From Fensome et al., 2019:
Alterbidinium nuculum, Vasilyeva in Andreeva-Grigorovich et al., 2011, p.42–43, pl.11, figs.5–8,11–14; text-fig.18b ex Williams and Fensome, 2016, p.138.
Holotype: Andreeva-Grigorovich et al., 2011, pl.11, figs.5–6; text-fig.18b, designated by Williams and Fensome (2016, p.138).
This name was not validly published by Vasilyeva in Andreeva-Grigorovich et al. (2011, p.42–43) since the holotype citation (pl.11, figs.5–8,11–14 and text-fig.18b) includes more than one specimen. The holotype was clearly designated in Williams and Fensome (2016), thus validating the name Alterbidinium nuculum.
Age: Thanetian–Ypresian.

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