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Rottnestia wetzelii ssp. brevispinosa
From Fensome et al., 2019:
Rottnestia wetzelii subsp. brevispinosa Slimani, 1994, p.58–59, pl.9, figs.7–13. Holotype: Slimani, 1994, pl.9, figs.12–13. Taxonomic junior synonym: Hystrichosphaeropsis jubata (name not validly published), according to Slimani (1994, p.58)- however, Slimani did not acknowledge the synonymy of Hystrichosphaeropsis jubata with Hystrichosphaera (now Rottnestia) borussica by May (1980). Age: late Campanian.
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Original description (Slimani, 1994) Not yet translated from French.
Name derivation: Latin: brevis, short; spina, spine; referring to the short processes. Holotype: Turnhout -933 m, preparation 1, E.F. coordinates Z54/4. Paratype: Turnhout -933 m, preparation 1, E.F. coordinates U28/2. Type locality: Turnhout -933 m. Type horizon: Campanian.
Diagnosis: Relatively large Rottnestia cyst. It bears a ventrally inclined apical pericoel, occupying almost the entire ventral surface of the repicyst, and a longitudinal antapical pericoel. It is characterized by its typically rudimentary gonal processes with a truncated to slightly forked distal end. The paratabulation is of the gonyaulacoid type and conforms to the following formula: 3 - 4", 6", 6c, 5 - 6'". lp, 1"", xs; it is indicated by prominent parasutural ridges supported at their junctions by gonal axes.
Dimensions: Holotvpe: whole cyst, length: 80 µm, width: 56 µm; endocyst diameter: 40 µm. Variations: whole cyst, length: 84–100 µm, width: 54–70 µm, endocyst diameter: 40–54 µm. Number of specimens measured: 7. Material: 12 specimens.
Description: The cyst is bicavate and subrectangular. The endophragm, generally smooth to scabrous, is in contact with the foveal periphragm (0.2 to 1.5 µm in diameter) in a broad equatorial area. The two walls separate elsewhere, forming two prominent polar pericoels that are generally of equal size (20 to 30 µm long), with square or rectangular outlines and lacking horns. The apical surface of the pericyst has a subcircular opening (4 to 6 µm in diameter). The pericyst is supported by prominent parasutural ridges, smooth to scabrous, with an undulating to finely denticulate distal margin and a height (2 to 12 µm) that is greatest at their junctions. These ridges are in turn supported by gonal axes. The ridges extend slightly higher around the gonal axes, with which they form very short, barely projecting processes. The ridges are frequently higher in the paracingular region than in the apical and antapical regions. The endocyst is subcircular to subtriangular with a generally flattened base, and shows a slight ventral constriction often present just below a 5- to 8-pm-long, hollow, rounded apical protrusion that is consistently inclined ventrally. The paracingulum (6 to 12 pm wide) is laevorotatory; the parasulcus is not tabulated but indicated ventrally by a longitudinally elongated subrectangular surface extending from the apex to the antapex.
The archeopyl is precingular, P-type (3"), with a free pentagonal operculum.
Note: Although the processes are not merely rudimentary, their presence in gonal positions allows us to assign this species to the genus Rottnestia, referring to the descriptions of this genus by Stover and Evitt (1978: p. 185) and Jan du Chêne et al. (1986a: p. 309).
Comparison: Rottnestia wetzelii subsp. brevispinosa subsp. nov. is distinguished from all previously described species of the genus Rottnestia by the presence of a ventrally inclined apical pericoel, a foveolate periphragm, and the absence of developed processes. The specimens of Hystrichosphaeropsis jubata from Wilson illustrated in his unpublished Ph.D. work (1974: pl. 9, fig. 5–9) probably correspond to the present species. With the exception of its well-developed processes, Rottnestia wetzelii (Deflandre, 1937b) subsp. wetzellii comb. nov. exhibits the same characteristics as the subspecies brevispina. Rottnestia sp. from the Upper Maastrichtian of Hemoor, illustrated by Gocht (1976: pl. 18, fig. a, b, c), is represented by a cyst that also possesses very short processes, but it has a granular endocyst and a pericyst with an apical horn.
Stratigraphic distribution: Turnhout: -933 m, Upper Campanian. In Wilson (1974), Lower Maastrichtian (Occidentalis Zone), Denmark.
