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Oligosphaeridium albertense
Oligosphaeridium albertense (Pocock, 1962) Davey and Williams, 1969
Originally Hystrichosphaeridium, subsequently (and now) Oligosphaeridium.
Tax. sr. synonym of Oligosphaeridium irregulare (Pocock, 1962) Davey and Williams, 1969, according to Jansonius, 1986, which species Stover and Evitt, 1978, considered to be a tax. sr. synonym of the following species: Oligosphaeridium? coelenteratum (Tasch, 1964) Davey and Williams, 1969; Oligosphaeridium? dispare (Tasch, 1964) Davey and Williams, 1969; and Oligosphaeridium reniforme (Tasch, 1964) Davey, 1969.
This combination was not validly published in Davey and Williams, 1966, since these authors did not fully reference the basionym.
Holotype: Pocock, 1962, pl.15, fig.226; Brideaux, 1977, pl.11, figs.34; Jansonius, 1986, pl.4, figs. 4-5
Locus typicus: Imperial Kurkoi
Stratum typicum: Barremian
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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.
Oligosphaeridium albertense (Pocock, 1962) Davey and Williams, 1969. According to Jansonius (1986) and based on the holotype, Oligosphaeridium albertense has 13 processes, 25-30 µm long, nearly cylindrical at their bases, but gently widening distally, with the distal half more or less strongly flaring; distal margin thin, occasionally scalloped, carrying numerous coarse to fine, slender spinules. Wall of vesicle and processes thin (0.3-0.4 µm). Brideaux (1977) provided a revised diagnosis. He noted that the processes were hollow, flared to tubiform, distally open, with the margins variably secate, occasionally aculeate, or serrate; the distal third of some processes are variably fenestrate; one process, probably sulcal, reduced, shorter, acuminate to foliate or with reduced distal secate margin. Process formula is 4', 6", 0c, 5"’, 1p, 1"”. Size: holotype overall 100 x 110 µm, central body 70 x 47 µm, Brideaux’s specimens: maximum, excluding processes, 52-70 µm.
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Original description: Pocock, 1962, p.82: Hystrichosphaeridium albertense
Vesicle laevigate, thin, vitreous, circular in cross section; prosesses trumped shaped, being faintly narrow at the bases and widening continuously along the length to the apex; processes faintly long compared with the diameter of the vesicle, hollow; lips of processes irregular and frequently broken up into a series of short spines.
Size range: Diameter of vesicle 60 (63) 65 Ám; holotype 65 Ám. Length of processes 25 (32) 40 Ám; holotype ¦ 30 Ám. Basal diameter of processes 3 (5.5) 10 Ám, holotype ¦ 7 Ám. Apical diameter of processes 15 (27) 35 Ám; holotype ¦ 27 Ám. Number of processes 12 (14) 16 Ám; holotype 14 Ám.
Revised diagnosis: Brideaux, 1977, p.27-28
Shape: Pericyst, excluding processes, subcircular. Endocyst closely appressed except at loci of processes arising from pericyst. Pericoel not developed; slight dorso-ventral compression.
Phragma: Pericyst less than 0.5 µm thick, smooth or with scabrate sculpture; periphragm produced to form hollow, flared to tubiform processes, the processes open distally, the distal margins variably secate, occasionally aculeate or serrate; the distal third of some processes variably fenestrate; one process, probably sulcal in position, reduced, shorter, acuminate to foliate or with reduced distal secate margin; processes from 10-30 µm long, 3-7 µm wide basally (Pocock, 1962, p. 82 gives 25-40 µm, 3-10 µm respectively). Endophragm less than 0.5 Ám thick, apparently smooth. Paratabulation: Process formula determined as 4', 6", 0c, 5''', 1p, 1s, maximum of 17 processes observed on complete specimens, 13 on specimens with archeopyle developed; archeopyle outline denotes epiparatabulation of four apical paraplates and six precingular paraplates Of the precingular processes, 6" smallest, 5" broadest and tubiform, 1"-4" intermediate in size; of the postcingular processes, 1''' often with a V-shaped extension of the distal opening down the column, 2''' broad-columned and tubiform, 3''' largest process on pericyst; antapical process often strongly secate, the secae broad and dissected; sulcal process variable, from an acuminate to foliate closed process to a reduced tubiform process, distally open; posterior intercalary process (1p) as large or larger than the process 6". Archeopyle/operculum: Archeopyle formed by the loss of four apical paraplates; the operculum simple, free, occasionally lying in the archeopyle, and bearing four apical processes little differentiated in size and structure. Formula. A.
