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Molassedinium bicornutum
Molassedinium bicornutum gen. et sp. nov., Soliman and Slimani, 2019, p. 663-665
Holotype: Soliman and Slimani, 2019, pl. 1, fig 1–4 (Sample Osch1-59, depth 1371.98 m)
Type locality: Oberschauersberg-1 borehole (Osch-1), Upper Austria, near the city of Linz.
Type stratum: Eggerding Formation, Molasse Basin
Stratigraphic range: Rupelian
Original description: Soliman and Slimani, 2019:
Diagnosis:
An intermediate-sized species of Molassedinium characterised by its granulate to verrucose autophragm and partially perforate ectophragm. Gonyaulacoid (leptodinioidean) tabulation reflected by sutural crests on the autophragm and often by dense and aligned sutural perforations or cracks on the ectophragm in the sutural areas. Apical archaeopyle. Operculum free or in place.
Description:
Subspherical to ovoidal holocavate cyst. The epicyst and hypocyst, including horns, are of more or less similar sizes.
Cyst wall: consists of a moderately thick (~1.5 µm thick) and granulate to verrucate autophragm, and a thin (~0.1 µm thick) ectophragm, which is partially perforate (perforations 0.5 to 2.5 µm in diameter). The ectophragm is densely perforated or interrupted at the sutural areas and supported by short (~7 µm length) and slender, penitabular columellae rising from the autophragm, but it is detached at the polar areas to form apical and antapical horns.
The antapical horn is tapering and pointed distally, while the apical horn is longer and truncated distally.
An antapical nipple-like boss (2 mm long) is seen rarely on the autophragm (Plate 1, figures 13, 14).
Tabulation: leptodinioidean, indicated by sutural ridges on the autophragm and also by dense and aligned sutural perforations or cracks on the ectophragm, formula 4', 6'', 6c, 6''', 1p, 1'''', as, ps, xs.
Cingulum: (ca. 6 µm wide) slightly laevorotatory
Archaeopyle: apical, type (tA), with a zigzag margin, accessory sutures and a sulcal notch.
Operculum: simple and free. It consists of four apical plates (10–40) with a central thickening, which probably corresponds to the apical pore complex
Dimensions:
The observed cysts of Molassedinium bicornutum gen. et sp. nov. are rarely complete; therefore, the following measurements depend on the nature of the encountered specimens and the central body measurements include the ectophragm.
Holotype: central body length/width 61/53 µm; apical horn length 38 µm; antapical horn length 29 µm.
Paratype: central body length/width 70/60 µm; antapical horn length 32 µm.
Range: central body length/width 53 (60) 63/49 (52) 58 µm; apical horn length 28 (32) 38 µm; antapical horn length 22 (32) 43 µm; 4 specimens measured
Cysts without operculum and with an antapical horn only: central body length/width 41 (48) 52/48 (53) 57 µm; antapical horn length 15 (24) 31 µm; 12 specimens measured. Cyst with operculum and an antapical horn: central body length/width 70/59 µm; antapical horn length 32 µm; 1 specimen measured
Holotype: Soliman and Slimani, 2019, pl. 1, fig 1–4 (Sample Osch1-59, depth 1371.98 m)
Type locality: Oberschauersberg-1 borehole (Osch-1), Upper Austria, near the city of Linz.
Type stratum: Eggerding Formation, Molasse Basin
Stratigraphic range: Rupelian
Original description: Soliman and Slimani, 2019:
Diagnosis:
An intermediate-sized species of Molassedinium characterised by its granulate to verrucose autophragm and partially perforate ectophragm. Gonyaulacoid (leptodinioidean) tabulation reflected by sutural crests on the autophragm and often by dense and aligned sutural perforations or cracks on the ectophragm in the sutural areas. Apical archaeopyle. Operculum free or in place.
Description:
Subspherical to ovoidal holocavate cyst. The epicyst and hypocyst, including horns, are of more or less similar sizes.
Cyst wall: consists of a moderately thick (~1.5 µm thick) and granulate to verrucate autophragm, and a thin (~0.1 µm thick) ectophragm, which is partially perforate (perforations 0.5 to 2.5 µm in diameter). The ectophragm is densely perforated or interrupted at the sutural areas and supported by short (~7 µm length) and slender, penitabular columellae rising from the autophragm, but it is detached at the polar areas to form apical and antapical horns.
The antapical horn is tapering and pointed distally, while the apical horn is longer and truncated distally.
An antapical nipple-like boss (2 mm long) is seen rarely on the autophragm (Plate 1, figures 13, 14).
Tabulation: leptodinioidean, indicated by sutural ridges on the autophragm and also by dense and aligned sutural perforations or cracks on the ectophragm, formula 4', 6'', 6c, 6''', 1p, 1'''', as, ps, xs.
Cingulum: (ca. 6 µm wide) slightly laevorotatory
Archaeopyle: apical, type (tA), with a zigzag margin, accessory sutures and a sulcal notch.
Operculum: simple and free. It consists of four apical plates (10–40) with a central thickening, which probably corresponds to the apical pore complex
Dimensions:
The observed cysts of Molassedinium bicornutum gen. et sp. nov. are rarely complete; therefore, the following measurements depend on the nature of the encountered specimens and the central body measurements include the ectophragm.
Holotype: central body length/width 61/53 µm; apical horn length 38 µm; antapical horn length 29 µm.
Paratype: central body length/width 70/60 µm; antapical horn length 32 µm.
Range: central body length/width 53 (60) 63/49 (52) 58 µm; apical horn length 28 (32) 38 µm; antapical horn length 22 (32) 43 µm; 4 specimens measured
Cysts without operculum and with an antapical horn only: central body length/width 41 (48) 52/48 (53) 57 µm; antapical horn length 15 (24) 31 µm; 12 specimens measured. Cyst with operculum and an antapical horn: central body length/width 70/59 µm; antapical horn length 32 µm; 1 specimen measured