Miocene dinocysts from Deep Sea Drilling Project Leg 81, Rockall Plateau, eastern North Atlantic Ocean.

Abstract

The biostratigraphic occurrences of dinoflagellate cysts from the Miocene sediments of DSDP Leg 81 are documented using 38 fossiliferous samples from Holes 555, 553A, 552, 552A, 554, and 544A, Rockall Plateau, eastern North Atlantic Ocean. Lower Miocene dinocysts were recovered from Hole 555, middle Miocene dinocysts from Holes 555 and 553A, and upper Miocene dinocysts from Holes 555, 552, 552A, 554, and 554A. In the middle Miocene, important species at Leg 81 sites include 'Nematosphaeropsis' aquaeducta (lowest and highest occurrences within the middle Miocene), Tectatodinium simplex n. comb. (lowest occurrence within the middle Miocene), Danea sp. (lowest and highest occurrences). Labyrinthodinium truncatum (lowest and highest occurrences), Hystrichostrogylon sp. (lowest occurrence), Batiacasphaera sp. I (highest occurrence), Invertocysta tabulata n. gen., n. sp. (lowest occurrence), Invertocysta lacrymosa n. gen., n. sp. (lowest occurrence), Operculodinium sp. of Jan du Chene (lowest occurrence), Incertae sedis sp. I (lowest occurrence), Fibrocysta? fusiforma n. sp. (lowest occurrence), and Pentadinium laticinctum (highest occurrence). In the upper Miocene, important species from Leg 81 sites include: Incertae sedis sp. II (lowest occurrence), Fibrocysta? fusiforma n. sp., (highest occurrence), and Incertae sedis sp. I (highest occurrence). Invertocysta tabulata n. gen., n. sp. reveals a unique and well-developed paratabulation. -Author