Planinosphaeridium membranaceum

"*membranaceum" Eisenack, 1965b, p.151, pl.14, fig.4; pl.15, fig.6; text-fig.1.  Holotype: Eisenack, 1965b, pl.14, fig.4; text-fig.1; Jan du Chêne et al., 1986a, pl.80, figs.4–7.  NOW Pentadinium.  Originally Planinosphaeridium, subsequently (and now) Pentadinium.  Taxonomic junior synonym: Ataxiodinium choane, according to Dale (1976, p.45; footnote to table II) — however, Edwards and Andrle (1992, p.265) retained Ataxiodinium choane.  Motile equivalent: Gonyaulax spinifera (Claparède and Lachmann, 1859) Diesing, 1866, according to Dale (1976, table 2 — p.45).  Age: late Eocene–early Oligocene.

Parent: Planinosphaeridium