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Endoceratium pentagonum
Endoceratium pentagonum Singh, 1983
Now Nyktericysta. Originally Endoceratium, subsequently (and now) Nyktericysta.
Holotype: Singh, 1983, pl.44, fig.2
Locus typicus: Dunvegan Formation of the Peace River area
Stratum typicum: Middle Cenomanian
Original description: Singh, 1983, p. 128
Proximate, cavate cysts; body pentagonal with one apical, one antapical, and one slightly lower postcingular horn; the posterior edge of paracingulum with two antapically pointed, minute, cingular horns; apical and antapical horns pointed, 18 to 24 Ám long; postcingular horn broad based, sharply pointed, and about 12 Ám long; cingular horns minute, conical, sharply pointed, and 3 to 5 Ám long; endocyst dark, pentagonal, protruding into the horns up to the tips, and in contact with the pericyst only in the paracingular region and near the tips of the horns; periphragm smooth and membranous; surface of the endophragm faintly reticulate; lumina imperfect, 3 to 5 Ám wide; muri 0.5 to 1 Ám wide; fine pillars with bifid tips occasionally arising from the muri junctions and supporting the periphragm; paratabulation and parasulcus not discernible; position of paracingulum indicated by minute, cingular horns; archeopyle apical, type tA; operculum free, usually adherent.
Size range: Length of the pericyst 109(111)113 Ám. Holotype 109 Ám. Breadth of the pericyst 73(75)77 Ám. Holotype 73 Ám. Specimens measured 3.
Affinities:
Singh, 1983, p. 128: Endoceratium pentagonum differs from other species of the genus Endoceratium in having a pentagonal shape and a slightly lower postcingular horn, which give it a peridinioid rather than a ceratioid appearance. However, some morphological features of E. pentagonum n. sp. are comparable to those of other species of Endoceratium. The reticulate pattern on the endocyst and the occasional supporting pillars between the endophragm and periphragm of E. pentagonum resemble those of Endoceratium ludbrookiae (Cookson and Eisenack) Loeblich and Loeblich, 1966. The specimens of Endoceratium dettmanniae (Cookson and Hughes) Stover and Evitt, 1978 exhibit rudimentary cingular processes similar to those of E. pentagonum.
Now Nyktericysta. Originally Endoceratium, subsequently (and now) Nyktericysta.
Holotype: Singh, 1983, pl.44, fig.2
Locus typicus: Dunvegan Formation of the Peace River area
Stratum typicum: Middle Cenomanian
Original description: Singh, 1983, p. 128
Proximate, cavate cysts; body pentagonal with one apical, one antapical, and one slightly lower postcingular horn; the posterior edge of paracingulum with two antapically pointed, minute, cingular horns; apical and antapical horns pointed, 18 to 24 Ám long; postcingular horn broad based, sharply pointed, and about 12 Ám long; cingular horns minute, conical, sharply pointed, and 3 to 5 Ám long; endocyst dark, pentagonal, protruding into the horns up to the tips, and in contact with the pericyst only in the paracingular region and near the tips of the horns; periphragm smooth and membranous; surface of the endophragm faintly reticulate; lumina imperfect, 3 to 5 Ám wide; muri 0.5 to 1 Ám wide; fine pillars with bifid tips occasionally arising from the muri junctions and supporting the periphragm; paratabulation and parasulcus not discernible; position of paracingulum indicated by minute, cingular horns; archeopyle apical, type tA; operculum free, usually adherent.
Size range: Length of the pericyst 109(111)113 Ám. Holotype 109 Ám. Breadth of the pericyst 73(75)77 Ám. Holotype 73 Ám. Specimens measured 3.
Affinities:
Singh, 1983, p. 128: Endoceratium pentagonum differs from other species of the genus Endoceratium in having a pentagonal shape and a slightly lower postcingular horn, which give it a peridinioid rather than a ceratioid appearance. However, some morphological features of E. pentagonum n. sp. are comparable to those of other species of Endoceratium. The reticulate pattern on the endocyst and the occasional supporting pillars between the endophragm and periphragm of E. pentagonum resemble those of Endoceratium ludbrookiae (Cookson and Eisenack) Loeblich and Loeblich, 1966. The specimens of Endoceratium dettmanniae (Cookson and Hughes) Stover and Evitt, 1978 exhibit rudimentary cingular processes similar to those of E. pentagonum.