Back
Cyclonephelium eisenackii
From Fensome et al., 2019:
Cyclonephelium eisenackii Davey, 1969a, p.170, pl.8, figs.3–4; pl.9, fig.4; text-figs.16a–b.
Holotype: Davey, 1969a, pl.8, fig.4. Originally Cyclonephelium, subsequently Aptea, thirdly Pseudoceratium.
Taxonomic senior synonym: Aptea (now Pseudoceratium) polymorpha, according to Cookson and Eisenack (1974, p.74) — however, Below (1981a, p.7) retained Cyclonephelium (as Aptea) eisenackii.
Taxonomic senior synonym: Cyclonephelium compactum, according to Fensome et al. (2019a, p.40).
Age: late Albian.
---------------------------------------------------------------------------------------------------
Original diagnosis: Davey, 1969, p.170
Shell subtriangular, flattened, with convex sides. Apical horn well developed; antapical horns, if present, very reduced. Greater part of shell surface ornamented by complex network of low crests and short, capitate processes. In centre of both dorsal and ventral sides there is a circular area devoid of ornamentation. Apical archaeopyle always present.
Dimensions: shell length 70-92 µm (4 complete specimens measured); shell length (operculum missing) 55 (63.1) 71 µm, width 66 (72.1) 84 µm, height of crests 2 (4.2) 7 µm.
Original description: Davey, 1969, p.171
The shell surface is ornamented by a very characteristic network of low crests or lamellae which are often broken, so forming isolated processes. A poorly-marked cingulum, outlined by the crests, is occasionally discernible. The apical operculum is often in position.
Cyclonephelium eisenackii Davey, 1969a, p.170, pl.8, figs.3–4; pl.9, fig.4; text-figs.16a–b.
Holotype: Davey, 1969a, pl.8, fig.4. Originally Cyclonephelium, subsequently Aptea, thirdly Pseudoceratium.
Taxonomic senior synonym: Aptea (now Pseudoceratium) polymorpha, according to Cookson and Eisenack (1974, p.74) — however, Below (1981a, p.7) retained Cyclonephelium (as Aptea) eisenackii.
Taxonomic senior synonym: Cyclonephelium compactum, according to Fensome et al. (2019a, p.40).
Age: late Albian.
---------------------------------------------------------------------------------------------------
Original diagnosis: Davey, 1969, p.170
Shell subtriangular, flattened, with convex sides. Apical horn well developed; antapical horns, if present, very reduced. Greater part of shell surface ornamented by complex network of low crests and short, capitate processes. In centre of both dorsal and ventral sides there is a circular area devoid of ornamentation. Apical archaeopyle always present.
Dimensions: shell length 70-92 µm (4 complete specimens measured); shell length (operculum missing) 55 (63.1) 71 µm, width 66 (72.1) 84 µm, height of crests 2 (4.2) 7 µm.
Original description: Davey, 1969, p.171
The shell surface is ornamented by a very characteristic network of low crests or lamellae which are often broken, so forming isolated processes. A poorly-marked cingulum, outlined by the crests, is occasionally discernible. The apical operculum is often in position.