The aim of this work is to begin: in a systematic way, the aplication of teeth, ichthyodorulites and scales of fish in the strayigraphy. New tecntcs of morphologic descriptions and sistematizaton were created to permit a more efictent and adequate stratigraphical work. In the other hand It is started their aplication in the study of the Passa Dois Group. It is described the ichthyodonts and ichthyodorulites of Estrada Nova Formation and, parcely, of Irati Formation.