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Aprobolocysta humilis
Original description Duxbury, 2024
Plate 12 Figures 1-3
Holotype: Plate 12, Figures 1, 2
Type Locality: Vergol outcrop, late Berriasian, Bed B129M, alpillensis ammonite Zone, otopeta Sub-zone. Holotype: Slide B129M(2), E.F. J45.0.
Derivation of Name: From the Latin humilis, modest, humble - in reference to the relatively small size of this species.
Diagnosis: A relatively small species of Aprobolocysta which is proximochorate, ovoidal and without horns. Both wall layers are smooth and the periphragm is folded, forming a reticulum of approximately even mesh size over the entire cyst surface. There is no clear reflection of tabulation, although the position of the cingulum can be suggested by some alignment of the reticulum. Archeopyle apical, typical of the genus.
Dimensions: Holotype (complete specimen): Length – 53 μm.
Width – 46 μm.
Overall: 68 (61) 53 μm × 58 (49) 43 μm.
Specimens measured – 8.
Remarks: This species is most similar to Aprobolocysta neista and A. plicata, species which have periphragm folds forming a relatively coarse reticulum. Whereas A. neista has high, irregular, spiky crests, A. humilis and A. plicata have lower, distally entire crests of even height over much of the cyst. In addition, Aprobolocysta plicata displays a cingulum marked by a row of relatively small fields and can possess a prominent apical horn. In contrast, Aprobolocysta humilis has a significantly finer reticulum than Aprobolocysta neista and A. plicata, is relatively squat, possesses no horns and has only faint reflection of the cingulum, if any. In some respects, Aprobolocysta humilis resembles species of Cassiculosphaeridia Davey 1969a and Valensiella Eisenack 1963. However, the archeopyle margin in both of those genera is parallel to the cingulum whereas in A. humilis it slopes markedly towards the sulcus, a feature typical of Aprobolocysta and Batioladinium Brideaux 1975.
This species was restricted to an interval spanning the Berriasian/ Valanginian boundary at Vergol, beds B121M to B136M, alpillensis Zone, otopeta Sub-zone to base pertransiens Zone, premolicus Sub-zone.
Plate 12 Figures 1-3
Holotype: Plate 12, Figures 1, 2
Type Locality: Vergol outcrop, late Berriasian, Bed B129M, alpillensis ammonite Zone, otopeta Sub-zone. Holotype: Slide B129M(2), E.F. J45.0.
Derivation of Name: From the Latin humilis, modest, humble - in reference to the relatively small size of this species.
Diagnosis: A relatively small species of Aprobolocysta which is proximochorate, ovoidal and without horns. Both wall layers are smooth and the periphragm is folded, forming a reticulum of approximately even mesh size over the entire cyst surface. There is no clear reflection of tabulation, although the position of the cingulum can be suggested by some alignment of the reticulum. Archeopyle apical, typical of the genus.
Dimensions: Holotype (complete specimen): Length – 53 μm.
Width – 46 μm.
Overall: 68 (61) 53 μm × 58 (49) 43 μm.
Specimens measured – 8.
Remarks: This species is most similar to Aprobolocysta neista and A. plicata, species which have periphragm folds forming a relatively coarse reticulum. Whereas A. neista has high, irregular, spiky crests, A. humilis and A. plicata have lower, distally entire crests of even height over much of the cyst. In addition, Aprobolocysta plicata displays a cingulum marked by a row of relatively small fields and can possess a prominent apical horn. In contrast, Aprobolocysta humilis has a significantly finer reticulum than Aprobolocysta neista and A. plicata, is relatively squat, possesses no horns and has only faint reflection of the cingulum, if any. In some respects, Aprobolocysta humilis resembles species of Cassiculosphaeridia Davey 1969a and Valensiella Eisenack 1963. However, the archeopyle margin in both of those genera is parallel to the cingulum whereas in A. humilis it slopes markedly towards the sulcus, a feature typical of Aprobolocysta and Batioladinium Brideaux 1975.
This species was restricted to an interval spanning the Berriasian/ Valanginian boundary at Vergol, beds B121M to B136M, alpillensis Zone, otopeta Sub-zone to base pertransiens Zone, premolicus Sub-zone.