From Fensome et al., 2019:
Operculodinium psilatum Wall, 1967, p.111–112, pl.16, figs.6–8. Holotype: Wall, 1967, pl.16, figs.6–8. Motile equivalent:
Protoceratium reticulatum (Claparède and Lachmann, 1859) Bütschli, 1885, according to Wall and Dale (1967, p.352). Age: Holocene.

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Locus typicus: Core A240/18, Cariaco Trench, (10¦ 30.8" N, 64¦ 40" W).
Stratum typicum: Holocene

Original description: Wall, 1967, p. 111
The test is ovoid and without polar structures. The wall is smooth, with a tectate appearance and has sparse, extremely small and delicate spines which are scarcely visible at low magnifications except as darker spots on the test wall. There is a very well defined, narrow equatorial girdle, which is displaced slightly at the mid-ventral point. Below it there is a smaller sulcal depression with an ellipsoidal scar. The archeopyle is trapezoidal, precingular, and dorsal.
Dimensions: Test dimensions 50-60 µm maximum. Numerous examples.

Affinities:
Wall, 1967, p. 111: The minute spines and well-developed girdle distinguish this species from O. israelianum.