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Cyclonephelium vannophorum

Cyclonephelium vannophorum Davey, 1969

Holotype: Davey, 1969, pl. 9, fig. 3; pl.11, figs.11
Locus typicus: Compton Bay, Isle of Wight, 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.

Cyclonephelium compactum Deflandre and Cookson, 1955, has processes which are generally short and joined to one another, forming lamella like projections arranged either parallel to the margin, or in the form of an irregular network. Sometimes a series of processes are joined by short trabeculae. Size: shell 61-72 µm, processes 5-10 µm, overall 72-87 µm.
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Original diagnosis: Davey, 1969, p. 168
Shell subcircular in outline, with slight apical prominence and one or two reduced antapical horns. Shell wall coarsely granular with areas devoid of processes of moderate size. Processes numerous, short, solid, of irregular shape and often confluent distally. Apical archaeopyle with zigzag margin.
Dimensions: length of shell (without operculum) 47(57.8)70 µm, width 56(65.5)78 µm, maximum length of processes 3(5.3)8 µm.

Original description: Davey, 1969, p.168
When two antapical horns are present the portion of the shell between them is concave and from this region a broad furrow passes towards the apex. The furrow or sulcus decreases in width and depth in this direction and disappears just posterior to the archaeopyle margin. The processes vary greatly in size from mere enlarged granules (0.5µm) to 8 µm in length. In the larger processes the stem is quite narrow, the distal third widening rapidly and is sometimes bifurcate. The processes are often joined to form a short line on the shell surface. Rarely the cingulum is just discernible by a concentration of small processes along its borders.

Affinities:
Davey, 1969, p. 168: C. vannophorum sp. nov. is most closely comparable to ?C. attadalicum Cookson & Eisenack (1962) from the AptianlAlbian of Australia. The processes are similar in form but the shell of ?C. attadalicum is more polygonal and the cingulum is always well defined.
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