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Spiniferites crassipellis
Spiniferites crassipellis (Deflandre and Cookson, 1955) Sarjeant, 1970
Now Achomosphaera. Originally Hystrichosphaera, subsequently Spiniferites, thirdly (and now) Achomosphaera.
Possible tax. sr. synonym of Achomosphaera sagena Davey and Williams, 1966, according to May, 1980. Lentin and Williarns, 1981, retained Achomosphaera sagena as a separate species.
Taxonomic junior synonyms: Achomosphaera recurvata and Hystrichosphaera (subsequently Spiniferites) membranosa, according to Quattrocchio and Sarjeant (1996, p.116).
Holotype: Deflandre and Cookson, 1955, pl. 6, figs.2-3
Locus typicus: Victoria, Australia
Stratum typicum: Early Eocene
Original descrpition: Deflandre and Cookson, 1955, p. 265: Hystrichosphaera crassipellis
Shell globular, almost sphaerical, with an unusually thick membrane; lines seperating 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.
Supplemental descripition: Davey and Williams, 1960, p. 40: Hystrichosphaera crassipellis
H. crassipellis possesses a thick central body wall (up to 6.5µm 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.
Now Achomosphaera. Originally Hystrichosphaera, subsequently Spiniferites, thirdly (and now) Achomosphaera.
Possible tax. sr. synonym of Achomosphaera sagena Davey and Williams, 1966, according to May, 1980. Lentin and Williarns, 1981, retained Achomosphaera sagena as a separate species.
Taxonomic junior synonyms: Achomosphaera recurvata and Hystrichosphaera (subsequently Spiniferites) membranosa, according to Quattrocchio and Sarjeant (1996, p.116).
Holotype: Deflandre and Cookson, 1955, pl. 6, figs.2-3
Locus typicus: Victoria, Australia
Stratum typicum: Early Eocene
Original descrpition: Deflandre and Cookson, 1955, p. 265: Hystrichosphaera crassipellis
Shell globular, almost sphaerical, with an unusually thick membrane; lines seperating 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.
Supplemental descripition: Davey and Williams, 1960, p. 40: Hystrichosphaera crassipellis
H. crassipellis possesses a thick central body wall (up to 6.5µm 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.