Geiselodinium tyonekensis sp. nov., a dinoflagellate cyst from the nonmarine tertiary (miocene) of Alaska

Abstract The peridinoid dinoflagellate cyst Geiselodinium tyonekensis sp. nov. is described from samples in several wells in the Cook Inlet Basin, Alaska. The portion of the wells from which the cysts were recovered is within the Tyonek Formation, considered to be Miocene in age. The Tertiary sediments in the Cook Inlet Basin are considered to be of terrigenous origin.