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Hystrichostrogylon coninckii
Hystrichostrogylon coninckii Heilmann-Clausen in Thomsen and Heilmann-Clausen, 1985
Tax. sr. synonym of Hystrichostrogylon palliatum Hultberg, 1985, according to Marheinecke, 1992.
Holotype: Thomsen and Heilmann-Clausen, 1985, pl.7, figs.9-10; text-figs.10C-D
Locus typicus: Svejstrup, Denmark
Stratum typicum: Danian limestone, sample SVI.
Age: Maastrichtian-Paleocene
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Hystrichostrogylon coninckii Heilmann-Clausen in Thomsen and Heilmann-Clausen, 1985. According to Heilmann-Clausen in Thomsen and Heilmann-Clausen (1985), Hystrichostrogylon coninckii has a periphragm which is dorsally closely appressed to the endocyst. On the ventral side there is a large pericoel which separates the much expanded periphragm from the endophragm. The line of separation between the endophragm and periphragm follows approximately the ambitus of the endocyst. In ambital view the pericyst is subcircular with the endocyst placed in a central position. The pericoel communicates with the exterior through a large hole in the mid-ventral part of the periphragm. There are gonal and sutural processes. There are parasutural lines and processes on the periphragm. Size: holotype endocyst length 30 µm, width 28 µm, pericyst length 50 µm, width 52 µm.
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Diagnosis: Thomson and Heilmann-Clausen 1985, p. 353: Hystrichostrogylon coninckii
The endocyst is subspherical. Dorsally the periphragm is closely appressed to the endophragm. On the ventral slde a large pericoel separates the much expanded periphragm from the endophragm. The line of separation between endophragm and periphragm follows approximately the ambitus of the endocyst. In ambital view the pencyst is subcircular with the endocyst placed in a central position. The pencoel communicates with the exterior through a large hole in the mid-ventral part of the periphragm. Wall layers are thin and smooth. Gonal and intergonal processes are present. The distal endings of processes are usually bi- or trifurcate. Where the pericoel is present underneath, the processes are reduced in length and often only the bi- or trifurcate endings are present. Paratabulation is expressed as a precingular archaeopyle representing paraplate 3" and as parasutural lines and processes on the penphragm. The parasutural features are most distinct on the dorsal surface and clearly indicate the paraplates 4' and 1', 2"-5", 2c-5c (6c), 3"'-5"'(6"'), 1"" and ps. The ventral hole in the periphragm intersects the paracingulum, which is otherwise continuous. The parasulcus therefore is partly included in the ventral hole in the penphragm.
Dimensions: Endocyst length = 30 µm, breadth = 28 µm Pericyst length = 50 µm, breadth = 52 µm.
Discussion. Hystrichostrogylon coninckii sp. nov. differs from H. membraniphorum Agelopoulos 1964 and H. holohymenium Islam 1983, in the position of the pericoel and in the presence of a large hole in the periphragm in the parasulcal area.
Occurrence. Upper Maastrichtian, The Netherlands-Belgium (Wilson 1971). Danian and basal Selandian, Sweden (De Coninck 1975). Danian and Lower Selandian, Denmark. Bartonian, Belgium and Southern England (Jan De Coninck, pers. comm. 1984).
synonym:
1971 ?Spinifentes sp. Wilson: 1265; pl. 4, figs 1 4.
1975 Spiniferites sp. A De Coninck: 332; fig. 3F,G,H.
Tax. sr. synonym of Hystrichostrogylon palliatum Hultberg, 1985, according to Marheinecke, 1992.
Holotype: Thomsen and Heilmann-Clausen, 1985, pl.7, figs.9-10; text-figs.10C-D
Locus typicus: Svejstrup, Denmark
Stratum typicum: Danian limestone, sample SVI.
Age: Maastrichtian-Paleocene
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Hystrichostrogylon coninckii Heilmann-Clausen in Thomsen and Heilmann-Clausen, 1985. According to Heilmann-Clausen in Thomsen and Heilmann-Clausen (1985), Hystrichostrogylon coninckii has a periphragm which is dorsally closely appressed to the endocyst. On the ventral side there is a large pericoel which separates the much expanded periphragm from the endophragm. The line of separation between the endophragm and periphragm follows approximately the ambitus of the endocyst. In ambital view the pericyst is subcircular with the endocyst placed in a central position. The pericoel communicates with the exterior through a large hole in the mid-ventral part of the periphragm. There are gonal and sutural processes. There are parasutural lines and processes on the periphragm. Size: holotype endocyst length 30 µm, width 28 µm, pericyst length 50 µm, width 52 µm.
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Diagnosis: Thomson and Heilmann-Clausen 1985, p. 353: Hystrichostrogylon coninckii
The endocyst is subspherical. Dorsally the periphragm is closely appressed to the endophragm. On the ventral slde a large pericoel separates the much expanded periphragm from the endophragm. The line of separation between endophragm and periphragm follows approximately the ambitus of the endocyst. In ambital view the pencyst is subcircular with the endocyst placed in a central position. The pencoel communicates with the exterior through a large hole in the mid-ventral part of the periphragm. Wall layers are thin and smooth. Gonal and intergonal processes are present. The distal endings of processes are usually bi- or trifurcate. Where the pericoel is present underneath, the processes are reduced in length and often only the bi- or trifurcate endings are present. Paratabulation is expressed as a precingular archaeopyle representing paraplate 3" and as parasutural lines and processes on the penphragm. The parasutural features are most distinct on the dorsal surface and clearly indicate the paraplates 4' and 1', 2"-5", 2c-5c (6c), 3"'-5"'(6"'), 1"" and ps. The ventral hole in the periphragm intersects the paracingulum, which is otherwise continuous. The parasulcus therefore is partly included in the ventral hole in the penphragm.
Dimensions: Endocyst length = 30 µm, breadth = 28 µm Pericyst length = 50 µm, breadth = 52 µm.
Discussion. Hystrichostrogylon coninckii sp. nov. differs from H. membraniphorum Agelopoulos 1964 and H. holohymenium Islam 1983, in the position of the pericoel and in the presence of a large hole in the periphragm in the parasulcal area.
Occurrence. Upper Maastrichtian, The Netherlands-Belgium (Wilson 1971). Danian and basal Selandian, Sweden (De Coninck 1975). Danian and Lower Selandian, Denmark. Bartonian, Belgium and Southern England (Jan De Coninck, pers. comm. 1984).
synonym:
1971 ?Spinifentes sp. Wilson: 1265; pl. 4, figs 1 4.
1975 Spiniferites sp. A De Coninck: 332; fig. 3F,G,H.