Hystrichosphaeridium oligacanthum ssp. complanatum W. Wetzel, 1952

Now Solisphaeridium stimuliferum ssp. complanatum. Originally Hystrichosphaeridium oligacanthum ssp. complanatum, subsequently Baltisphaeridium oligacanthum ssp. complanatum, thirdly Cleistosphaeridium? oligacanthum ssp. complanatum, fourthly (and now) Solisphaeridium stimuliferum ssp. complanatum.
Holotype: W. Wetzel, 1952, pl.A, figs.11a-b; Sarjeant, 1984, pl.4, fig.6; text-fig.13
Age: Paleocene