Microdinium opacum
From dinoflaj3
opacum Brideaux, 1971, p.76–77, pl.21, figs.19–22; text-figs.7d–e. Holotype: Brideaux, 1971, pl.21, figs.21–22; text-figs.7d–e. Originally (and now) Microdinium, subsequently Phanerodinium. Lentin and Williams (1989, p.245) retained this species in Microdinium. Taxonomic junior synonym: Microdinium spinosum, according to Below (1987b, p.38). Below (1987b, p.39) considered Microdinium (as Phanerodinium) distinctum to be the questionable taxonomic senior synonym of this species. Age: middle-late Albian.
