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Cyclonephelium deconinckii
From Fensome et al., 2019:
Cyclonephelium deconinckii Boltenhagen, 1977, p.52–53, pl.4, figs.5a–b,6. Holotype: Boltenhagen, 1977, pl.4, figs.5a–b; Fauconnier and Masure, 2004, pl.18, figs.5–6; Fensome et al., 2019a, figs.15K–L. Age: Campanian.
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Original description: [Boltenhagen, 1977] (translated from French):
Pointe-Clairette Series, Campanian, Upper Senonian, Port-Gentil (Gabon, Equatorial Africa).
DIAGNOSIS
Subcircular to polygonal shell, characterized by apical and antapical protuberances, ornamented along the periphery by rows of appendages forming an openwork serration; apical archaeopyle, acuminate operculum.
DESCRIPTION
The shell of our specimens, with a subcircular to rounded polygonal outline, is equipped with an apical protuberance and two antapical protuberances. The central part is devoid of appendages; these form a peripheral ornamentation by implanting themselves on a punctuated or microgranular membrane. They are, for the most part, joined at mid-height in rows by diagonal bars, thus forming a kind of openwork serration. Those of the antapical protuberances are longer and occur in tufts.
The apical archaeopyle has zigzagging edges; the operculum, in meridian optical section, has a roughly diamond-shaped outline.
DIMENSIONS
Holotype: shell (without appendages): d'' = 64 x 67 μ
tufted appendages on the antapex: L' = up to 15 μ
appendages in rows: L'' = up to 8 μ
Paratypes:
shell (without appendages): d = 74 x 78 μ
tufted appendages: L' = up to 13 μ
appendages in rows: L'' = up to 8μ
COMPARISON
This species is distinguished from other described species by the peripheral rows of short, interconnected appendages and by the longer, tufted appendages located on the antapical protuberances. Furthermore, its outline is rounded polygonal.
Stratigraphic and geographic position
Upper Cretaceous: Upper Senonian; Gabon (Port-Gentil).
Cyclonephelium deconinckii Boltenhagen, 1977, p.52–53, pl.4, figs.5a–b,6. Holotype: Boltenhagen, 1977, pl.4, figs.5a–b; Fauconnier and Masure, 2004, pl.18, figs.5–6; Fensome et al., 2019a, figs.15K–L. Age: Campanian.
---------------------------------------------------------------------------------------------------
Original description: [Boltenhagen, 1977] (translated from French):
Pointe-Clairette Series, Campanian, Upper Senonian, Port-Gentil (Gabon, Equatorial Africa).
DIAGNOSIS
Subcircular to polygonal shell, characterized by apical and antapical protuberances, ornamented along the periphery by rows of appendages forming an openwork serration; apical archaeopyle, acuminate operculum.
DESCRIPTION
The shell of our specimens, with a subcircular to rounded polygonal outline, is equipped with an apical protuberance and two antapical protuberances. The central part is devoid of appendages; these form a peripheral ornamentation by implanting themselves on a punctuated or microgranular membrane. They are, for the most part, joined at mid-height in rows by diagonal bars, thus forming a kind of openwork serration. Those of the antapical protuberances are longer and occur in tufts.
The apical archaeopyle has zigzagging edges; the operculum, in meridian optical section, has a roughly diamond-shaped outline.
DIMENSIONS
Holotype: shell (without appendages): d'' = 64 x 67 μ
tufted appendages on the antapex: L' = up to 15 μ
appendages in rows: L'' = up to 8 μ
Paratypes:
shell (without appendages): d = 74 x 78 μ
tufted appendages: L' = up to 13 μ
appendages in rows: L'' = up to 8μ
COMPARISON
This species is distinguished from other described species by the peripheral rows of short, interconnected appendages and by the longer, tufted appendages located on the antapical protuberances. Furthermore, its outline is rounded polygonal.
Stratigraphic and geographic position
Upper Cretaceous: Upper Senonian; Gabon (Port-Gentil).