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Aprobolocysta arguta
Aprobolocysta? arguta, Yu Jingxian, 1982
Originally Aprobolocysta, subsequently (and now) Aprobolocysta?.
Stover and Williams, 1987, considered this to be a "provisionally accepted species" of Aprobolocysta.
Holotype: Yu Jingxian, 1982, pl.1, fig.4
Age: Late Jurassic-Early Cretaceous
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Original description: [Yu Jingxian, 1982]:
Description:
Proximate cysts, elliptical in outline. Periphragm and endophragm but only in hypocyst are they conspicuously separated. Surface granulate. Epicyst gradually narrows towards apex. End splits to form a notch. No conspicuous formation of apical horn. Close to the paracingulum, ornamentation weakens to form a polygonal thinning zone. Further research is needed to determine whether this is equivalent to a precingular archeopyle.
Paracingulum narrow, annular, decorated on edges with ridges of unequal width, and dividing cyst into unequal upper and lower parts. Epicyst conspicuously larger than hypocyst. Epicyst subquadrilateral and hypocyst subcircular.
Paratabulation and parasulcus do not show.
Dimensions:
Size: Cysts 66.7 - 79 µm long and 29.6 - 34.5 µm wide.
Affinities/Comparison:
The new species has some similarities to Aprobolocysta eilema in outline and size but is distinguished from the latter by the fact that its paracingulum does not project beyond the cyst and the double-layered wall separates conspicuously only in the hypocyst.
Originally Aprobolocysta, subsequently (and now) Aprobolocysta?.
Stover and Williams, 1987, considered this to be a "provisionally accepted species" of Aprobolocysta.
Holotype: Yu Jingxian, 1982, pl.1, fig.4
Age: Late Jurassic-Early Cretaceous
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Yu Jingxian, 1982]:
Description:
Proximate cysts, elliptical in outline. Periphragm and endophragm but only in hypocyst are they conspicuously separated. Surface granulate. Epicyst gradually narrows towards apex. End splits to form a notch. No conspicuous formation of apical horn. Close to the paracingulum, ornamentation weakens to form a polygonal thinning zone. Further research is needed to determine whether this is equivalent to a precingular archeopyle.
Paracingulum narrow, annular, decorated on edges with ridges of unequal width, and dividing cyst into unequal upper and lower parts. Epicyst conspicuously larger than hypocyst. Epicyst subquadrilateral and hypocyst subcircular.
Paratabulation and parasulcus do not show.
Dimensions:
Size: Cysts 66.7 - 79 µm long and 29.6 - 34.5 µm wide.
Affinities/Comparison:
The new species has some similarities to Aprobolocysta eilema in outline and size but is distinguished from the latter by the fact that its paracingulum does not project beyond the cyst and the double-layered wall separates conspicuously only in the hypocyst.