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Chiropteridium brevifolium
Chiropteridium brevifolium, Schindler, 1992
Holotype: Schindler, 1992, fig.6b
Locus typicus: Albig, Germany
Stratum typicum: Rupelian (Middle Oligocene)
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Original description: [Schindler, 1992, p. 204-206]: (Translation: GSC, courtesy R. Fensome):
Diagnosis:
Cyst two-layered. The endocyst is globose to ellipsoidal, ventrally and antapically flattened to shallowly concave.
The periphragm completely encloses the endophragm and exhibits altogether four characteristically short lateral fimbriae on the dorsal and ventral side, extending meridionally with uniform width from the apical to the antapical region (fig. 6).
The two ventral fimbriae run from the archeopyle to the vicinity of the antapex, connecting only proximally with the antapical processes. Each fimbria has a U-shaped, arcuate incision approximately at the middle (fig. 6d). On the dorsal side, the fimbriae are limited to approximately the upper 2/3 to 4/5 of the region between archeopyle and antapex. They start just below the line of dehiscence and end very abruptly towards the antapex (fig. 6a-c), instead of tapering downward with gradually diminishing breadth as in other forms. Distally the dorsal and ventral fimbriae exhibit at wide intervals roundish notches of different depth; sometimes they are tapered to fine cusps. On the operculum, there is not an apical process as, e.g., in Chiropteridium lobospinosum, but two transverse fimbriae, of which the dorsal one is distinctly narrower than the ventral at the proximal end (fig. 6c). Distally, both expand fanlike and frequently show distal notches and a deep, wide arcuate incision at the middle (fig. 6c).
At the antapex, as in C. aspinatum and C. lobospinosum, there is a horizontal dorsal fimbria, connected proximally with the lateral fimbriae on the dorsal side (fig. 6a). Its distal end is cleft and usually produced into relatively short processes, only seldom into longer processes. In this species, it may be trimmed with a few small spinules. Ventrally, there are two antapical processes. They are applanate-cylindrical and distally foliate, produced into short cusps (fig. 6). All fimbriae and processes represent hollow evaginations of the periphragm and are closed distally.
Description and supplementary remarks:
As in the other species of Chiropteridium, the apical archeopyle exhibits a zigzag suture with six points. Presumably there are four apical (4") and six precingular (6"") plates. More precise information regarding the paratabulation can not be given here, either. However, the outline of the archeopyle margin serves for dorsoventral orientation: Dorsally, there is a notch slightly offset to the left and a cusp offset to the right. Ventrally, the angular parasulcal notch offset to the left is distinctly expressed (fig. 6d). Also in this form, the endophragm-periphragm detachment boundaries can be used for orientation. They form a horizontal oval on the dorsal side and a vertical oval on the ventral side. Again, the surface of the periphragm is granulate where it is appressed to the endophragm and smoother on fimbriae and processes. Frequently there are recesses in the periphragm at the base of the dorsal antapical fimbria and under the proximal lateral fimbriae.
Dimensions/Measurements (30 specimens examined):
Holotype: entire cyst: length: 156 µm; breadth: 135 µm; endocyst: length: 96 µm; breadth: 97 µm
other specimens: entire cyst: length: 131-156 µm; breadth: 75-135 µm; endocyst: length: 67-96 µm; breadth: 51-97 µm
Holotype: Schindler, 1992, fig.6b
Locus typicus: Albig, Germany
Stratum typicum: Rupelian (Middle Oligocene)
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Schindler, 1992, p. 204-206]: (Translation: GSC, courtesy R. Fensome):
Diagnosis:
Cyst two-layered. The endocyst is globose to ellipsoidal, ventrally and antapically flattened to shallowly concave.
The periphragm completely encloses the endophragm and exhibits altogether four characteristically short lateral fimbriae on the dorsal and ventral side, extending meridionally with uniform width from the apical to the antapical region (fig. 6).
The two ventral fimbriae run from the archeopyle to the vicinity of the antapex, connecting only proximally with the antapical processes. Each fimbria has a U-shaped, arcuate incision approximately at the middle (fig. 6d). On the dorsal side, the fimbriae are limited to approximately the upper 2/3 to 4/5 of the region between archeopyle and antapex. They start just below the line of dehiscence and end very abruptly towards the antapex (fig. 6a-c), instead of tapering downward with gradually diminishing breadth as in other forms. Distally the dorsal and ventral fimbriae exhibit at wide intervals roundish notches of different depth; sometimes they are tapered to fine cusps. On the operculum, there is not an apical process as, e.g., in Chiropteridium lobospinosum, but two transverse fimbriae, of which the dorsal one is distinctly narrower than the ventral at the proximal end (fig. 6c). Distally, both expand fanlike and frequently show distal notches and a deep, wide arcuate incision at the middle (fig. 6c).
At the antapex, as in C. aspinatum and C. lobospinosum, there is a horizontal dorsal fimbria, connected proximally with the lateral fimbriae on the dorsal side (fig. 6a). Its distal end is cleft and usually produced into relatively short processes, only seldom into longer processes. In this species, it may be trimmed with a few small spinules. Ventrally, there are two antapical processes. They are applanate-cylindrical and distally foliate, produced into short cusps (fig. 6). All fimbriae and processes represent hollow evaginations of the periphragm and are closed distally.
Description and supplementary remarks:
As in the other species of Chiropteridium, the apical archeopyle exhibits a zigzag suture with six points. Presumably there are four apical (4") and six precingular (6"") plates. More precise information regarding the paratabulation can not be given here, either. However, the outline of the archeopyle margin serves for dorsoventral orientation: Dorsally, there is a notch slightly offset to the left and a cusp offset to the right. Ventrally, the angular parasulcal notch offset to the left is distinctly expressed (fig. 6d). Also in this form, the endophragm-periphragm detachment boundaries can be used for orientation. They form a horizontal oval on the dorsal side and a vertical oval on the ventral side. Again, the surface of the periphragm is granulate where it is appressed to the endophragm and smoother on fimbriae and processes. Frequently there are recesses in the periphragm at the base of the dorsal antapical fimbria and under the proximal lateral fimbriae.
Dimensions/Measurements (30 specimens examined):
Holotype: entire cyst: length: 156 µm; breadth: 135 µm; endocyst: length: 96 µm; breadth: 97 µm
other specimens: entire cyst: length: 131-156 µm; breadth: 75-135 µm; endocyst: length: 67-96 µm; breadth: 51-97 µm