A review of rare and less well known extant marine organic-walled dinoflagellate cyst taxa of the orders Gonyaulacales and Suessiales from the Northern Hemisphere

Dinoflagellate resting cysts with rare exception produce the only discrete link between the biology of extant dinoflagellate species and their fossil record. The geological preservability of such cysts allows them to be used for quantitative paleoecological reconstructions, especially in the Quaternary, and for biostratigraphy and the calibration of molecular clocks with the geological record. This contribution reviews and updates the taxonomy of 27 uncommon dinoflagellate cyst species and morphotypes belonging to the orders Gonyaulacales and Suessiales with occurrences in upper Quaternary marine sediments of the Northern Hemisphere. Comparative descriptions and illustrations are provided along with the biological affinity of each taxon where known and lowest stratigraphic occurrence. •25 rare or endemic extant dinoflagellate cyst species and two morphotypes are briefly described and illustrated.•23 belong to the Gonyaulacales and 4 to the Suessiales.•Their stratigraphic ranges are provided.