Albertiana Research Article: Halobia austriaca in North America with a reappraisal of its distribution across the Carnian-Norian boundary interval at Black Bear Ridge (northeastern British Columbia, Canada)

Albertiana Research Article

McRoberts, C.A. 2021.Halobia austriaca in North America with a reappraisal of its distribution across the Carnian-Norian boundary interval at Black Bear Ridge (northeastern British Columbia, Canada). Albertiana, vol. 46, 13–46.

Abstract – The pelagic pterioid bivalve Halobia austriaca occurs most commonly in earliest Norian deep-marine facies in the Tethyan and circum-Panthalassan realms, including the candidate GSSPs at the Pizzo Mondello (Sicily) and at Black Bear Ridge (British Columbia, Canada) and other localities in Haida Gwaii (western British Columbia), southern Alaska, California and Oregon and questionably in Arctic Alaska. Reported occurrences of H. austriaca from other North American localities are shown to be either misidentifications or based on specimens too poorly preserved for identification. Previous work on the halobiid biostratigraphy at Black Bear Ridge suggested a first occurrence of H. austriaca from bed 18f, at a position coinciding with a major conodont turnover between the lower and middle subdivisions of the Metapolygnathus parvus Subzone of the Primatella primitia conodont Zone, and several meters below the traditionally Norian ammonoid zone of Stikinoceras kerri. Reappraisal of H. austriaca from Black Bear Ridge now places the lower occurrence of the species from bed 22. This revised datum integrated with ammonoids and conodonts, provides for a more parsimonious correlation with the basal-Norian GSSP candidate section at Pizzo Mondello and elsewhere across Panthalassa and Tethys.