Abstract

Condonts were examined from over 150 samples from Lower, Middle, and Upper Ordovician strata using collections of the Geological Survey of Canada and J. C. Sproule and Associates Ltd., Calgary. The samples were collected from the Franklinian Miogeosyncline (Bathurst, Devon and Ellesmere Islands), Foxe Basin and northwest Baffin Island, and the northern part of Hudson Bay Basin. All principal formations were sampled; 85 per cent of samples were productive, yielding about 7,000 specimens.

Most of the 17 Ordovician conodont faunas known in North America have been recognized. Early Canadian faunas (Copes Bay Formation) are sparse. Late Canadian faunas (Baumann Fiord, lower Eleanor River and Ship Point Formations) are dominated by scolopodans in shallow water facies, but deeper water faunas are intercalated. Greater diversity of conodonts is apparent in the early Middle Ordovician (Bay Fiord, upper Eleanor River and Ship Point Formations), with new species of Oulodus, Phragmodus, Belodella, and some new genera. Panderodans and belodinans, with several new species, characterize upper Middle Ordovician strata (Thumb Mountain Formation). Atlantic Province conodonts form a significant proportion of the Late Ordovician faunas, especially from strata bearing the Arctic Ordovician megafauna (Irene Bay, Baillarge and Allen Bay Formations, and Churchill River Group). The presence of Amorphognathus ordovicicus Branson & Mehl demonstrates the Irene Bay Formation to be no older than early Maysvillian in some parts of the Canadian Arctic Islands.

Formation ages have been confirmed and, in some instances, defined with greater precision. Their rapid evolution and almost ubiquitous occurrence make conodonts one of the most useful fossils for Ordovician biostratigraphy in the Canadian Arctic.