Cambrian Multichambered Foraminifera from the Halifax and Goldenville Groups of the Meguma Supergroup, Nova Scotia

Abstract

Foraminifera in the Cambrian are rare; only ten genera have been recorded and these were all simple tubular and branching unilocular forms found in West Africa. The discovery of an organic lens within the Goldenville Group by amateur collector Colin Corkum and articulate brachiopods within the Halifax Group by Armgard Zentilli, provided sample locations for the study. Both locations yielded multichambered foraminifera. The Halifax Group specimens were made up of Trochammina in a monospecific assemblage, with one specimen identified to species level as Trochammina macrescens (Brady). The Goldenville Group yielded specimens of Trochammina as well as Ammotium and Haplaphragmoides. The Halifax and Goldenville Group assemblages are not only the oldest foraminiferal community discovered, they also are the oldest multichambered foraminiferal find, existing in the mid-Cambrian some 50-60 million years before Reophax blackriveranus, in the mid-Ordovician. The presence of Trochammina macrescens, a shallow marine species, in a formation interpreted on sedimentological grounds as deep sea turbidites requires further investigation.