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Gonyaulacysta membranea
Gonyaulacysta? membranea Yu Jingxian, 1982
Originally Gonyaulacysta, subsequently Gonyaulacysta?. Pending re-examination of the holotype, Lentin and Williams, 1985, regarded this taxon as a provisionally accepted species of Gonyaulacysta.
Holotype: Yu Jingxian, 1982, pl.3, fig.9
Age: Late Jurassic-Early Cretaceous
Description: Proximate cysts, elliptical; length about twice the width. Apical horn elongated to appear finely clavate. Apical pore at end. Periphragm thin. Surface has granulate decoration. Parasuture membrane-shaped, with finely granulate decoration, especially conspicuous at antapex of hypocyst. Paratabulation same as genus diagnosis, largest plates being 3""" and 4""". Precingular archeopyle, subpolygonal in outline. Paracingulum helical, quite narrow, about 3 µm wide, decorated on edges with stout ridges, and dividing cyst into roughly equivalent upper and lower sections. Parasulcus narrow, extending to epicyst.
Size: Cysts 110 - 115 µm long and 59 - 60 µm wide.
Comparison: This new species resembles G. perforans Cookson & Eisenack in its narrow paracingulum and membrane-shaped suture. It differs, however, in that its individuals are smaller, its paraplates have granulate ornamentation, and its membrane-shaped suture lacks perforations.
Originally Gonyaulacysta, subsequently Gonyaulacysta?. Pending re-examination of the holotype, Lentin and Williams, 1985, regarded this taxon as a provisionally accepted species of Gonyaulacysta.
Holotype: Yu Jingxian, 1982, pl.3, fig.9
Age: Late Jurassic-Early Cretaceous
Description: Proximate cysts, elliptical; length about twice the width. Apical horn elongated to appear finely clavate. Apical pore at end. Periphragm thin. Surface has granulate decoration. Parasuture membrane-shaped, with finely granulate decoration, especially conspicuous at antapex of hypocyst. Paratabulation same as genus diagnosis, largest plates being 3""" and 4""". Precingular archeopyle, subpolygonal in outline. Paracingulum helical, quite narrow, about 3 µm wide, decorated on edges with stout ridges, and dividing cyst into roughly equivalent upper and lower sections. Parasulcus narrow, extending to epicyst.
Size: Cysts 110 - 115 µm long and 59 - 60 µm wide.
Comparison: This new species resembles G. perforans Cookson & Eisenack in its narrow paracingulum and membrane-shaped suture. It differs, however, in that its individuals are smaller, its paraplates have granulate ornamentation, and its membrane-shaped suture lacks perforations.