Corculodinium inaffectum, (Drugg, 1978, p.68, pl.3, figs.10-12), Courtinat, 2000, p.173.

Originally Geiselodinium, subsequently Subtilisphaera, thirdly Subtilisphaera?, fourthly (and now) Corculodinium.
Taxonomic junior synonym: Geiselodinium paeminosum, according to Courtinat (2000, p.173).

Holotype: Drugg, 1978, pl.3, fig.10.
Age: Early Kimmeridgian.

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Original description: [Drugg, 1978, p. 68]:

Description:
Cavate cysts with a pentagonal to elliptical outline. The endocyst is circular to elliptical in outline. The pericoel is generally restricted except at the apex where the periphragm forms a broad conical horn. Specimens with a pentagonal outline sometimes exhibit a slightly expanded antapical pericoel and occasionally there is a weak development of two low antapical horns.
A paracingulum about 6 µm wide is often, but not always, present. The paracingulum is delineated by low folds or wrinkles developed on the periphragm. Additional folds are often present but there is no suggestion of any true paratabulation.
The parasulcus is suggested by a break in the paracingular folds.
The endophragm is slightly thicker than the periphragm but both are very thin and smooth to faintly and finely granulate.
No archeopyle has been observed.

Dimensions:
The length ranges from 49 to 62 µm with most specimens being about 55 µm. The width ranges from 42 to 52 µm.