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Gerdiocysta aciculata
From Fensome et al., 2019:
Gerdiocysta aciculata Châteauneuf, 1980, p.139, pl.24, figs.2,5. Holotype: Châteauneuf, 1980, pl.24, fig.5. Age: Middle
Eocene–Oligocene (Lutetian–Stampian).
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Original description (Châteauneuf, 1980) (translated from French):
Geridocysta aciculata n. sp.
PL. 24, n° 2-5
Origin of the name: from the spinous termination of the trabeculae
Holotype: Sondage des Hogues, slide 1162, coordinates: 73.9/
Type locality: Les Hogues, Sables cuisiens, Lower Cuisian, Paris Basin.
Diagnosis: Geridocysta cyst with greatly reduced ornamentation. Skolochorate, lenticular cyst, bearing peritabular processes with an annular or arcuate base, sometimes occupying the entire surface of the plate. These complex processes are joined distally but very irregularly and bear spinous expansions at their distal end. There is no mid-dorsal depression but a simple mid-ventral zone corresponding to the position of the sulcus. Apical archaeopyle with a zigzag-cut margin. Cyst dimensions: 70/50 u, process height: 5 to 10 u
- Note: The genus Geridocysta differs from the genus Glaphyrocysta (L.E. Stover, WV.R. Evitt 1978), which includes all Tertiary species previously assigned to the genus Cyclonephelium, by the absence of a mid-ventral and mid-dorsal zone free of appendages and, above all, by the very distinct organization of the peritabular processes, grouped in plates, leaving between them more or less smooth zones corresponding to the parasutural areas. This genus differs from the genus Adnatosphaeridium by the more often lenticular than circular appearance of the cyst, by the plate-like organization of the process complexes, and by the nature of the projections: absence of solid, often tabular processes characteristic of the genus Adnatosphaeridium.
Stratigraphy: Lutetian to Upper Stampian (common)
Gerdiocysta aciculata Châteauneuf, 1980, p.139, pl.24, figs.2,5. Holotype: Châteauneuf, 1980, pl.24, fig.5. Age: Middle
Eocene–Oligocene (Lutetian–Stampian).
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Original description (Châteauneuf, 1980) (translated from French):
Geridocysta aciculata n. sp.
PL. 24, n° 2-5
Origin of the name: from the spinous termination of the trabeculae
Holotype: Sondage des Hogues, slide 1162, coordinates: 73.9/
Type locality: Les Hogues, Sables cuisiens, Lower Cuisian, Paris Basin.
Diagnosis: Geridocysta cyst with greatly reduced ornamentation. Skolochorate, lenticular cyst, bearing peritabular processes with an annular or arcuate base, sometimes occupying the entire surface of the plate. These complex processes are joined distally but very irregularly and bear spinous expansions at their distal end. There is no mid-dorsal depression but a simple mid-ventral zone corresponding to the position of the sulcus. Apical archaeopyle with a zigzag-cut margin. Cyst dimensions: 70/50 u, process height: 5 to 10 u
- Note: The genus Geridocysta differs from the genus Glaphyrocysta (L.E. Stover, WV.R. Evitt 1978), which includes all Tertiary species previously assigned to the genus Cyclonephelium, by the absence of a mid-ventral and mid-dorsal zone free of appendages and, above all, by the very distinct organization of the peritabular processes, grouped in plates, leaving between them more or less smooth zones corresponding to the parasutural areas. This genus differs from the genus Adnatosphaeridium by the more often lenticular than circular appearance of the cyst, by the plate-like organization of the process complexes, and by the nature of the projections: absence of solid, often tabular processes characteristic of the genus Adnatosphaeridium.
Stratigraphy: Lutetian to Upper Stampian (common)