Polysphaeridium williamsii
From dinoflaj3
"williamsii" Boltenhagen, 1977, p.41–42, pl.2, figs.6–7. Holotype: Boltenhagen, 1977, pl.2, fig.6; Fauconnier and Masure, 2004, pl.50, fig.6. NOW Impletosphaeridium. Originally Polysphaeridium, subsequently Cleistosphaeridium?, thirdly (and now) Impletosphaeridium. Age: Cenomanian–early Turonian.
Parent: Polysphaeridium