Carboniferous bivalves from the La Capilla Formation in the Las Cambachas area, San Juan Province, Argentina

CARBONIFEROUS BIVALVES FROM THE LA CAPILLA FORMATION IN THE LAS CAMBACHAS AREA, SAN JUAN PROVINCE, ARGENTINA. A taxonomic analysis of the bivalve fauna from the Carboniferous La Capilla Formation was carried out. La Capilla Formation outcrops are located approximately 300 meters west of Las Cambachas village, San Juan province. Three species of bivalves are described and figured: Phestia sp., Schizodus sp. and Oriocrassatella ? sp. Bivalves are analized from a morpho-functional viewpoint mainly based on shell characters, they are infaunal shallow burrowers. Relationships between morphology and hypothetical life strategies are proposed. Compositional and taphonomic differences between the analyzed fauna from the Las Cambachas section and bivalves from the Las Juntas section are found, probably due to environmental variations. A Late Carboniferous age is suggested for the studied bivalves, in view of their occurrence with brachiopods belonging to the Levispustilla Zone.