Spinidinium argentinium Lentin and Williams, 1985, p.325. Holotype: Pöthe de Baldis and Ramos, 1983, pl.2, figs.7,11. Originally Dioxya denticulata, subsequently (and now) Spinidinium argentinium, thirdly Magallanesium denticulatum. Substitute name for Dioxya denticulata Pöthe de Baldis and Ramos, 1983, p.438, pl.2, figs.7,11; pl.4, fig.2. This species was retained in Spinidinium by Sluijs et al. (2009, p.46). Age: early Aptian.