New dinoflagellate cyst species of the Areoligeraceae, Ceratiaceae, Gonyaulacaceae, and Peridiniaceae from the Santonian–Campanian (Upper Cretaceous) of the Nanaimo Group, British Columbia, Canada

Abstract

This is the first study of the late Santonian–early late Campanian dinoflagellate cyst assemblages from the Nanaimo Group strata along eastern Vancouver Island and Denman Island, British Columbia. Four new dinoflagellate cyst species are reported from twenty samples recovered from six localities from the Haslam, Trent River, and Cedar District formations: Alterbidinium? fusiforme sp. nov., Canningia grahamii sp. nov., Nematosphaeropsis snunymuxwensis sp. nov. and Odontochitina kwutlkwuensis sp. nov. Emended diagnoses are proposed for the genera Alterbidinium and Odontochitina, and each of the new species are presented in high resolution scanning electron microscopy images which extend the parameters of morphologies previously recognized as occurring within the families Areoligeraceae, Ceratiaceae, Gonyaulacaceae, and Peridiniaceae. These taxa carry biostratigraphic utility within a temporally constrained interval for the Late Cretaceous toward correlation with other regions in the Northern Hemisphere as well as applications for paleoenvironmental interpretations drawing from their relative and absolute abundances.