Mesozoic palynology of svalbard IV. toarcian dinoflagellates from spitsbergen

Well preserved dinoflagellate cyst assemblages from phosphorite pebbles of the Brentskardhaugen Bed (Toarcian) in Spitsbergen are described. They are dominated by a unique species complex of small cysts possessing simple, hexagonal intercalary archeopyles of the Broomea/Moesiodinium‐type. Some of the species reflect the tabulation formula 4–5’, 3a, 6–7 “, 5 ‘”;, 2 “”;. A pareodinoid relationship is suggested. The assemblages present wide morphological variation within an evolutionary lineage not described previously and they may be of importance for the understanding of dinoflagellate evolution. Eighteen species are recorded, nine of which are formally described as new and are referred to four genera also proposed as new: Parvocysta n. gen. (P. bullula n. sp., P. contracta n. sp., P. nasuta n. sp., P. barbata n. sp., ?P. cracens n. sp.), Facetodinium n. gen. (F. faustum n. sp., F. inflatum n. sp.), Ovalicysta hiata n. gen. & sp. and Mikrocysta erugata n. gen. & sp. In addition, six species are described but not formally named.