Pachysphaeridium balticum (Eisenack, 1951, p.190, pl.3, figs.10–11) Ribecai and Tongiorgi, 1999, p.122.

Acritarch species.
Originally Hystrichosphaeridium, subsequently Pulvinosphaeridium (combination not validly published, Acritarch), thirdly Veryhachium (Acritarch), fourthly Goniosphaeridium (Acritarch), fifthly Baltisphaeridium (Acritarch), sixthly Estiastra (Acritarch), seventhly (and now) Pachysphaeridium.

Holotype: Eisenack, 1951, pl.3, fig.10.
Age: Early Ordovician.