Baltisphaeridium uncinatum, (Downie, 1958), Martin, 1966

Now Stellechinatum uncinatum (an acritarch species). Originally Hystrichosphaeridium longispinosum var. uncinatum, subsequently Baltisphaeridium longispiniosum var. uncinatum (an acritarch varietas), thirdly Baltisphaeridium uncinatum, fourthly Micrhystridium uncinatum (an acritarch species), fifthly Goniosphaeridium uncinatum (an acritarch species), sixthly Polygonium uncinatum (an acritarch species), seventhly (and now) Stellechinatum uncinatum (an acritarch species); see also Goniosphaeridium polygonale ssp. uncinatum (an acritarch subspecies; combination not validly published).
Tax. sr. synonym of the acritarch species Goniosphaeridium regulare Yin Leiming in Chen Yunyuan et al., 1985, according to Yin Leiming, 1986. This taxon was raised to specific rank by Martin, 1966 as Baltisphaeridium uncinatum.

Holotype: Downie, 1958, text-fig.2a
Age: Early ordovician