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Palaeohystrichophora cheit
Palaeohystrichophora cheit (Below, 1981a, p.126–127, pl.9, figs.23–24; text-fig.85) Mahmoud, 1998, p.93–94.
Originally Subtilisphaera, subsequently (and now) Palaeohystrichophora.
Holotype: Below, 1981a, pl.9, fig.23; Fensome et al., 1991, fig.1 — p.611.
Age: Aptian–Vraconian.
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Original description: [Below, 1981a]:
Subtilisphaera cheit n. sp.
Etymology: From arabic "cheit" = thread, after the surface sculpture of the cyst.
Holotype: Mount I-4641 44.3/95.5
Paratypes: Mount I-4641 44.3/95.6; I-4641 40.2/109.9; I-4641 30.5/99.7.
Type location: Profile E, Profile depth 112 m; Tizi.
Type stratum: Albian.
1973 Paleohystrichophora cf. infusorioidies DEFLANDRE 1934 - DAVEY & VERDIER, p. 199; Plate 2, Fig. 5, 8; Text Figs. 7-9 (Vraconnian; France).
1978 Subtilisphaera cf. perlucida (ALBERTI 1961) JAIN & MILLEPIED
1973 - WILLIAMS, Plate 7, Fig. l: Text Fig. 4 (Hauterivian, Barremian; Leg 41, Site 370; offshore West Africa).
Diagnosis: Bicavate to cavate, dorso-ventrally flattened, non-tabular cyst. The elongate-oval, more rarely spherical or rhombic endocyst
consisting of a smooth endophragn fills the rhombic, slightly pentagonal or fusiform pericyst; consequently, only apically and antapically, more rarely ambitally, a pericoel develops. The equatorial, planar paracingulum which is only weakly imınersed in the pericyst, divides the cyst unevenly. The triangular epipericyst apically forms a pointed horn and is larger than the trapezohedral or antapically rounded hypopericyst. The latter develops only a single, non-axial conical, distally rounded or triangular and dístally pointed antapical horn. There is no archaeopyle. The periphragm bears dense, fusiform, extremely thin appendages that are maximally 6 μ long.
Description: Supplemental to the diagnosis only remarks concerning the varialbility of certain characteristics will be added. As a rule the endocyst is elongate-oval, oval or ideally spheric, rhombic, rarely also transverse-oval in outline. Usually the endocyst fills the pericyst completely with exception of the polar regions. Nevertheless, in addition to transitional forms there occur also specimens with ambital pericoel.
The epipericyst is triangular. Its sides are bent outward; in this manner a more rounded fora develops. Consequently, the apical horn appears as the tip of the epipericyst , fused with it as. one unit or grafted on it.
Comparison: From all species of Subtilisphacra JAIN & MILLEPIED, Subtilisphaera cheit n. sp. differs by its filiform appendages. Confusion with Palaeohystrichopliora infusorioides DEFLANDRE is only possible if the species is examined in marginal view wíth the apical and the antapical horns in the longitudinal axis. Palaeohystrichophora infusorioides DEFLANDRE is then characterised by longer and stouter appendages and - according to DAVEY (1970) - by a precingular archaeopyle .
Measurements:
Holotype: length of pericyst 62 μ; width of pericyst 46 μ; length of enducyst 46 μ; width of endocyst 46 μ; length of appendages 6 μ.
Other specimens : length of pericyst 48-78 μ (mean 62 μ); width of pericyst 28-48 μ (mean 40 μ); length of endocyst 36-50 μ (mean 43 μ); width of endocyst 24-48 μ (mean 39 μ); length of appendages 2.5-6 μ.
Material examined: Approximately 500 specimens.
Distribution: Profile E (26): Albian; Profile IAB (26): Vraconnian; Profile KV (26): Vraconnian, Albian; Profile Chichaoua I (53): Albian; Profile Timinoun (37): Aptian.
Originally Subtilisphaera, subsequently (and now) Palaeohystrichophora.
Holotype: Below, 1981a, pl.9, fig.23; Fensome et al., 1991, fig.1 — p.611.
Age: Aptian–Vraconian.
---------------------------------------------------------------------------------------------------------------
Original description: [Below, 1981a]:
Subtilisphaera cheit n. sp.
Etymology: From arabic "cheit" = thread, after the surface sculpture of the cyst.
Holotype: Mount I-4641 44.3/95.5
Paratypes: Mount I-4641 44.3/95.6; I-4641 40.2/109.9; I-4641 30.5/99.7.
Type location: Profile E, Profile depth 112 m; Tizi.
Type stratum: Albian.
1973 Paleohystrichophora cf. infusorioidies DEFLANDRE 1934 - DAVEY & VERDIER, p. 199; Plate 2, Fig. 5, 8; Text Figs. 7-9 (Vraconnian; France).
1978 Subtilisphaera cf. perlucida (ALBERTI 1961) JAIN & MILLEPIED
1973 - WILLIAMS, Plate 7, Fig. l: Text Fig. 4 (Hauterivian, Barremian; Leg 41, Site 370; offshore West Africa).
Diagnosis: Bicavate to cavate, dorso-ventrally flattened, non-tabular cyst. The elongate-oval, more rarely spherical or rhombic endocyst
consisting of a smooth endophragn fills the rhombic, slightly pentagonal or fusiform pericyst; consequently, only apically and antapically, more rarely ambitally, a pericoel develops. The equatorial, planar paracingulum which is only weakly imınersed in the pericyst, divides the cyst unevenly. The triangular epipericyst apically forms a pointed horn and is larger than the trapezohedral or antapically rounded hypopericyst. The latter develops only a single, non-axial conical, distally rounded or triangular and dístally pointed antapical horn. There is no archaeopyle. The periphragm bears dense, fusiform, extremely thin appendages that are maximally 6 μ long.
Description: Supplemental to the diagnosis only remarks concerning the varialbility of certain characteristics will be added. As a rule the endocyst is elongate-oval, oval or ideally spheric, rhombic, rarely also transverse-oval in outline. Usually the endocyst fills the pericyst completely with exception of the polar regions. Nevertheless, in addition to transitional forms there occur also specimens with ambital pericoel.
The epipericyst is triangular. Its sides are bent outward; in this manner a more rounded fora develops. Consequently, the apical horn appears as the tip of the epipericyst , fused with it as. one unit or grafted on it.
Comparison: From all species of Subtilisphacra JAIN & MILLEPIED, Subtilisphaera cheit n. sp. differs by its filiform appendages. Confusion with Palaeohystrichopliora infusorioides DEFLANDRE is only possible if the species is examined in marginal view wíth the apical and the antapical horns in the longitudinal axis. Palaeohystrichophora infusorioides DEFLANDRE is then characterised by longer and stouter appendages and - according to DAVEY (1970) - by a precingular archaeopyle .
Measurements:
Holotype: length of pericyst 62 μ; width of pericyst 46 μ; length of enducyst 46 μ; width of endocyst 46 μ; length of appendages 6 μ.
Other specimens : length of pericyst 48-78 μ (mean 62 μ); width of pericyst 28-48 μ (mean 40 μ); length of endocyst 36-50 μ (mean 43 μ); width of endocyst 24-48 μ (mean 39 μ); length of appendages 2.5-6 μ.
Material examined: Approximately 500 specimens.
Distribution: Profile E (26): Albian; Profile IAB (26): Vraconnian; Profile KV (26): Vraconnian, Albian; Profile Chichaoua I (53): Albian; Profile Timinoun (37): Aptian.