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Polystephanephorus calathus
Polystephanephorus calathus (Sarjeant, 1961) Sarjeant, 1961; Emendation: Stancliffe and Sarjeant, 1990, p.205, as Polystephanephorus calathus.
Originally Polystephanosphaera, subsequently (and now) Polystephanephorus, thirdly Hystrichosphaerina. Duxbury, 1980 transferred this species to Hystrichosphaerina Alberti, 1961; however, Lentin and Williams, 1981 retained it in Polystephanephorus. The transfer of this species to Polystephanephorus by Sarjeant, 1961 was effected under the International Code of Zoological Nomenclature and therefore was validly published.
Holotype: Sarjeant, 1961, pl.14, fig.7; text-fig.7; Stancliffe and Sarjeant, 1990, pl.2, figs.1-4; text-fig. 1
Locus typicus: Scarborough Castle cliff
Stratum typicum: Early Oxfordian
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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.
Polystephanephorus calathus (Sarjeant, 1961a) Sarjeant, 1961b, emend. Stancliffe and Sarjeant, 1990. According to Stancliffe and Sarjeant (1990), Cyst proximochorate, acavate and without crests. The major paraplates are each defined by a cluster of straight, simple or distally branching processes. Processes may be interconnected medially or proximally, or may repeatedly branch. One single process per cluster bifurcates to form a ring trabecula, which may be smooth or may give rise to very short spinelets. Isolated processes, distally closed and usually with bifid tips, mark the cingulum and sulcus. Paratabulation ?4', 5", 5c, 6"’, 0p, 1"”, 4s. Surface of phragma laevigate, punctate, or infrareticulate. Archeopyle type apical (tA), operculum free. Size: Holotype diameter 40 µm, process length 18-25 µm.
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Original diagnosis: Sarjeant, 1961, p.104: Polystephanosphaera calathus
A species of Polystephanosphaera in which the processes are solid and are arranged in circles and connected together by trabeculae in the form of a ring, each cluster of processes thus forming an open-walled and open-ended tube. It is estimated that on a complete specimen there would be twelve to sixteen such tubes, each ring trabecula borne by five to ten processes.
Dimensions: Holotype: overall diameter 88 µm, shell diameter 45 µm, length of process clusters c. 22 µm. Paratype: overall diameter 90 µm, shell diameter 45 µm, length of process clusters c. 23 µm.
Emended diagnosis: Stancliffe and Sarjeant, 1990, p. 205
Cyst phragmochorate, acavate and without crests. The major paraplates are each defined by a cluster of straight, simple or distally branching processes. Processes may be interconnected medially, or may repeatedly branch. One single process per cluster bifurcates to form a ring trabecula, which may be smooth or may give rise to very short spinelets. Isolate processes, distally closed and usually with bifid tips, mark the cingulum and sulcus. Paratabulation: ?4'. 5'', 5c, 6''', 0p, 1'''', 4s. Surface of phragma laevigate, punctate, or infrareticulate. Archeopyle apical, type (tA); operculum free.
Originally Polystephanosphaera, subsequently (and now) Polystephanephorus, thirdly Hystrichosphaerina. Duxbury, 1980 transferred this species to Hystrichosphaerina Alberti, 1961; however, Lentin and Williams, 1981 retained it in Polystephanephorus. The transfer of this species to Polystephanephorus by Sarjeant, 1961 was effected under the International Code of Zoological Nomenclature and therefore was validly published.
Holotype: Sarjeant, 1961, pl.14, fig.7; text-fig.7; Stancliffe and Sarjeant, 1990, pl.2, figs.1-4; text-fig. 1
Locus typicus: Scarborough Castle cliff
Stratum typicum: Early Oxfordian
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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.
Polystephanephorus calathus (Sarjeant, 1961a) Sarjeant, 1961b, emend. Stancliffe and Sarjeant, 1990. According to Stancliffe and Sarjeant (1990), Cyst proximochorate, acavate and without crests. The major paraplates are each defined by a cluster of straight, simple or distally branching processes. Processes may be interconnected medially or proximally, or may repeatedly branch. One single process per cluster bifurcates to form a ring trabecula, which may be smooth or may give rise to very short spinelets. Isolated processes, distally closed and usually with bifid tips, mark the cingulum and sulcus. Paratabulation ?4', 5", 5c, 6"’, 0p, 1"”, 4s. Surface of phragma laevigate, punctate, or infrareticulate. Archeopyle type apical (tA), operculum free. Size: Holotype diameter 40 µm, process length 18-25 µm.
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Original diagnosis: Sarjeant, 1961, p.104: Polystephanosphaera calathus
A species of Polystephanosphaera in which the processes are solid and are arranged in circles and connected together by trabeculae in the form of a ring, each cluster of processes thus forming an open-walled and open-ended tube. It is estimated that on a complete specimen there would be twelve to sixteen such tubes, each ring trabecula borne by five to ten processes.
Dimensions: Holotype: overall diameter 88 µm, shell diameter 45 µm, length of process clusters c. 22 µm. Paratype: overall diameter 90 µm, shell diameter 45 µm, length of process clusters c. 23 µm.
Emended diagnosis: Stancliffe and Sarjeant, 1990, p. 205
Cyst phragmochorate, acavate and without crests. The major paraplates are each defined by a cluster of straight, simple or distally branching processes. Processes may be interconnected medially, or may repeatedly branch. One single process per cluster bifurcates to form a ring trabecula, which may be smooth or may give rise to very short spinelets. Isolate processes, distally closed and usually with bifid tips, mark the cingulum and sulcus. Paratabulation: ?4'. 5'', 5c, 6''', 0p, 1'''', 4s. Surface of phragma laevigate, punctate, or infrareticulate. Archeopyle apical, type (tA); operculum free.