Rottnestia wetzelii subsp. brevispinosa Slimani, 1994, p.58–59, pl.9, figs.7–13. Holotype: Slimani, 1994, pl.9, figs.12–13. Taxonomic junior synonym: Hystrichosphaeropsis jubata (name not validly published), according to Slimani (1994, p.58)- however, Slimani did not acknowledge the synonymy of Hystrichosphaeropsis jubata with Hystrichosphaera (now Rottnestia) borussica by May (1980). Age: late Campanian.
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Original description (Slimani, 1994) Not yet translated from French.
Name derivation: Latin: brevis, short; spina, spine; referring to the short processes. Holotype: Turnhout -933 m, preparation 1, E.F. coordinates Z54/4. Paratype: Turnhout -933 m, preparation 1, E.F. coordinates U28/2. Type locality: Turnhout -933 m. Type horizon: Campanian.
Diagnosis: Relatively large Rottnestia cyst. It bears a ventrally inclined apical pericoel, occupying almost the entire ventral surface of the repicyst, and a longitudinal antapical pericoel. It is characterized by its typically rudimentary gonal processes with a truncated to slightly forked distal end. The paratabulation is of the gonyaulacoid type and conforms to the following formula: 3 - 4", 6", 6c, 5 - 6'". lp, 1"", xs; it is indicated by prominent parasutural ridges supported at their junctions by gonal axes.
Dimensions: Holotvpe: whole cyst, length: 80 µm, width: 56 µm; endocyst diameter: 40 µm. Variations: whole cyst, length: 84–100 µm, width: 54–70 µm, endocyst diameter: 40–54 µm. Number of specimens measured: 7. Material: 12 specimens.
Description: The cyst is bicavate and subrectangular. The endophragm, generally smooth to scabrous, is in contact with the foveal periphragm (0.2 to 1.5 µm in diameter) in a broad equatorial area. The two walls separate elsewhere, forming two prominent polar pericoels that are generally of equal size (20 to 30 µm long), with square or rectangular outlines and lacking horns. The apical surface of the pericyst has a subcircular opening (4 to 6 µm in diameter). The pericyst is supported by prominent parasutural ridges, smooth to scabrous, with an undulating to finely denticulate distal margin and a height (2 to 12 µm) that is greatest at their junctions. These ridges are in turn supported by gonal axes. The ridges extend slightly higher around the gonal axes, with which they form very short, barely projecting processes. The ridges are frequently higher in the paracingular region than in the apical and antapical regions. The endocyst is subcircular to subtriangular with a generally flattened base, and shows a slight ventral constriction often present just below a 5- to 8-pm-long, hollow, rounded apical protrusion that is consistently inclined ventrally. The paracingulum (6 to 12 pm wide) is laevorotatory; the parasulcus is not tabulated but indicated ventrally by a longitudinally elongated subrectangular surface extending from the apex to the antapex.
The archeopyl is precingular, P-type (3"), with a free pentagonal operculum.
Note: Although the processes are not merely rudimentary, their presence in gonal positions allows us to assign this species to the genus Rottnestia, referring to the descriptions of this genus by Stover and Evitt (1978: p. 185) and Jan du Chêne et al. (1986a: p. 309).
Comparison: Rottnestia wetzelii subsp. brevispinosa subsp. nov. is distinguished from all previously described species of the genus Rottnestia by the presence of a ventrally inclined apical pericoel, a foveolate periphragm, and the absence of developed processes. The specimens of Hystrichosphaeropsis jubata from Wilson illustrated in his unpublished Ph.D. work (1974: pl. 9, fig. 5–9) probably correspond to the present species. With the exception of its well-developed processes, Rottnestia wetzelii (Deflandre, 1937b) subsp. wetzellii comb. nov. exhibits the same characteristics as the subspecies brevispina. Rottnestia sp. from the Upper Maastrichtian of Hemoor, illustrated by Gocht (1976: pl. 18, fig. a, b, c), is represented by a cyst that also possesses very short processes, but it has a granular endocyst and a pericyst with an apical horn.
Stratigraphic distribution: Turnhout: -933 m, Upper Campanian. In Wilson (1974), Lower Maastrichtian (Occidentalis Zone), Denmark.