Baltisphaeridium aculeatum Appendix A

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