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Psaligonyaulax circularis
Psaligonyaulax circularis He Chengquan, 1991
Holotype: He Chengquan, 1991, pl.29, fig.11
Age: Paleocene
Description from He Chengquan, 1991, translated by Suning Hou, 07-01-2019
Description: Bicavate cyst, outline elongated shape, divided into nearly 2 equal parts by the cingulum, or the lower cyst slightly larger. Upper cyst nearly triangle, the sides slightly concave, with a conical apical horn, 10μm long, top blunt. Lower cyst nearly square, lack of antapical horn. Cingulum spiral, width 6μm, the edge is marked by smooth fine ridges, paratabulation of the cingulum is clear. Sulcus extends into the upper cyst. The outer wall is thin, with plates; Plates are marked by sutural smooth ridges, the surface is smooth. The inner contour is nearly round, surface smooth-nearly smooth; The outer cavate only develops at the apex and antapex, the inner and outer wall contact with each other. Archeopyle precingular, P-type, formed by the movement of the third precingular cyst. Operculum preserved in situ. Cyst length 64μm, width 43μm, inner body length 43μm, width 40μm.
Comparison: This species differs from Psaligonyaulax simplicial in smaller individuals and nearly-round inner body.
Location and stratigraphy: Wuqia County Basebulak; Qimugen fm lower member.
Holotype: He Chengquan, 1991, pl.29, fig.11
Age: Paleocene
Description from He Chengquan, 1991, translated by Suning Hou, 07-01-2019
Description: Bicavate cyst, outline elongated shape, divided into nearly 2 equal parts by the cingulum, or the lower cyst slightly larger. Upper cyst nearly triangle, the sides slightly concave, with a conical apical horn, 10μm long, top blunt. Lower cyst nearly square, lack of antapical horn. Cingulum spiral, width 6μm, the edge is marked by smooth fine ridges, paratabulation of the cingulum is clear. Sulcus extends into the upper cyst. The outer wall is thin, with plates; Plates are marked by sutural smooth ridges, the surface is smooth. The inner contour is nearly round, surface smooth-nearly smooth; The outer cavate only develops at the apex and antapex, the inner and outer wall contact with each other. Archeopyle precingular, P-type, formed by the movement of the third precingular cyst. Operculum preserved in situ. Cyst length 64μm, width 43μm, inner body length 43μm, width 40μm.
Comparison: This species differs from Psaligonyaulax simplicial in smaller individuals and nearly-round inner body.
Location and stratigraphy: Wuqia County Basebulak; Qimugen fm lower member.