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

• Published in: Journal of Paleontology
• Main Authors: Rong-Yu, Li, Jones, Brian
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 2002
• Subjects: Paleontology; Arctic; Canada; Bird Fiord; Baad Fiord; Blubber Point
• Online Access: http://dx.doi.org/10.1017/s0022336000041925; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022336000041925

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 Grinnellathyis. The strophomenid 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 strophomenid Arcticastrophia, which is distinctive because of its stout transmuscle septa, its narrow and low medium septum, and elevated ventral muscle field, 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 Grinnellathyris and Johnsonathyris Savage, Eberlein, and Churkin, 1978, in terms of their shell size and internal structures, may indicate that the latter evolved from the former.