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.