Conodonts from the Upper Ordovician – Lower Silurian carbonate platform of North Greenland

Abstract

Samples from Upper Ordovician and Lower Silurian strata of the North Greenland carbonate platform have yielded approximately 16 500 identifiable conodont elements referable to 25 multi-element genera and 71 species and subspecies. A single genus, Pseudobelodella and 17 species and subspecies are new. In addition, 8 informal groups of indeterminate species of Oulodus are described. The Upper Ordovician conodont species can be referred to 'Fauna 12' of the American Midcontinent Province where the presence of Rhipodognathus symmetrius in the late Richmondian is typical of shallow water deposits. The Ordovician-Silurian boundary is difficult to place in this study using conodonts. New conodont zonations are proposed for Lower Silurian shelf and slope biofacies; two new early Llandovery conodont zones are erected in the slope biofacies, the Aspelundia expansa Biozone (?earliest Rhuddanian to early Aeronian) and the Aspelundia fluegeli Biozone (early Aeronian to early Telychian). The Pterospathodus celloni Biozone is shown to be particularly valuable in the correlation of strata of late Llandovery age throughout North Greenland.