Pericingulum/perisulcus: Pericingular processes absent, the pericingular region defined by their absence; perisulcus represented by a single reduced process of variable morphology.
Dimensions. (40 measured specimens) - Maximum pericyst diameter, 52-70 µm, excluding processes.
Supplemental description: Jansonius, 1986, p.213
(Holotype) ca 100 x 110 µm overall, body 70 x 47 µm. Processes 13 in number, 25-30 µm long, nearly cylindrical at their bases, but gently widening distally, with the distal half more or less strongly varing; distal margin thin, occasionally scalloped, carrying numerous coarse to fine, slender spinules. Wall of vesicle and processes thin (0.3-0.4 µm). The opening just below the center is not the archeopyle, but a tear caused by the disengagement of the paraplate carrying the process pointing towards 7 o'clock. The paraplate just above this one also is separated at its left margin (ca 9 o'clock), and some other paraplate boundaries show separation.
Affinities:
Brideaux, 1977, p.28: The distally secate margins of the essentially similar flared to tubiform processes of Oligosphaeridium albertense distinguish this species from species with buccinate columns and entire to serrate distal margins (Oligosphaeridium totum Brideaux, 1971) and from species with highly variable columns and complex distal terminations [Oligosphaeridium irregulare (Pocock) Davey and Williams, 1969]. The species, Oligosphaeridium reniforme (Tasch) Davey, 1969, may be a synonym of O. albertense, but this cannot be determined from the original description and illustration (Tasch et al., 1964, p.193, pl.2, fig.6). The same comments apply to Oligosphaeridium? dispare (Tasch) Davey and Williams, 1969.
Originally Hystrichosphaeridium, subsequently (and now) Oligosphaeridium.
Tax. sr. synonym of Oligosphaeridium irregulare (Pocock, 1962) Davey and Williams, 1969, according to Jansonius, 1986, which species Stover and Evitt, 1978, considered to be a tax. sr. synonym of the following species: Oligosphaeridium? coelenteratum (Tasch, 1964) Davey and Williams, 1969; Oligosphaeridium? dispare (Tasch, 1964) Davey and Williams, 1969; and Oligosphaeridium reniforme (Tasch, 1964) Davey, 1969.
This combination was not validly published in Davey and Williams, 1966, since these authors did not fully reference the basionym.
Holotype: Pocock, 1962, pl.15, fig.226; Brideaux, 1977, pl.11, figs.34; Jansonius, 1986, pl.4, figs. 4-5
Locus typicus: Imperial Kurkoi
Stratum typicum: Barremian
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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.
Oligosphaeridium albertense (Pocock, 1962) Davey and Williams, 1969. According to Jansonius (1986) and based on the holotype, Oligosphaeridium albertense has 13 processes, 25-30 µm long, nearly cylindrical at their bases, but gently widening distally, with the distal half more or less strongly flaring; distal margin thin, occasionally scalloped, carrying numerous coarse to fine, slender spinules. Wall of vesicle and processes thin (0.3-0.4 µm). Brideaux (1977) provided a revised diagnosis. He noted that the processes were hollow, flared to tubiform, distally open, with the margins variably secate, occasionally aculeate, or serrate; the distal third of some processes are variably fenestrate; one process, probably sulcal, reduced, shorter, acuminate to foliate or with reduced distal secate margin. Process formula is 4', 6", 0c, 5"’, 1p, 1"”. Size: holotype overall 100 x 110 µm, central body 70 x 47 µm, Brideaux’s specimens: maximum, excluding processes, 52-70 µm.
