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Adnatosphaeridium vittatum
Adnatosphaeridium vittatum, Williams and Downie, 1966
Holotype: Williams and Downie, 1966, pl.24, fig.7
Locus typicus: London Clay, Sheppey, Kent, England
Stratum typicum: Early Eocene
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Original description: [Williams and Downie, 1966, p. 215-216]:
Diagnosis:
Ellipsoidal central body, with thin granular wall bearing processes of two types: slender to broadly taeniate, greatly expanded distally, and hollow open branched. Former type predominating. Adjacent processes often united distally.
Reflected tabulation ?', 6'', 5''', 1p, and 1''''.
Archaeopyle apical.
Description:
Adnatosphaeridium vittatum has strongly developed taeniate processes, often exceeding 10 µm in width, which may be arranged in linear, soleate, or annular complexes. In outline, the complexes can be tubiform to flaring, distally having two orthogonal or recurved branches. The outer margin of the branches is frequently finely serrate. Branches of processes are interconnected with other processes on the same or adjacent plates. The interlinking of processes gives to them the appearance of natural arches. Some of the processes are simple and are oblate or bifid distally. Occasionally hollow branched open processes are present on the central body. Unconnected acuminate spines may arise from the processes.
Dimensions:
Holotype: diameter of central body 37 µm, by 47 µm, length of processes up to 20 µm.
Range: diameter of central body, width 37-66 µm, length 28 (when archaeopyle present) to 52 µm; length of processes up to 31 µm.
4 specimens measured.
Affinities:
Remarks: A. vittatum is characterized by its taeniate processes of varying width, the presence of free and united processes and the occasional hollow branched processes. The distal serrate terminations are unusual in this genus.
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Supplemental description:
Gocht, 1969, p. 65: (Translation: Geological Survey of Canada):
Description/Remarks:
Only one, moderately preserved specimen was recovered. The processes are very fragile, infundibuliform or saccate membrane structures with a narrow base. Distally they are joined together by thin bridges or filaments, which in some places widen into planar surfaces or strips. The apical archeopyle has a jagged edge. The processes directly below the archeopyle, which belong to the precingular series, are absent at the middle of the ventral side.
Measurements:
Maximal extension 121 µm, main body diameter 68: 64 µm.
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Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Adnatosphaeridium vittatum Williams and Downie, 1966c has taeniate processes of varying width, both free and united processes and occasional hollow, branched processes. The distal serrate terminations, reminiscent of those found in Enneadocysta, are unusual in this genus. Central body 37-66 µm, processes up to 31 µm.
Holotype: Williams and Downie, 1966, pl.24, fig.7
Locus typicus: London Clay, Sheppey, Kent, England
Stratum typicum: Early Eocene
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Williams and Downie, 1966, p. 215-216]:
Diagnosis:
Ellipsoidal central body, with thin granular wall bearing processes of two types: slender to broadly taeniate, greatly expanded distally, and hollow open branched. Former type predominating. Adjacent processes often united distally.
Reflected tabulation ?', 6'', 5''', 1p, and 1''''.
Archaeopyle apical.
Description:
Adnatosphaeridium vittatum has strongly developed taeniate processes, often exceeding 10 µm in width, which may be arranged in linear, soleate, or annular complexes. In outline, the complexes can be tubiform to flaring, distally having two orthogonal or recurved branches. The outer margin of the branches is frequently finely serrate. Branches of processes are interconnected with other processes on the same or adjacent plates. The interlinking of processes gives to them the appearance of natural arches. Some of the processes are simple and are oblate or bifid distally. Occasionally hollow branched open processes are present on the central body. Unconnected acuminate spines may arise from the processes.
Dimensions:
Holotype: diameter of central body 37 µm, by 47 µm, length of processes up to 20 µm.
Range: diameter of central body, width 37-66 µm, length 28 (when archaeopyle present) to 52 µm; length of processes up to 31 µm.
4 specimens measured.
Affinities:
Remarks: A. vittatum is characterized by its taeniate processes of varying width, the presence of free and united processes and the occasional hollow branched processes. The distal serrate terminations are unusual in this genus.
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Supplemental description:
Gocht, 1969, p. 65: (Translation: Geological Survey of Canada):
Description/Remarks:
Only one, moderately preserved specimen was recovered. The processes are very fragile, infundibuliform or saccate membrane structures with a narrow base. Distally they are joined together by thin bridges or filaments, which in some places widen into planar surfaces or strips. The apical archeopyle has a jagged edge. The processes directly below the archeopyle, which belong to the precingular series, are absent at the middle of the ventral side.
Measurements:
Maximal extension 121 µm, main body diameter 68: 64 µm.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Adnatosphaeridium vittatum Williams and Downie, 1966c has taeniate processes of varying width, both free and united processes and occasional hollow, branched processes. The distal serrate terminations, reminiscent of those found in Enneadocysta, are unusual in this genus. Central body 37-66 µm, processes up to 31 µm.