Brachiopods from Bird Fiord Formation (Devonian) of Arctic Canada

Abstract

The upper Lower to Middle Devonian Bird Fiord Formation (late Emsian to late Eifelian) is a carbonate–siliciclastic succession, up to 900 m thick, that contains a diverse brachiopod-dominated fauna. Twenty-two species belonging to 21 genera have been recognized from the collection of more than 45 000 specimens, among which the atrypids form 52% of the biota, spiriferids ~13%, orthids ~8%, productids ~3%, rhynchonellids ~2%, terebratulids ~1%, and the strophomenids, pentamerids, and athyridids each <1%. Spinatrypina, Schizophoria, Elythyna, Desqumatia (Independentrypa), Cupularostrum, and Atrypa that collectively form more than 80% of the brachiopod biota. The following species are described here: Schizophoria (Schizophoria) sulcata, Ivdelinia grinnellensis, Cupularostrum repetitor, Hypothyridina cf. bifurcata, Atrypa sp., Emanuella bisinuata, Elythyna sverdrupi, Perryspirifer scheii, Costacranaena marlenae. Despite its endemic character, the brachiopod fauna from the Bird Fiord Formation of Arctic Canada can be assigned to the Old World Realm. Its strong affinity to Europe and western Canada supports the notion that, during the Devonian, faunal exchanges between Europe and North America took place via Arctic Canada.