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Trichodinium calvum
Trichodinium calvum Harding, 1990b, p.37, pl.19, figs.7–12 ex Harding in Williams et al. 1998, p.614.
This name was not validly published in Harding (1990b) since the lodgement of the holotype was not specified (I.C.N. Article 40.7).
Holotype: Harding, 1990, pl.19, fig.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.
This name was not validly published in Harding (1990b) since the lodgement of the holotype was not specified (I.C.N. Article 40.7).
Holotype: Harding, 1990, pl.19, fig.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.