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Talimudinium scissurum
Talimudinium scissurum Mao Shaozhi and Norris, 1988
Holotype: Mao Shaozhi and Norris, 1988, pl.15, fig.12; text-fig.18, no.1
Locus typicus: Yigeziya Formation, Simuhana section, China
Stratum typicum: Late Cretaceous
Original diagnosis: Mao Shaozhi and Norris, 1988, p. 48-49
Cyst proximate and cavate, typically bicavate with apical horn and two unequally developed antapical horns. Wall thin; periphragm smooth or with scattered granules, delicate and transparent; endophragm sparsely granulate. Endoblast large, subspherical. Low sutural ridges imperfectly developed or absent. Archeopyle transapical, type (tA3I2P), formed by the loss of apical intercalary and two precingular (1", 2") plates. Archeopyle suture zigzag. Cingulum always present, marked by ridges of low to medium height.
Original description: Mao Shaozhi and Norris, 1988, p. 49
Cyst peridinioid, subspherical in ambital view. Apical horn usually well developed, bluntly pointed, 6 to 10 µm high. Two antapical horns weakly to moderately developed, left one always longer and more distinct and pointed than right. Wall thin, less than 1 µm thick. Periphragm colourless or very light, not staining readily.
Endophragm thicker than periphragm, sparsely granulate; granules usually less than 1 µm across. Subspherical endoblast filling major space of pericoel, resulting in ambital pericoel being narrow (about 2 to 3 µm) or even completely absent. Cingulum planar, 4 to 6 µm wide, distinctly bounded by low- to medium-height ridges, indenting outline laterally. Sulcus sometimes discernible, restricted to hypotract, defined by low ridges. Tabulation not always indicated; when discernible marked by low and imperfect sutural ridges; probably 4", 3a, 7", (6-7)c,5", 2"""".
Length 50 to 80 µm (holotype 66 µm), width 32 to 50 µm (holotype 56 µm).
Affinities:
Mao Shaozhi and Norris, 1988, p. 50: Talimudinium scissurum resembles Palaeoperidinium cretaceum but differs in having a distinct spherical to subspherical endoblast and a transapical combination archeopyle of (tA3I2P). P. cretaceum has a transpical combination archeopyle of (tAtl3P) and usually lacks a distinct endoblast.
Holotype: Mao Shaozhi and Norris, 1988, pl.15, fig.12; text-fig.18, no.1
Locus typicus: Yigeziya Formation, Simuhana section, China
Stratum typicum: Late Cretaceous
Original diagnosis: Mao Shaozhi and Norris, 1988, p. 48-49
Cyst proximate and cavate, typically bicavate with apical horn and two unequally developed antapical horns. Wall thin; periphragm smooth or with scattered granules, delicate and transparent; endophragm sparsely granulate. Endoblast large, subspherical. Low sutural ridges imperfectly developed or absent. Archeopyle transapical, type (tA3I2P), formed by the loss of apical intercalary and two precingular (1", 2") plates. Archeopyle suture zigzag. Cingulum always present, marked by ridges of low to medium height.
Original description: Mao Shaozhi and Norris, 1988, p. 49
Cyst peridinioid, subspherical in ambital view. Apical horn usually well developed, bluntly pointed, 6 to 10 µm high. Two antapical horns weakly to moderately developed, left one always longer and more distinct and pointed than right. Wall thin, less than 1 µm thick. Periphragm colourless or very light, not staining readily.
Endophragm thicker than periphragm, sparsely granulate; granules usually less than 1 µm across. Subspherical endoblast filling major space of pericoel, resulting in ambital pericoel being narrow (about 2 to 3 µm) or even completely absent. Cingulum planar, 4 to 6 µm wide, distinctly bounded by low- to medium-height ridges, indenting outline laterally. Sulcus sometimes discernible, restricted to hypotract, defined by low ridges. Tabulation not always indicated; when discernible marked by low and imperfect sutural ridges; probably 4", 3a, 7", (6-7)c,5", 2"""".
Length 50 to 80 µm (holotype 66 µm), width 32 to 50 µm (holotype 56 µm).
Affinities:
Mao Shaozhi and Norris, 1988, p. 50: Talimudinium scissurum resembles Palaeoperidinium cretaceum but differs in having a distinct spherical to subspherical endoblast and a transapical combination archeopyle of (tA3I2P). P. cretaceum has a transpical combination archeopyle of (tAtl3P) and usually lacks a distinct endoblast.