Back
Hystrichokolpoma globulus
From Fensome et al., 2019:
Hystrichokolpoma globulus Michoux, 1985, p.143, pl.1, figs.1–4,12; text-figs.2A–B. Holotype: Michoux, 1985, pl.1, figs.1–4; textfigs.
2A–B; Fauconnier and Masure, 2004, pl.38, figs.4–5. NIA. Age: Early Eocene.
---------------------------------------------------------------------------------------------------
Original description: [Michoux, 1985] (translated from French):
Hystrichokolpoma globula n. sp.
(Pl. 1, fig. 1-4, 12, text-fig. 2)
1977. - Hystrichokolpoma cinctum JAN Du CHÈNE, p. 106, pl. 1, fig. 11.
Holotype: Slide DZ-10, coordinates L32-L33.
Name origin: From the globose shape of the processes.
Type locality: Donzacq beds, Donzacq tile factory.
Diagnosis: Species of the genus Hystrichokolpoma, with a spherical central body, bearing several types of processes. The apical, pre-, and postcingulate processes are globose to subconical. The cingulate and sulcal processes are short, shaped like blunt cones. The antapical process is longer than the other processes and tapers distally.
Description: The central body of the cyst is spherical. The periphragm and endophragm are smooth. The periphragm forms the processes, which are closed distally. The operculum is present in all specimens observed and bears four processes. Processes 1', 3', and 4' are subconical in shape with a rounded tip. Process 2' is larger; its size and shape are comparable to those of the pre- and postcingulate processes. These have a rounded to quadrangular base, and their shape resembles a pyramid with rounded corners and apex, or a more or less flattened cone. The 1"' process is smaller than the other postcingulate processes. The antapical process is slightly longer than the other processes. Its base is circular. It tapers distally, slowly at first, then more rapidly from two-thirds of its length, to terminate in a point.
The cingulate processes, shaped like blunt, very low cones, number 3 to 5 per paraplate. They are sometimes connected proximally. The sulcal processes are similar in shape but isolated. Those in the medial part of the sulcus are larger than those in the posterior part.
Tabulation: 4', 6", 6c, 5'", xs, 1"".
Dimensions: Diameter of the central body: 43 to 45 μm. Pre- and postcingulate processes, length 15 to 18 μm, width 18 to 23 μm. Antapical process: length 18 to 25 μm, 2 specimens measured.
Discussion: This species is superficially similar to Hystrichokolpoma cinctum. However, it differs markedly in its much smaller size, its shorter antapical process relative to the size of the cyst, the absence of tubules on the pre- and postcingulate processes, and its short, conical cingulate and sulcal processes.
We attribute to this species the specimen attributed by Jan du Chène (1977 b) to Hystrichokolpoma cinctum in his study from the Andalusian Miocene.
The illustration (Pl. 1, fig. 11) clearly shows the characteristics of Hystrichokolpoma globula n. sp.: Conical pre- and postcingulate processes devoid of tubules; the dimensions are consistent with those of the Chalosse specimens: basal diameter of the processes 24 μm, height 13.5 μm. The cingulate diameter of the cyst is slightly larger: 57 μm. The operculum is also in place. This unusual feature in Hystrichokolpoma appears as another distinctive feature of H. globula n. sp.
--------------------------------------------------
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Hystrichokolpoma globulus Michoux, 1985, has apical, pre- and postcingular processes which are globular and subconical. The cingular and sulcal processes are short and in the form of blunt cones. The antapical process is longer than the others and tapers distally. Size: central body 43-45 µm, pre- and postcingular process length 15-18 µm, width 18-23 µm. Antapical process length 18-25 µm
--------------------------------------------------
Hystrichokolpoma globulus Michoux, 1985, p.143, pl.1, figs.1–4,12; text-figs.2A–B. Holotype: Michoux, 1985, pl.1, figs.1–4; textfigs.
2A–B; Fauconnier and Masure, 2004, pl.38, figs.4–5. NIA. Age: Early Eocene.
---------------------------------------------------------------------------------------------------
Original description: [Michoux, 1985] (translated from French):
Hystrichokolpoma globula n. sp.
(Pl. 1, fig. 1-4, 12, text-fig. 2)
1977. - Hystrichokolpoma cinctum JAN Du CHÈNE, p. 106, pl. 1, fig. 11.
Holotype: Slide DZ-10, coordinates L32-L33.
Name origin: From the globose shape of the processes.
Type locality: Donzacq beds, Donzacq tile factory.
Diagnosis: Species of the genus Hystrichokolpoma, with a spherical central body, bearing several types of processes. The apical, pre-, and postcingulate processes are globose to subconical. The cingulate and sulcal processes are short, shaped like blunt cones. The antapical process is longer than the other processes and tapers distally.
Description: The central body of the cyst is spherical. The periphragm and endophragm are smooth. The periphragm forms the processes, which are closed distally. The operculum is present in all specimens observed and bears four processes. Processes 1', 3', and 4' are subconical in shape with a rounded tip. Process 2' is larger; its size and shape are comparable to those of the pre- and postcingulate processes. These have a rounded to quadrangular base, and their shape resembles a pyramid with rounded corners and apex, or a more or less flattened cone. The 1"' process is smaller than the other postcingulate processes. The antapical process is slightly longer than the other processes. Its base is circular. It tapers distally, slowly at first, then more rapidly from two-thirds of its length, to terminate in a point.
The cingulate processes, shaped like blunt, very low cones, number 3 to 5 per paraplate. They are sometimes connected proximally. The sulcal processes are similar in shape but isolated. Those in the medial part of the sulcus are larger than those in the posterior part.
Tabulation: 4', 6", 6c, 5'", xs, 1"".
Dimensions: Diameter of the central body: 43 to 45 μm. Pre- and postcingulate processes, length 15 to 18 μm, width 18 to 23 μm. Antapical process: length 18 to 25 μm, 2 specimens measured.
Discussion: This species is superficially similar to Hystrichokolpoma cinctum. However, it differs markedly in its much smaller size, its shorter antapical process relative to the size of the cyst, the absence of tubules on the pre- and postcingulate processes, and its short, conical cingulate and sulcal processes.
We attribute to this species the specimen attributed by Jan du Chène (1977 b) to Hystrichokolpoma cinctum in his study from the Andalusian Miocene.
The illustration (Pl. 1, fig. 11) clearly shows the characteristics of Hystrichokolpoma globula n. sp.: Conical pre- and postcingulate processes devoid of tubules; the dimensions are consistent with those of the Chalosse specimens: basal diameter of the processes 24 μm, height 13.5 μm. The cingulate diameter of the cyst is slightly larger: 57 μm. The operculum is also in place. This unusual feature in Hystrichokolpoma appears as another distinctive feature of H. globula n. sp.
--------------------------------------------------
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Hystrichokolpoma globulus Michoux, 1985, has apical, pre- and postcingular processes which are globular and subconical. The cingular and sulcal processes are short and in the form of blunt cones. The antapical process is longer than the others and tapers distally. Size: central body 43-45 µm, pre- and postcingular process length 15-18 µm, width 18-23 µm. Antapical process length 18-25 µm
--------------------------------------------------