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Senegalinium microspinosum
Senegalinium microspinosum (Boltenhagen, 1977) Lentin and Williams, 1980
Originally Deflandrea, subsequently (and now) Senegalinium.
Holotype: Boltenhagen, 1977, pl.17, figs.1a-c
Age: Campanian-Maastrichtian
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Original description: [Boltenhagen, 1977] (translated from French):
Deflandrea microspinosus nov. sp.
Pointe-Clairette Series, Campanian; Port-Gentil (Gabon, Equatorial Africa).
DlAGNOSIS
Subspherical shape with short, conical horns of similar size; microwarty theca; smooth capsule filling the theca and partially adhering to its walls. Pentagonal archaeopyle with two straight lateral sides and three others arched. Broad, circular cingulum; open sulcus with a subtriangular outline.
DESCRIPTION
This fragile species has a thin membrane that is rarely well preserved and is generally torn or deformed by folds. Projecting dorsiventrally, the theca is subcircular in outline. The rounded epitheca extends into a more or less pronounced conical horn, often blunt or pointed at the apex. The hypotheca is flattened between the two antapical horns. The latter, of similar size, are also conical and generally pointed at their tips. Their broad bases are visible between folds of the theca. The theca is entirely covered by microspinules or conical microwarts about 0.5 u high. This microsculpture is only clearly visible at 800 magnification and especially in phase contrast. At 320 magnification, only microgranulation or, on some specimens, simply a punctuation mark is visible. The smooth, voluminous capsule with a subcircular outline is almost adherent to the theca. When folded or crumpled, it detaches entirely. The relatively wide cingulum is often masked by marginal folds but, in this case, detaches in a median optical section thanks to lateral notches. The sulcus observed on some specimens opens widely towards the cingulum; it ends with an acuminate furrow on two-thirds of the hypotheca. The archaeopyle of the theca,
with a roughly pentagonal outline, is 22-25u x 18-24u diagonally open; its outline roughly coincides with that of the capsule. On the latter, a tear is observed along the direction of the anterior suture of the operculum of the archaeopyle. This tear causes a fold across the capsule, a phenomenon quite frequently observed on the capsules of various species of the genus Deflandrea.
DIMENSIONS
Holotype:
theca (with horns): L' = 83 μ
theca (without horns): L'' x l = 67 x 76 μ
capsule: L x l = 64 x 72 μ
apical horns: h' = 12 μ
antapical horns: h'-h" = 12-13 μ
cingulum: l = 6 μ
Paratype:
theca (without horns): L'' x l = 66 x 68 μ
apical horns (blunted): h = 7 μ
cingulum: l = 6 μ
Based on 4 other specimens and their state of conservation:
theca (with horns): L' = 82 - 78 μ
theca (without horns): L'' x l = 52-62 x 69-72 μ
apical horns: h' = 10 - 14 μ
antapical horns: h" = 12 - 15 μ
cingulum: l = 5 - 7 μ
COMPARISON
The described species bears some resemblance to Deflandrea sp. MAN. 1960 (p. 20, PI. I, Fig. 9) in the outline of its theca. It is distinguished primarily by the echinulate microsculpture of its theca, rather than its grooved form.
Stratigraphic and Geographic Position
Upper Cretaceous: Campanian - Maastrichtian, Gabon (Port-Gentil and Fernan-Vaz),
Originally Deflandrea, subsequently (and now) Senegalinium.
Holotype: Boltenhagen, 1977, pl.17, figs.1a-c
Age: Campanian-Maastrichtian
------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Boltenhagen, 1977] (translated from French):
Deflandrea microspinosus nov. sp.
Pointe-Clairette Series, Campanian; Port-Gentil (Gabon, Equatorial Africa).
DlAGNOSIS
Subspherical shape with short, conical horns of similar size; microwarty theca; smooth capsule filling the theca and partially adhering to its walls. Pentagonal archaeopyle with two straight lateral sides and three others arched. Broad, circular cingulum; open sulcus with a subtriangular outline.
DESCRIPTION
This fragile species has a thin membrane that is rarely well preserved and is generally torn or deformed by folds. Projecting dorsiventrally, the theca is subcircular in outline. The rounded epitheca extends into a more or less pronounced conical horn, often blunt or pointed at the apex. The hypotheca is flattened between the two antapical horns. The latter, of similar size, are also conical and generally pointed at their tips. Their broad bases are visible between folds of the theca. The theca is entirely covered by microspinules or conical microwarts about 0.5 u high. This microsculpture is only clearly visible at 800 magnification and especially in phase contrast. At 320 magnification, only microgranulation or, on some specimens, simply a punctuation mark is visible. The smooth, voluminous capsule with a subcircular outline is almost adherent to the theca. When folded or crumpled, it detaches entirely. The relatively wide cingulum is often masked by marginal folds but, in this case, detaches in a median optical section thanks to lateral notches. The sulcus observed on some specimens opens widely towards the cingulum; it ends with an acuminate furrow on two-thirds of the hypotheca. The archaeopyle of the theca,
with a roughly pentagonal outline, is 22-25u x 18-24u diagonally open; its outline roughly coincides with that of the capsule. On the latter, a tear is observed along the direction of the anterior suture of the operculum of the archaeopyle. This tear causes a fold across the capsule, a phenomenon quite frequently observed on the capsules of various species of the genus Deflandrea.
DIMENSIONS
Holotype:
theca (with horns): L' = 83 μ
theca (without horns): L'' x l = 67 x 76 μ
capsule: L x l = 64 x 72 μ
apical horns: h' = 12 μ
antapical horns: h'-h" = 12-13 μ
cingulum: l = 6 μ
Paratype:
theca (without horns): L'' x l = 66 x 68 μ
apical horns (blunted): h = 7 μ
cingulum: l = 6 μ
Based on 4 other specimens and their state of conservation:
theca (with horns): L' = 82 - 78 μ
theca (without horns): L'' x l = 52-62 x 69-72 μ
apical horns: h' = 10 - 14 μ
antapical horns: h" = 12 - 15 μ
cingulum: l = 5 - 7 μ
COMPARISON
The described species bears some resemblance to Deflandrea sp. MAN. 1960 (p. 20, PI. I, Fig. 9) in the outline of its theca. It is distinguished primarily by the echinulate microsculpture of its theca, rather than its grooved form.
Stratigraphic and Geographic Position
Upper Cretaceous: Campanian - Maastrichtian, Gabon (Port-Gentil and Fernan-Vaz),