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Impagidinium rigidaseptatum
From Fensome et al., 2019:
Impagidinium rigidaseptatum Slimani, 1994, p.104–105, pl.17, figs.1–9; text-fig.13A. Holotype: Slimani, 1994, pl.17, figs.1–7. Taxonomic junior synonym: Spiniferites cingulatus var. prominoseptatus (name not validly published), according to Slimani (2001a, p.193). Age: late Campanian–Danian.
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Original description (Slimani, 1994)
Diagnosis: Murochorate, acavate cyst with a subcircular outline; the central body is ovoid to subspheroidal and bears a small apical protrusion. This cyst is characterized by its rigid parasutural septa of uniform height (approximately 1/5 of the total diameter) and T-shaped in cross-section. These septa are supported by solid, gonal, non-protruding axes and by trabecular thickenings that connect them distally. The paratabuIation is of the Impagidinium type, it corresponds to the following formula: 4', 6", 6c, 6'". lp, 1"", 2 - ?3s.
Dimensions:
Holotype. Central body, length: 50 µm, width: 44 µm; total cyst diameter: 80 µm.
Variations: Central body, length: 32-50 µm, width: 30-46 µm, total cyst diameter: 60-82 µm.
Height of septa: 10-20 µm.
Length of the apical horn of the endocyst: 4-8 µm.
Number of specimens measured: 12.
Material: > 44 specimens.
Name derivation: Latin: rigida, rigid; refers to the rigid parasutural septa.
Holotype: Halembaye sample 43, preparation 3, EF coord. U30/4.
Paratype: Halembaye sample 54, preparation 3, EF coord. Y54/4.
Type locality: Halembaye sample 43.
Type horizon: Upper Maastrichtian (Vijlen Member).
Synonymy: 1974: Spiniferites cingulatus vor. prominoseptatus - in Wilson, p. 323, pl. 29, fig. 10-12.
1977: "Forma c" - Schumacker-Lambry, in Streel et al. pl. 4, fig. 14.
71980: Cannosphaeropsis cf. pusuiosa Morgenroth, 1966b - May, p. 44.45, pl. 2, fig. 3.
1992: Nematosphaeropsis cf. pusuhsa Morgenroth, 1966b - Marheinecke, p. 42, pl. 6, fig. 5.7.
Description:
The autophragm is thin (0.5 to 1 μm) and smooth. The parasutural septa consist of rigid, smooth to microperforated membranes and often have a fibrous appearance; their base is constantly marked by thickenings of about 1 μm in width, their distal margin is also bordered by thickenings of the same width as the previous ones and reminiscent of trabeculae. At their distal margin, the parasutural septa bear laterally membranous ridges of the same nature; these distal ridges are irregularly cut into thin, acuminate, straight or recurved processes. The gonal axes, the proximal and distal thickenings of the septa have almost the same width and form a skeleton that supports the central body and the septa. The paraplates 1 and 4' are symmetrical and 6" has no contact with 1'; there is no parasutural septum separating the parasulcus and 6"; it is sometimes represented by a tip on the left end of the anterior margin of the paracingulum. The paracingulum reaching up to 12 pm in width in Phototype is laevogyrous, the displacement distance of its two ends is around 10 pm. The pentagonal outline archaeopyle is precingulate of type P (3" only), the operculum is free.
Comparison: Impagidinium rigidaseptatum sp. nov. corresponds to Spiniferites cingidatus var. prominoscptatus of Wilson (1974) and also to "forma c" of Schumacker-Lambry in Streel et al. (1977). It apparently also corresponds to the forms attributed to Cannosphaeropsis cf. pusulosa Morgenroth (1966b), by May (1980) and Nematosphaeropsis cf. pusulosa by Marheinecke (1992). However, the morphological characteristics of Nematosphaeropsis pusulosa (Morgenroth, 1966b) Stover and Evitt (1978) are largely different from those of the species studied here and are more reminiscent of Nematosphaeropsis retiatlensis (Pastiels, 1948) Sarjeant, 1986. Our species is reminiscent of the forms listed under the name Nematosphaeropsis cf. velata Clarke and Verdier (1967) by Foucher (1974: p. 15, pl. 2, fig. 8,9) and Nematosphaeropsis velata Clarke and Verdier (1967) by Foucher (1976: p. 19, pl. 3, fig. 7,8), encountered respectively in the upper Turonian. from Ruyaulcourt to Pas-de-Calais, and from the Turonian to the base of the Campanian of Beauvais. However, the type material of this latter species has been defined as having processes which are prominent; by referring to the Phototype figures, it is therefore certain that it is far from being comparable to Impagidinium rigidaseptatum sp. nov.; it is provisionally replaced in the genus Spiniferites by Stover and Evitt (1978).
Stratigraphic distribution:
Beutenaken: ex. 2 to 14, Halembaye: ex. 18 to 80; Upper Campanian - Maastrichtian upper. (B. mucronata zone -
Zone at B. junior). Turnhout: -956 to -739.31 m, upper Campanian. - Danien. In Wilson (1974), Campanian - Maastrichtian sup. (Langei Zone - junior Zone), Denmark and Maastricht region. Schumacker-Lambry in S T Reel et al. (1977), Campanian, Schumacker-Lambry Zone II, N.E. Belgium. M A Y (1980). Maastrichtian sup., New Jersey, U.S.A. Marheinecke (1992). Upper Maastrichtian, Hemmoor, Germany.
