Back
Lanterna foveolata
(Plate IV, 1–6)
Holotype: Plate IV, 1–3
Diagnosis: A species of Lanterna with an irregularly foveolate autophragm. Penitabular margins separated by narrow pandasutural bands. Tabulation gonyaulacacean, archeopyle apical, Type (tA), operculum free.
Etymology: ‘foveolata' in reference to the species foveolate ornament.
Material: Palynological strew samples; 2810 m, Jansz-3; 3198.2 m, Laminaria-2
Age: Oxfordian (W. spectabilis Zone; Fig. 5) Lithostratigraphic occurrence: The Frigate and lower Vulcan fms of the Bonaparte Basin. The Dingo Claystone, Jansz Sandstone and Eliassen Fm of the Northern Carnarvon Basin.
Description: A small to intermediate-sized, proximate dinoflagellate cyst with a spherical to subspherical ambitus. The spongy to foveolate autophragm is divided by 0.5–2 μm-wide pandasutural bands of reduced ornamentation. The subspherical to irregularly ovoidal foveolae range from 0.5–2 μm in diameter. The pandasutural bands indicate a gonyaulacacean tabulation formula:?pr, 4′, 0-1a, 6″, 6c, 6″’, 1p, 1″”,? 5–6 s. Archeopyle apical, Type (tA), operculum free, accessory archeopyle sutures variable in length. Rare specimens express a flagellar scar.
Dimensions: (23 specimens measured)
Length with operculum: 44 (47) 51
Length without operculum: 40 (47) 55
Width: 40 (48) 59
Comparison and remarks: Lanterna foveolata is most similar to Lanterna spongiosa but differs from it and all other species of Lanterna in having an irregularly foveolate autophragm. SEM images reveal a wall structure differentiated into a spongeous lower section overlaid by a ~ 0.5 μm-thick irregularly and coarsely foveolate outer section, which is absent, or greatly reduced, in pandasutural areas (Plate IV, 6). The high degree of structural similarity between the inner and outer part of the autophragm prevents division into more individualised layers.
Holotype: Plate IV, 1–3
Diagnosis: A species of Lanterna with an irregularly foveolate autophragm. Penitabular margins separated by narrow pandasutural bands. Tabulation gonyaulacacean, archeopyle apical, Type (tA), operculum free.
Etymology: ‘foveolata' in reference to the species foveolate ornament.
Material: Palynological strew samples; 2810 m, Jansz-3; 3198.2 m, Laminaria-2
Age: Oxfordian (W. spectabilis Zone; Fig. 5) Lithostratigraphic occurrence: The Frigate and lower Vulcan fms of the Bonaparte Basin. The Dingo Claystone, Jansz Sandstone and Eliassen Fm of the Northern Carnarvon Basin.
Description: A small to intermediate-sized, proximate dinoflagellate cyst with a spherical to subspherical ambitus. The spongy to foveolate autophragm is divided by 0.5–2 μm-wide pandasutural bands of reduced ornamentation. The subspherical to irregularly ovoidal foveolae range from 0.5–2 μm in diameter. The pandasutural bands indicate a gonyaulacacean tabulation formula:?pr, 4′, 0-1a, 6″, 6c, 6″’, 1p, 1″”,? 5–6 s. Archeopyle apical, Type (tA), operculum free, accessory archeopyle sutures variable in length. Rare specimens express a flagellar scar.
Dimensions: (23 specimens measured)
Length with operculum: 44 (47) 51
Length without operculum: 40 (47) 55
Width: 40 (48) 59
Comparison and remarks: Lanterna foveolata is most similar to Lanterna spongiosa but differs from it and all other species of Lanterna in having an irregularly foveolate autophragm. SEM images reveal a wall structure differentiated into a spongeous lower section overlaid by a ~ 0.5 μm-thick irregularly and coarsely foveolate outer section, which is absent, or greatly reduced, in pandasutural areas (Plate IV, 6). The high degree of structural similarity between the inner and outer part of the autophragm prevents division into more individualised layers.