Fossil crinoids from the basal West Point Formation (Silurian), southeast Gaspé Peninsula, Québec, eastern Canada

Atlantic Geology

Stephen K. Donovan²  David G. Keighley¹ 

[1] University of New Brunswick, Fredericton;Naturalis Biodiversity Center, Leiden, the Netherlands

关键词: Paleontology;    Crinoids;    Systematics;    Stratigraphy;    Correlation;   

DOI  :  

学科分类：地质学

来源: Atlantic Geoscience Society

【 摘 要 】

Silurian strata of Atlantic Canada and southern Québec locally preserve common fossil crinoids, albeit mostly as disarticulated remains. New crinoids from the Chaleurs Group, West Point Formation (Ludlow to Pridoli?; Upper Silurian) of the Gaspé Peninsula includeIocrinus ?maennili(Yeltysheva) (otherwise known from the Katian of Estonia),Bystrowicrinus(col.)depressussp. nov. andCyclocyclicus(col.) sp. aἀ. C. (col.)echinusDonovan. On the basis of both its gross morphology and stratigraphic position,Iocrinus ?maenniliis unlikely to be an iocrinid disparid, a family that became extinct at the end of the Ordovician. The trivial name has hitherto been erroneously spelled asmännili ,manniliandmjannili . Most specimens of the commonBystrowicrinus(col.)depressusappear cyclocyclic because the pentastellate lumen occurs in a deeply sunken claustrum that is commonly occluded by sediment; clean specimens are highly distinctive.Cyclocyclicus(col.) sp. aἀ. C. (col.)echinusis similar to a species known from the Katian of North Wales. Taken together, this assemblage is more reminiscent of Katian strata (Upper Ordovician). Ḁis is problematic given the current mapping of the outcrop as West Point Formation (Upper Silurian), suggesting further stratigraphic studies in the area are required.

【 授权许可】

Unknown