New organic-walled dinoflagellate cysts from the Cenomanian to Maastrichtian of the Trunch borehole, UK

Abstract. A high-resolution palynological study of Cenomanian to Maastrichtian chalks from the Trunch borehole (southeastern UK) has revealed twelve new species and one new subspecies of organic-walled dinoflagellate cysts: Alterbidinium ioannidesii sp. nov., Cassiculosphaeridia alta sp. nov., Chatangiella eminens sp. nov., Cordosphaeridium catherineae sp. nov., Eatonicysta exilis sp. nov., Eatonicysta? mutabilireta sp. nov., Hystrichostrogylon robustum sp. nov., Membranilarnacia wilsonii sp. nov., Nelsoniella incomposita sp. nov., Odontochitina diducta sp. nov., Spiniferites jarvisii sp. nov., Spiniferites multispinulus sp. nov. and Spiniferites ramosus aquilus subsp. nov. Two new genera, Dimidium gen. nov. and Whitecliffia gen. nov. are described to necessitate the new combinations (with a former name in parentheses) of Dimidium striatum gen. et comb. nov. (Pterodinium? striatum) and Whitecliffia spinosa gen. et comb. nov. (Thalassiphora? spinosa).