Operculodinium bahiaense (Regali et al., 1974, p.289–290, pl.23, fig.5) Arai in Fauconnier and Masure, 2004, p.345.

Originally Hystrichosphaeridium, subsequently Cleistosphaeridium?, thirdly Impletosphaeridium?, fourthly (and now) Operculodinium.

Holotype: Regali et al., 1974, pl.23, fig.5.
Age: Eocene–Oligocene.

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Original description: [Regali et al., 1974] (translated from Portugese):

Hystrichosphaeridium bahiaensis -- Est. XXIII, no. 5.

Derivation: Species name derived from the state of Bahia, Brazil.
Diagnosis: Spherical, reticulated central capsule with numerous, long, thin radial processes bifurcated at the ends.
Holotype: Type slide no. 107 — Est. XXIII, no. 5.
Diameter: 100µ, including spines.
Type site: Well 3-GA-1-SES (Guaricema, Sergipe Submarino), 450-480 m.
Description: Spherical central capsule, 60 to 70µ in diameter, with a fine reticulum. Numerous radial processes, 20 to 30µ long, thin, smooth, and bifurcated at the ends.
Comparison: Differs from H. aracajuensis sp. n. due to the greater length of the processes and the absence of reticulation in them.
Distribution: Prorapertites operculatus and Cicatricosisporites dorogensis Superzone.
Age: Eocene to Oligocene.
Occurrence: Brazilian continental shelf.