Early Jurassic Caenogastropoda and Architectibranchia from the Neuquén Basin, Argentina

Abstract

AbstractEarly Jurassic marine gastropods are well represented in Argentina by three major taxa: Vetigastropoda, Caenogastropoda and Architectibranchia (=Opisthobranchia). The present paper aims at the description of six new caenogastropod species and one new architectibranch species from the Early Jurassic marine deposits of the Neuquén Basin, namelyProcerithium subimbricatumn. sp.,Microschiza weaverin. sp.,Naricopsina aequabilisn. sp.,Naricopsina ballentaen. sp.,Pictavia rothin. sp.,Oonia acutan. sp., andCylindrobullina brevispiran. sp. Seven other caenogastropods are reported for the first time in the area, includingCryptaulax redeliiFerrari,Procerithium nulloi(Ferrari),Rhabdocolpus patagoniensis(Ferrari),Rhabdocolpus? sp.,Pseudomelania feruglioiFerrari,Pseudomelaniaaff.baugieriana(d’Orbigny), andAnulifera chubutensisFerrari, extending their palaeobiogeographical distribution to the Andean region of Argentina during the Early Jurassic. Caenogastropods such asGlobularia catanlilensis(Weaver) andMicroschiza?americana(Möricke), and the architectibranch speciesStriactaeonina transatlantica(Behrendsen) andCylindrobullina ovata(Behrendsen) are redescribed and discussed based on new specimens from the type and other localities. The new fossils described here expand the known diversity of the gastropod faunas in the Early Jurassic of Argentina and contribute to the paleontological knowledge of the group in the Mesozoic of South America.