Spongodinium extremum

?extremum (Cookson and Eisenack, 1974, p.48, pl.20, fig.4) Lentin and Williams, 1976, p.40.  Holotype: Cookson and Eisenack, 1974, pl.20, fig.4.  Originally Deflandrea, subsequently (and now) Spongodinium?, thirdly Isabelidinium?.  Questionable assignment: Lentin and Williams (1976, p.40).  Williams et al. (2017) retained this species questionably in Spongodinium.  Age: Albian–Cenomanian.

Parent: Spongodinium