Back
Achomosphaera ramulifera ssp. gabonensis
From Fensome et al., 2019:
Achomosphaera ramulifera ssp. gabonensis, (Boltenhagen, 1977, p.36–37, pl.3, figs.7a–b,8–9) Lentin and Williams, 1981, p.3.
Holotype: Boltenhagen, 1977, pl.3, figs.7a–b; Fensome et al., 1993a, figs.1–2 — p.1209.
Originally Achomosphaera ramulifera var. gabonensis, subsequently (and now) Achomosphaera ramulifera subsp. gabonensis.
Age: Campanian–Maastrichtian.
Paratypes: Boltenhagen, 1977
Locus typicus: Port Gentil, Gabon; Mandji Section, 1600-1605 m
---------------------------------------------------------------------------------------------------
Original description as Achomosphaera ramulifera ssp. gabonensis: [Boltenhagen, 1977, p. 36] (Translation: Fensome et al., 1993):
Description:
The shell of this variety has an ovoidal or subspherical shape. The membrane comprises a compact and smooth endophragm and a thinner periphragm covered by a network of rounded perforations which form a loose reticulum. The total thickness of the membrane is about 1 µm.
The appendages emanate from the periphragm which forms their conical bases. Most of these appendages, which are also reticulate, are branched above half or 3/4 of their height and terminate in points or in several minute spines. The others are only bifurcate at their tips; some are also truncate.
Their distribution over the shell reflects the tabulation of the genus Hystrichosphaera. This is especially apparent in the apical and antapical regions, where the broad bases of the appendages are prolonged and form folds analogous to crests between each other, thus outlining the plates. In contrast, the more slender cingular appendages only show alignment corresponding to the margins of presumed plates.
The archeopyle extended in the direction of the large axis is precingular.
Dimensions:
Holotype: central body without processes 51 x 58 µm; length of processes 11-14 µm.
Range of 6 specimens: central body without processes 47(50)53 x 51(57)60 µm; length of processes 10-15 µm.
Achomosphaera ramulifera ssp. gabonensis, (Boltenhagen, 1977, p.36–37, pl.3, figs.7a–b,8–9) Lentin and Williams, 1981, p.3.
Holotype: Boltenhagen, 1977, pl.3, figs.7a–b; Fensome et al., 1993a, figs.1–2 — p.1209.
Originally Achomosphaera ramulifera var. gabonensis, subsequently (and now) Achomosphaera ramulifera subsp. gabonensis.
Age: Campanian–Maastrichtian.
Paratypes: Boltenhagen, 1977
Locus typicus: Port Gentil, Gabon; Mandji Section, 1600-1605 m
---------------------------------------------------------------------------------------------------
Original description as Achomosphaera ramulifera ssp. gabonensis: [Boltenhagen, 1977, p. 36] (Translation: Fensome et al., 1993):
Description:
The shell of this variety has an ovoidal or subspherical shape. The membrane comprises a compact and smooth endophragm and a thinner periphragm covered by a network of rounded perforations which form a loose reticulum. The total thickness of the membrane is about 1 µm.
The appendages emanate from the periphragm which forms their conical bases. Most of these appendages, which are also reticulate, are branched above half or 3/4 of their height and terminate in points or in several minute spines. The others are only bifurcate at their tips; some are also truncate.
Their distribution over the shell reflects the tabulation of the genus Hystrichosphaera. This is especially apparent in the apical and antapical regions, where the broad bases of the appendages are prolonged and form folds analogous to crests between each other, thus outlining the plates. In contrast, the more slender cingular appendages only show alignment corresponding to the margins of presumed plates.
The archeopyle extended in the direction of the large axis is precingular.
Dimensions:
Holotype: central body without processes 51 x 58 µm; length of processes 11-14 µm.
Range of 6 specimens: central body without processes 47(50)53 x 51(57)60 µm; length of processes 10-15 µm.