Revisions of conodont biostratigraphy across the Silurian-Devonian boundary

Abstract

The current conodont biozonation near the Silurian/Devonian boundary includes problematic biozones and is revised. Global applications of the zonal concepts concerning the current standard conodont zones eosteinhornensis, remscheidensis, detorta, and woschmidti are revised. New correlations are based on conodont faunas from the Požáry section (the stratotype of the Přd̂oli Series, Barrandian) and the Elbersreuth Orthoceratid Limestone (Frankenwald); they enable correlations with Baltic conodont faunas. The new data show that the eosteinhornensis Zone s.s. begins amid the Přídolí. The Delotaxis "detorta" plexus is not limited to the final Přídolí because it enters before the eosteinhornensis Zone. Accordingly, the use of a detorta Zone for global correlation is not recommended. The type stratum of the very particular Icriodus woschmidti is much younger than the entry of Icriodus postwoschmidti in Podolia. A succession of a woschmidti Zone and a postwoschmidti Zone in the early Lochkovian is problematic. Three new spathognathodontid species with stratigraphic potential: Zieglerodina? ivochlupaci sp. nov., Zieglerodina? klonkensis sp. nov. and Zieglerodina? zellmeri sp. nov. are described.