Polysphaeridium congregatum
From dinoflaj3
congregatum (Stover, 1977, p.79, pl.3, figs.39–44) Bujak et al., 1980, p.34. Holotype: Stover, 1977, pl.3, figs.39–42. Originally Hemicystodinium, subsequently (and now) Polysphaeridium. Age: middle Oligocene.