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Ellipsoidictyum minusculum
Plate 7, Figures 4, 5, 9, 10-13
Holotype: Plate 7, Figures 12, 13
Paratype: Plate 7, Figures 4, 5, 9
Type Locality: Vergol outcrop, Valanginian. Holotype: early Valanginian, Bed V94M, , inostranzewi ammonite Zone, inostranzewi Sub-zone, Slide V94M(schulze), E.F. C55.2. Paratype: late Valanginian, Bed V102M, verrucosum ammonite Zone, verrucosum Sub-zone, Slide V102M/(schulze), E.F. F39.3.
Derivation of Name: From the Latin minusculus, rather small - in reference to the size of this species.
Diagnosis: A small, relatively thick-walled species with a spheroidal main body and with the epicyst approximately equal in length to the hypocyst. The epicyst is rounded triangular in outline and typically extends into a low apical prominence. The hypocyst is semicircular. A vestigial reticulum of variable mesh size covers the cyst, and some lineation of crests marks a broad cingulum. The archeopyle is apical, with the operculum attached.
Dimensions: Holotype 35 × 35 μm
Paratype 41 × 41 μm
Overall 43 (38) 33 μm × 43 (38) 33 μm.
Specimens measured – 8.
Remarks: The presence of a cingulum associated with a surface reticulum allows this species to be placed in Ellipsoidictyum; its small size and the characteristic presence of an apical prominence are particularly notable features.
The consistent occurrence of this species at Vergol spans the early/late Valanginian boundary, ranging from Bed V88, inostranzewi Zone, inostranzewi Sub-zone to Bed V102M, verrucosum Zone, verrucosum Sub-zone. A single, isolated specimen was also recorded from Bed V42M, early Valanginian, neocomiensiformis Zone, neocomiensiformis Sub-zone.
Holotype: Plate 7, Figures 12, 13
Paratype: Plate 7, Figures 4, 5, 9
Type Locality: Vergol outcrop, Valanginian. Holotype: early Valanginian, Bed V94M, , inostranzewi ammonite Zone, inostranzewi Sub-zone, Slide V94M(schulze), E.F. C55.2. Paratype: late Valanginian, Bed V102M, verrucosum ammonite Zone, verrucosum Sub-zone, Slide V102M/(schulze), E.F. F39.3.
Derivation of Name: From the Latin minusculus, rather small - in reference to the size of this species.
Diagnosis: A small, relatively thick-walled species with a spheroidal main body and with the epicyst approximately equal in length to the hypocyst. The epicyst is rounded triangular in outline and typically extends into a low apical prominence. The hypocyst is semicircular. A vestigial reticulum of variable mesh size covers the cyst, and some lineation of crests marks a broad cingulum. The archeopyle is apical, with the operculum attached.
Dimensions: Holotype 35 × 35 μm
Paratype 41 × 41 μm
Overall 43 (38) 33 μm × 43 (38) 33 μm.
Specimens measured – 8.
Remarks: The presence of a cingulum associated with a surface reticulum allows this species to be placed in Ellipsoidictyum; its small size and the characteristic presence of an apical prominence are particularly notable features.
The consistent occurrence of this species at Vergol spans the early/late Valanginian boundary, ranging from Bed V88, inostranzewi Zone, inostranzewi Sub-zone to Bed V102M, verrucosum Zone, verrucosum Sub-zone. A single, isolated specimen was also recorded from Bed V42M, early Valanginian, neocomiensiformis Zone, neocomiensiformis Sub-zone.