Back
Pentadinium lophophorum
Pentadinium lophophorum Benedek, 1972, p.44, pl.6, figs.8a–b; text-fig.19. Emendation: Benedek et al., 1982, p.275, as Pentadinium lophophorum.
Originally Pentadinium laticinctum ssp. Iophophorum, subsequently (and now) Pentadinium lophophorum. Benedek et al., 1982 emended this taxon when they raised it to the species level.
Holotype: Benedek, 1972, pl.6, figs.8a-b, text-fig. 19; Benedek et al., 1982, figs.5A-B, 7B,D,F
Paratype: Benedek, 1972; Benedek et al., 1982
Locus typicus: Tönisberg , Niederrhein, Germany
Stratum typicum: Middle Oligocene
Translation Benedek, 1972: GSC
---------------------------------------------------------
Original diagnosis: Benedek 1972, p.44: Pentadinium laticinctum lophorum
A sub-speceis of the P. laticinctum GERLACH, with thick-walled internal body and large hump-like sculptures.
Original description: Benedek 1972, p.44: Pentadinium laticinctum lophorum
The capsules which predominate in the Middle Oligocene of Tönisberg are those which correspond in size and in shape to the "nominifer"-species of GERLACH. In the case of the new subspecies which is represented by three specimens, the capsule-membrane is thick-walled and, owing to the presence of hump-like proturberances, is quite noticeable. The tabulated external envelope is thin and often damaged. Owing to fine parallel folds along the sutures, the tabulation has come to light to a greater extent. he epitheca consists of the apical plate and of five precingular plates, the boundaries of which are difficult to establish (Plate 6, figure 8 illustrates the apical region). Out of the precingular "wreath", an opening forms the detachment of field 3"".
The hypotheca is made up of a four-cornered antapical plate and of four or five precingular plates. As it has already been stated by GERLACH 1961, it can not be ascertained with 100% certainty, whether a plate, namely the fifth 5 ""-plate exists in the region of the longitudinal furrow or whether this plate does not exists there.
Affinities/Comparison:
In comparison with the "nominfer"-species, the P.laticinctum lophophorum n. subsp. possesses a more thick-walled and more granular appearing internal capsule, whereas in comparison with the P. laticinctum granulatum GOCHT 1969, the absence of radial wall structures must be mentioned.
Dimensions:
Capsule diameter 56 microns (52/62 microns), specimen diameter 77 microns (65/83 microns), holotype capsule diameter 62 microns, specimen diameter 80 microns (3 measurements). Number of examined specimens: 3.
--------------------------------------------------------------
Emended diagnosis: Benedek et al., 1982, p. 275-277
Cyst proximate to proximochorate. Central body broadly ovoidal to rounded-subpentagonal, without horns. Phragma two-layered, in part suturocavate and elsewhere bearing relatively high sutural crests. Paratabulation 4", 6", ?6c, 5""", 1p, 1pv, 1""""; the crests between the apical paraplates may be incompletely expressed or lacking, only faint lines marking these boundaries. Sulcus broad and relatively short; cingulum broad. Endophragm thick; periphragm verrucate to rugulate or irregularly reticulate. Height of sutural cavations surrounding the cingulum up to one-quarter of the cyst length-elsewhere, the crests or sutural cavations are lower. Archaeopyle single-plate precingular, formed by loss of paraplate 3".
Emended description: Benedek et al., 1982, p. 276-277
In polar view, this species may appear to have a spheroidal central body; in lateral view, however, it typically exhibits some measure of polygonality, especially towards the antapex. The cingulum is bordered by sutural cavations; similar structures separate the larger paraplates of the dorsal surface. Elsewhere, however, the structures on the sutures are not conspicuously V-shaped in section and are better simply regarded as moderately high crests. The surfaces of the sutural cavations and crests may be punctate, may bear low ridges and granules, and may be slightly or markedly folded. The greater part of the periphragm surface is occupied by a variable ornament consisting, at its simplest, of wart-like outgrowths. However, these are often connected by irregular ridges. The ridges themselves frequently coalesce, in some instances forming an incompletely developed reticulum of irregular mesh size, in others occupying a penitabular position or running at angles across the paraplates. Verrucae and ridges are virtually absent from the cingulum and reduced, in some measure, on the sulcus. The apical paraplate series is bordered by crests, but its constituent paraplates are only in part thus delimited and no crests traverse the apex itself. Where crests are absent, lines on the surface mark the paraplate boundaries; but these may be obscured by the overall periphragmal ornament. Paraplate 1" is the smallest and somewhat elongate; the other apical paraplates are of roughly equal size.
Five of the six precingular paraplates are large; the sixth (6") is smaller and may show apexward displacement. In the postcingular series, paraplate 1""" is reduced to accommodate a small posterior intercalary paraplate; paraplates 2""" to 4""" are of fairly uniform size, 5""" somewhat smaller. An asymmetrically hexagonal paraplate of moderate size occupies the antapex.
The cingulum is laevorotatory, of fair breadth and subdivided into six, possibly seven paraplates. The sulcus is relatively broad; since no specimens in ventral presentation were seen, its exact character remains to be elucidated.
Dimensions:
Holotype (in apical view): maximum overall diameter 80 µm maximum diameter of central body 62 µm.
Paratype (in lateral view): overall length 73 µm, overall breadth 77 µm.
Range of dimensions: Specimens in apical view: maximum overall diameter 65-83 µm, maximum diameter of central body 52-62 µm.
Specimens in lateral view: overall length 72-75 µm, length of central body 72-75 µm (5 specimens).
Heilmann-Clausen in Heilmann-Clausen and Costa, 1989, p. 470, pl.18, fig.12: Pentadinium cf. Iophophorum
The ornament of the endophragm is not as coarse as in typical specimens of P. Iophophorum.
