Abstract. Three new calcareous dinoflagellate species from the Middle Coniacian to Upper Santonian chalks of Lägerdorf (northern Germany) are formally described: Calcicarpinum macrogranulum n. sp., Pirumella fragilis n. sp. and Ruegenia quinqueangulata n. sp. The species show differing vertical distribution patterns which might result from local sea-level changes: P. fragilis and R. quinqueangulata are restricted to the possibly transgressive upper Mid-Coniacian to Lower Santonian interval and C. macrogranulum occurs consistently only in the probably regressive lower Mid-Coniacian and Middle to Upper Santonian intervals.