Palaeoperidinium pyramidale (Harris, 1974) Lentin and Williams, 1976
Now Morkallacysta. Originally (and now) Morkallacysta, subsequently Palaeoperidinium. Stover and Evitt, 1978 retained this species in Morkallacysta. Holotype: Harris, 1974, pl.1, fig.5
Age: Paleocene