Back
Pentadinium taeniagerum
From Fensome et al., 2019:
Pentadinium taeniagerum Gerlach, 1961, p.167–168, pl.26, figs.8–9,12,15; text-fig.8. Holotype: Gerlach, 1961, pl.26, fig.8; textfig. 8; Benedek et al., 1982, text-fig.4D; Fensome et al., 1995, fig.1 — p.1841; figs.1–2 — p.1845. Benedek et al. (1982, p.275) suggested "that this name be restricted to the holotype and [one of the] paratype[s]...." Age: middle Oligocene–Middle Miocene.
---------------------------------------------------------------------------------------------------
Original description [Gerlach, 1961] (translated from German):
Pentadinium taeniagerum n. g. n. sp.
Plate 26, Figs. 8, 9, 12 and 15, Fig. 8
Holotype: Pr 1170/20 (564). Plate 26, Fig. 8 and Fig. 8
Paratypoids: Pr 1170/21 (398), Pr 1170/22 (520), Pr 1170/78 (675) and Pr 1170/79 (598).
Typical location: Emsbüren 9 borehole.
Typical strata: Middle Miocene at a depth of 120 m.
Etymology: tainia = ridge, due to the ridge-bearing sutures.
Diagnosis: A species of the genus Pentadinium with the following distinctive characteristics: Epi- and hypothecium trapezoidal in outline, theca apically blunt to bulbously protruding. Outer membrane shell projecting prominently at the level of the girdle groove. Tabulation clearly developed only dorsally: 3", 3"' and 1"''. Number of apical plates uncertain.
Description:
The epitheca appears trapezoidal in outline. Forms with a widely projecting apical margin and those in which the outer membrane of the inner capsule lies close to the body encompass the range of variation within the species. In the majority of specimens, the outer membrane is apically projecting like a tubercle. A central lobe is flanked by a lateral lobe on each side. At the level of the girdle groove, the outer margin of the membrane appears strongly angular and bulging, so that in this region the length-to-width ratio is equal or even greater than the width. The epitheca and hypotheca are separated by a spirally wound, dorsally very shallow girdle groove. On the ventral side, the girdle groove is massively sunken. Its two ends are offset from each other by approximately 1.5 groove widths. The outer membrane is attached to The sutures are drawn upwards into narrow ridges. Between the offset ends of the girdle groove runs a longitudinal furrow region, which cannot be further characterized due to the lack of sutures. The outline of the hypothecium is squat and trapezoidal, showing a strong flattening towards the antapical pole. The tabulation is clearly pronounced only dorsally. On the ventral side, it must remain uncertain, as the sutures are only very weakly developed. Three trapezoidal plates each lie in the dorsal circumferential region of the epithecium and hypothecium. Ventrally, two more plates are likely added due to the spatial relationships, resulting in a total of five praccingular and five postcingular plates. In place of the trapezoidal 3'', a pylomelum is developed in most specimens, which is bounded by convex sides. The shape and number of apical plates cannot be definitively determined due to the greatly reduced sutures of the apex regions. Presumably, one or two apical plates lie on the dorsal epithecium, bordered ventrally by two further plates. The apical plate outline is polygonal.
The inner capsule, an integral part of the shell in all forms, is oval and sometimes slightly pointed towards the apex. In contrast to the delicate outer shell, the inner body appears quite robust.
The carapace membrane is granulated and yellowish-brown in color. The specimens are in moderate to good condition.
Relationships:
The two species differ in the number of apical plates, the outline of the theca, and the width of the margins formed by the outer shell and attached to the sutures.
The margins of P. laticinctum are significantly wider than those of P. taeniagerum.
Number of specimens: 21
Mass: holotype = 80 : 87
Paratypoids = 86 : 93
= 84 : 79
= 84 : 84
= 80 : 90
Maximum = 94 : 103
Minimum = 80 : 76
Average = 84 : 88
(10 measurements)
Occurrence:
Middle Miocene: Emsbüren 7, K 94 and 120 m
Emsbüren 9, K 85 and 100 m
? Middle Miocene: Emsbüren 9, K 120 m
? Late Oligocene: Emsbüren 7, K 150 m
Late Oligocene: Emsbüren 7, K 151 m
Middle Oligocene: Emsbüren 9, K 141 and 155 m
Pentadinium taeniagerum Gerlach, 1961, p.167–168, pl.26, figs.8–9,12,15; text-fig.8. Holotype: Gerlach, 1961, pl.26, fig.8; textfig. 8; Benedek et al., 1982, text-fig.4D; Fensome et al., 1995, fig.1 — p.1841; figs.1–2 — p.1845. Benedek et al. (1982, p.275) suggested "that this name be restricted to the holotype and [one of the] paratype[s]...." Age: middle Oligocene–Middle Miocene.
