Peteinosphaeridium hymenoferum (Eisenack, 1938) Fensome et al., 1990

Originally Hystrichosphaeridium, subsequently Baltisphaeridium (an acritarch
genus), thirdly (and now) Peteinosphaeridium. This combination was not validly published in Eisenack, 1969 since that author did not fully reference the basionym. Holotype: Eisenack, 1938, pl.3, fig.2
Age: Ordovician (based on material from an erratic)