Cleistosphaeridium heteracanthum
From dinoflaj2
"heteracanthum" (Deflandre and Cookson, 1955, p.276, pl.2, figs.5-6; text-figs.40-41) Davey et al., 1966, p.168. Holotype: Deflandre and Cookson, 1955, pl.2, fig.5; Fauconnier and Masure, 2004, pl.35, figs.7-8. NOW Heterosphaeridium. Originally Hystrichosphaeridium, subsequently Baltisphaeridium (Appendix A), thirdly Cleistosphaeridium, fourthly (and now) Heterosphaeridium, fifthly Heterosphaeridium?. Age: ?Late Cretaceous-Early Eocene.
Parent: Cleistosphaeridium