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Cladopyxidium marheineckei
From Fensome et al., 2019:
Cladopyxidium marheineckei Williams et al., 1998, p.118. Holotype: Marheinecke, 1992, pl.21, figs.8–10, as Cladopyxidium velatum. Originally Cladopyxidium velatum Marheinecke, subsequently (and now) Cladopyxidium marheineckei. This is the substitute name for Cladopyxidium velatum Marheinecke 1992, p.104, pl.21, figs.8–10; pl.22, figs.13–15 (an illegitimate name). Age: late Maastrichtian.
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Original description: [Marheinecke, 1992, p. 104] (translated from German):
Cladopyxidium velatum n. sp.
Derivatio nominis: Velare (Latin) veiled, after the veil-like enlarged septa of the hypocyst.
Holotype: The specimen shown on Plate 21, Figs. 8-10 from VF9493 at 15.3/168.8; MARHEINECKE Collection.
Locus typicus: Former chalk pit Hemmoor (Lower Saxony).
Stratum typicum: Upper Upper Maastrichtian (Baltica/Danica zone), flint.
Description: Cyst small, proximochorate, acavate, ovaloidal. Wall consisting of a smooth pedium with luxuria forming finate septa. The height of the septa on the epicyst corresponds to the values known from other species of this genus, i.e., approx. 2-3. On the hypocyst, the height of the septa increases sharply from the cingulum to the antapex, so that the septal height at the antapex can reach more than half the length of the cincture duct. Typical values are 0.3–0.5 cincture duct lengths. Despite their great height, the structure of the septa remains unchanged, i.e., there is no enveloping membrane, as might easily appear in the LM. In addition to finite septa, nonfinite septa can also occur. The overall appearance of the septal arrangement lies between the very clearly recognizable arrangement of C. saeptum and the very poorly recognizable arrangement of C. reticulatum n.comb. The cincture duct displays irregular ornamentation consisting mostly of a few pores. The arrangement shows the typical Cladopyxidium pattern with a triangular 1".
Arranging formula: 4', 4a, 7", 7c, 6'", 2"", as, FM, Is. Archeopyl apical, ?PR+2'+3'. Operculum secat, foederate, (?PR+2'+3'). The archeopyl is circular, the margin is usually bent over like a bottleneck.
Remarks: The wall structure appears to correspond to the pattern known from SEM examinations of other species.
Comparison: C. velatum is distinguished from all other species of this genus by the very conspicuous formation of the septa on the hypocyst. Since the overall pattern of the septa is intermediate between C. saeptum and C. reticulatum, it is not possible to consider C. velatum a subspecies of either of these species.
Specimens: >20.
Statistics Holotype: Length: 23, Width: 20, Max. Height of Septa: 10
Statistics: Length: 21(22)24, Width: 19(20)22, Max. height of septa: 6-12.
Measured specimens: 10.
Known range: Upper Maastrichtian
Cladopyxidium marheineckei Williams et al., 1998, p.118. Holotype: Marheinecke, 1992, pl.21, figs.8–10, as Cladopyxidium velatum. Originally Cladopyxidium velatum Marheinecke, subsequently (and now) Cladopyxidium marheineckei. This is the substitute name for Cladopyxidium velatum Marheinecke 1992, p.104, pl.21, figs.8–10; pl.22, figs.13–15 (an illegitimate name). Age: late Maastrichtian.
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Original description: [Marheinecke, 1992, p. 104] (translated from German):
Cladopyxidium velatum n. sp.
Derivatio nominis: Velare (Latin) veiled, after the veil-like enlarged septa of the hypocyst.
Holotype: The specimen shown on Plate 21, Figs. 8-10 from VF9493 at 15.3/168.8; MARHEINECKE Collection.
Locus typicus: Former chalk pit Hemmoor (Lower Saxony).
Stratum typicum: Upper Upper Maastrichtian (Baltica/Danica zone), flint.
Description: Cyst small, proximochorate, acavate, ovaloidal. Wall consisting of a smooth pedium with luxuria forming finate septa. The height of the septa on the epicyst corresponds to the values known from other species of this genus, i.e., approx. 2-3. On the hypocyst, the height of the septa increases sharply from the cingulum to the antapex, so that the septal height at the antapex can reach more than half the length of the cincture duct. Typical values are 0.3–0.5 cincture duct lengths. Despite their great height, the structure of the septa remains unchanged, i.e., there is no enveloping membrane, as might easily appear in the LM. In addition to finite septa, nonfinite septa can also occur. The overall appearance of the septal arrangement lies between the very clearly recognizable arrangement of C. saeptum and the very poorly recognizable arrangement of C. reticulatum n.comb. The cincture duct displays irregular ornamentation consisting mostly of a few pores. The arrangement shows the typical Cladopyxidium pattern with a triangular 1".
Arranging formula: 4', 4a, 7", 7c, 6'", 2"", as, FM, Is. Archeopyl apical, ?PR+2'+3'. Operculum secat, foederate, (?PR+2'+3'). The archeopyl is circular, the margin is usually bent over like a bottleneck.
Remarks: The wall structure appears to correspond to the pattern known from SEM examinations of other species.
Comparison: C. velatum is distinguished from all other species of this genus by the very conspicuous formation of the septa on the hypocyst. Since the overall pattern of the septa is intermediate between C. saeptum and C. reticulatum, it is not possible to consider C. velatum a subspecies of either of these species.
Specimens: >20.
Statistics Holotype: Length: 23, Width: 20, Max. Height of Septa: 10
Statistics: Length: 21(22)24, Width: 19(20)22, Max. height of septa: 6-12.
Measured specimens: 10.
Known range: Upper Maastrichtian