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Raphidodinium fucatum ssp. compactum
Raphidodinium fucatum subsp. compactum Marheinecke, 1992, p.79, pl.16, figs.1–2. Holotype: Marheinecke, 1992, pl.16, figs.1–2. Contrary to the opinion of Lentin and Williams (1993, p.557), Williams et al. (1998, p.525) considered this name to be validly published. Age: early–late Maastrichtian.
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Original description: [Marheinecke, 1992] (translated from German):
Derivatio nominis: Based on the more compact form compared to the nominate subspecies.
Holotype: The specimen shown on Plate 16, Fig. 1-2 from preparation K872.5 at 11.9/161.1.
Locus typicus: Former chalk pit in Hemmoor (Lower Saxony).
Stratum typicum: Upper Lower Maastrichtian (sumensis zone), chalk.
Description: Cyst habit subspheroidal to polygonal. Wall composed of pedium and luxuria, forming approximately 16-20 gonal processes and septa connecting the process bases. The surface of the cyst is smooth or weakly granulated.
Process structure: Slender, acuminate, distally closed, always unbranched. Length on the order of the cyst diameter. The processes arise from the fusion of the meeting septa. Septal structure: Muri claudate, basal hiatus. The septa are not always continuous, i.e., the
The septa extending from the bases of the processes converge, but do not always meet intergonally. Areation: Not reliably assessable. The pre- and postcingular areas are very large, the apical areas are negligible.
Archeopyle: uncertain, precingular.
Remarks: Since no SEM studies could be carried out on this taxon, no satisfactory data on areation are available. However, the general habitus as well as the process structure and size show a great morphological similarity to R. fucatum.
Comparison: The present taxon differs from the nominate subspecies in the shorter development of the processes and the generally more easily recognizable ridges.
Specimens: approx. 28.
Holotype statistics: length of central capsule: 16, width of central capsule: 13, process length: 12-14.
Statistics: length of central capsule: 16(18)19, width of rib: 13(15)16, process length: 12-17.
Measured specimens: 14.
Known range: Maastrichtian.
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Original description: [Marheinecke, 1992] (translated from German):
Derivatio nominis: Based on the more compact form compared to the nominate subspecies.
Holotype: The specimen shown on Plate 16, Fig. 1-2 from preparation K872.5 at 11.9/161.1.
Locus typicus: Former chalk pit in Hemmoor (Lower Saxony).
Stratum typicum: Upper Lower Maastrichtian (sumensis zone), chalk.
Description: Cyst habit subspheroidal to polygonal. Wall composed of pedium and luxuria, forming approximately 16-20 gonal processes and septa connecting the process bases. The surface of the cyst is smooth or weakly granulated.
Process structure: Slender, acuminate, distally closed, always unbranched. Length on the order of the cyst diameter. The processes arise from the fusion of the meeting septa. Septal structure: Muri claudate, basal hiatus. The septa are not always continuous, i.e., the
The septa extending from the bases of the processes converge, but do not always meet intergonally. Areation: Not reliably assessable. The pre- and postcingular areas are very large, the apical areas are negligible.
Archeopyle: uncertain, precingular.
Remarks: Since no SEM studies could be carried out on this taxon, no satisfactory data on areation are available. However, the general habitus as well as the process structure and size show a great morphological similarity to R. fucatum.
Comparison: The present taxon differs from the nominate subspecies in the shorter development of the processes and the generally more easily recognizable ridges.
Specimens: approx. 28.
Holotype statistics: length of central capsule: 16, width of central capsule: 13, process length: 12-14.
Statistics: length of central capsule: 16(18)19, width of rib: 13(15)16, process length: 12-17.
Measured specimens: 14.
Known range: Maastrichtian.