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Cauca redacta
Original description Duxbury, 2024:
Plate 11, Figures 8, 11, 12, 15, 16
Holotype: Plate 11, Figures 11, 12
Paratype: Plate 11, Figure 16
Type Locality: Vergol outcrop, Valanginian. Holotype: early Valanginian, Bed V97M, inostranzewi ammonite Zone, platycostatus Sub-zone, Slide V97M(A), E.F. P45.4. Paratype: early Valanginian, Bed V97M, inostranzewi ammonite Zone, platycostatus Subzone, Slide V97M(A), E.F. R37.4.
Derivation of Name: From the Latin redactus, reduced - in reference to the loss of crestal spine height in this species.
Diagnosis: A small, thin-walled species with an ovoidal main body, and with the epicyst smaller than the hypocyst. The epicyst is rounded triangular in outline, extending into a low apical prominence and the hypocyst outline is semicircular. The endophragm bears a cover of granules or is ornament-free. The periphragm bears sutural crests which are low and smooth and which can be distally entire or bear very short acuminate spines. The archeopyle is epicystal, with the operculum attached.
Dimensions: Holotype 41 × 38 μm.
Paratype 38 × 33 μm.
Overall - 43 (41) 38 μm × 38 (35) 33 μm.
Specimens measured – 5.
Remarks: This species is characterised by the small size of its main body and very reduced to absent crestal spines. The endocyst can bear surface granules, although these may be absent, particularly in specimens lacking spines. In some specimens, spines may be restricted to crests fringing the antapex.
Some similarities were observed here between Cauca redacta and Heslertonia inferior n. sp., a species which also has reduced sutural crests and can bear short crestal spines. This is discussed under Heslertonia Sarjeant 1966b, below.
The observed range of this species at Vergol was between samples V45M (early Valanginian, neocomiensiformis Zone, neocomiensiformis Sub-zone) and V124M (late Valanginian, peregrinus Zone, peregrinus Sub-zone), although its consistent occurrence was restricted to the interval between samples V91M and V111M, bracketing the early/late Valanginian boundary.
Plate 11, Figures 8, 11, 12, 15, 16
Holotype: Plate 11, Figures 11, 12
Paratype: Plate 11, Figure 16
Type Locality: Vergol outcrop, Valanginian. Holotype: early Valanginian, Bed V97M, inostranzewi ammonite Zone, platycostatus Sub-zone, Slide V97M(A), E.F. P45.4. Paratype: early Valanginian, Bed V97M, inostranzewi ammonite Zone, platycostatus Subzone, Slide V97M(A), E.F. R37.4.
Derivation of Name: From the Latin redactus, reduced - in reference to the loss of crestal spine height in this species.
Diagnosis: A small, thin-walled species with an ovoidal main body, and with the epicyst smaller than the hypocyst. The epicyst is rounded triangular in outline, extending into a low apical prominence and the hypocyst outline is semicircular. The endophragm bears a cover of granules or is ornament-free. The periphragm bears sutural crests which are low and smooth and which can be distally entire or bear very short acuminate spines. The archeopyle is epicystal, with the operculum attached.
Dimensions: Holotype 41 × 38 μm.
Paratype 38 × 33 μm.
Overall - 43 (41) 38 μm × 38 (35) 33 μm.
Specimens measured – 5.
Remarks: This species is characterised by the small size of its main body and very reduced to absent crestal spines. The endocyst can bear surface granules, although these may be absent, particularly in specimens lacking spines. In some specimens, spines may be restricted to crests fringing the antapex.
Some similarities were observed here between Cauca redacta and Heslertonia inferior n. sp., a species which also has reduced sutural crests and can bear short crestal spines. This is discussed under Heslertonia Sarjeant 1966b, below.
The observed range of this species at Vergol was between samples V45M (early Valanginian, neocomiensiformis Zone, neocomiensiformis Sub-zone) and V124M (late Valanginian, peregrinus Zone, peregrinus Sub-zone), although its consistent occurrence was restricted to the interval between samples V91M and V111M, bracketing the early/late Valanginian boundary.