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Polysphaeridium pseudocolligerum
Polysphaeridium pseudocolligerum Stover, 1977
NOW Dapsilidinium. Originally Polysphaeridium, subsequently (and now) Dapsilidinium.
Taxonomic senior synoym: Polysphaeridium (now Dapsilidinium) pastielsii according to Mertens et al. (2014, p.532) — however, Fensome et al., in press, retained Dapsilidinium pseudocolligerum as a separate species
Holotype: Stover, 1977, pl.1, fig.14-16
Paratype: Stover, 1977
Locus typicus: Corehole 5/5B, Blake Plateau, Western N Atlantic
Stratum typicum: Middle Oligocene
Original description: Stover, 1977, p. 75
Description: Cysts are chorate with a spherical to subspherical body from which arise 40 or more nontabular processes. Endophragm is typically thicker than the periphragm, and the wall layers are appressed between processes. Processes are nearly uniform in size and shape, hollow, generally slightly wider proximally than near their tips, more or less circular in cross-section, and expanded and open distally. Surface of processes is smooth, faintly granular or striate, and areas between processes are granular or punctoreticulate. Archeopyle is apical, type A, principal archeopyle suture only slightly angular and accessory sutures are rarely developed. Operculum is free and constituent apical paraplates are not delineated on its surface. Except for the archeopyle, indicators of paratabulation and parasulcus are lacking; paracingulum not expressed or indicated by equatorial alignment of processes. Overall size 60 to 92 µm; body 36 to 45 µm in diameter; processes 15 to 23 µm in length and 3 to 7 µm in basal diameter.
Affinities:
Stover, 1977, p. 75: Specimens of Polysphaeridium pseudocolligerum are nearly identical to those of Diphyes colligerum (Deflandre & Cookson) Cookson 1965, but differ in that D. colligerum has an enlarged, single antapical process that P. pseudocolligerum lacks. The new species differs from P. pastielsii Davey & Williams in Davey et al. 1966 by having longer, narrower and more widely separated processes.
NOW Dapsilidinium. Originally Polysphaeridium, subsequently (and now) Dapsilidinium.
Taxonomic senior synoym: Polysphaeridium (now Dapsilidinium) pastielsii according to Mertens et al. (2014, p.532) — however, Fensome et al., in press, retained Dapsilidinium pseudocolligerum as a separate species
Holotype: Stover, 1977, pl.1, fig.14-16
Paratype: Stover, 1977
Locus typicus: Corehole 5/5B, Blake Plateau, Western N Atlantic
Stratum typicum: Middle Oligocene
Original description: Stover, 1977, p. 75
Description: Cysts are chorate with a spherical to subspherical body from which arise 40 or more nontabular processes. Endophragm is typically thicker than the periphragm, and the wall layers are appressed between processes. Processes are nearly uniform in size and shape, hollow, generally slightly wider proximally than near their tips, more or less circular in cross-section, and expanded and open distally. Surface of processes is smooth, faintly granular or striate, and areas between processes are granular or punctoreticulate. Archeopyle is apical, type A, principal archeopyle suture only slightly angular and accessory sutures are rarely developed. Operculum is free and constituent apical paraplates are not delineated on its surface. Except for the archeopyle, indicators of paratabulation and parasulcus are lacking; paracingulum not expressed or indicated by equatorial alignment of processes. Overall size 60 to 92 µm; body 36 to 45 µm in diameter; processes 15 to 23 µm in length and 3 to 7 µm in basal diameter.
Affinities:
Stover, 1977, p. 75: Specimens of Polysphaeridium pseudocolligerum are nearly identical to those of Diphyes colligerum (Deflandre & Cookson) Cookson 1965, but differ in that D. colligerum has an enlarged, single antapical process that P. pseudocolligerum lacks. The new species differs from P. pastielsii Davey & Williams in Davey et al. 1966 by having longer, narrower and more widely separated processes.