Hystrichosphaeridium tuberatum
From dinoflaj2
"tuberatum" Downie, 1958, p.338, pl.17, fig.3; text-fig.3f. Holotype: Downie, 1958, pl.17, fig.3. NOW Acanthodiacrodium (Appendix A). Originally Hystrichosphaeridium, subsequently Baltisphaeridium (Appendix A), thirdly (and now) Acanthodiacrodium (Appendix A), fourthly Vulcanisphaera (Appendix A), fifthly Goniosphaeridium (Appendix A). Age: Early Ordovician.
Parent: Hystrichosphaeridium
