Conodonts of the Middle Ordovician Table Head Formation, western Newfoundland

The transgressive Table Head Formation has been described and sampled from eight localities on Great Northern Peninsula, western Newfoundland. The Table Head sediments all along the westcoast of Newfoundland are comparable, but the thickness of the different units varies considerably. The detailed investigation of the rocks revealed that carbonate accumulation was interrupted by 'catastrophic' downwarps of the shelf. These may be related to the emplacement of the allochthons. Two Phylozones and four local assemblage-zones are defined . The phylozones are based on phylogenetically related species of Histiodella. The speeies from the basal lower Table Head belong to Midcontinent Fauna 4. The North Atlantic Province conodonts from the middle Table Head correlate with Eoplacognathus suecieus Zone and E. suecieus-P. sulcatus Subzone of Scandinavia. The Table Head strata accumulated in lagoonal, shelf (inner-outer) and slope environments. The lateral distribution of conodonts has been directly related to these depositional environments, and a sequence of three biofacies and three subbiofacies is introduced . The conodont fauna is described in multielement taxonomy, and a suprageneric classification is applied. Thirty-five genera and 70 species are described of which two genera and 20 species are new. The Superfamily Panderodontacea Lindström is subdivided into the families Acanthodontidae, Panderodontidae, and the new family Cornuodontidae.