Heterosphaeridium heteracanthum
From dinoflaj2
heteracanthum (Deflandre and Cookson, 1955, p.276, pl.2, figs.5-6; text-figs.40-41) Eisenack and Kjellström, 1972, p.451. Holotype: Deflandre and Cookson, 1955, pl.2, fig.5; Fauconnier and Masure, 2004, pl.35, figs.7-8. Originally Hystrichosphaeridium, subsequently Baltisphaeridium (Appendix A), thirdly Cleistosphaeridium, fourthly (and now) Heterosphaeridium, fifthly Heterosphaeridium?. Questionable assignment: Stover and Evitt (1978, p.52); however, Fauconnier and Begouën in Fauconnier and Masure (2004, p.269) considered that this species should be assigned to Heterosphaeridium without question. Age: ?Late Cretaceous-Early Eocene.
Parent: Heterosphaeridium
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