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Ctenidodinium combazii
From Fensome et al., 2019:
Ctenidodinium combazii Dupin, 1968, p.2, pl.1, figs.1–6; text-figs.1–4. Holotype: Dupin, 1968, pl.1, figs.4–5. Woollam (1983, p.193) considered Gonyaulax (as Hystrichogonyaulax) cornigera to be the possible taxonomic senior synonym of this species. Age: middle–late Bathonian.
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Original description: [Dupin, 1968] (translated from French):
Ctenidodinium combazi n.sp.
Pl. I, figs. 1 to 6.
Species dedicated to Mr. A. Combaz, C.F., P., Bordeaux.
Diagnosis: The species is characterized by the presence, on the sutures, of particularly large ribs, the tips of which can themselves be highly ornamented, presenting long, simple, bifurcated, trifurcated, and often even complexly branched spines (figs. 3 and 4).
It possesses a transverse helical groove, the lower part of which is bordered by the wide belt described by Deflandre, separating the shell into two parts: a hypotherium consisting of a small polygonal antapical plate, and six post-equatorial plates (three large trapezoidal and three smaller) and an intercalary one (1 p.). The 1"' is very small. The epitheca could not be observed with such precision; it has six large pre-equatorial plates and four apical plates (figs. 1 and 2).
The longitudinal groove widens on the hypotheca. The size of the individual with the ridges averages 126 to 135 μ. The width of the ridges varies between 9 and 22 μ.
Holotype, - P1. 1, figs. 4 and 5. Preparation 4961 A, (BT 89- England location, U 48.3 =3290),
Le Porge-1, preserved at the Micropaleontology Laboratory of the E, P.H,E., Museum, Paris.
Type locality. - Drilling, Le Porge-1, core 25, 1810 m (Gironde).
Note: This species is very close to Ctenidodinium ornatum Deflandre, from which it differs by its larger size, its broader and more ome-shaped crests, and mainly by the structure of the hypotheca, in which the apical plate is small rather than very large.
Very abundant in the preparations we studied, it has the particularity of most often showing only the hypotheca. In the numerous preparations examined, whole individuals are quite rare, and epithecae alone have never been encountered: are they more fragile? Does this correspond to a reproductive phenomenon or is it linked to an ecological factor? The question remains.
G. Deflandre noted a similar phenomenon for Ctenidodinium ornatum Defl.
Stratigraphic extension: The stratigraphic extension of this species is very limited. It is found only in the upper Bathonian, in the upper part of the Filament Limestones, themselves located between the anhydrite and dolomite zone (below) and the ammonite marls (above). The species then truly abounds, dominating the association by 90%. This Ctenidodinium combazi palynofacies has been found in several boreholes in western Aquitaine.
These organisms correspond to a marine advance that began in the Liassic, indicating the presence of a warm, shallow sea throughout the region, favoring the expansion of dinoflagellates.
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Ctenidodinium combazii Dupin, 1968. According to Woollam (1983), this species may be conspecific with Hystrichogonyaulax (now Ctenidodinium) cornigera. The species is characterised by the presence on the sutures of membranes which distally are very ornamented, and bear long, simple bifurcate spines. Some spines can be more complex being trifurcate distally. Size: 126-135 µm, crests 9-22 µm.
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Ctenidodinium combazii Dupin, 1968, p.2, pl.1, figs.1–6; text-figs.1–4. Holotype: Dupin, 1968, pl.1, figs.4–5. Woollam (1983, p.193) considered Gonyaulax (as Hystrichogonyaulax) cornigera to be the possible taxonomic senior synonym of this species. Age: middle–late Bathonian.
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Original description: [Dupin, 1968] (translated from French):
Ctenidodinium combazi n.sp.
Pl. I, figs. 1 to 6.
Species dedicated to Mr. A. Combaz, C.F., P., Bordeaux.
Diagnosis: The species is characterized by the presence, on the sutures, of particularly large ribs, the tips of which can themselves be highly ornamented, presenting long, simple, bifurcated, trifurcated, and often even complexly branched spines (figs. 3 and 4).
It possesses a transverse helical groove, the lower part of which is bordered by the wide belt described by Deflandre, separating the shell into two parts: a hypotherium consisting of a small polygonal antapical plate, and six post-equatorial plates (three large trapezoidal and three smaller) and an intercalary one (1 p.). The 1"' is very small. The epitheca could not be observed with such precision; it has six large pre-equatorial plates and four apical plates (figs. 1 and 2).
The longitudinal groove widens on the hypotheca. The size of the individual with the ridges averages 126 to 135 μ. The width of the ridges varies between 9 and 22 μ.
Holotype, - P1. 1, figs. 4 and 5. Preparation 4961 A, (BT 89- England location, U 48.3 =3290),
Le Porge-1, preserved at the Micropaleontology Laboratory of the E, P.H,E., Museum, Paris.
Type locality. - Drilling, Le Porge-1, core 25, 1810 m (Gironde).
Note: This species is very close to Ctenidodinium ornatum Deflandre, from which it differs by its larger size, its broader and more ome-shaped crests, and mainly by the structure of the hypotheca, in which the apical plate is small rather than very large.
Very abundant in the preparations we studied, it has the particularity of most often showing only the hypotheca. In the numerous preparations examined, whole individuals are quite rare, and epithecae alone have never been encountered: are they more fragile? Does this correspond to a reproductive phenomenon or is it linked to an ecological factor? The question remains.
G. Deflandre noted a similar phenomenon for Ctenidodinium ornatum Defl.
Stratigraphic extension: The stratigraphic extension of this species is very limited. It is found only in the upper Bathonian, in the upper part of the Filament Limestones, themselves located between the anhydrite and dolomite zone (below) and the ammonite marls (above). The species then truly abounds, dominating the association by 90%. This Ctenidodinium combazi palynofacies has been found in several boreholes in western Aquitaine.
These organisms correspond to a marine advance that began in the Liassic, indicating the presence of a warm, shallow sea throughout the region, favoring the expansion of dinoflagellates.
--------------------------------------------------
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Ctenidodinium combazii Dupin, 1968. According to Woollam (1983), this species may be conspecific with Hystrichogonyaulax (now Ctenidodinium) cornigera. The species is characterised by the presence on the sutures of membranes which distally are very ornamented, and bear long, simple bifurcate spines. Some spines can be more complex being trifurcate distally. Size: 126-135 µm, crests 9-22 µm.
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