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Alterbia xinjiangensis
Alterbia xinjiangensis, He Chengquan, 1991
Following I.C.N. Article 55.1, the species name Alterbia xinjiangensis is validly published even though the generic name Alterbia is illegitimate.
Holotype: He Chengquan, 1991, pl.28, fig.3.
Location and stratigraphy: Wuqia County Basebulak;, lower member of the Qimugen Fm.
Age: Paleocene
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Original description: [He Chengquan, 1991]: (translated by Suning Hou, 07-01-2019):
Description:
The cyst is dorsal-ventral flattened, outer contour nearly spindle or nearly pentagonal. Epicyst slightly larger than the hypocyst, nearly an isosceles triangle. A tapering apical horn extends from the top, the top is blunt; The hypocyst is nearly trapezoidal, the sides are flat or slightly concave, with two unequal antapical horns; The larger one is longer, cone usually straight, end blunt, 15-20μm long; The smaller one degenerate into a convex or rounded stair shape. The waist extends more or less outward but lack the lateral horns.
The cingulum is located at the widest position of the cyst, shallow flat, annular, width 6 μm, the edge is marked by a smooth fine ridge.
The sulcus is fuzzy or missing.
The outer wall is thin, the surface is smooth. The outline of the inner body is very close to the outer wall, and usually protrudes strongly into the apical and antapical horns and attaches to or slightly separated from the outer wall by the sides. The inner body surface is smooth.
The archeopyle is intercalary, trapezoidal, but its outline is generally obscure, length is larger than width.
Dimensions:
The cyst length is 60-87.5μm, width 48-60μm, the inner body length 55-72μm, width 48-60μm (measured 4);
The holotype is 84μm long, 50μm wide, The inner body is 67.5μm long, the 50μm wide, the length of the big antapical horn is 15μm, the cingulum is 6μm wide
Affinities/Discussion:
The new species is characterized by the obvious apical and antapical horns of the inner body and the significant unequality of the 2 antapical horns. This species is similar to Alterbia curvicornis in appearance , but the former has a smaller cyst with narrow apical and antapical horns, lacks lateral horns, and the inner body is attached to the outer wall at the sides; Lateral horns are developed in the latter species, the antapical horns are bended into a claw.
Following I.C.N. Article 55.1, the species name Alterbia xinjiangensis is validly published even though the generic name Alterbia is illegitimate.
Holotype: He Chengquan, 1991, pl.28, fig.3.
Location and stratigraphy: Wuqia County Basebulak;, lower member of the Qimugen Fm.
Age: Paleocene
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [He Chengquan, 1991]: (translated by Suning Hou, 07-01-2019):
Description:
The cyst is dorsal-ventral flattened, outer contour nearly spindle or nearly pentagonal. Epicyst slightly larger than the hypocyst, nearly an isosceles triangle. A tapering apical horn extends from the top, the top is blunt; The hypocyst is nearly trapezoidal, the sides are flat or slightly concave, with two unequal antapical horns; The larger one is longer, cone usually straight, end blunt, 15-20μm long; The smaller one degenerate into a convex or rounded stair shape. The waist extends more or less outward but lack the lateral horns.
The cingulum is located at the widest position of the cyst, shallow flat, annular, width 6 μm, the edge is marked by a smooth fine ridge.
The sulcus is fuzzy or missing.
The outer wall is thin, the surface is smooth. The outline of the inner body is very close to the outer wall, and usually protrudes strongly into the apical and antapical horns and attaches to or slightly separated from the outer wall by the sides. The inner body surface is smooth.
The archeopyle is intercalary, trapezoidal, but its outline is generally obscure, length is larger than width.
Dimensions:
The cyst length is 60-87.5μm, width 48-60μm, the inner body length 55-72μm, width 48-60μm (measured 4);
The holotype is 84μm long, 50μm wide, The inner body is 67.5μm long, the 50μm wide, the length of the big antapical horn is 15μm, the cingulum is 6μm wide
Affinities/Discussion:
The new species is characterized by the obvious apical and antapical horns of the inner body and the significant unequality of the 2 antapical horns. This species is similar to Alterbia curvicornis in appearance , but the former has a smaller cyst with narrow apical and antapical horns, lacks lateral horns, and the inner body is attached to the outer wall at the sides; Lateral horns are developed in the latter species, the antapical horns are bended into a claw.