Geiselodinium ovatum (Jiabo, 1978) Chen et al., 1988; Emendation: Mao Shaozhi et al., 1995, p.51, as Sanshuia ovata.

Now Saeptodinium. Originally Deflandrea, subsequently Subtilisphaera, thirdly Sanshuia, fourthly Geiselodinium, fifthly (and now) Saeptodinium.
Holotype: Jiabo, 1978, pl.4, fig.2
Age: Early Tertiary

Sanshuia ovata (Jiabo)
Description: Outline elliptical. Periphragm thin. Endophragm weak. Endocyst elliptical and filling entire periphragm, with separation only at apical and antapical horns, or boundary of endocyst indistinct. Surface granulate. Upper test triangular, with edge slightly convex. Upper test gradually contracting, so that no apical horn is shown. Apical pore circular. Lower test trapezoidal. Edge straight or faintly convex. Antapical horns short and small. No indication of tabulation or archaeopyle. Cingulum annular, about 5 µm wide, decorated on edge with fine ridge. Ventral region has "nuclei".
Size: Cysts 50 - 57.5 µm long and 36.5 - 40 µm wide.

Discussion: This species resembles Subtilisphaera in its elliptical outline, developed cingulum, broadly blunted apical horn and absence of any indication of tabulation or archaeopyle but is also distinguished from it by its left-right symmetry and inconspicuous endocyst. Since the characters observed in Figures 1 - 3 of Plate 4 in "Tertiary Dinoflagellates and Acritarchs in the Coastal Region of the Bo Hai" resemble those of this species, it is improperly assigned to Deflandrea, so a new combination is made here.