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Trichodinium calvum
From Fensome et al., 2019:
Trichodinium calvum Harding, 1990b, p.37, pl.19, figs.7–12 ex Harding in Williams et al. 1998, p.614.
Holotype: Harding, 1990b, pl.19, fig.7.
This name was not validly published in Harding (1990b) since the lodgement of the holotype was not specified (ICN Article 40.7).
Locus typicus: O. Gott, Lower Saxony, Germany
Stratum typicum: Late Barremian
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Original diagnosis: Harding, 1990, p.37
Shape: Ambitus subspherical to prolate ovoidal. Apex produced into a narrow apical horn. Greatest width across paracingulum. Epicyst (less apical horn) and hypocyst of equal length. No dorso-ventral compression.
Phragma: Differentiated autophragm up to 2.5 µm thick. Surface sculpture pseudoreticulate to microrugulate. Network of sporopollenin rugulae amastomoses into short, fibrous tubercles (up to 2 µm long). The distribution of the tubercles is intratabular. Short, narrow apical horn reaches 12 µm in length in some specimens.
Paratabulation: Parasutures are delineated by "scarp"-like ridges and by the orientation of the tubercles.
Paratabulation appears to be L-type sexiform gonyaulacoid, but the details of the apical paratabulation have not been worked out as yet.
ArchaeopyIe: Type P4 - operculum free, monoplacoid.
Paracingulum: Indicated by alignment of tubercles or by "scarp"-like ridges. Laevorotatory, displaced by ca. 1/2 cingulum widths.
Parasulcus: L-type, slightly indented. Flagellar scar developed. Precise paratabulation indistinct.
Dimensions: Length (84) 69 (56) µm. Width (66) 58 (43) µm. Specimens = 28 (18).
Harding, 1990, p.37: The narrow, true apical horn distinguishes this species from Trichodinium speetonense which has a false apical horn in the form of a tuft of fused spinules. The sparse tuberculation distinguishes this new species the other species of the genus, which have evenly distributed tuberculate/spinose sculptural elements. Restricted to deposits of late Barremian age.
Trichodinium calvum Harding, 1990b, p.37, pl.19, figs.7–12 ex Harding in Williams et al. 1998, p.614.
Holotype: Harding, 1990b, pl.19, fig.7.
This name was not validly published in Harding (1990b) since the lodgement of the holotype was not specified (ICN Article 40.7).
Locus typicus: O. Gott, Lower Saxony, Germany
Stratum typicum: Late Barremian
---------------------------------------------------------------------------------------------------
Original diagnosis: Harding, 1990, p.37
Shape: Ambitus subspherical to prolate ovoidal. Apex produced into a narrow apical horn. Greatest width across paracingulum. Epicyst (less apical horn) and hypocyst of equal length. No dorso-ventral compression.
Phragma: Differentiated autophragm up to 2.5 µm thick. Surface sculpture pseudoreticulate to microrugulate. Network of sporopollenin rugulae amastomoses into short, fibrous tubercles (up to 2 µm long). The distribution of the tubercles is intratabular. Short, narrow apical horn reaches 12 µm in length in some specimens.
Paratabulation: Parasutures are delineated by "scarp"-like ridges and by the orientation of the tubercles.
Paratabulation appears to be L-type sexiform gonyaulacoid, but the details of the apical paratabulation have not been worked out as yet.
ArchaeopyIe: Type P4 - operculum free, monoplacoid.
Paracingulum: Indicated by alignment of tubercles or by "scarp"-like ridges. Laevorotatory, displaced by ca. 1/2 cingulum widths.
Parasulcus: L-type, slightly indented. Flagellar scar developed. Precise paratabulation indistinct.
Dimensions: Length (84) 69 (56) µm. Width (66) 58 (43) µm. Specimens = 28 (18).
Harding, 1990, p.37: The narrow, true apical horn distinguishes this species from Trichodinium speetonense which has a false apical horn in the form of a tuft of fused spinules. The sparse tuberculation distinguishes this new species the other species of the genus, which have evenly distributed tuberculate/spinose sculptural elements. Restricted to deposits of late Barremian age.