New brachiopod genera from Bird Fiord Formation (Devonian), arctic Canada

Brachiopods are common in the lower part of the late Early to Middle Devonian Bird Fiord Formation that is a carbonate-clastic transition Succession found in Arctic Canada. These brachiopods, which lived in a shallow, near-shore, marine environment, includes three new genera: Borealistrophia, Arcticastrophia, and Grintiellathyris. The strophornenid Borealistrophia, which is characterized by two pairs of straight side septa, prominent and thick socket ridges, a thick but short median septum, and a cordate ventral Muscle field, is found in the Baad Fiord. Blubber Point, and Norwegian members on Bathurst. Devon, North Kent, and Ellesmere islands. The strophornenid Arcticastrophia, which is distinctive because of its Stout transmuscle septa. its narrow and low medium septum, and elevated ventral Muscle held. is found in the Baad Fiord Member on Bathurst and Devon islands. The athyridid Grinnellathyris, which is characterized by an imperforated cardinal plate and inverted U-shaped jugum, is found in the Baad Fiord Member on Bathurst, North Kent. and Devon islands. The similarities between Grinnellathris and Johnsonathyris Savage, Eberlein. and Churkin, 1978, in terms of their shelf size and internal structures. play indicate that the latter evolved from the former.