Sentusidinium biornatum (Jiabo, 1978, p.52, pl.22, figs.21–29; pl.23, figs.1–4) He Chengquan, Zhu Shenzhao and Jin Guangxing in He Chengquan et al., 1989, p.67. Holotype: Jiabo, 1978, pl.22, fig.24. Originally Tenua biornata, subsequently Kallosphaeridium biornatum (combination not validly published), thirdly Kallosphaeridium biparatum, fourthly Batiacasphaera biornata, fifthly (and now) Sentusidinium biornatum. Lentin and Williams (1993, p.53) retained this species in Batiacasphaera, but He Chengquan et al. (2009, p.249) retained it in Sentusidinium. Age: Early Tertiary.