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Hystrichokolpoma proprium
From Fensome et al., 2019:
Hystrichokolpoma proprium (Marheinecke, 1992, p.60–61, pl.11, figs.4–8) Foucher in Fauconnier and Masure, 2004, p.283. Holotype: Marheinecke, 1992, pl.11, figs.4–6; Fauconnier and Masure, 2004, pl.40, figs.1–3. Originally Hystrichosphaeridium, subsequently (and now) Hystrichokolpoma. Contrary to the opinion of Lentin and Williams (1993, p.327), Williams et al. (1998, p.310) considered the name Hystrichosphaeridium proprium to be validly published. Age: late Maastrichtian.
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Original description: [Marheinecke, 1992] (translated from German):
Derivation of the name: Proper (lat.): Characteristic.
Holotype: The specimen shown on Plate 11, Fig. 4-6 from preparation 1949.3 at 10.7/140.6.
Locus typicus: Former Hemmoor chalk pit (Lower Saxony).
Stratum typicalum: Lower Upper Maastrichtian (Argentral Junior Zone), flint.
Description: Chorate cyst, sphaeroidal to subsphaeroidal. Wall consisting of pedium and luxuria. The luxuria forms hollow, broad-tubiform, intraareate processes, distally partly open, partly closed with a thin membrane with an aculeate, rounded margin.
Accedation formula: 1?pr, 4', 6", 6c, 5-6'", 1p, 1"", 3-5s.
Archeopyle: apical, ?pr+1'+2'+3'+4', operculum secat, foederate (?pr+1'+2'+3'+4'). The luxuria is usually alveolate and forms a foveolate tegillum between the processes. Forms with a compactly fused pedium/luxuria form a smooth surface. The apical, precingular, postcingular, and antapic processes form subangular attachment scars. The cingular processes form oval scars and an oval cross-section; the sulcal processes have an almost round cross-section, round scars, and are overall slimmer. The terminal margin of the processes can range from aculeate to strongly frayed.
Additional note: No specimens with an operculum in situ could be found in the available material, so the presence of a proprium process is only based on the discovery of a single operculum. The archeopyle is formed by the same plates as in Hystrichosphaeridium tubiferum, but the resulting opening is larger in relation to the central capsule.
Comparison: Hystrichosphaeridium proprium differs from Hystrichosphaeridium tubiferum in the shape of the processes, their attachment scars, the ratio of process length to central capsule diameter, and the appearance of the archeopyle.
Specimens: 85.
Holotype statistics: Central capsule length: 50, central capsule width: 48, process length: 24-28, archeopyle diameter: 38.
Statistics: central capsule length: 39(47)51, central capsule width: 38(44)48, length of the processes: 15-28, archaeopyle diameter: 22-40.
Measured specimens: 12.
Known range: Maastrichtian-Paleocene.
Hystrichokolpoma proprium (Marheinecke, 1992, p.60–61, pl.11, figs.4–8) Foucher in Fauconnier and Masure, 2004, p.283. Holotype: Marheinecke, 1992, pl.11, figs.4–6; Fauconnier and Masure, 2004, pl.40, figs.1–3. Originally Hystrichosphaeridium, subsequently (and now) Hystrichokolpoma. Contrary to the opinion of Lentin and Williams (1993, p.327), Williams et al. (1998, p.310) considered the name Hystrichosphaeridium proprium to be validly published. Age: late Maastrichtian.
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Original description: [Marheinecke, 1992] (translated from German):
Derivation of the name: Proper (lat.): Characteristic.
Holotype: The specimen shown on Plate 11, Fig. 4-6 from preparation 1949.3 at 10.7/140.6.
Locus typicus: Former Hemmoor chalk pit (Lower Saxony).
Stratum typicalum: Lower Upper Maastrichtian (Argentral Junior Zone), flint.
Description: Chorate cyst, sphaeroidal to subsphaeroidal. Wall consisting of pedium and luxuria. The luxuria forms hollow, broad-tubiform, intraareate processes, distally partly open, partly closed with a thin membrane with an aculeate, rounded margin.
Accedation formula: 1?pr, 4', 6", 6c, 5-6'", 1p, 1"", 3-5s.
Archeopyle: apical, ?pr+1'+2'+3'+4', operculum secat, foederate (?pr+1'+2'+3'+4'). The luxuria is usually alveolate and forms a foveolate tegillum between the processes. Forms with a compactly fused pedium/luxuria form a smooth surface. The apical, precingular, postcingular, and antapic processes form subangular attachment scars. The cingular processes form oval scars and an oval cross-section; the sulcal processes have an almost round cross-section, round scars, and are overall slimmer. The terminal margin of the processes can range from aculeate to strongly frayed.
Additional note: No specimens with an operculum in situ could be found in the available material, so the presence of a proprium process is only based on the discovery of a single operculum. The archeopyle is formed by the same plates as in Hystrichosphaeridium tubiferum, but the resulting opening is larger in relation to the central capsule.
Comparison: Hystrichosphaeridium proprium differs from Hystrichosphaeridium tubiferum in the shape of the processes, their attachment scars, the ratio of process length to central capsule diameter, and the appearance of the archeopyle.
Specimens: 85.
Holotype statistics: Central capsule length: 50, central capsule width: 48, process length: 24-28, archeopyle diameter: 38.
Statistics: central capsule length: 39(47)51, central capsule width: 38(44)48, length of the processes: 15-28, archaeopyle diameter: 22-40.
Measured specimens: 12.
Known range: Maastrichtian-Paleocene.