski's Online Genus Database]