Songiella longicaulis Xu Jinli et al., 1997, p.61–62, pl.2, figs.4a–b; pl.3, figs.5a–b; pl.48; figs.1a–b,2; text-fig.4 ex He Chengquan et al., 2009, p.370,669. Holotype: Xu Jinli et al., 1997, pl.2, figs.4a–b; text-fig.4. 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.669–670) validated the name by publishing an English diagnosis. Age: middle-late Eocene.