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Laciniadinium conpicuum
Laciniadinium conpicuum (Yu Jingxian et al., 1981, p.261, pl.1, figs.20–22,24; text-fig.2) He Chengquan et al., 2009, p.387.
Originally Bellatudinium, subsequently (and now) Laciniadinium. He Chengquan et al. (2009, p.387) spelled the epithet as "conspicuum".
Holotype: Yu Jingxian et al., 1981, pl.1, fig.20.
Age: Late Cretaceous.
Description: Outline asymmetrically pyriform to elongatedly pentagonal. Periphragm only, thin, transparent, with fine sutural ridge along margin of body perpendicular to edge. Surface rough. Upper test conspicuously larger than lower test, looking like a distorted triangle or elongated isosceles triangle; sides straight or one side curves in an arc; 23 - 32 µm in height. Apical horn not conspicuous, being formed by the gradual compression of the apical end of the upper test. Apical pore circular. Lower test irregularly quadrilateral or trapezoidal, 16 - 20 µm high. Two antapical horns, slightly developed and of unequal size. No tabulation or archaeopyle observed. Cingulum annular, 3 - 4 µm wide, [opening into] staggered [pattern] in Ventral region; conspicuous sutural ridge on edge. Sulcus long, with apex reaching upper test. Ridge along edge of sulcus often has 2 - 3 circular "nuclei" arranged in a row.
Size: Cysts 52.9 - 57.5 µm long and 23 - 29 µm wide. Holotype 52.9 x 39 µm.
Discussion: This species is distinguished from others in the same genus by its large individuals, the asymmetrically pyriform to elongatedly pentagonal outline, its long, wide sulcus and the 2 - 3 circular "nuclei" that commonly appear aligned along the edge of the sulcus.
Originally Bellatudinium, subsequently (and now) Laciniadinium. He Chengquan et al. (2009, p.387) spelled the epithet as "conspicuum".
Holotype: Yu Jingxian et al., 1981, pl.1, fig.20.
Age: Late Cretaceous.
Description: Outline asymmetrically pyriform to elongatedly pentagonal. Periphragm only, thin, transparent, with fine sutural ridge along margin of body perpendicular to edge. Surface rough. Upper test conspicuously larger than lower test, looking like a distorted triangle or elongated isosceles triangle; sides straight or one side curves in an arc; 23 - 32 µm in height. Apical horn not conspicuous, being formed by the gradual compression of the apical end of the upper test. Apical pore circular. Lower test irregularly quadrilateral or trapezoidal, 16 - 20 µm high. Two antapical horns, slightly developed and of unequal size. No tabulation or archaeopyle observed. Cingulum annular, 3 - 4 µm wide, [opening into] staggered [pattern] in Ventral region; conspicuous sutural ridge on edge. Sulcus long, with apex reaching upper test. Ridge along edge of sulcus often has 2 - 3 circular "nuclei" arranged in a row.
Size: Cysts 52.9 - 57.5 µm long and 23 - 29 µm wide. Holotype 52.9 x 39 µm.
Discussion: This species is distinguished from others in the same genus by its large individuals, the asymmetrically pyriform to elongatedly pentagonal outline, its long, wide sulcus and the 2 - 3 circular "nuclei" that commonly appear aligned along the edge of the sulcus.