Baltisphaeridium pseudhystrichodinium, (Deflandre, 1937), Downie and Sarjeant, 1965

Now Pervosphaeridium. Originally Hystrichosphaeridium, subsequently Baltisphaeridium, thirdly Exochosphaeridium?, fourthly (and now) Pervosphaeridium.
Tax. sr. synonym of Exochosphaeridium? palmatum (Deflandre and Courteville, 1939) Davey et al., 1969, according to Yun, 1981. This combination was not validly published in Downie and Sarjeant, 1963 since these authors did not fully reference the basionym.

Holotype: Deflandre, 1937, pl.16 [al. pl.12], fig.3
Age: Late Cretaceous