Baltisphaeridium aculeatum Appendix A
From dinoflaj3
aculeatum (Timofeev, 1959, p.56, pl.4, fig.21) Downie and Sarjeant, 1965, p.87. Holotype: Timofeev, 1959, pl.4, fig.21. Originally Hystrichosphaeridium, subsequently (and now) Baltisphaeridium. This combination was not validly published in Downie and Sarjeant (1963, p.89), since these authors did not fully reference the basionym. Age: Early Ordovician.
Parent: Baltisphaeridium_Appendix A