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Achomosphaera crassipellis
From Fensome et al., 2019:
Achomosphaera crassipellis, (Deflandre and Cookson, 1955, p.265, pl.6, figs.2–3; text-fig.20) Stover and Evitt, 1978, p.138.
Holotype: Deflandre and Cookson, 1955, pl.6, figs.2–3.
Originally Hystrichosphaera, subsequently Spiniferites, thirdly (and now) Achomosphaera.
Taxonomic junior synonyms: Achomosphaera recurvata and Hystrichosphaera (subsequently Spiniferites) membranosa, according to Quattrocchio and Sarjeant (1996, p.116). May (1980, p.64) considered Achomosphaera sagena to be a possible taxonomic junior synonym of this species.
Age: Early Eocene.
Locus typicus: Victoria, Australia
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Original description as Hystrichosphaera crassipellis: [Deflandre and Cookson, 1955, p. 265]:
Description:
Shell globular, almost sphaerical, with an unusually thick membrane; lines separating the fields sometimes rather indistinct, sometimes aliform; fields polygonal, the elongated equatorial series present. Processes apparently fragile, formed of a thin transparent membrane, forked or more or less divided at the apex. Surface of shell membrane ornamented with a clearly marked reticulum, the meshes being about 1.5-2 µm. In certain examples the mesh is finer and closer. The membrane is nonhomogeneous and shows a fibrillar structure.
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Supplemental description as Hystrichosphaera crassipellis:
Davey and Williams, 1960, p. 40:
Description:
H. crassipellis possesses a thick central body wall (up to 6.5 µm in thickness) which is coarsely reticulate. The reticulation is rather irregular having from almost circular to polygonal fields. The processes are gonal, subconical in shape and commonly bifurcate with bifurcating extremities. The paired cingular processes are joined by a membrane. The crests are proximal, reasonably well developed and may be reticulate, especially at their outer edges. H. cvassipellis is a rare species occurring throughout the Cenomanian of England.
Achomosphaera crassipellis, (Deflandre and Cookson, 1955, p.265, pl.6, figs.2–3; text-fig.20) Stover and Evitt, 1978, p.138.
Holotype: Deflandre and Cookson, 1955, pl.6, figs.2–3.
Originally Hystrichosphaera, subsequently Spiniferites, thirdly (and now) Achomosphaera.
Taxonomic junior synonyms: Achomosphaera recurvata and Hystrichosphaera (subsequently Spiniferites) membranosa, according to Quattrocchio and Sarjeant (1996, p.116). May (1980, p.64) considered Achomosphaera sagena to be a possible taxonomic junior synonym of this species.
Age: Early Eocene.
Locus typicus: Victoria, Australia
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Original description as Hystrichosphaera crassipellis: [Deflandre and Cookson, 1955, p. 265]:
Description:
Shell globular, almost sphaerical, with an unusually thick membrane; lines separating the fields sometimes rather indistinct, sometimes aliform; fields polygonal, the elongated equatorial series present. Processes apparently fragile, formed of a thin transparent membrane, forked or more or less divided at the apex. Surface of shell membrane ornamented with a clearly marked reticulum, the meshes being about 1.5-2 µm. In certain examples the mesh is finer and closer. The membrane is nonhomogeneous and shows a fibrillar structure.
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Supplemental description as Hystrichosphaera crassipellis:
Davey and Williams, 1960, p. 40:
Description:
H. crassipellis possesses a thick central body wall (up to 6.5 µm in thickness) which is coarsely reticulate. The reticulation is rather irregular having from almost circular to polygonal fields. The processes are gonal, subconical in shape and commonly bifurcate with bifurcating extremities. The paired cingular processes are joined by a membrane. The crests are proximal, reasonably well developed and may be reticulate, especially at their outer edges. H. cvassipellis is a rare species occurring throughout the Cenomanian of England.