Shandongidinium baculatum Xu Jinli et al., 1997, p.56, pl.5, figs.2–3; pl.52, figs.3a–b ex He Chengquan et al., 2009, p.663. Holotype: Xu Jinli et al., 1997, pl.5, fig.3. This name was not validly published in Xu Jinli et al. (1997), since no English or Latin description was provided; He Chengquan et al. (2009, p.663) validated the name by publishing an English diagnosis. Age: middle-late Eocene.