Arkellidinium triapertum
From dinoflaj2
"*triapertum" Beju, 1979, p.4-5, fig.1, nos.1-6; figs.2A-A',B-E. Holotype: Beju, 1979, fig.1, no.1; figs.2A-A'; Fensome et al., 1995, figs.1,7-8 - p.1847. Originally Arkellidinium, subsequently Sirmiodiniopsis. Taxonomic senior synonym: Sirmiodiniopsis orbis, according to Riley and Fenton (1982, p.199). Age: Late Callovian.
Parent: Arkellidinium
