Saeptodinium sphaericum (Yu Jingxian et al., 1981, p.259, pl.1, figs.1–2,6) Lentin and Williams, 1989, p.325. Emendation: Mao Shaozhi et al., 1995, p.52, as Sanshuia sphaerica.

NOW Sanshuia. Originally (and now) Sanshuia, subsequently Geiselodinium, thirdly Saeptodinium.
Holotype: Yu Jingxian et al., 1981, pl.1, fig.1
Age: Late Cretaceous

Sanshuia sphaerica gen. et sp. nov.
Description: Cysts spherical, subcircular. Periphragm thin, about 0.5 µm thick. Endocyst subcircular, filling entire periphragm and separating only at apical and antapical horns. Periphragm has several very slender and irregular creases. Upper test larger than lower test, 27.6 - 29.6 µm high, forming a laterally protuberant triangle. Apical horns in shape of truncated cones or short clubs; bases wide; ends have circular pore. Lower tests trapezoidal, 16.1 - 23 µm high, with two unequal antapical horns, longer ones being about 3 - 4.6 µm, and shorter ones 2.3 µm. No indication of tabulation. No archeopyle. Cingulum annular, concave, 3 - 4.6 µm wide, decorated on edge with narrow microwave-shaped ridge protruding conspicuously beyond the contour line. Sulcus undeveloped, with 2 - 4 brownish-yellow "nuclei" near the ventral section.
Size: Cysts 48.3 - 55.2 µm long and 46 - 52 µm wide. Holotype 48.3 - 49 µm.

Discussion: This species is distinguished from others of the same genus by its spherical and subcircular outlines and the near equivalency of length and width. Figures 1, 3 and 4 of Plate 2 in the book "Early Tertiary Dinoflagellates and Acritarchs in the Coastal Region of the Bo Hai" would seem to be properly assigned to this species.