From Fensome et al., 2019:
Vozzhennikova? filigrana (Benedek, 1972) Lentin and Williams, 1976
Now Phthanoperidinium. Originally Deflandrea?, subsequently Vozzhennikovia?, thirdly Dioxya, fourthly (and now) Phthanoperidinium.
At the time of the transfer, Lentin and Williams, 1976, questionably included this species in Vozzhennikovia.
Morgan, 1977, transferred the species to Dioxya Cookson and Eisenack, 1958. Lentin and Williams, 1981, retained it in Vozzhennikovia.

Holotype: Benedek, 1972, pl.4, figs.3a-b; Benedek and Sarjeant, 1981, figs.4,8, nos.1-2
Locus typicus: Tönisberg, Lower Rhine Embayment, Germany
Stratum typicum: Middle Oligocene
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Translation Benedek, 1972: LPP

Original diagnosis: Benedek, 1972, p.12: ?Deflandrea filigrana
A species of the genus ?Deflandrea with one antapical horn. The thinwalled, granular capsule is circular. Trapezoid pylome developed below the apex.

Original description: Benedek, 1972, p.13: ?Deflandrea filigrana
Capsule circular to elliptical with transparent, brownish surface. The smooth, thinwalled inner capsule is of ellipsoidal outline. Outer membrane closely appressed to inner membrane and densely covered by numerous irregular spines. Transverse furrow relatively wide and ventrally bordered by low ridges, which turn into the longitudinal furrow of the hypotheca. Tabulation not indicated. Apical horn short and pointed. Antapical horn weakly developed. Trapezodal pylome developed below the apex.
Dimensions: Capsule length 40-45 µm, breadth 43-45 µm, apical horn 2.5-3 µm (10 specimens).