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Pseudoceratium iveri
Pseudoceratium iveri Nohr-Hansen, 1993
Holotype: Nohr-Hansen, 1993, pl.19, fig.1, text-fig.11
Locus typicus: Section 17, Aucella Bjerg, Wollaston Forland, East Greenland
Stratum typicum: Uppermost Barremian
Original diagnosis: Nohr-Hansen, 1993, p.100
The species is a large, dorso-ventrally compressed ceratioid cyst, with long, pointed apical, right lateral and left antapical horns. The species has two wall layers. The ectophragm consists of a complicated network, supported by processes. The network extends the horn terminations and is concentrated on the plates, leaving the pandasutural areas free of ornamentation. Tabulation is ceratioid. Cingulum is characterised by a narrow broken flange and sulcal plates have low ornamentation. The archeopyle is apical (type tA).
Original description: Nohr-Hansen, 1993, p.101
Cyst type. Proximate, ceratioid.
Shape. Dorso-ventrally compressed cyst with three moderately long horns, an apical, a right lateral (cingular/ post-cingular) and an antapical horn. The three horns are situated with approximately 120¦ spacing.
Wall relationship. The cyst-wall is two-layered and composed of autophragm and ectophragm.
Wall features. The autophragm has a shagreenate to microperforate outer surface in the pandasuture areas (Plate 19, Fig. 4) whereas the plates are covered with processes. The processes supports the ectophragm which consist of an irregular intratabular network. The ectophragm extends the horn terminations up to 15 µm. Ectophragm and autophragm are close in the sulcal area and on plate 6" PIate 19, Fig. 5) whereas elsewhere the ectophragm is elevated up to 7 µm by processes and pillars on the plates Plate 19, Figs 3-5).
Tabulation. The tabulation is difficult to observe in transmitted light. In SEM the tabulation is seen to be ceratioid 4", 6", ?6c, 6""", 1p, 1"""" with probably 5 small sulcal plates (as, ls, ras, rs, ls and ps). The tabulation is expressed by the pandasutures which are devoid of the reticulate ectophragm. The antapical plate 1"""" is rather large, sexiform, and together with plate 1p, composes the antapical horn. The small plate 1""" is situated above plate 1p, and extends slightly into the sulcal area. Cingulum appears to be composed of a broken flange. The plate 6" is large and a distinct sulcal notch is formed between 6" and 1". The length-axis of the sulcal area is twisted from the right side of the hypocyst to the left side of the epicyst. Five sulcal plates of very low relief have been distinguished.
Archeopyle. Apical (type tA).
Holotype: Nohr-Hansen, 1993, pl.19, fig.1, text-fig.11
Locus typicus: Section 17, Aucella Bjerg, Wollaston Forland, East Greenland
Stratum typicum: Uppermost Barremian
Original diagnosis: Nohr-Hansen, 1993, p.100
The species is a large, dorso-ventrally compressed ceratioid cyst, with long, pointed apical, right lateral and left antapical horns. The species has two wall layers. The ectophragm consists of a complicated network, supported by processes. The network extends the horn terminations and is concentrated on the plates, leaving the pandasutural areas free of ornamentation. Tabulation is ceratioid. Cingulum is characterised by a narrow broken flange and sulcal plates have low ornamentation. The archeopyle is apical (type tA).
Original description: Nohr-Hansen, 1993, p.101
Cyst type. Proximate, ceratioid.
Shape. Dorso-ventrally compressed cyst with three moderately long horns, an apical, a right lateral (cingular/ post-cingular) and an antapical horn. The three horns are situated with approximately 120¦ spacing.
Wall relationship. The cyst-wall is two-layered and composed of autophragm and ectophragm.
Wall features. The autophragm has a shagreenate to microperforate outer surface in the pandasuture areas (Plate 19, Fig. 4) whereas the plates are covered with processes. The processes supports the ectophragm which consist of an irregular intratabular network. The ectophragm extends the horn terminations up to 15 µm. Ectophragm and autophragm are close in the sulcal area and on plate 6" PIate 19, Fig. 5) whereas elsewhere the ectophragm is elevated up to 7 µm by processes and pillars on the plates Plate 19, Figs 3-5).
Tabulation. The tabulation is difficult to observe in transmitted light. In SEM the tabulation is seen to be ceratioid 4", 6", ?6c, 6""", 1p, 1"""" with probably 5 small sulcal plates (as, ls, ras, rs, ls and ps). The tabulation is expressed by the pandasutures which are devoid of the reticulate ectophragm. The antapical plate 1"""" is rather large, sexiform, and together with plate 1p, composes the antapical horn. The small plate 1""" is situated above plate 1p, and extends slightly into the sulcal area. Cingulum appears to be composed of a broken flange. The plate 6" is large and a distinct sulcal notch is formed between 6" and 1". The length-axis of the sulcal area is twisted from the right side of the hypocyst to the left side of the epicyst. Five sulcal plates of very low relief have been distinguished.
Archeopyle. Apical (type tA).