A microfauna associated with Early Cambrian trilobites of the Callavia Zone, norther Antigonish Highlands, Nova Scotia

Abstract

Trilobites of the Callavia Zone s.l. occurring together with phosphatic fossils in the Little Hollow Formation are the 1st known Early Cambrian faunas from mainland Nova Scotia. The tectono-stratigraphic affinity of the northern Antigonish Highlands with less intensely deformed portions of the Avalonian Platform is indicated by the Avalonian character of the trilobites and Early Ordovician brachiopods; the nature of the lithologic sequence of the Iron Brook Group and local evidence for a Hadrynian orogeny. Rhombocorniculum cancellatum (Cobbold 1921) comb. nov. [Helenia cancellata] is here informally designated a pseudoconodont, based on its unique histology and is regarded as a conodontophorid-like organism. Eccentrotheca kanesia gen. et sp. nov. is a multiplated organism with apparent abilities to groups regarded as mitrosagophorans. Sunnaginia imbricata Missarzhevsky and possibly Turcutheca occur in strata younger than Tommotian (lowest Lower Cambrian).