From Fensome et al., 2019:
Operculodinium nitidum Islam, 1983a, p.242, pl.4, figs.2–3. Holotype: Islam, 1983a, pl.4, fig.3. Age: Early Eocene.

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Paratype: Islam, 1983
Locus typicus: Isle of Sheppey, SE England
Stratum typicum: Early Eocene

Original diagnosis: Islam, 1983, p.242
The cyst is subspherical to ellipsoidal, proximochorate to skolochorate and biphragmal; the periphragm is reticulate to fibroreticulate and closely adpressed to endophragm except under bases of processes; possesses numerous nontabular solid finely fibrous processes, which are well broad at bases and frequently coalescing with one another, taper to very thin necks before very fine distal aculeation; paracingulum may be indicated by rows of processes; the archeopyle is precingular type P.

Dimensions: Holotype: cyst body 45 X 42 µm, length of processes 5-7 µm. Range: cyst length 45(39)35 µm, breadth 42(36)31 µm, length of processes 4-10 µm. Specimens measured 9.

Affinities:
Islam, 1983, p.242: It differs from other species of the genus in possessing fibrous processes which are frequently proximally joined to one another.