Estiastra baltica (Eisenack, 1951, p.190, pl.3, figs.10–11) Sarjeant and Stancliffe, 1994, p.50.

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

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