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Impletosphaeridium cracens
From Fensome et al., 2019:
Impletosphaeridium cracens Eaton, 1976, p.306, pl.21, fig.6; text-fig.25E. Holotype: Eaton, 1976, pl.21, fig.6; Bujak et al., 1980, pl.5,
fig.4. Age: Early-Middle Eocene (see Aubry, 1986).
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Original diagnosis: Eaton, 1976, p. 306
Cyst body spherical or subspherical, with a smooth surface. Processes numerous, consisting of erect membranes of variable breadth, strengthened by rod-like thickenings. Processes simple or branched, frequently proximally united by lateral extension of the membranes. Distally the processes have a digitate or aculeate margin.
Dimensions: Holotype: diameter of cyst body 29 µm; length of processes up to 12 µm. Observed range: diameter of cyst body 18-30 µm; length of processes up to 13 µm. (n = 10).
Affinities:
Eaton, 1976, p. 306: The membranous processes with their rod-like thickenings distinguish I. cracens n. sp. from all described species of Impletosphaeridium. Cordosphaeridium? minimum (Morgenroth) Benedek 1972 also has rod-like thickenings in its processes, but the latter are distinctly tubular, and not erect membranes as in I. cracens.
Impletosphaeridium cracens Eaton, 1976, p.306, pl.21, fig.6; text-fig.25E. Holotype: Eaton, 1976, pl.21, fig.6; Bujak et al., 1980, pl.5,
fig.4. Age: Early-Middle Eocene (see Aubry, 1986).
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Original diagnosis: Eaton, 1976, p. 306
Cyst body spherical or subspherical, with a smooth surface. Processes numerous, consisting of erect membranes of variable breadth, strengthened by rod-like thickenings. Processes simple or branched, frequently proximally united by lateral extension of the membranes. Distally the processes have a digitate or aculeate margin.
Dimensions: Holotype: diameter of cyst body 29 µm; length of processes up to 12 µm. Observed range: diameter of cyst body 18-30 µm; length of processes up to 13 µm. (n = 10).
Affinities:
Eaton, 1976, p. 306: The membranous processes with their rod-like thickenings distinguish I. cracens n. sp. from all described species of Impletosphaeridium. Cordosphaeridium? minimum (Morgenroth) Benedek 1972 also has rod-like thickenings in its processes, but the latter are distinctly tubular, and not erect membranes as in I. cracens.