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Dapsilidinium laminaspinosum

Dapsilidinium laminaspinosum (Davey and Williams, 1966) Lentin and Williams, 1981

Originally Polysphaeridium, subsequently (and now) Dapsilidinium.
Holotype: Davey and Williams, 1966, pl.8, fig.8
Locus typicus: Fetcham Mill, Surrey, England
Stratum typicum: Cenomanian

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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.

Dapsilidinium laminaspinosum (Davey and Williams, 1966b) Lentin and Williams, 1981, is spherical to subspherical with reticulate endophragm. Processes numerous, ca 36, composed of periphragm, cylindrical, smooth and delicate, terminating in entire margin. Characteristic circular impression occurring where processes arise from central body. Processes up to 5 µm wide. A few of the processes are truncated at their distal extremity but most splay out slightly and have a corrugated entire margin. Size: diameter of central body 23-28 µm, processes 11-17 µm.
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Original diagnosis: Davey and Williams, 1966, p. 94: Polysphaeridium laminaspinosum
Spherical to sub-spherical central body composed of reticulate endophragm. Processes numerous, approximately 36 in number, composed of periphragm; cylindrical, smooth and delicate, terminating in entire margin. Characteristic circular impression occurring where process arises from central body.
Dimensions: holotype: diameter of central body 27x27 µm, length of processes 11-15 µm, number of processes 36. Range; diameter of central body 23-28 µm, length of processes 11-17 µm.

Original description: Davey and Williams, p. 94: Polysphaeridium laminaspinosum
The endophragm appears to be granular until examined under high magnification when the reticulate nature becomes apparent. The processes are broadly tubular, up to 5 Ám in width, usually flattened and are often bent. A few of the processes are clearly truncated at their distal extremity, but most splay out slightly and have a corrugated entire margin. A 6-sided apical archaeopyle has been observed in one specimen. The number of processes present indicate that there are two per plate.
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