Acanthaulax downiei

"?downiei" (Sarjeant, 1960a, p.138–139) Sarjeant, 1976c, p.6.  Holotype: Downie, 1957, pl.20, fig.10, as Hystrichosphaeridium pattei; Jan du Chêne et al., 1986a, pl.3, figs.7–9.  NOW Cribroperidinium?.  Originally Baltisphaeridium (Appendix A), subsequently Acanthaulax, thirdly Acanthaulax?, fourthly Cyclonephelium, fifthly (and now) Cribroperidinium? Questionable assignment: Stover and Evitt (1978, p.137) — however, Sarjeant (1982b, p.47) retained the species in Acanthaulax without question.  Age: Kimmeridgian.

Parent: Acanthaulax