Riasanodinium fedorovae Iosifova, 1992

Holotype: Iosifova1992: pl. IX, la,b; figs. la,b; Iosifova 1996: Plate XIII, 4a-c; Fig. l l .
Locus typicus: Tchernaya Retchka outcrop, the Ryazan district, Russia.
Stratum typicum: the Ryazanian, R. riasanensis ammonite zone, E. pharo dinocyst subzone.
Possible synonym: 1984 Algae fam. et gen. indet. Fedorova and Gryazeva, pl. XXIV, 5

Original description: Iosifova 1992, p. 77
(fig. la, b). Corresponds to diagnosis of genus. Endophragm in granular. Periphragm is thin and smooth. Processes are wide, short, and approximately same size. Inner body may not be present.

Dimensions in microns:Holotype 4831/4198-24831/4198-4
(without apex)
Length of body 92.282.6
Length of inner body 76.8
Length of proces s7.77.7
Width of inner body 42.2
Width 57.6
Distribution. Ryazan horizon of Moscow syneclise.
Material. Two specimens from type locality.

Diagnosis: Iosifova 1996, p. 231: Same as for the genus.
Dimensions: Length (without operculum): holotype: 92 µm, range: 83-92 µm; width: holotype: 58 µm; length of inner body: holotype: 77 µm; length of the processes: holotype: 8 µm, paratype: 8 µm; width of the inner body: holotype: 42 µm. Two specimens measured.
Description (translation): Iosifova 1996, p. 231: Same as for the diagnosis of the genus.
Endophragm granular. Periphragm thin, smooth. Processes are wide, relatively short, of about equal size. Endocyst may be found in isolation.
Comparison: It differs from Aprobolocysta alata Backhouse, 1987 mainly by its process formula: presence of distinct cingular processes and absence of intercalaries.
Occurrence: Tchernaya Retchka outcrop, the Ryazanian, R. riasanensis ammonite zone, E. pharo dinocyst subzone.