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Chiropteridium eocenicum
Chiropteridium eocenicum, Heilmann-Clausen and Van Simaeys, 2005, p.154, pl.2, figs.1–5.
Holotype: Heilmann-Clausen and Van Simaeys, 2005, pl.2, figs.1–2.
Paratype: Heilmann-Clausen and Van Simaeys, 2005, Paratype1: Plate 2, fig. 3; Paratype 2: Plate 2, figs. 4-5
Age: middle Eocene.
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Original description: [Heilmann-Clausen and Van Simaeys, 2005]:
Description:
Marginate, cavate, skolochorate cysts. The granulate endocyst is dorsoventrally flattened and lenticular.
The periphragm completely encloses the endophragm, and is smooth with very small perforations. Both phragma are mid-dorsally and mid-ventrally appressed. Well-developed pericoels are present at the lateral margins of the ventral surface of the cyst. The two pericoels extend to a lesser degree to the lateral margins of the dorsal surface. These two mainly lateral lobes extend from the apical to the antapical region and form antapical lobes of the same length. At some places within these lobes, the periphragm is supported by columellae.
The lobes bear smooth, slender projections with bifurcate distal endings. Solid processes, which may branch distally, occur on the dorsal surface adjacent to the lobes and the archeopyle margin.
No paratabulation is indicated, except for the archeopyle.
The archeopyle is apical (Type tA), and exhibits a markedly angular suture.
The parasulcal notch is distinctly offset. The operculum bears one large, transverse lobe with slender bifurcate projections.
Dimensions:
Pericyst length (excysted) 66 (91) 107 µm. Pericyst breadth 83 (94) 109 µm. Endocyst length (excysted) 45 (60) 71 µm. Endocyst breadth 55 (63) 76 µm. (28 specimens measured).
Holotype: Pericyst length (excysted) 87 µm; pericyst breadth 96 µm; endocyst length (excysted) 57 µm; endocyst breadth 63 µm.
Affinities:
Chiropteridium eocaenicum sp. nov. differs from all other species of Chiropteridium in having two lateral pericoels extending continuously from the apical to antapical region. Chiropteridium eocaenicum sp.nov. therefore lacks the highly irregular and often jagged outline typical for the genus. Chiropteridium eocaenicum sp. nov. resembles Membranophoridium aspinatum Gerlach 1961, but differs by having projections on the lobes and on the lateral margins of the dorsal surface. It is concluded that Chiropteridium eocaenicum sp. nov. has a morphological position between Chiropteridium and Membranophoridium. The presence of two pericoels is also shared with Palynodinium. However, in Palynodinium the pericoels are ventrolateral in position, not lateral as in Chiropteridium eocaenicum sp. nov. Furthermore, in Palynodinium the position of the paracingulum is clearly reflected by aligned processes on the dorsal surface, and the central body is spherical, not lenticular.
Holotype: Heilmann-Clausen and Van Simaeys, 2005, pl.2, figs.1–2.
Paratype: Heilmann-Clausen and Van Simaeys, 2005, Paratype1: Plate 2, fig. 3; Paratype 2: Plate 2, figs. 4-5
Age: middle Eocene.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Heilmann-Clausen and Van Simaeys, 2005]:
Description:
Marginate, cavate, skolochorate cysts. The granulate endocyst is dorsoventrally flattened and lenticular.
The periphragm completely encloses the endophragm, and is smooth with very small perforations. Both phragma are mid-dorsally and mid-ventrally appressed. Well-developed pericoels are present at the lateral margins of the ventral surface of the cyst. The two pericoels extend to a lesser degree to the lateral margins of the dorsal surface. These two mainly lateral lobes extend from the apical to the antapical region and form antapical lobes of the same length. At some places within these lobes, the periphragm is supported by columellae.
The lobes bear smooth, slender projections with bifurcate distal endings. Solid processes, which may branch distally, occur on the dorsal surface adjacent to the lobes and the archeopyle margin.
No paratabulation is indicated, except for the archeopyle.
The archeopyle is apical (Type tA), and exhibits a markedly angular suture.
The parasulcal notch is distinctly offset. The operculum bears one large, transverse lobe with slender bifurcate projections.
Dimensions:
Pericyst length (excysted) 66 (91) 107 µm. Pericyst breadth 83 (94) 109 µm. Endocyst length (excysted) 45 (60) 71 µm. Endocyst breadth 55 (63) 76 µm. (28 specimens measured).
Holotype: Pericyst length (excysted) 87 µm; pericyst breadth 96 µm; endocyst length (excysted) 57 µm; endocyst breadth 63 µm.
Affinities:
Chiropteridium eocaenicum sp. nov. differs from all other species of Chiropteridium in having two lateral pericoels extending continuously from the apical to antapical region. Chiropteridium eocaenicum sp.nov. therefore lacks the highly irregular and often jagged outline typical for the genus. Chiropteridium eocaenicum sp. nov. resembles Membranophoridium aspinatum Gerlach 1961, but differs by having projections on the lobes and on the lateral margins of the dorsal surface. It is concluded that Chiropteridium eocaenicum sp. nov. has a morphological position between Chiropteridium and Membranophoridium. The presence of two pericoels is also shared with Palynodinium. However, in Palynodinium the pericoels are ventrolateral in position, not lateral as in Chiropteridium eocaenicum sp. nov. Furthermore, in Palynodinium the position of the paracingulum is clearly reflected by aligned processes on the dorsal surface, and the central body is spherical, not lenticular.