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Rhombodinium majus
From Fensome et al., 2019:
Rhombodinium majus Yu Jingxian, 1982, p.257, pl.8, fig.8. Holotype: Yu Jingxian, 1982, pl.8, fig.8. Questionable assignment: Lentin and Williams (1985, p.307). Williams et al. (2015, p.311) recommended that the name be restricted to the holotype. Age: Late Jurassic–Early Cretaceous.
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Description: Cysts rhombic. Periphragm and endophragm closely appressed. Surface punctately ornamented. Apical horn clavate, hollow, 39.1 µm long, with one pore at end that meets outer furrow. Apical horn fully rounded. Only one lateral horn observed. Paracingulum 16 µm wide, annular, decorated on edges with thick ridges. Precingular archeopyle. Size: Cysts 218.5 µm long and 182.6 µm wide.
Comparison: On the basis of its outline and structure, this new species should be assigned to genus Rhombodinium. It is distinguished from other species in the genus by its large individuals, precingular archeopyle and the presence of only one apical horn.
Rhombodinium majus Yu Jingxian, 1982, p.257, pl.8, fig.8. Holotype: Yu Jingxian, 1982, pl.8, fig.8. Questionable assignment: Lentin and Williams (1985, p.307). Williams et al. (2015, p.311) recommended that the name be restricted to the holotype. Age: Late Jurassic–Early Cretaceous.
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Description: Cysts rhombic. Periphragm and endophragm closely appressed. Surface punctately ornamented. Apical horn clavate, hollow, 39.1 µm long, with one pore at end that meets outer furrow. Apical horn fully rounded. Only one lateral horn observed. Paracingulum 16 µm wide, annular, decorated on edges with thick ridges. Precingular archeopyle. Size: Cysts 218.5 µm long and 182.6 µm wide.
Comparison: On the basis of its outline and structure, this new species should be assigned to genus Rhombodinium. It is distinguished from other species in the genus by its large individuals, precingular archeopyle and the presence of only one apical horn.