Polygonium nanum (Deflandre, 1945) Jacobson, 1978

Now Solisphaeridium nanum (an acritarch species). Originally Hystrichosphaeridium brevispinosum var. nanum, subsequently Baltisphaeridium nanum (an acritarch species), thirdly Micrhystridium nanum (an acritarch species), fourthly Polygonium nanum, fifthly (and now) Solisphaeridium nanum (an acritarch species); see also Baltisphaeridium brevispinosum var. nanum (an acritarch varietas; combination not validly published).
Tax. sr. synonym of the acritarch Baltisphaeridium brevispinosum var. wenlockense (al. Salopidium wenlockense) Downie, 1959, according to Lister, 1970 and Turner, 1984. This taxon was raised to specific rank by Stockmans and Williere, 1962 as Baltisphaeridium nanum.
Holotype: Deflandre, 1945, pl.1, figs.5-6
Age: Silurian