Microdinium granulatum He Chengquan, 1991

Name illegitimate — senior homonym: Microdinium granulatum (Jiabo, 1978) Lentin and Williams, 1989.
Substitute name: Microdinium chengquani.
Originally Microdinium granulatum (name illegitimate), subsequently (and now) Microdinium chengquani

Holotype: He Chengquan, 1991, pl.5, fig.8
Age: Late Turonian-Eocene

Description by He Chengquan, 1991, translated by Suning Hou, 07-01-2019
Description: Cyst is small, outline oval, length is equal to width or slightly longer than the width. No apical and antapical horn. The upper cyst is clearly smaller than the lower cyst. Cingulum is close to the front of the cyst, ring, width 5-7μm, the edge is defined by the fine ridge. Sulcus fuzzy. Paaratabulation is not fully displayed, the sutural ridge is weak, smooth; Paratype archeopyle edge reveals 4 apical plates; On the other specimens, the number of the apical plates can not be resolved, there is only one antapical plate, front and back cingulum paratabulation is also vague., probably six of each, pre- and postcingular paratabulation is difficult to identify, so we speculated that the paratabulatio is at least: 4 ', 6 ",, xc, 6 "', 1" ". The cyst wall is thin, plates are granular, the size of the grain is variable, coarse or weak and irregular. Archeopyle small, apical, edge anguar or incision. The operculum is completely separated, small, fell off or preserved in situ. Cyst length 30-40μm, width 26-40 μm (measured 9); Holotype length 40μm, width 38 μm, cingulum width 5μm.
Comparison: The newer species is similar in morphology and size to Microdinium opacum from the North American Lower Cretaceous., but the former plates are granular, the latter plates are smooth, sulcus well developed. The difference between it and M. ornatum is smooth ridge without beads (like Candida).
Location and Stratigraphy: Ulugqat County Basebulak; Lower Zimgen fm, Wulagen fm and Basebulak fm two, three member.