Microdinium dentatum subsp. sphaericum

"subsp. sphaericum" (Vozzhennikova, 1967, p.95-96, pl.36, figs.2a-b; pl.38, figs.1a-b) Lentin and Williams, 1973, p.95.  Emendation: Lentin and Vozzhennikova, 1990, p.115, as Sokolovidinium sphaericum.  Holotype: Vozzhennikova, 1967, pl.38, figs.1a-b; Lentin and Vozzhennikova, 1990, pl.13, figs.5-6; text-fig.67.  NOW Sokolovidinium sphaericum.  Originally Microdinium dentatum forma sphaericum, subsequently Microdinium dentatum subsp. sphaericum, thirdly (and now) Sokolovidinium sphaericum.  Age: Late Cretaceous. Parent: Microdinium dentatum