Originally Pentadinium laticinctum ssp. Iophophorum, subsequently (and now) Pentadinium lophophorum. Benedek et al., 1982 emended this taxon when they raised it to the species level.
Holotype: Benedek, 1972, pl.6, figs.8a-b, text-fig. 19; Benedek et al., 1982, figs.5A-B, 7B,D,F
Paratype: Benedek, 1972; Benedek et al., 1982
Locus typicus: Tönisberg , Niederrhein, Germany
Stratum typicum: Middle Oligocene
Translation Benedek, 1972: GSC
---------------------------------------------------------
Original diagnosis: Benedek 1972, p.44: Pentadinium laticinctum lophorum
A sub-speceis of the P. laticinctum GERLACH, with thick-walled internal body and large hump-like sculptures.
Original description: Benedek 1972, p.44: Pentadinium laticinctum lophorum
The capsules which predominate in the Middle Oligocene of Tönisberg are those which correspond in size and in shape to the "nominifer"-species of GERLACH. In the case of the new subspecies which is represented by three specimens, the capsule-membrane is thick-walled and, owing to the presence of hump-like proturberances, is quite noticeable. The tabulated external envelope is thin and often damaged. Owing to fine parallel folds along the sutures, the tabulation has come to light to a greater extent. he epitheca consists of the apical plate and of five precingular plates, the boundaries of which are difficult to establish (Plate 6, figure 8 illustrates the apical region). Out of the precingular "wreath", an opening forms the detachment of field 3"".
The hypotheca is made up of a four-cornered antapical plate and of four or five precingular plates. As it has already been stated by GERLACH 1961, it can not be ascertained with 100% certainty, whether a plate, namely the fifth 5 ""-plate exists in the region of the longitudinal furrow or whether this plate does not exists there.
Affinities/Comparison:
In comparison with the "nominfer"-species, the P.laticinctum lophophorum n. subsp. possesses a more thick-walled and more granular appearing internal capsule, whereas in comparison with the P. laticinctum granulatum GOCHT 1969, the absence of radial wall structures must be mentioned.
Dimensions:
Capsule diameter 56 microns (52/62 microns), specimen diameter 77 microns (65/83 microns), holotype capsule diameter 62 microns, specimen diameter 80 microns (3 measurements). Number of examined specimens: 3.
--------------------------------------------------------------
Emended diagnosis: Benedek et al., 1982, p. 275-277
Cyst proximate to proximochorate. Central body broadly ovoidal to rounded-subpentagonal, without horns. Phragma two-layered, in part suturocavate and elsewhere bearing relatively high sutural crests. Paratabulation 4", 6", ?6c, 5""", 1p, 1pv, 1""""; the crests between the apical paraplates may be incompletely expressed or lacking, only faint lines marking these boundaries. Sulcus broad and relatively short; cingulum broad. Endophragm thick; periphragm verrucate to rugulate or irregularly reticulate. Height of sutural cavations surrounding the cingulum up to one-quarter of the cyst length-elsewhere, the crests or sutural cavations are lower. Archaeopyle single-plate precingular, formed by loss of paraplate 3".
Emended description: Benedek et al., 1982, p. 276-277
In polar view, this species may appear to have a spheroidal central body; in lateral view, however, it typically exhibits some measure of polygonality, especially towards the antapex. The cingulum is bordered by sutural cavations; similar structures separate the larger paraplates of the dorsal surface. Elsewhere, however, the structures on the sutures are not conspicuously V-shaped in section and are better simply regarded as moderately high crests. The surfaces of the sutural cavations and crests may be punctate, may bear low ridges and granules, and may be slightly or markedly folded. The greater part of the periphragm surface is occupied by a variable ornament consisting, at its simplest, of wart-like outgrowths. However, these are often connected by irregular ridges. The ridges themselves frequently coalesce, in some instances forming an incompletely developed reticulum of irregular mesh size, in others occupying a penitabular position or running at angles across the paraplates. Verrucae and ridges are virtually absent from the cingulum and reduced, in some measure, on the sulcus. The apical paraplate series is bordered by crests, but its constituent paraplates are only in part thus delimited and no crests traverse the apex itself. Where crests are absent, lines on the surface mark the paraplate boundaries; but these may be obscured by the overall periphragmal ornament. Paraplate 1" is the smallest and somewhat elongate; the other apical paraplates are of roughly equal size.
Five of the six precingular paraplates are large; the sixth (6") is smaller and may show apexward displacement. In the postcingular series, paraplate 1""" is reduced to accommodate a small posterior intercalary paraplate; paraplates 2""" to 4""" are of fairly uniform size, 5""" somewhat smaller. An asymmetrically hexagonal paraplate of moderate size occupies the antapex.
The cingulum is laevorotatory, of fair breadth and subdivided into six, possibly seven paraplates. The sulcus is relatively broad; since no specimens in ventral presentation were seen, its exact character remains to be elucidated.
Dimensions:
Holotype (in apical view): maximum overall diameter 80 µm maximum diameter of central body 62 µm.
Paratype (in lateral view): overall length 73 µm, overall breadth 77 µm.
Range of dimensions: Specimens in apical view: maximum overall diameter 65-83 µm, maximum diameter of central body 52-62 µm.
Specimens in lateral view: overall length 72-75 µm, length of central body 72-75 µm (5 specimens).
Heilmann-Clausen in Heilmann-Clausen and Costa, 1989, p. 470, pl.18, fig.12: Pentadinium cf. Iophophorum
The ornament of the endophragm is not as coarse as in typical specimens of P. Iophophorum.