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Cyclonephelium reductum
Cyclonephelium "reductum" Châteauneuf, 1980, p.136, pl.21, fig.10.
NOW Tenua Eisenack. Originally Cyclonephelium, subsequently (and now) Tenua Eisenack.
Holotype: Châteauneuf, 1980, pl.21, fig.10; Fauconnier and Masure, 2004, pl.18, figs.11–15.
Age: late Eocene (Marinesian–Ludian).
Original decription (Châteauneuf, 1980): Translation PKB 2024
Cyclonephelium reductum n.sp. (Pl. 1493)
Origin of the name: from the nature of the appendages
Holotype: Chelles survey, Sc. 4, slide 9218, coordinates: 41.2/121/10
Type locality: Chelles, St. Ouen Limestone, Marinesian, Paris Basin
Diagnosis: Lenticular cyst with asymmetrical antapical protuberance. Cut apical margin, dorsal-ventral flattening and medial constriction of the cyst. Cyst wall made up of a thin layer or autophragm. Sutural characters not discernible. There is no process in this type of cingulate alignment. The tabulation is expressed only by the zig-zag division of the margin of the archeopyle. Apical archaeopyle with free operculum. Dense ornamentation, composed only of spines of very variable length, with a less widened base and an unordered arrangement on the surface of the cyst. Reduction of ornamentation in the mid-ventral and dorsal areas. The autophagm is decorated between the thorns.
Dimensions de l’holotype : Hauteur 60 µm, largeur 70 µm, dimensions des épines : 2 à 5 µm – variations de taille kyste : 55-65 µm/60-70 µm, épines : 1 à 7 µm.
Stratigraphy: Marinesian to Lundien (common)
Note: this species characterizes highly desalinated deposits in the Paris Basin. It is part of quasi-monospecific groups and can reach high values, particularly in the St. Ouen Limestone.
NOW Tenua Eisenack. Originally Cyclonephelium, subsequently (and now) Tenua Eisenack.
Holotype: Châteauneuf, 1980, pl.21, fig.10; Fauconnier and Masure, 2004, pl.18, figs.11–15.
Age: late Eocene (Marinesian–Ludian).
Original decription (Châteauneuf, 1980): Translation PKB 2024
Cyclonephelium reductum n.sp. (Pl. 1493)
Origin of the name: from the nature of the appendages
Holotype: Chelles survey, Sc. 4, slide 9218, coordinates: 41.2/121/10
Type locality: Chelles, St. Ouen Limestone, Marinesian, Paris Basin
Diagnosis: Lenticular cyst with asymmetrical antapical protuberance. Cut apical margin, dorsal-ventral flattening and medial constriction of the cyst. Cyst wall made up of a thin layer or autophragm. Sutural characters not discernible. There is no process in this type of cingulate alignment. The tabulation is expressed only by the zig-zag division of the margin of the archeopyle. Apical archaeopyle with free operculum. Dense ornamentation, composed only of spines of very variable length, with a less widened base and an unordered arrangement on the surface of the cyst. Reduction of ornamentation in the mid-ventral and dorsal areas. The autophagm is decorated between the thorns.
Dimensions de l’holotype : Hauteur 60 µm, largeur 70 µm, dimensions des épines : 2 à 5 µm – variations de taille kyste : 55-65 µm/60-70 µm, épines : 1 à 7 µm.
Stratigraphy: Marinesian to Lundien (common)
Note: this species characterizes highly desalinated deposits in the Paris Basin. It is part of quasi-monospecific groups and can reach high values, particularly in the St. Ouen Limestone.