Baltisphaeridium danicum, (W. Wetzel, 1952), Downie and Sarjeant, 1965

Now Achomosphaera. Originally Areoligera, subsequently Baltisphaeridium, thirdly Hystrichosphaeridium, fourthly Cleistosphaeridium, fifthly (and now) Achomosphaera.
Tax. jr. synonym of Areoligera senonensis Lejeune-Carpentier, 1938, according to Lejeune-Carpentier and Sarjeant, 1981; however, Sarjeant, 1984 retained Baltisphaeridium (as Achomosphaera) danicum as a separate species. This combination was not validly published in Downie and Sarjeant, 1963 since these authors did not fully reference the basionym.

Holotype: W. Wetzel, 1952, pl.A, fig.6
Age: Paleocene

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Original diagnosis as Areoligera danica: [W. Wetzel, 1952, p. 396]:

Diagnosis:
A species of the genus Areoligera with high-arched capsule and distinctive, separately formed processes.

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Emended diagnosis:

Sarjeant, 1984, p. 129:

Diagnosis:
Cyst proximochorate, spiniferate, hercotabulate. Ambitus broadly ovoidal to rounded-subpolygonal.
Processes gonal and intergonal in situation, relatively short and stubby (in length c. one-fifth of the cyst breadth), bifid to trifid, with brief branches of equal, or almost equal, length and undivided.
Phragma of moderate thickness, its surface apparently granular.
Archaeopyle single plate precingular (Type P).