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Pseudostephodinium sanshuiense
Pseudostephodinium sanshuiense Yu Jingxian et al., 1981
Holotype: Yu Jingxian et al., 1981, pl.1, fig.34
Age: Late Cretaceous
Description: Outline rhombic, pentagonal, or in shape of a top with lopped-off bottom. Periphragm thin. Endocyst closely appressed to periphragm. Periphragm and endophragm show only on two sides of apex of upper test. Surface is wrinkled. Upper test triangular; sides straight or concave; 27.6 - 30.6 µm high. Apical horn conspicuous, protruding beyond contour line, 4 - 6 µm high; circular pore at end. Lower test rhombic, subtriangular or trapezoidal; 17 - 20.4 µm high. No development of antapical horns. Cingulum annular. Surrounding girdle zone is a wing annulus, ~ - 9.2 µm wide, with fibrously ramified thickening or creases perpendicular to annular edge. Pressure of wing annulus on membrane creates a rhombic [frame-like] decorative wrinkling zone. Sulcus crevice-shaped; apex reaches upper test. No archaeopyle or tabulation observed.
Size: Cysts 44.2 - 51 µm long and 34 - 40.8 µm wide. Holotype 44.2 x 40.8 µm.
Discussion: Because of its unique wing annulus structure, this species is not easily confused with other genera or species.
Holotype: Yu Jingxian et al., 1981, pl.1, fig.34
Age: Late Cretaceous
Description: Outline rhombic, pentagonal, or in shape of a top with lopped-off bottom. Periphragm thin. Endocyst closely appressed to periphragm. Periphragm and endophragm show only on two sides of apex of upper test. Surface is wrinkled. Upper test triangular; sides straight or concave; 27.6 - 30.6 µm high. Apical horn conspicuous, protruding beyond contour line, 4 - 6 µm high; circular pore at end. Lower test rhombic, subtriangular or trapezoidal; 17 - 20.4 µm high. No development of antapical horns. Cingulum annular. Surrounding girdle zone is a wing annulus, ~ - 9.2 µm wide, with fibrously ramified thickening or creases perpendicular to annular edge. Pressure of wing annulus on membrane creates a rhombic [frame-like] decorative wrinkling zone. Sulcus crevice-shaped; apex reaches upper test. No archaeopyle or tabulation observed.
Size: Cysts 44.2 - 51 µm long and 34 - 40.8 µm wide. Holotype 44.2 x 40.8 µm.
Discussion: Because of its unique wing annulus structure, this species is not easily confused with other genera or species.