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Oligosphaeridium fenestratum
Oligosphaeridium fenestratum Duxbury, 1980, p.130–131, pl.9, figs.8–9.
Holotype: Duxbury, 1980, pl.9, figs.8–9; Fauconnier and Masure, 2004, pl.59, figs.1–2.
Age: middle Barremian.
Original diagnosis: Duxbury, 1980, p. 130
A large, thin-walled, chorate dinoflagellate cyst consisting of a smooth to finely granular, spheroidal central body bearing 19 long processes, intratabular, assumed to be one per paraplate. The processes flare slightly proximally and greatly distally so that the process ends may be equivalent in diameter to half the main body. Process terminations are polygonal in plan view and have short, flaccid spines at each angle. Processes are very highly fenestrate from about 1/3 Of their length to the distal terminations and each small fenestration is elongate in the direction of the process axis. A paratabulation of the formula 4", 6", 6""", 1p., 1p.v., 1"""", is suggested by process grouping with the dorsal processes, especially those on the hypocyst, being the larger. The archeopyle is apical, tetratabular. Observed dimensions: Holotype--116 x 105 µm. Overall--140 (127) 103 x 130 (112) 100 µm.
Affinities:
Duxbury, 1980, p. 130: The process type demonstrated by this species renders it different from all others. The process terminations are reminiscent, in plan view, of those of Oligosphaeridium perforatum (Gocht, 1959) Davey & Williams, 1969 but in lateral view, the very highly fenestrate, distally greatly flaring processes of 0. fenestratum are most distinctive.
Holotype: Duxbury, 1980, pl.9, figs.8–9; Fauconnier and Masure, 2004, pl.59, figs.1–2.
Age: middle Barremian.
Original diagnosis: Duxbury, 1980, p. 130
A large, thin-walled, chorate dinoflagellate cyst consisting of a smooth to finely granular, spheroidal central body bearing 19 long processes, intratabular, assumed to be one per paraplate. The processes flare slightly proximally and greatly distally so that the process ends may be equivalent in diameter to half the main body. Process terminations are polygonal in plan view and have short, flaccid spines at each angle. Processes are very highly fenestrate from about 1/3 Of their length to the distal terminations and each small fenestration is elongate in the direction of the process axis. A paratabulation of the formula 4", 6", 6""", 1p., 1p.v., 1"""", is suggested by process grouping with the dorsal processes, especially those on the hypocyst, being the larger. The archeopyle is apical, tetratabular. Observed dimensions: Holotype--116 x 105 µm. Overall--140 (127) 103 x 130 (112) 100 µm.
Affinities:
Duxbury, 1980, p. 130: The process type demonstrated by this species renders it different from all others. The process terminations are reminiscent, in plan view, of those of Oligosphaeridium perforatum (Gocht, 1959) Davey & Williams, 1969 but in lateral view, the very highly fenestrate, distally greatly flaring processes of 0. fenestratum are most distinctive.