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Trithyrodinium vozzhennikovae
From Fensome et al., 2019:
Trithyrodinium vozzhennikovae (Boltenhagen, 1977, p.108, pl.19, figs.5a–c,6–7) Masure et al., 1996, p.182.
Emendation: Masure et al., 1996, p.182, as Trithyrodinium vozzhennikovae.
Holotype: Boltenhagen, 1977, pl.19, figs.5a–c. Originally Svalbardella, subsequently Andalusiella, thirdly (and now) Trithyrodinium.
Age: Campanian.
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Original description: [Boltenhagen, 1977] (translated from French):
Svalbardella vozzhennikovae nov. sp.
Pointe-Clairette Series, Campanian; Part-Gentil (Gabon, Equatorial Africa).
DAGNOSE
Very thin, smooth, fusiform theca, with more or less conical horns at the poles and enclosing a globular capsule covered with microwarts.
DESCRIPTION
This species is characterized by a smooth and very thin fusiform theca formed by a globular body extended by two conical polar horns, large but short, rounded or pointed at the apex. The thicker, subspherical capsule is entirely covered by conical granules approximately 0.5 μm high. The theca adheres entirely to the capsule except around the horns. Therefore, its microsculpture, at first glance, appears to be theca infrastructure. The capsule's archaeopyle would be hexagonal, with two upper sides three times longer than the two lower ones; the lower base is about a third longer than the upper one. The sutures of the operculum indicate these relationships. Under these conditions, in profile, this archaeopyle would appear as a broken line composed of four segments. On the apex of one of the specimens, traces of tabulation can be seen starting from the angles of the archaeopyle. On the theca, the outline of the latter is indeterminate due to the fragility of the membrane, which tears and forms folds. The presence of traces of a cingulum is possible.
DIMENSIONS
Holotype:
theca (with horns): L = 75 μ
theca (without horns): L' x l' = 51 x 45 μ
capsule: L" x l" = 50 x 44 μ
horns: h' - h" = 14 - 18 μ
2 paratypes:
theca (without horns): L x l = 48 x 50 μ and 56 x 55 μ
capsule: L' x l' = 48 x 50 μ and 56 x 55 μ
horns: h' - h" = ± 11 μ and 18 μ
COMPARISON
We provisionally place this species in the genus Svalbardella MAN. 1960 (p. 21). It should be noted, however, that the theca is not clearly fusiform, having a globular body, and that the cingulum was not clearly observed. It is therefore possible that this is in fact a new genus.
Stratigraphic and Geographic Position
Upper Cretaceous: Campanian; Gabon (Port-Gentil).
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Emended diagnosis: Masure, Tea and Yao 1996, p. 182
Proximate, cornucavate dinoflagellate cyst, subspherical to ellipsoidal central body, with one short apical horn and two poorly developed antapical horns of inequal size; granulous endophragm, smooth periphragm; paratabulation indicated by endoarcheopyle, intercalary archeopyle, type 3I/3I, operculum polyplacoid, free, occasionaly adherent.
Trithyrodinium vozzhennikovae (Boltenhagen, 1977, p.108, pl.19, figs.5a–c,6–7) Masure et al., 1996, p.182.
Emendation: Masure et al., 1996, p.182, as Trithyrodinium vozzhennikovae.
Holotype: Boltenhagen, 1977, pl.19, figs.5a–c. Originally Svalbardella, subsequently Andalusiella, thirdly (and now) Trithyrodinium.
Age: Campanian.
---------------------------------------------------------------------------------------------------
Original description: [Boltenhagen, 1977] (translated from French):
Svalbardella vozzhennikovae nov. sp.
Pointe-Clairette Series, Campanian; Part-Gentil (Gabon, Equatorial Africa).
DAGNOSE
Very thin, smooth, fusiform theca, with more or less conical horns at the poles and enclosing a globular capsule covered with microwarts.
DESCRIPTION
This species is characterized by a smooth and very thin fusiform theca formed by a globular body extended by two conical polar horns, large but short, rounded or pointed at the apex. The thicker, subspherical capsule is entirely covered by conical granules approximately 0.5 μm high. The theca adheres entirely to the capsule except around the horns. Therefore, its microsculpture, at first glance, appears to be theca infrastructure. The capsule's archaeopyle would be hexagonal, with two upper sides three times longer than the two lower ones; the lower base is about a third longer than the upper one. The sutures of the operculum indicate these relationships. Under these conditions, in profile, this archaeopyle would appear as a broken line composed of four segments. On the apex of one of the specimens, traces of tabulation can be seen starting from the angles of the archaeopyle. On the theca, the outline of the latter is indeterminate due to the fragility of the membrane, which tears and forms folds. The presence of traces of a cingulum is possible.
DIMENSIONS
Holotype:
theca (with horns): L = 75 μ
theca (without horns): L' x l' = 51 x 45 μ
capsule: L" x l" = 50 x 44 μ
horns: h' - h" = 14 - 18 μ
2 paratypes:
theca (without horns): L x l = 48 x 50 μ and 56 x 55 μ
capsule: L' x l' = 48 x 50 μ and 56 x 55 μ
horns: h' - h" = ± 11 μ and 18 μ
COMPARISON
We provisionally place this species in the genus Svalbardella MAN. 1960 (p. 21). It should be noted, however, that the theca is not clearly fusiform, having a globular body, and that the cingulum was not clearly observed. It is therefore possible that this is in fact a new genus.
Stratigraphic and Geographic Position
Upper Cretaceous: Campanian; Gabon (Port-Gentil).
---------------------------------------------------------------------------------------------------
Emended diagnosis: Masure, Tea and Yao 1996, p. 182
Proximate, cornucavate dinoflagellate cyst, subspherical to ellipsoidal central body, with one short apical horn and two poorly developed antapical horns of inequal size; granulous endophragm, smooth periphragm; paratabulation indicated by endoarcheopyle, intercalary archeopyle, type 3I/3I, operculum polyplacoid, free, occasionaly adherent.