Baltisphaeridium hirsutoides var. hamatum Appendix A

"var. hamatum" (Downie, 1958, p.335, pl.16, fig.1; text-figs.2j–k) Downie and Sarjeant, 1965, p.91.  Holotype: Downie, 1958, pl.16, fig.1.  NOW Baltisphaeridium hamatum (Appendix A).  Originally Hystrichosphaeridium hirsutoides var. hamatum, subsequently Baltisphaeridium hirsutoides var. hamatum, thirdly Micrhystridium hamatum (Appendix A), fourthly Acanthodiacrodium hamatum (Appendix A), fifthly (and now) Baltisphaeridium hamatum (an acritarch species, Appendix A).  Age: Early Ordovician.

Parent: Baltisphaeridium hirsutoides_Appendix A