Hystrichosphaeridium bimarginatum
From dinoflaj2
"bimarginatum" Timofeev, 1959, p.54, pl.4, fig.12. Holotype: Timofeev, 1959, pl.4, fig.12. NOW Baltisphaeridium (Appendix A). Originally Hystrichosphaeridium, subsequently (and now) Baltisphaeridium (Appendix A). Age: Early Ordovician.
Parent: Hystrichosphaeridium
