Hystrichosphaeridium xanthiopyxides var. parvispinum Deflandre, 1937

Now Prolixosphaeridium parvispinum. Originally Hystrichosphaeridium? xanthiopyxides var. parvispinum, subsequently Hystrichosphaeridium parvispinum, thirdly Baltisphaeridium parvispinum, fourthly (and now) Prolixosphaeridium parvispinum.
Tax. sr. synonym of Prolixosphaeridium elongatum Jain, 1977, according to Lentin and Williams, 1985.
Tax. sr. synonym of Prolixosphaeridium deirense Davey et al., 1966, according to Davey and Verdier, 1974. Harding, 1990, retained Prolixosphaeridium deirense as a separate species.

Holotype: Deflandre, 1937, pl.16 [al. pl.13], fig.5
Age: Late Aptian