Sirmiodiniopsis "frisia" (Raynaud, 1978, p.394, pl.1, fig.11) Lentin and Williams, 1981, p.256. Holotype: Raynaud, 1978, pl.1, fig.11. Originally Senoniasphaera?, subsequently Sirmiodiniopsis. Taxonomic senior synonym: Meiourogonyaulax (as Ambonosphaera?) staffinensis, according to Poulsen and Riding (1992, p.26). Age: Oxfordian–mid Valanginian.