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Tenua aucda
From Fensome et al., 2019:
Tenua aucda (Below, 1981a, p.8–9, pl.4, figs.3,5a–b; pl.12, fig.20; text-figs.6a–c,g) Lentin and Williams, 1993, p.638.
Holotype: Below, 1981a, pl.4, fig.3; Fensome et al., 1991, fig.1 — p.577.
NOW Cerbia. Originally (and now) Cerbia, subsequently Tenua Eisenack. NIA.
Paratype: Below, 1981, pl.4, figs. 5a-b
Locus typicus: Chichaoua I borehole; southwest Marocco
Stratum typicum: Barremian
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Translation Below, 1981: Fensome, 1991, p. 578-579
Original diagnosis: Below, 1981, p. 8: Cerbia aucda
Proximate, dorso-ventrally flattened, tabulate cyst with a single-layered wall; elongate-oval to pentagonal in outline. Epicyst triangular or with rounded apex, hypocyst trapezoidal. Antapex rounded, flattened or with a lobe; this results in two symmetrical bulges of equal size. The archeopyle corresponds to type (A). Paracingulum spiral, subdivided; parasulcus sigmoidal. The paratabulation scheme 4", 6", Xc, 6""", pc, 1"""" can be reconstructed from penitabular rows of low, flat or conical, solid tubercles. The surface is verrucate to smooth.
Original description: Below, 1981, p. 8-9: Cerbia aucda
Most specimens have a pentagonal outline; i.e. a triangular epicyst and a trapezoidal hypocyst. The antapex is flattened or weakly notched; as a result, there are two flat, triangular to rounded, antapical bulges. Rounded poles result in rare, elongate-oval or, even, rounded cysts.
The archeopyle is of type (A). As in Cerbia tabulata (Davey and Verdier 1974) comb. nov. undifferentiated fragments are detached along the archeopyle margin, or the operculum becomes "enlarged" and contains parts of the precingulars in addition to the four apical paraplates.
The paracingulum spirals equatorially around the body and is distinctly offset along the parasulcus. The parasulcus is sigmoidal and slightly indented.
Penitabular rows of knots are arranged as in Cerbia tabulata (Davey and Verdier 1974) comb. nov. ([Below, 1981a] text-fig.5). The six precingular paraplates are approximately of the same size. Of the six postcingulars, 1""" is considerably reduced in size, narrow, and not separated from the parasulcus; consequently, 1""", if observed without prejudice, is considered part of an apparently broadened parasulcus. The form of the penitabular components varies ([Below, 1981a] text-fig.6). In typical cases, they are wide, distally rounded, low tubercles with circular or oval bases, finely pointed tubercles, or low, solid cones which may be truncate distally. Variants include solid, wide but short spines or humps (bacula). In numerous specimens some tubercles, humps or spines are replaced by long, distally capitate appendages like those of Cerbia tabulata (Davey and Verdier 1974) comb. nov. Cerbia aucda may be derived from that species by successive replacement of penitabular appendages by tuberculate structures. Specimens of the new species that do not indicate this close affinity by possession of one or two capitate appendages are rare.
Size.
Holotype: length 88 µm, width 83 µm. Range of other specimens: length 72(83)93 µm, width 66(76)86 µm; length of appendages 1 - 3.5 µm.
Tenua aucda (Below, 1981a, p.8–9, pl.4, figs.3,5a–b; pl.12, fig.20; text-figs.6a–c,g) Lentin and Williams, 1993, p.638.
Holotype: Below, 1981a, pl.4, fig.3; Fensome et al., 1991, fig.1 — p.577.
NOW Cerbia. Originally (and now) Cerbia, subsequently Tenua Eisenack. NIA.
Paratype: Below, 1981, pl.4, figs. 5a-b
Locus typicus: Chichaoua I borehole; southwest Marocco
Stratum typicum: Barremian
---------------------------------------------------------------------------------------------------
Translation Below, 1981: Fensome, 1991, p. 578-579
Original diagnosis: Below, 1981, p. 8: Cerbia aucda
Proximate, dorso-ventrally flattened, tabulate cyst with a single-layered wall; elongate-oval to pentagonal in outline. Epicyst triangular or with rounded apex, hypocyst trapezoidal. Antapex rounded, flattened or with a lobe; this results in two symmetrical bulges of equal size. The archeopyle corresponds to type (A). Paracingulum spiral, subdivided; parasulcus sigmoidal. The paratabulation scheme 4", 6", Xc, 6""", pc, 1"""" can be reconstructed from penitabular rows of low, flat or conical, solid tubercles. The surface is verrucate to smooth.
Original description: Below, 1981, p. 8-9: Cerbia aucda
Most specimens have a pentagonal outline; i.e. a triangular epicyst and a trapezoidal hypocyst. The antapex is flattened or weakly notched; as a result, there are two flat, triangular to rounded, antapical bulges. Rounded poles result in rare, elongate-oval or, even, rounded cysts.
The archeopyle is of type (A). As in Cerbia tabulata (Davey and Verdier 1974) comb. nov. undifferentiated fragments are detached along the archeopyle margin, or the operculum becomes "enlarged" and contains parts of the precingulars in addition to the four apical paraplates.
The paracingulum spirals equatorially around the body and is distinctly offset along the parasulcus. The parasulcus is sigmoidal and slightly indented.
Penitabular rows of knots are arranged as in Cerbia tabulata (Davey and Verdier 1974) comb. nov. ([Below, 1981a] text-fig.5). The six precingular paraplates are approximately of the same size. Of the six postcingulars, 1""" is considerably reduced in size, narrow, and not separated from the parasulcus; consequently, 1""", if observed without prejudice, is considered part of an apparently broadened parasulcus. The form of the penitabular components varies ([Below, 1981a] text-fig.6). In typical cases, they are wide, distally rounded, low tubercles with circular or oval bases, finely pointed tubercles, or low, solid cones which may be truncate distally. Variants include solid, wide but short spines or humps (bacula). In numerous specimens some tubercles, humps or spines are replaced by long, distally capitate appendages like those of Cerbia tabulata (Davey and Verdier 1974) comb. nov. Cerbia aucda may be derived from that species by successive replacement of penitabular appendages by tuberculate structures. Specimens of the new species that do not indicate this close affinity by possession of one or two capitate appendages are rare.
Size.
Holotype: length 88 µm, width 83 µm. Range of other specimens: length 72(83)93 µm, width 66(76)86 µm; length of appendages 1 - 3.5 µm.