Tetrachacysta biconvexa

biconvexa (Jiabo, 1978, p.95, pl.29, figs.20–21) He Chengquan et al., 2009, p.374.  Holotype: Jiabo, 1978, pl.29, fig.21.  Originally Horologinella, subsequently (and now) Tetrachacysta.  Age: Early Tertiary.

Parent: Tetrachacysta

Infrataxon List:

Tetrachacysta biconvexa subsp. biconvexa
Tetrachacysta biconvexa subsp. granulata
Tetrachacysta biconvexa subsp. laevigata