Multiplicisphaeridium erraticum (Eisenack 1954) Eisenack et al., 1973

Now Visbysphaera (an acritarch genus). Originally Hystrichosphaeridium, subsequently Baltisphaeridium (an acritarch genus), thirdly (and now) Visbysphaera (an acritarch genus), fourthly Multiplicisphaeridium.
Holotype: Eisenack, 1954, pl.1, fig.6
Age: Silurian (Late Ludlow)