Batiacasphaera laevigata, (Smelror, 1988b, p.152-153, figs.10G-H), Feist-Burkhardt and Monteil, 1997, p.40.

Originally Escharisphaeridia, subsequently (and now) Batiacasphaera.
Taxonomic senior synonym: Escharisphaeridia psilata, according to Poulsen (1996, p.80) - however, Feist-Burkhardt and Monteil (1997, p.40) retained Batiacasphaera laevigata.
Taxonomic junior synonym: Escharisphaeridia nuda, according to Prauss in Lentin and Williams (1993, p.213).

Holotype: Smelror, 1988b, fig.10G.
Age: Late Bathonian-Early Oxfordian.

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Original description as Escharisphaeridia: [Smelror, 1988, p. 152]:

Description:
Dinoflagellate cysts generally subspherical in outline, occasionally appearing more ovoidal in shape. The cyst wall is composed of only one layer. The autophragm is smooth, i.e. Iaevigate with no kind of ornamentation visible even when examined with scanning electron microscopy at high magnifications. Evidence of paracingulum or parasulcus has not been observed, and the only indication of paratabulation is expressed by the apical archeopyle and accessory archeopyle sutures, suggesting the presence of 4 apical and 6 precingular paraplates. A sulcal notch formed where lu extends toward the paracingulum to meet ai is a typical feature. Specimens with the operculum in place have not been observed, but the shape of the archeopyle indicates that the archeopyle is of type (4A).

Dimensions:
Length 36-53 µm, width 30-41 µm (19 specimens measured).