Abstract

Sphaeroschwagerina faunas are well known from the Ural, Arctic and Tethyan fusulinacean biogeographic provinces, but they are absent from the Middle Cordilleran and Midcontinent-Andean provinces. Representatives of Sphaeroschwagerina from the lower part of the Tanquary Formation in the Sverdrup Basin include Sphaeroschwagerina glomerosa (Schwager) [=S. sphaerica (Scherbovich)], S. pavlovi (Rauser-Chernousova), and S. sp.; these are associated with Eoparafusulina paralinearis (Thorsteinsson) and Triticites? sp. All these taxa first appeared in the middle and upper Asselian where they flourished. Although Sphaeroschwagerina glomerosa extends into the lower Sakmarian in Timan-Pechora, all other occurrences of Sphaeroschwagerina in the Ural and Arctic provinces are confined to the Asselian. Thus strata containing species of Sphaeroschwagerina in the lower part of the Tanquary Formation are undoubtedly of late Asselian age and can be correlated with the Sphaeroschwagerina sphaerica (=S. glomerosa)-Schwagerina firma zone and its equivalents in the Russian Platform, the Urals, Darvas, Timan, Fergana, China, Thailand, Japan, Southern Alps, Greenland and Spitsbergen. Considering the extremely low diversity of Schwagerinidae and the presence of the endemic Eoparafusulina paralinearis in the Sphaeroschwagerina fauna in the Sverdrup Basin, it appears that the Arctic area, including the Canadian Arctic Archipelago. Greenland and Spitsbergen constituted a single fusulinacean biogeographic province during late Asselian time.