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Oligosphaeridium diastema
Oligosphaendium "diastema" Singh, 1971, p.337, pl.55, figs.4–5; pl.56, figs.1–2.
Holotype: Singh, 1971, pl.55, fig.4. Taxonomic senior synonym: Oligosphaeridium totum, according to Harker and Sarjeant (1975, p.226) and Brideaux and McIntyre (1975, p.29). Fauconnier and Cornu in Fauconnier and Masure (2004, p.403) listed this as a problematic species but apparently accepted the synonymy cited above. N.I.A.
Age: late Albian.
Original description: Singh, 1971, p. 337
Central body ovoidal, bearing 9 to 11 long processes; reflected tabulation not clear; processes concentrated in the apical and antapical regions and separated by a wide, smooth cingular zone (diastema) without processes; stalks of the processes long, smooth, cylindrical, and 3 to 6 µm wide; processes hollow and widening distally into 8- to 18 µm wide terminal expansions; rim of the terminal expansions entire and usually without spines; length of the processes from 1/2 to 3/4 of the length of the central body; archeopyle apical; wall of the central body double layered and smooth. Size range: Total length of the test, including the processes (7 specimens) 72(87)96 µm. Holotype 96 µm. Length of the central body (7 specimens) 38(44)48 µm. Holotype 48 µm. Breadth of the central body (4 specimens) 29(34)38 µm. Holotype 36 µm. Length of the processes (7 specimens) 19(26)36 µm. Holotype 30 µm.
Affinities:
Singh, 1971, p. 337: Oligosphaeridium diastema is characterized by a wide cingular zone without processes (i.e. diastema) and few (9 to 11), long, cylindrical processes whose terminal expansions usually lack spines. The arrangement and the number of the processes in 0. diastema differs from that of the genus. However, this species has been tentatively assigned here to the genus Oligosphaeridium because of the absence of cingular processes.
Holotype: Singh, 1971, pl.55, fig.4. Taxonomic senior synonym: Oligosphaeridium totum, according to Harker and Sarjeant (1975, p.226) and Brideaux and McIntyre (1975, p.29). Fauconnier and Cornu in Fauconnier and Masure (2004, p.403) listed this as a problematic species but apparently accepted the synonymy cited above. N.I.A.
Age: late Albian.
Original description: Singh, 1971, p. 337
Central body ovoidal, bearing 9 to 11 long processes; reflected tabulation not clear; processes concentrated in the apical and antapical regions and separated by a wide, smooth cingular zone (diastema) without processes; stalks of the processes long, smooth, cylindrical, and 3 to 6 µm wide; processes hollow and widening distally into 8- to 18 µm wide terminal expansions; rim of the terminal expansions entire and usually without spines; length of the processes from 1/2 to 3/4 of the length of the central body; archeopyle apical; wall of the central body double layered and smooth. Size range: Total length of the test, including the processes (7 specimens) 72(87)96 µm. Holotype 96 µm. Length of the central body (7 specimens) 38(44)48 µm. Holotype 48 µm. Breadth of the central body (4 specimens) 29(34)38 µm. Holotype 36 µm. Length of the processes (7 specimens) 19(26)36 µm. Holotype 30 µm.
Affinities:
Singh, 1971, p. 337: Oligosphaeridium diastema is characterized by a wide cingular zone without processes (i.e. diastema) and few (9 to 11), long, cylindrical processes whose terminal expansions usually lack spines. The arrangement and the number of the processes in 0. diastema differs from that of the genus. However, this species has been tentatively assigned here to the genus Oligosphaeridium because of the absence of cingular processes.