Hystrichosphaeridium arrectum
From dinoflaj3
"arrectum" Timofeev, 1959, p.53, pl.4, fig.8. Holotype: Timofeev, 1959, pl.4, fig.8. NOW Baltisphaeridium (Appendix A). Originally Hystrichosphaeridium, subsequently (and now) Baltisphaeridium (Appendix A). Age: Early-Mid Ordovician.
Parent: Hystrichosphaeridium