The Ordovician brachiopod genus Bimuria from the eastern Klamath Mountains, northern California

• Published in: Journal of Paleontology
• Main Author: Potter, A. W.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1990
• Subjects: Paleontology; Yukon; Northwest Territories; Alaska; Siberia
• Online Access: http://dx.doi.org/10.1017/s0022336000018369; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022336000018369

The genus Bimuria Ulrich and Cooper, 1942, is a biogeographically important member of middle and late Ordovician brachiopod faunas of the Callahan–Gazelle area in the eastern Klamath Mountains of northern California. In middle Ordovician deposits the genus is widespread and ranges from Nevada in the west to southwestern Siberia in the east; however, in late Ordovician beds it was previously known only in Sweden and Northern Ireland. In addition to the northern California occurrence reported here, new late Ordovician occurrences are also noted in east-central Alaska–Yukon Territory and Northwest Territories. Three species of Bimuria are described, including the new species, B. californiensis. A preliminary survey of species described in the literature suggests that the ratio of the length of the dorsal adductor field to the length of the elongate area in the brachial valve decreases from middle to late Ordovician species, and thus may be of biostratigraphic value.