Impagidinium rigidaseptatum Slimani, 1994, p.104–105, pl.17, figs.1–9; text-fig.13A. Holotype: Slimani, 1994, pl.17, figs.1–7. Taxonomic junior synonym: Spiniferites cingulatus var. prominoseptatus (name not validly published), according to Slimani (2001a, p.193). Age: late Campanian–Danian.
---------------------------------------------------------------------------------------------------
Original description (Slimani, 1994)
Diagnosis: Murochorate, acavate cyst with a subcircular outline; the central body is ovoid to subspheroidal and bears a small apical protrusion. This cyst is characterized by its rigid parasutural septa of uniform height (approximately 1/5 of the total diameter) and T-shaped in cross-section. These septa are supported by solid, gonal, non-protruding axes and by trabecular thickenings that connect them distally. The paratabuIation is of the Impagidinium type, it corresponds to the following formula: 4', 6", 6c, 6'". lp, 1"", 2 - ?3s.
Dimensions:
Holotype. Central body, length: 50 µm, width: 44 µm; total cyst diameter: 80 µm.
Variations: Central body, length: 32-50 µm, width: 30-46 µm, total cyst diameter: 60-82 µm.
Height of septa: 10-20 µm.
Length of the apical horn of the endocyst: 4-8 µm.
Number of specimens measured: 12.
Material: > 44 specimens.
Name derivation: Latin: rigida, rigid; refers to the rigid parasutural septa.
Holotype: Halembaye sample 43, preparation 3, EF coord. U30/4.
Paratype: Halembaye sample 54, preparation 3, EF coord. Y54/4.
Type locality: Halembaye sample 43.
Type horizon: Upper Maastrichtian (Vijlen Member).
Synonymy: 1974: Spiniferites cingulatus vor. prominoseptatus - in Wilson, p. 323, pl. 29, fig. 10-12.
1977: "Forma c" - Schumacker-Lambry, in Streel et al. pl. 4, fig. 14.
71980: Cannosphaeropsis cf. pusuiosa Morgenroth, 1966b - May, p. 44.45, pl. 2, fig. 3.
1992: Nematosphaeropsis cf. pusuhsa Morgenroth, 1966b - Marheinecke, p. 42, pl. 6, fig. 5.7.
Description:
The autophragm is thin (0.5 to 1 μm) and smooth. The parasutural septa consist of rigid, smooth to microperforated membranes and often have a fibrous appearance; their base is constantly marked by thickenings of about 1 μm in width, their distal margin is also bordered by thickenings of the same width as the previous ones and reminiscent of trabeculae. At their distal margin, the parasutural septa bear laterally membranous ridges of the same nature; these distal ridges are irregularly cut into thin, acuminate, straight or recurved processes. The gonal axes, the proximal and distal thickenings of the septa have almost the same width and form a skeleton that supports the central body and the septa. The paraplates 1 and 4' are symmetrical and 6" has no contact with 1'; there is no parasutural septum separating the parasulcus and 6"; it is sometimes represented by a tip on the left end of the anterior margin of the paracingulum. The paracingulum reaching up to 12 pm in width in Phototype is laevogyrous, the displacement distance of its two ends is around 10 pm. The pentagonal outline archaeopyle is precingulate of type P (3" only), the operculum is free.
Comparison: Impagidinium rigidaseptatum sp. nov. corresponds to Spiniferites cingidatus var. prominoscptatus of Wilson (1974) and also to "forma c" of Schumacker-Lambry in Streel et al. (1977). It apparently also corresponds to the forms attributed to Cannosphaeropsis cf. pusulosa Morgenroth (1966b), by May (1980) and Nematosphaeropsis cf. pusulosa by Marheinecke (1992). However, the morphological characteristics of Nematosphaeropsis pusulosa (Morgenroth, 1966b) Stover and Evitt (1978) are largely different from those of the species studied here and are more reminiscent of Nematosphaeropsis retiatlensis (Pastiels, 1948) Sarjeant, 1986. Our species is reminiscent of the forms listed under the name Nematosphaeropsis cf. velata Clarke and Verdier (1967) by Foucher (1974: p. 15, pl. 2, fig. 8,9) and Nematosphaeropsis velata Clarke and Verdier (1967) by Foucher (1976: p. 19, pl. 3, fig. 7,8), encountered respectively in the upper Turonian. from Ruyaulcourt to Pas-de-Calais, and from the Turonian to the base of the Campanian of Beauvais. However, the type material of this latter species has been defined as having processes which are prominent; by referring to the Phototype figures, it is therefore certain that it is far from being comparable to Impagidinium rigidaseptatum sp. nov.; it is provisionally replaced in the genus Spiniferites by Stover and Evitt (1978).
Stratigraphic distribution:
Beutenaken: ex. 2 to 14, Halembaye: ex. 18 to 80; Upper Campanian - Maastrichtian upper. (B. mucronata zone -
Zone at B. junior). Turnhout: -956 to -739.31 m, upper Campanian. - Danien. In Wilson (1974), Campanian - Maastrichtian sup. (Langei Zone - junior Zone), Denmark and Maastricht region. Schumacker-Lambry in S T Reel et al. (1977), Campanian, Schumacker-Lambry Zone II, N.E. Belgium. M A Y (1980). Maastrichtian sup., New Jersey, U.S.A. Marheinecke (1992). Upper Maastrichtian, Hemmoor, Germany.