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Occisucysta wierzbowskii
Occisucysta wierzbowskii Poulsen 1996
Occisucysta balia Gitmez 1970, emend. Jan du Chene et al. 1976, sensu Courtinat 1989, pl. 25, fig. 7, text-fig. 84-B.
Holotype. Poulsen 1996, pl. 25, figs. 1-3; DGU catalogue no.: 1991-NEP-10; from Blogie-Nadzieja borehole (Poland) at 22.0 m, Brzostowka Marly Siltstone, Volgian.
Paratype. Poulsen 1996, pl. 25, pig. 4; DGU catalogue no.: 1991-NEP-11, sample details as for the holotype.
Diagnosis. A proximate subspherical cyst with a short apical horn. Autophragm with scattered intratabular granules. Parasutural ridges distally smooth to weakly denticulate. The cingular parasutures are septa with small denticles. The posterior paracingular septum is slightly higher than its anterior counterpart. Adjacent to the other parasutures, the posterior paracingular flange has subtriangular fenestrations. Paratabulation gonyaulacoid, sexiform, 1"""" small and asymmetrical. Archeopyle, type 2P2""-3"". Parasulcus narrow, slightly depressed.
Description: A species of Occisucysta which bears a small blunt apical horn. The autophragm is ornamented with scattered granules on the paraplates. The parasutural crests are smooth to faintly denticulate and low except for the paracingular ridges. The posterior paracingular suture is often the widest and is developed as a septum. Distinct subtriangular fenestrations are developed adjacent to the parasutural triple junctions. The paratabulation is gonyaulacoid, sexiform. The antapical paraplate 1"""" is small and asymmetrical, paraplate boundary 6"""/1"""" closer to the paracingulum than paraplate boundary 1p/1"""". The archeopyle is precingular, involving two paraplates (paraplate 2"" and 3""). The operculum is free. Paracingulum indicated by the two paracingular flanges (parasutures). The parasulcus is relatively narrow in a shallow subdivided depression, paraplate ps distinct. The size is intermediate.
Comparison. Occisucysta wierzbowskii differs from other species of Occisucysta in having a paracingular flange with distinct subtriangular fenestrations. In antapical view it resembles Limbodinium absidatum (Drugg 1978) Riding 1987 in having a small asymmetrical paraplate 1"""" and a similar paracingular flange with subtriangular fenestrations. It differs from L. absidatum in having an apical horn and a precingular archeopyle; L. absidatum has a hemicystal archeopyle and a nearly flat epicystal cone without any apical horn.
Distribution. Polish specimens are from the Sokolovi Zone, Early Volgian of the Blogie-Nadzieja borehole (22-38 m). The specimen figured in Courtinat (1989) is from the Early Tithonian. A specimen was found in sample CC243 of G.U. Gitmez (now lodged at British Geological Survey); the stratigraphic position of this sample is not given in Gitmez (1970).
Dimensions. 9 specimens measured. The length of this species is unknown, because it is usually; found in apical or antapical view. This indicates, however, that it is compressed in the apical-antapical direction. Holotype: length ?, width 60 µm, dorso-ventral width 51 µm. Paratype: length ?, width 67 µm, dorso-ventral width 62 µm. Overall cyst length 75 µm (1 spp.). Dorso-ventral width (minimum-mean-maximum) 50 µm - 60 µm - 72 µm. Overall cyst width (minimum-mean-maximum) 56 µm -63 µm- 76 µm.
Occisucysta balia Gitmez 1970, emend. Jan du Chene et al. 1976, sensu Courtinat 1989, pl. 25, fig. 7, text-fig. 84-B.
Holotype. Poulsen 1996, pl. 25, figs. 1-3; DGU catalogue no.: 1991-NEP-10; from Blogie-Nadzieja borehole (Poland) at 22.0 m, Brzostowka Marly Siltstone, Volgian.
Paratype. Poulsen 1996, pl. 25, pig. 4; DGU catalogue no.: 1991-NEP-11, sample details as for the holotype.
Diagnosis. A proximate subspherical cyst with a short apical horn. Autophragm with scattered intratabular granules. Parasutural ridges distally smooth to weakly denticulate. The cingular parasutures are septa with small denticles. The posterior paracingular septum is slightly higher than its anterior counterpart. Adjacent to the other parasutures, the posterior paracingular flange has subtriangular fenestrations. Paratabulation gonyaulacoid, sexiform, 1"""" small and asymmetrical. Archeopyle, type 2P2""-3"". Parasulcus narrow, slightly depressed.
Description: A species of Occisucysta which bears a small blunt apical horn. The autophragm is ornamented with scattered granules on the paraplates. The parasutural crests are smooth to faintly denticulate and low except for the paracingular ridges. The posterior paracingular suture is often the widest and is developed as a septum. Distinct subtriangular fenestrations are developed adjacent to the parasutural triple junctions. The paratabulation is gonyaulacoid, sexiform. The antapical paraplate 1"""" is small and asymmetrical, paraplate boundary 6"""/1"""" closer to the paracingulum than paraplate boundary 1p/1"""". The archeopyle is precingular, involving two paraplates (paraplate 2"" and 3""). The operculum is free. Paracingulum indicated by the two paracingular flanges (parasutures). The parasulcus is relatively narrow in a shallow subdivided depression, paraplate ps distinct. The size is intermediate.
Comparison. Occisucysta wierzbowskii differs from other species of Occisucysta in having a paracingular flange with distinct subtriangular fenestrations. In antapical view it resembles Limbodinium absidatum (Drugg 1978) Riding 1987 in having a small asymmetrical paraplate 1"""" and a similar paracingular flange with subtriangular fenestrations. It differs from L. absidatum in having an apical horn and a precingular archeopyle; L. absidatum has a hemicystal archeopyle and a nearly flat epicystal cone without any apical horn.
Distribution. Polish specimens are from the Sokolovi Zone, Early Volgian of the Blogie-Nadzieja borehole (22-38 m). The specimen figured in Courtinat (1989) is from the Early Tithonian. A specimen was found in sample CC243 of G.U. Gitmez (now lodged at British Geological Survey); the stratigraphic position of this sample is not given in Gitmez (1970).
Dimensions. 9 specimens measured. The length of this species is unknown, because it is usually; found in apical or antapical view. This indicates, however, that it is compressed in the apical-antapical direction. Holotype: length ?, width 60 µm, dorso-ventral width 51 µm. Paratype: length ?, width 67 µm, dorso-ventral width 62 µm. Overall cyst length 75 µm (1 spp.). Dorso-ventral width (minimum-mean-maximum) 50 µm - 60 µm - 72 µm. Overall cyst width (minimum-mean-maximum) 56 µm -63 µm- 76 µm.