Impletosphaeridium brevibaculum (Song Zhichen in Song Zhichen et al., 1985, p.31, pl.4, fig.10) Islam, 1993, p.85. Holotype: Song Zhichen et al., 1985, pl.4, fig.10.
Originally Cleistosphaeridium, subsequently (and now) Impletosphaeridium.
Age: Cenozoic.