Uppermost Ordovician to lowermost Devonian conodonts from the Valentintorl section and comments on the post Hirnantian hiatus in the Carnic Alps

摘要

A detailed biostratigraphic investigation has been carried out by means of conodonts in the uppermost Ordovician-lowermost Devonian sector of the Valentintorl cliff, located in the Austrian part of the Carnic Alps. Biostratigraphic data document in continuity all conodont biozones from the lowermost Ludlow to the upper Pridoli, with such a limited thickness to suggest that the Valentintorl section exposes the most condensed upper Silurian section in the Carnic Alps documented so far. A general discussion on the extension of the hiatus between Ordovician and Silurian sequences in the Carnic Alps is presented. Three new conodont species belonging to genera Cuspigrandiosa, Wurmiella and Zieglerodina are described, but left in open nomenclature awaiting more specimens to be collected.