Original paper

Early/Middle Arenig (Late Floian) Radiolarian Faunal Assemblages from Cow Head Group, Western Newfoundland

Won, Mun-Zu; Iams, William J.


Diverse radiolarians are reported from the D. bifidus graptolite Zone of lower/middle Arenig (upper Floian) strata of the Cow Head Group in Gros Morne National Park, Newfoundland. The radiolarian faunal assemblages come from three localities – St. Paul’s Inlet (SPI) North, Cow Head Peninsula – Point of Head (PH), and Western Brook Pond (WBP) South. They include 7 families, 19 genera and more than 40 species. Among them, seven genera (Cancellisphaera, Cavasphaera, Gigantospiculum, Neoechidnina, Parabeothuka, Sanctipaulelum, Varispiculum) and 26 species are new. Cancellisphaera is the most notable new taxon as it is characterized by the earliest shell with regular latticed meshwork and an internal spicule. Based on species compositions the several faunas from Unit 60 at the SPI section represent the older assemblage, one of which is closely similar to Chewtonian radiolarians from the D. bifidus Zone of the Valhallfonna Formation, Spitsbergen. The younger assemblage from Unit 11. 5 of the PH section and Unit 23f, h of the WBP section, is the first recovered new assemblage.


RadiolariansLower OrdovicianLower/Middle Arenig (Upper Floian)Didymograptellus bifidus ZoneCow Head