New Taxa of Pennsylvanian productide brachiopods from West Central Argentina: Implications for biostratigraphy and palaeobiogeography in the Tivertonia jachalensis-Streptorhynchus inaequiornatus Zone

Abstract

Two new species of productide brachiopods are described from the Carboniferous Quebrada Larga Formation, San Juan Province, in the Río Blanco Basin, Argentina: Brachiosvalbardia archboldi sp. nov. and Coronalosia vergelae sp. nov. These new species increase the known brachiopod diversity of the Tivertonia jachalensis-Streptorhynchus inaequiornatus Zone (TS, Moscovian-Kasimovian?) and contribute to the analysis of its compositional variations and distribution patterns across the central western Argentinian basins (i.e., Western Paganzo, Río Blanco, Calingasta-Uspallata, and San Rafael basins). Analysis of an occurrence database of brachiopods from the TS Fauna, including 22 genera from 13 localities in these basins, were grouped into three major groups that allow the identification of compositional variations along the north-south latitudinal gradient. This diversity pattern is also influenced by environmental features (i.e., bathymetric gradient and nutrient availability) related to the climatic amelioration registered in this part of Gondwana during the late Carboniferous-early Permian interval.