Hystrichosphaeridium isocalamum
From dinoflaj2
"isocalamum" Deflandre and Cookson, 1955, p.272, pl.2, figs.7-8; text-figs.30-35. Holotype: Deflandre and Cookson, 1955, pl.2, figs.7-8; Fauconnier and Masure, 2004, pl.78, figs.5-8. NOW Tanyosphaeridium. Originally Hystrichosphaeridium, subsequently (and now) Tanyosphaeridium. Age: Early Cretaceous.
Parent: Hystrichosphaeridium