Proconchidium brodeurensis n. sp. occurs 212 m above the base of member B of the Baillarge Formation on Brodeur Peninsula, Baffin Island, 8 m below the Ordovician–Silurian boundary. Study of Proconchidium shows that it can be easily distinguished from Eoconchidium but possesses many characters that are similar to those in Tcherskidium. Analysis of internal structures suggests that the three genera can be distinguished from each other and belong to Virgianidae. Tcherskidiidae is a synonym of Virgianidae and should be abandoned.This represents the first recorded occurrence of Proconchidium in North America. Although this genus and its related genera Tcherskidium Sapelnikov, 1972, and Eoconchidium Rozman, 1967, are common in Ashgill strata of Eurasia, they have not been recorded or illustrated from North America. This led to the suggestion that distinct brachiopod biogeographic provinces may have existed during the Ashgill. The occurrence of these genera probably indicates that they may have lived in mostly tropical and subtropical zones.
Supplementary material to "Episodic Neoglacial expansion and rapid 20th Century retreat of a
small ice cap on Baffin Island, Arctic Canada and modeled
temperature change"