---------------------------------------------------------------------------------------------------
Original description [Gerlach, 1961] (translated from German):
Pentadinium taeniagerum n. g. n. sp.
Plate 26, Figs. 8, 9, 12 and 15, Fig. 8
Holotype: Pr 1170/20 (564). Plate 26, Fig. 8 and Fig. 8
Paratypoids: Pr 1170/21 (398), Pr 1170/22 (520), Pr 1170/78 (675) and Pr 1170/79 (598).
Typical location: Emsbüren 9 borehole.
Typical strata: Middle Miocene at a depth of 120 m.
Etymology: tainia = ridge, due to the ridge-bearing sutures.
Diagnosis: A species of the genus Pentadinium with the following distinctive characteristics: Epi- and hypothecium trapezoidal in outline, theca apically blunt to bulbously protruding. Outer membrane shell projecting prominently at the level of the girdle groove. Tabulation clearly developed only dorsally: 3", 3"' and 1"''. Number of apical plates uncertain.
Description:
The epitheca appears trapezoidal in outline. Forms with a widely projecting apical margin and those in which the outer membrane of the inner capsule lies close to the body encompass the range of variation within the species. In the majority of specimens, the outer membrane is apically projecting like a tubercle. A central lobe is flanked by a lateral lobe on each side. At the level of the girdle groove, the outer margin of the membrane appears strongly angular and bulging, so that in this region the length-to-width ratio is equal or even greater than the width. The epitheca and hypotheca are separated by a spirally wound, dorsally very shallow girdle groove. On the ventral side, the girdle groove is massively sunken. Its two ends are offset from each other by approximately 1.5 groove widths. The outer membrane is attached to The sutures are drawn upwards into narrow ridges. Between the offset ends of the girdle groove runs a longitudinal furrow region, which cannot be further characterized due to the lack of sutures. The outline of the hypothecium is squat and trapezoidal, showing a strong flattening towards the antapical pole. The tabulation is clearly pronounced only dorsally. On the ventral side, it must remain uncertain, as the sutures are only very weakly developed. Three trapezoidal plates each lie in the dorsal circumferential region of the epithecium and hypothecium. Ventrally, two more plates are likely added due to the spatial relationships, resulting in a total of five praccingular and five postcingular plates. In place of the trapezoidal 3'', a pylomelum is developed in most specimens, which is bounded by convex sides. The shape and number of apical plates cannot be definitively determined due to the greatly reduced sutures of the apex regions. Presumably, one or two apical plates lie on the dorsal epithecium, bordered ventrally by two further plates. The apical plate outline is polygonal.
The inner capsule, an integral part of the shell in all forms, is oval and sometimes slightly pointed towards the apex. In contrast to the delicate outer shell, the inner body appears quite robust.
The carapace membrane is granulated and yellowish-brown in color. The specimens are in moderate to good condition.
Relationships:
The two species differ in the number of apical plates, the outline of the theca, and the width of the margins formed by the outer shell and attached to the sutures.
The margins of P. laticinctum are significantly wider than those of P. taeniagerum.
Number of specimens: 21
Mass: holotype = 80 : 87
Paratypoids = 86 : 93
= 84 : 79
= 84 : 84
= 80 : 90
Maximum = 94 : 103
Minimum = 80 : 76
Average = 84 : 88
(10 measurements)
Occurrence:
Middle Miocene: Emsbüren 7, K 94 and 120 m
Emsbüren 9, K 85 and 100 m
? Middle Miocene: Emsbüren 9, K 120 m
? Late Oligocene: Emsbüren 7, K 150 m
Late Oligocene: Emsbüren 7, K 151 m
Middle Oligocene: Emsbüren 9, K 141 and 155 m