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Original description: Pocock, 1962, p.82: Hystrichosphaeridium albertense
Vesicle laevigate, thin, vitreous, circular in cross section; prosesses trumped shaped, being faintly narrow at the bases and widening continuously along the length to the apex; processes faintly long compared with the diameter of the vesicle, hollow; lips of processes irregular and frequently broken up into a series of short spines.
Size range: Diameter of vesicle 60 (63) 65 Ám; holotype 65 Ám. Length of processes 25 (32) 40 Ám; holotype ¦ 30 Ám. Basal diameter of processes 3 (5.5) 10 Ám, holotype ¦ 7 Ám. Apical diameter of processes 15 (27) 35 Ám; holotype ¦ 27 Ám. Number of processes 12 (14) 16 Ám; holotype 14 Ám.
Revised diagnosis: Brideaux, 1977, p.27-28
Shape: Pericyst, excluding processes, subcircular. Endocyst closely appressed except at loci of processes arising from pericyst. Pericoel not developed; slight dorso-ventral compression.
Phragma: Pericyst less than 0.5 µm thick, smooth or with scabrate sculpture; periphragm produced to form hollow, flared to tubiform processes, the processes open distally, the distal margins variably secate, occasionally aculeate or serrate; the distal third of some processes variably fenestrate; one process, probably sulcal in position, reduced, shorter, acuminate to foliate or with reduced distal secate margin; processes from 10-30 µm long, 3-7 µm wide basally (Pocock, 1962, p. 82 gives 25-40 µm, 3-10 µm respectively). Endophragm less than 0.5 Ám thick, apparently smooth. Paratabulation: Process formula determined as 4', 6", 0c, 5''', 1p, 1s, maximum of 17 processes observed on complete specimens, 13 on specimens with archeopyle developed; archeopyle outline denotes epiparatabulation of four apical paraplates and six precingular paraplates Of the precingular processes, 6" smallest, 5" broadest and tubiform, 1"-4" intermediate in size; of the postcingular processes, 1''' often with a V-shaped extension of the distal opening down the column, 2''' broad-columned and tubiform, 3''' largest process on pericyst; antapical process often strongly secate, the secae broad and dissected; sulcal process variable, from an acuminate to foliate closed process to a reduced tubiform process, distally open; posterior intercalary process (1p) as large or larger than the process 6". Archeopyle/operculum: Archeopyle formed by the loss of four apical paraplates; the operculum simple, free, occasionally lying in the archeopyle, and bearing four apical processes little differentiated in size and structure. Formula. A.
Pericingulum/perisulcus: Pericingular processes absent, the pericingular region defined by their absence; perisulcus represented by a single reduced process of variable morphology.
Dimensions. (40 measured specimens) - Maximum pericyst diameter, 52-70 µm, excluding processes.
Supplemental description: Jansonius, 1986, p.213
(Holotype) ca 100 x 110 µm overall, body 70 x 47 µm. Processes 13 in number, 25-30 µm long, nearly cylindrical at their bases, but gently widening distally, with the distal half more or less strongly varing; distal margin thin, occasionally scalloped, carrying numerous coarse to fine, slender spinules. Wall of vesicle and processes thin (0.3-0.4 µm). The opening just below the center is not the archeopyle, but a tear caused by the disengagement of the paraplate carrying the process pointing towards 7 o'clock. The paraplate just above this one also is separated at its left margin (ca 9 o'clock), and some other paraplate boundaries show separation.
Affinities:
Brideaux, 1977, p.28: The distally secate margins of the essentially similar flared to tubiform processes of Oligosphaeridium albertense distinguish this species from species with buccinate columns and entire to serrate distal margins (Oligosphaeridium totum Brideaux, 1971) and from species with highly variable columns and complex distal terminations [Oligosphaeridium irregulare (Pocock) Davey and Williams, 1969]. The species, Oligosphaeridium reniforme (Tasch) Davey, 1969, may be a synonym of O. albertense, but this cannot be determined from the original description and illustration (Tasch et al., 1964, p.193, pl.2, fig.6). The same comments apply to Oligosphaeridium? dispare (Tasch) Davey and Williams, 1969.