Rhombodinium variabile (He Chengquan, 1991, p.92, pl.35, fig.1; text-fig.12) Williams et al., 2015, p.311. Holotype: He Chengquan, 1991, pl.35, fig.1; text-fig.12. Originally Dracodinium, subsequently (and now) Rhombodinium. Age: late Eocene.

Description from He Chengquan, 1991, translated by Suning Hou, 07-01-2019
Description: The cyst is dorsal-ventral flattened, the outline of the outer wall is nearly the diamond-shaped or elongated Epicyst is triangle, slightly convex at sides, a small apical horn is displayed slightly. Lower cyst is larger than the upper cyst, inverted trapezoid, the sides are nearly straight, the bottom is concave, two antapical horns degenerated to varying degrees, the left antapical horn is larger, papillary; right antapical horn is convex. Two lateral horns are degenerated obviously, the incision at the end is a sign of the cingulum. The outer wall is transparent, the surface is obviously granular. The inner body is similar to the outer wall in outline, especially in the antapex , also with two obvious antapical horns, inner body wall is thick, fibrous, with coarse surface; It is widely separated from the outer wall. The archeopyl is intercalary-style, outline round trapezoid. The operculum has been separated and preserved in situ. Cyst length 107μm, width 74μm, inner body length 84μm, width 65μm.
Comparison: This new species is quite similar to Dracodinium rhomboideum, but the former’s inner body is elongated and has two distinct antapical horns, which are significantly different from the latter.
Location and stratigraphy: Wuqia County Basebulak; Basebulak fm, member 2 and 3