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Trithyrodinium quinqueangulare
From Fensome et al., 2019:
Trithyrodinium quinqueangulare Marheinecke, 1992, p.95, pl.19, figs.9–11.
Holotype: Marheinecke, 1992, pl.19, figs.9–10.
Contrary to the opinion of Lentin and Williams (1993, p.653), Williams et al. (1998, p.618) considered this name to be be validly published.
Locus typicus: Hemmoor, Lower Saxony, Germany
Stratum typicum: Early Maastrichtian
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Translation Marheinecke, 1992: LPP
Original description: Marheinecke, 1992, p. 95
Periblast rounded pentagonal. Apex rounded or ending in a very short apical horn. Antapex straight. Two very small +/- symmetrical antapical horns may be developed. Length/breadth ratio >/= 1. Wall extremely thin, colourless, usually folded, smooth or granulate. The granulation may be traced from the endoblast. Endoblast: Pentgonal, closely appressed to the periblast except at the apical and antapical horns. Wall thick, light- to dark-brown. Areation indicated by cingulum and archaeopyle. Cingulum clearly developed, sinistral, indicated by two parallel folds. Sulcus indicated by concave indention on the hypocyst. Archaeopyle intercalary 1a+2a+3a; operculum secate, solvat 1a(s)+1a(s)+3a(s). Archaeopyle index >0.7.
The archaeopyle margin may by thickened and is usually more or less rounded. The intercalary area are large, the precingular area therefore weakly developed. Area 4"" often not visibly in LM. In this case, 2a seems to reach the cingulum.
Affinities:
Marheinecke, 1992, p. 95: T. quinqueangulare differs from T. striatum in form of the cyst, thickness of the wall and less frequently appaering antapical horns.
Trithyrodinium quinqueangulare Marheinecke, 1992, p.95, pl.19, figs.9–11.
Holotype: Marheinecke, 1992, pl.19, figs.9–10.
Contrary to the opinion of Lentin and Williams (1993, p.653), Williams et al. (1998, p.618) considered this name to be be validly published.
Locus typicus: Hemmoor, Lower Saxony, Germany
Stratum typicum: Early Maastrichtian
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Translation Marheinecke, 1992: LPP
Original description: Marheinecke, 1992, p. 95
Periblast rounded pentagonal. Apex rounded or ending in a very short apical horn. Antapex straight. Two very small +/- symmetrical antapical horns may be developed. Length/breadth ratio >/= 1. Wall extremely thin, colourless, usually folded, smooth or granulate. The granulation may be traced from the endoblast. Endoblast: Pentgonal, closely appressed to the periblast except at the apical and antapical horns. Wall thick, light- to dark-brown. Areation indicated by cingulum and archaeopyle. Cingulum clearly developed, sinistral, indicated by two parallel folds. Sulcus indicated by concave indention on the hypocyst. Archaeopyle intercalary 1a+2a+3a; operculum secate, solvat 1a(s)+1a(s)+3a(s). Archaeopyle index >0.7.
The archaeopyle margin may by thickened and is usually more or less rounded. The intercalary area are large, the precingular area therefore weakly developed. Area 4"" often not visibly in LM. In this case, 2a seems to reach the cingulum.
Affinities:
Marheinecke, 1992, p. 95: T. quinqueangulare differs from T. striatum in form of the cyst, thickness of the wall and less frequently appaering antapical horns.