Late Triassic-Early Jurassic extensional tectonics in the Neuquén Basin (Argentina). New insights from stratigraphic and structural analyses of the Chachil depocenter (39°S)

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.

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Palynofacies analysis and sedimentary environment of Early Jurassic coastal sediments at the southern border of the Neuquén Basin, Argentina

Journal of South American Earth Sciences ◽

10.1016/j.jsames.2007.06.006 ◽

2008 ◽

Vol 25 (2) ◽

pp. 227-245 ◽

Cited By ~ 17

Author(s):

Ana María Zavattieri ◽

Ulrich Rosenfeld ◽

Wolfgang Volkheimer

Keyword(s):

Sedimentary Environment ◽

Early Jurassic ◽

Coastal Sediments ◽

Neuquen Basin ◽

Southern Border ◽

Neuquén Basin

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Early Jurassic Trochotomidae (Vetigastropoda, Pleurotomarioidea) from the Neuquén Basin, Argentina

Journal of Paleontology ◽

10.1017/jpa.2014.28 ◽

2015 ◽

Vol 89 (2) ◽

pp. 331-345 ◽

Cited By ~ 3

Author(s):

S. Mariel Ferrari ◽

Susana E. Damborenea ◽

Miguel O. Manceñido ◽

Miguel Griffin

Keyword(s):

New Species ◽

Coral Reefs ◽

Adaptive Radiation ◽

New Genus ◽

Early Jurassic ◽

The Family ◽

Two New Species ◽

Neuquen Basin ◽

Local Patch ◽

Neuquén Basin

AbstractTrochotomidae is a small but distinctive extinct family of pleurotomarioidean gastropods characterized by trochiform shells with an elliptical trema. Two new species of trochotomids are described from Pliensbachian deposits in the Neuquén Basin, Argentina. The new genus-group namePlacotomais proposed to replace the pre-occupied nameDiscotomaHaber non Mulsant. The record ofTrochotoma(Trochotoma)protonotialisnew species andTrochotoma(Placotoma)neuquensisnew species in the early Jurassic of Argentina extends the paleobiogeographical distribution of the genus (and the family) to the Southern Hemisphere. The new taxa reported here represent a component of the pleurotomarioidean adaptive radiation that took place in the Tethyan region during the earliest Jurassic. They are related to local patch coral reefs of shallow, open-marine paleoenvironments, agreeing with the known habitat of most species of this family. The group was well represented in the Tethyan region during the Mesozoic, especially during the Jurassic, and the new species represent its southernmost occurrence.

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