CONICET | Buscador de Institutos y Recursos Humanos

The Levipustula Fauna (included in the Levipustula levis Zone), is a relatively diversified fossil assemblage composed of brachiopods, bivalves, bryozoans, gastropods and crinoids. This fauna appears usually associated to glaciomarine sequences related to the Carboniferous glacial event that affected the southeastern Gondwanan margin. The Levipustula Fauna has been identified in different stratigraphical sections (i.e. Hoyada Verde, La Capilla, Leoncito and Yalguaraz) inside of the Calingasta-Uspallata Basin. The Hoyada Verde Formation, herein proposed as a key section, encloses the most complete record of the Levipustula Fauna. A detailed compositional, taphonomic and palecological study in this section allows to propose: the Intra-glacial Levipustula Fauna, located in the lower part, interbedded with diamictitic horizons, and the Post-glacial Levipustula Fauna, located in the upper part of section. Features of the Intra-glacial Levipustula Fauna, scarce, poorly diversified and very scattered, suggest environmental stress conditions probably related to the low temperatures associated to the glaciar proximity. In comparison, the Post-glacial Levipustula Fauna, relatively more abundant and diverse, exhibits composition faunal variations related to paleoenvironmental changes associated to the bottom type and food supply, such as those identified in modern ecosystems. The identification of the Intra-glacial Levipustula Fauna and the Post-glacial Levipustula Fauna can constitute a new tool to understand the particular relationship between the faunal assemblages and the climatic variations linked to the glaciation in the Calingasta-Upallata Basin. Also, the new Intra-glacial Levipustula Fauna identified in the Hoyada Verde Formation would have biostratigraphical and paleogeographical implications in the intra and inter basinal correlation.