Problems of the Lower Triassic Conodont Stratigraphy and the Permian-Triassic Bounoa RY

Abstract

During the last few years conodonts have provided valuable tool for zonal subdivision and correlation of Permian and Triassic rocks exposed in different parts of the world. Within the Griesbachian succession of the Tethys, four conodont zones have been established, i.e., Anchignathodus typicalis, Anehignathodus parus, lsarcicella isarcica and Neogondolella carinata. The first appearance of Anchignathodus parvus and Isarcicella isarcica and extinction of the genus lsarcicella are important biological events in conodont biostratigraphy.