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Nannoceratopsis dictyambonis
Nannoceratopsis dictyambonis Riding, 1984
Holotype: Riding, 1984, pl.1, fig.1
Locus typicus: Cockle Pits Borehole, Humberside, England
Stratum typicum: Late Toarcian-Early Bajocian
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Nannoceratopsis dictyambonis Riding, 1984a, has a reticulate band and is Late Toarcian-Early Bajocian. This species has two unequal antapical horns. The sagittal band may possess a single, rarely two, rows of lacunae. Size: length 58-76 µm, width 34-46 µm
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Original description: Riding, 1984, p. 78
Diagnosis: Species of Nannoceratopsis, subtriangular in outline, possessing two antapical horns which are separated by a concave antapical margin. The dorsal horn is normally the longest. The autophragm is smooth with the exception of the sagittal area. The sagittal band is prominently thickened and is reticulate, usually possessing a single row (rarely two) of lacunae of variable length. Archaeopyle cingular (Piel and Evitt, 1980).
Dimensions: Length 58(68)76 Ám, width 34(40)46 Ám (24 specimens measured).
Affinities:
Riding 1984, p. 79 (annotated)
Members of the Nannoceratopsis gracilis/N. senex complex often have a reticulate autophragm, but this reticulation is present over the entire surface, not confined to the sagittal area as in N. dictyambonis. The lacunae present on the autophragm of N. gracilis/N. senex are also much smaller in diameter than those in the sagittal area of N. dictyambonis.
N. dictyambonis differs from N. ambonis by having a reticulate sagittal band. In most cases N. dictyambonis there is a single row of lacunae on the sagittal band, rarely rarely two parallel rows.
Holotype: Riding, 1984, pl.1, fig.1
Locus typicus: Cockle Pits Borehole, Humberside, England
Stratum typicum: Late Toarcian-Early Bajocian
--------------------------------------------------
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Nannoceratopsis dictyambonis Riding, 1984a, has a reticulate band and is Late Toarcian-Early Bajocian. This species has two unequal antapical horns. The sagittal band may possess a single, rarely two, rows of lacunae. Size: length 58-76 µm, width 34-46 µm
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Original description: Riding, 1984, p. 78
Diagnosis: Species of Nannoceratopsis, subtriangular in outline, possessing two antapical horns which are separated by a concave antapical margin. The dorsal horn is normally the longest. The autophragm is smooth with the exception of the sagittal area. The sagittal band is prominently thickened and is reticulate, usually possessing a single row (rarely two) of lacunae of variable length. Archaeopyle cingular (Piel and Evitt, 1980).
Dimensions: Length 58(68)76 Ám, width 34(40)46 Ám (24 specimens measured).
Affinities:
Riding 1984, p. 79 (annotated)
Members of the Nannoceratopsis gracilis/N. senex complex often have a reticulate autophragm, but this reticulation is present over the entire surface, not confined to the sagittal area as in N. dictyambonis. The lacunae present on the autophragm of N. gracilis/N. senex are also much smaller in diameter than those in the sagittal area of N. dictyambonis.
N. dictyambonis differs from N. ambonis by having a reticulate sagittal band. In most cases N. dictyambonis there is a single row of lacunae on the sagittal band, rarely rarely two parallel rows.