Oligosphaeridium abbreviatum Xu Jinli et al., 1997, p.82–83, pl.24, fig.10 ex He Chengquan et al., 2009, p.657. Holotype: Xu Jinli et al., 1997, pl.24, fig.10. 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.657) validated the name by publishing an English diagnosis. Age: middle-late Eocene.