Geiselodinium micropodum (Yu Jingxian et al., 1981) Chen et al., 1988; Emendation: Mao Shaozhi et al., 1995, p.50-51, as Sanshuia micropoda.

Now Saeptodinium. Originally (and now) Sanshuia, subsequently Geiselodinium, thirdly Saeptodinium.

Holotype: Yu Jingxian et al., 1981, pl.1, fig.3
Age: Late Cretaceous

Sanshuia micropoda gen. et sp. nov.
Description: Outline subpentagonal, with conspicuous lateral protrusion. Periphragm thin. Endocyst elliptical, filling entire periphragm. Separation only at apical and antapical horns. Surface rough or finely granulate. Upper test triangular, with side conspicuously or slightly protruding; height of 27.6 - 29 µm. Apical horn conical, 3 - 4 µm high, with circular pore at end. Lower test trapezoidal, 20 - 23 µm high. Antapical horns slightly developed and acicular in appearance; line connecting the two is straight. No indication of tabulation. Archaeopyle unclear. Cingulum annular, 4 - 6 µm wide, broadening at both ends, decorated on edge with a narrow undulate ridge. No sulcus observed. 1 - 2 "nuclei" appear near ventral section.
Size: Cysts 50.6 µm long and 39.1 µm wide. Holotype 50.6 x 39.1 µm.

Discussion: This species is distinguished from others in the genus by its slightly developed antapical horns.