Magallanesium denticulatum (Pöthe de Baldis and Ramos, 1983, p.438, pl.2, figs.7,11; pl.4, fig.2) Quattrocchio and Sarjeant, p.140.

NOW Spinidinium argentinium. Originally Dioxya denticulata, subsequently (and now) Spinidinium argentinium, thirdly Magallanesium denticulatum. Spinidinium argentinium is a substitute name, since the epithet "denticulatum" is preoccupied in Spinidinium.

Holotype: Pöthe de Baldis and Ramos, 1983, pl.2, figs.7,11; pl.4, fig.2.
Age: Early Aptian.