Systematics of the gastropods of the Lower–Middle Miocene Cantaure Formation, Paraguaná Formation, Paraguaná peninsula, Venezuela

Publication Type:Journal Article
Year of Publication:2016
Auteurs:Landau, B. M., Da Silva, C. M., Heitz A.
Journal:Bulletins of American Paleontology
Mots-clés:Cantaure Formation, Miocene (Venezuela)

A systematic account of the upper lower–lower middle Miocene upper Burdigalian to lower Langhian gastropod assemblage found in the Cantaure Formation of the Paraguaná Peninsula of Venezuela is given. In this work, 393 species are recorded belonging to 259 genera and subgenera, of which 72 are left in open nomenclature. Five new genera are proposed: Dentimides n. gen., Cantaurea n. gen., Glyptophos n. gen., Torqueoliva n. gen., and Marginocystiscus n. gen. Ninety species are described as new: Agathistoma paraguanensis n. sp., Lithopoma minutum n. sp., Marevalvata basilaevis n. sp., Neritina nunoi n. sp., N. meesi n. sp., N. isabelae n. sp., N. daani n. sp., N. seani n. sp., N. daisyae n. sp., Ochetoclava jungi n. sp., Hemisinus miocenicus n. sp., Charadreon wesselinghi n. sp., Stephopoma ruedigeri n. sp., Teinostoma olssoni n. sp., Solariorbis pilsbryi n. sp., Woodringilla lentiformis n. sp., Cochliolepis costata n. sp., Cyclostremiscus basicostatus n. sp., C. forticarinatus n. sp., Cantaurea mperforata n. sp., Trochita angusticostata n. sp., T. paucicostata n. sp., Macromphalina partimsculpturata n. sp., Erato falconensis n. sp., Polinices jungi n. sp., Elachisina crassilabrata n. sp., Ficus yesimae n. sp., Cerithiopsis (s. l.) wesselinghi n. sp., C. (s. l.) moritzhoernesi n. sp., Seila cantaurana n. sp., Gyroscala cantaurana n. sp., G. lilliputiana n. sp., G. paraguanensis n. sp., Scalenostoma conicum n. sp., Solenosteira (Fusinosteira) primitiva n. sp., Hesperisternia parva n. sp., H. vermeiji n. sp., Antillophos elongatus n. sp., Engoniophos schmidti n. sp., Glyptophos furreri n. sp., Metaphos caribbensis n. sp., Strombinophos pilsbryi n. sp., Colubraria praeprocera n. sp., Metula quasilaevis n. sp., Aesopus faberi n. sp., Costoanachis paraguanensis n. sp., C. lacrima n. sp., Mazatlania parva n. sp., Mitrella longispira n. sp., M. tutata n. sp., Steironepion variabile n. sp., Zanassarina phosiformis n. sp., Dorsina peterjungi n. sp., Nassarius kugleri n. sp., Nanarius gardnerae n. sp., Cymia hodsonorum n. sp., Conomitra cantaurana n. sp., Torqueoliva strictotorquata n. sp., Olivella robustodentata n. sp., O. paucidentata n. sp., Volvarina occultospira n. sp., Marginocystiscus subtilplicatus n. sp., Chelyconus manueltenorioi n. sp., Gradiconus johntuckeri n. sp., Glyptaesopus crocotillus n. sp., G. tuckeri n. sp., Glyphostoma inornatum n. sp., G. pauciornatum n. sp., Euglyphostoma wendelli n. sp., Acmaturris echinata n. sp., Agladrillia labiospinosa n. sp., A. falconensis n. sp., Clathrodrillia jungi n. sp., C. pupaeformis n. sp., C. totocostata n. sp., Globidrillia lanceolata n. sp., G. minutissima n. sp., Fusiturricula capeloi n. sp., Hindsiclava wiedenmayeri n. sp., Knefastia aenigmatica n. sp., K. etteri n. sp., Megasurcula centroamericana n. sp., Gemmula woodringi n. sp., Terebra harzhauseri n. sp., T. apporrecta n. sp., T. kronenbergi n. sp., Strioterebrum sinuosocostatum n. sp., Ringicula collaris n. sp., Atys gravidus n. sp., and Pyrunculus totostriatus n. sp. One species from the lower Pliocene Araya Formation of Cubagua, Venezuela, is described as new: Knefastia cubaguaensis n. sp. The following taxonomic changes are made: Persicula zuliana F. Hodson, 1927, and P. mirandana F. Hodson, 1927, are here considered synonyms, and as first revisers, the name P. mirandana is chosen. Narona wiedenmeyeri [sic] Landau, Petit, Etter, & Silva, 2012, is corrected to N. wiedenmayeri. Vasum quirosense F. Hodson, 1931, is considered a subjective synonym of Vasum haitense (G. B. Sowerby I, 1850). The Cantaure fauna corresponds to both soft and hard bottom habitats. Most of the assemblage suggests fully marine conditions with sandy bottom, coral, and rocky habitat, probably deposited in the shallow subtidal zone. Seagrass communities are conspicuously absent from the Cantaure assemblages. A small cohort of taxa suggests brackish conditions and a few groups of taxa are from fresh water. These are uncommon and usually represented by worn specimens, suggesting some degree of transport from river outflow and possibly lagoonal environments nearby. The importance of the assemblage is highlighted, because it is the richest southern Caribbean Miocene assemblage studied so far, comparable in diversity to the well-documented and roughly coeval Chipola Formation of northwestern Florida. The generic composition is similar to that of other lower Miocene Caribbean assemblages, however, the fauna is highly endemic at the species level, sharing relatively few species with other coeval Gatunian or Caloosahatchian assemblages. As is characteristic of Gatunian faunas, the species are relatively short-lived, with few surviving to the present day. At the generic level, the most striking difference between the Cantaure assemblage and the southern Caribbean present-day faunas is the presence of paciphile genera, that is, genera that during the Neogene had widespread distributions throughout the Pacific and the Atlantic Gatunian biogeographical province, but during or subsequent to the closure of the Central American Seaway became restricted to the Pacific side of their originally wider distributions. Even within extant genera in the tropical American region, the lower Miocene Cantaure species' closest similarities are often found among their Panamic Pacific congeners rather than their Caribbean or western Atlantic ones.

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