Heterosphaeridium difficile
From dinoflaj3
difficile (Manum and Cookson, 1964, p.12–14, pl.3, figs.1–3,7) Ioannides, 1986, p.24. Holotype: Manum and Cookson, 1964, pl.3, fig.1; Fauconnier and Masure, 2004, pl.36, figs.2–4. Originally Hystrichosphaeridium, subsequently Cordosphaeridium? (combination not validly published), thirdly (and now) Heterosphaeridium. Age: Cenomanian.
