Running across the Silurian/Devonian Boundary along Northern Gondwana: A Conodont Perspective

The Global Stratotype Section and Point (GSSP) of the Silurian/Devonian boundary, Lower Devonian Series Lochkovian Stage was formally placed in 1977 at Klonk, Czech Republic, first appearance graptolite Uncinatograptus uniformis (Přibyl). However, since then, correlation this limit has been often hampered carbonate facies where graptolites are uncommon or totally absent. A large calcareous deposition occurred boundary along northern peri-Gondwana margin, thus representing an ideal location to select test a possible additional biostratigraphic marker among conodonts. Caudicriodus hesperius almost simultaneously base Bohemia, Carnic Alps, Sardinia, Morocco elsewhere indicates that taxon is conodont best approximates beginning Period. last other species (e.g., Ozarkodina confluens, Zieglerodina klonkensis, Z. remscheidensis woschmidti) may help recognise as well.