Lenz et al., 2007
From dinoflaj3
Lenz, O.K., Wilde, V., Riegel, W. and Heinrichs, T., 2007: Distribution and paleoecologic significance of the freshwater dinoflagellate cyst Messelodinium thielepfeifferae gen et. sp. nov. from the Middle Miocene of Lake Messel, Germany. Palynology, v.31, p.119-134, pl.1-4.