Oligosphaeridium ?tubulatum (Menéndez, 1965, p.13, pl.2, fig.7; pl.3, fig.17) Sarjeant and Stancliffe, 1994, p.56. Holotype: Menéndez, 1965, pl.2, fig.7.
Originally Micrhystridium (Appendix A), subsequently (and now) Oligosphaeridium?. Questionable assignment: Sarjeant and Stancliffe (1994, p.56); and Fauconnier and Cornu in Fauconnier and Masure (2004, p.404) as a problematic species.
Age: Oligocene.