Abstract

TABOADA, Arturo César. Tivertonia Archbold (Chonetidina, Brachiopoda) from the lower Permian of Calingastauspallata subbasin, argentine Precordillera. Ameghiniana [online]. 2006, vol.43, n.4, pp.705-716. ISSN 1851-8044.

The brachiopods Tivertonia jachalensis (Amos) and Tivertonia leanzai sp. nov. are described and figured. The first comes from the Del Salto and Santa Elena (Jarillal Member) Formations and the second from the Agua del Jagüel Formation in the Calingasta- Uspallata subbasin. Some biostratigraphic and biochronologic considerations about the Tivertonia jachalensis (Amos)-Streptorhynchus inaequiornatus Leanza and Costatumulus amosi Taboada biozones are discussed. Both biozones are considered in stratigraphic contiguity representing the medium Asselian-Tastubian lapse in the Precordillera. The linking of the glacimarine levels intercalated in the Costatumulus amosi biozone of the Agua del Jagüel Formation and the expansion of the lower Permian Glacial Episode record of Gondwana is reaffirmed.

Keywords : Brachiopoda; Tivertonia; Biostratigraphy; Lower Permian; Glacial episodes; Calingasta-Uspallata subbasin; Argentina.