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Systematophora diversispinosa
Systematophora diversispinosa (Davey et al., 1966, p.167, pl.10, fig.7) Islam, 1993, p.88. Emendation: Eaton et al., 2001, p.177.
NOW Cleistosphaeridium. Originally (and now) Cleistosphaeridium, subsequently Systematophora. Eaton et al. (2001, p.177) retained this species in Cleistosphaeridium.
Taxonomic junior synonym: Areosphaeridium polypetellum, according to Islam (1993, p.88) — however, Eaton et al. (2001, p.194) retained Areosphaeridium (as and now Cleistosphaeridium) polypetellum.
Holotype: Davey et al., 1966, pl.10, fig.7; Bujak et al., 1980, pl.7, figs.7–8; Islam, 1993, pl.1, figs.1–10; text-figs.1A–B; Eaton et al., 2001, figs.1A–B,2A–B; Fauconnier and Masure, 2004, pl.77, fig.9.
Locus typicus: Whitecliff, England
Stratum typicum: London Clay, Eocene
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Systematophora diversispinosa (Davey et al., 1966) Islam, 1993, has a granular wall and apical archeopyle. Processes are solid, taeniate or tubular, usually slender and proximally expanded. Distal end forked or expanded. The expanded distal termination may be bifurcate, orthogonal, or patulate, one branch may be larger than the other. The edges are usually denticulate and the processes may be up to 5 µm wide, but are usually about 2 µm. Size: central body diameter 38-43 µm, process length 7-23 µm.
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Original diagnosis: Davey et al., 1966, p.167: Cleistosphaeridium diversispinosum
A Cleistosphaeridium with granular wall and polygonal archaeopyle. Processes solid, taeniate or tubular, usually slender and proximally expanded. Distal end forked or expanded.
Original description: Davey et al., 1966, p.167: Cleistosphaeridium diversispinosum
This species is distinguished by the variable nature of the process ends. The expanded termination may be bifurcate, orthogonal and patulate, one branch may be larger than the other. The edges are usually denticulate and the processes may be up to 5 µm wide; but are usually about 2 µm. There is more than one process to a plate.
Dimensions: Holotype: diameter of the body 38 µm, length of processes 9-16 µm. Observed range: diameter of body 38 µm, length of processes 7-23 µm.
Remarks: Islam, 1993, p. 88
Generic reassessment of the species became necessary following revelation of penitabular processes arranged in arcuate process complexes in the holotype. [...] As is typical in Systematophora, processes in C. diversispinosa are forks, branched and ramified, penitabular and grouped in arcuate process complexes. In some forms of A. polypetellum, a jr. synonym, processes are strongly ramified with occasional distal connections within or between process groups.
Affinities:
Davey et al., 1966, p.167: Cleistosphaeridium diversispinosum
Only Cleistosphaeridium pectiniforme (Gerlach, 1961) resembles C. diversispinosum to any degree. It has widely forked processes with spinose margins; it does not, however, have a variability of process ending shown by our species.
NOW Cleistosphaeridium. Originally (and now) Cleistosphaeridium, subsequently Systematophora. Eaton et al. (2001, p.177) retained this species in Cleistosphaeridium.
Taxonomic junior synonym: Areosphaeridium polypetellum, according to Islam (1993, p.88) — however, Eaton et al. (2001, p.194) retained Areosphaeridium (as and now Cleistosphaeridium) polypetellum.
Holotype: Davey et al., 1966, pl.10, fig.7; Bujak et al., 1980, pl.7, figs.7–8; Islam, 1993, pl.1, figs.1–10; text-figs.1A–B; Eaton et al., 2001, figs.1A–B,2A–B; Fauconnier and Masure, 2004, pl.77, fig.9.
Locus typicus: Whitecliff, England
Stratum typicum: London Clay, Eocene
--------------------------------------------------
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Systematophora diversispinosa (Davey et al., 1966) Islam, 1993, has a granular wall and apical archeopyle. Processes are solid, taeniate or tubular, usually slender and proximally expanded. Distal end forked or expanded. The expanded distal termination may be bifurcate, orthogonal, or patulate, one branch may be larger than the other. The edges are usually denticulate and the processes may be up to 5 µm wide, but are usually about 2 µm. Size: central body diameter 38-43 µm, process length 7-23 µm.
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Original diagnosis: Davey et al., 1966, p.167: Cleistosphaeridium diversispinosum
A Cleistosphaeridium with granular wall and polygonal archaeopyle. Processes solid, taeniate or tubular, usually slender and proximally expanded. Distal end forked or expanded.
Original description: Davey et al., 1966, p.167: Cleistosphaeridium diversispinosum
This species is distinguished by the variable nature of the process ends. The expanded termination may be bifurcate, orthogonal and patulate, one branch may be larger than the other. The edges are usually denticulate and the processes may be up to 5 µm wide; but are usually about 2 µm. There is more than one process to a plate.
Dimensions: Holotype: diameter of the body 38 µm, length of processes 9-16 µm. Observed range: diameter of body 38 µm, length of processes 7-23 µm.
Remarks: Islam, 1993, p. 88
Generic reassessment of the species became necessary following revelation of penitabular processes arranged in arcuate process complexes in the holotype. [...] As is typical in Systematophora, processes in C. diversispinosa are forks, branched and ramified, penitabular and grouped in arcuate process complexes. In some forms of A. polypetellum, a jr. synonym, processes are strongly ramified with occasional distal connections within or between process groups.
Affinities:
Davey et al., 1966, p.167: Cleistosphaeridium diversispinosum
Only Cleistosphaeridium pectiniforme (Gerlach, 1961) resembles C. diversispinosum to any degree. It has widely forked processes with spinose margins; it does not, however, have a variability of process ending shown by our species.