Semicavidinium mitra (Dürr, 1987) Dodkova 1994

Originally Meiourogonyaulax, subsequently Lithodinia, thirdly (and now) Semicavidinium.

Holotype: Dürr, 1987, fig.4, no.3; Dürr, 1988, pl.1, fig.5.
Age: middle Kimmeridgian.

Remarks. Dodkova 1994, p. 28
Dürr (1988, p. 84) mentions the cavation of the species. This is in conflict with the generic diagnosis of "Meiourogonyalllax . With all morphological features this species reveals differences which are considered to be significant at the generic level and did not coincides with any other generic dinocyst diagnosis. That is why it was necessary to errect a new genus Semicavidinium, and being cavate Meiourogonyaulax mitra does not belong in Meiourogonyaulax and requiring generic re-attribution is accepted as type species of the same. The new combination Semicavidinium mitra (Durr, 1987) is proposed. The intraspecific variability of the species is expressed as varying in height sutural and antapical cavities. The Bulgarian specimens coincide completely with description and photos of the German specimens.

Occurrence. Borehole R-1 Junak (depth 1605 m, Tica Fm., Middle Tithonian, Chitinoidella Zone).