Microdinium spinosum

"spinosum" Brideaux and McIntyre, 1975, p.23–24, pl.6, figs.3–5.  Holotype: Brideaux and McIntyre, 1975, pl.6, figs.3–4.  Taxonomic senior synonym: Microdinium (as Phanerodinium) opacum, according to Below (1987b, p.38).  Age: middle Albian.

Parent: Microdinium