From Fensome et al., 2019:
Bosedinia micirugosa ssp. minor He Chengquan, 1984b, p.175, pl.8, figs.6–8. Holotype: He Chengquan, 1984b, pl.8, fig.8.
Age: Middle Oligocene–Early Miocene.

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Original description: [He Chengquan, 1984b] (translated from Chinese with Google):

Bosedinia micirugosa subsp. minor (sp. et subsp. nov.)
(Plate VIII, Figures 6-8)

Description: The shell is small, with a nearly circular outline. The surface is decorated with distinct, fine wrinkles of uniform thickness, ranging from long (2-5 microns) and curved to short and straight. The shell diameter is 32.5-37.5 microns; the holotype is 32.5 microns in diameter. Other characteristics are similar to those of the species. This subspecies differs from the subspecies tricholoma by having a shell diameter less than 38 microns, typically 30 microns, and by having relatively long wrinkles.

Origin: Guangxi Shangsi, the second member of the Yongning Group; Hepu, the upper member of the Qiaotoupu Formation.