Baltisphaeridium biformoides, (Eisenack, 1954), Downie and Sarjeant, 1965

Now Achilleodinium. Originally Hystrichosphaeridium, subsequently Baltisphaeridium, thirdly Hystrichokolpoma, fourthly (and now) Achilleodinium, fifthly Florentinia. This combination was not validly published in Downie and Sarjeant, 1963 since these authors did not fully reference the basionym.

Holotype: Eisenack, 1954, pl.11, fig.18
Age: Late Eocene-early Oligocene