Paleontologia y ambientes del Triásico Medio en el sector noroccidental de la Cordillera Ibérica (provs. de Soria y Guadalajara, España)

Abstract

The Triassic of the NW Iberian Ranges consists of two carbonatic formations equivalent to the Upper Carbonatic Formation of the Muschelkalk Facies and pass laterally into siliciciastic deposits to the NW. Fossillocalities have been found in both formations. Taphonomic and sedimentologic studies allow for the interpretation as autochthonous associations of the infaunal Bivalves of shallow water marine environments with siliciciastic input. Three faunal associations have been distinguished: 1. Costatoria-Lyriomyophoria association, found in the lower carbonatic formation and the equivalent siliciciastic formation; 2. «Teruel Fauna» association, found in the upper carbonatic formation; 3. Lingula-Pseudocorbula association, found near the top of the upper carbonatic Formation. The «Teruel Fauna» is well represented in the Iberian Ranges, and always occur in the «Royuela Marls and Limestones» Formation, and our fossil localities are its most Northwestern record in the Iberian Ranges up to now, thus extending the presence of the endemic «Sephardic Faunas» during the Ladinian.