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Phthanoperidinium clithridium
Phthanoperidinium clithridum Bujak, 1994
Holotype: Bujak, 1994, pl.5, figs.1-2
Locus typicus: North Sea, UK16/16b-4 well
Stratum typicum: section at 5900ft, Lutetian, Middle Eocene
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP
Phthanoperidinium clithridium Bujak, 1994. Diagnosis from Bujak (1994, p.127,129). Pericyst ovoidal with one small apical horn and one or two unequal antapical horns, the right always being strongly reduced. Endocyst ovoidal, and in contact with the periphragm except sometimes beneath the apical and antapical horns. Periphragm chagrinate to granulate with or without extremely low parasutural crests. When present these partially delimit a paratabulation of 4', 3a, 7", xc, 5"’, 2"”. An archeopyle is always formed by the loss of paraplates 2a and 4". Size pericyst length 32-44 µm, width 27-40 µm, apical horn length less than 2 µm.
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Original diagnosis: Bujak, 1994, p.???
Pericyst ovoidal with one small apical horn and one or two unequal antapical horns, the right always being strongly reduced. Endocyst ovoidal, and in contact with the periphragm except sometimes beneath the apical and antapical horns. Periphragm chagrinate to granulate with or without extremely low parasutural crests. When present these partially delimit a paratabulation of 4', 3a, 7", xc, 5''', 2''''. An archeopyle is always formed by the loss of paraplates 2a and 4". Dimensions. Pericyst length 32-44 µm, breadth 27-40 µm, apical horn length less than 2 µm.
Affinities:
Bujak, 1994, p.???: P. clithridium is distinguished from all other species of Phthanoperidinium except P. regalis by the formation of an archeopyle by the loss of paraplates 2a and 4". The mode of archeopyle forrnation is identical in P. clithridium and P. regalis which differ in their ornament. P. clithridium does not possess the penitabular ornament present on P. regalis and has less well-defined parasutural ornament. Rare specimens intergrade between these taxa, but the majority of specimens comprise distinct morphological populations, which have different palaeogeographic distributions in the North Sea (Bujak, pers. obs.). P. clithridium has not been recorded outside the North Sea region.
Holotype: Bujak, 1994, pl.5, figs.1-2
Locus typicus: North Sea, UK16/16b-4 well
Stratum typicum: section at 5900ft, Lutetian, Middle Eocene
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP
Phthanoperidinium clithridium Bujak, 1994. Diagnosis from Bujak (1994, p.127,129). Pericyst ovoidal with one small apical horn and one or two unequal antapical horns, the right always being strongly reduced. Endocyst ovoidal, and in contact with the periphragm except sometimes beneath the apical and antapical horns. Periphragm chagrinate to granulate with or without extremely low parasutural crests. When present these partially delimit a paratabulation of 4', 3a, 7", xc, 5"’, 2"”. An archeopyle is always formed by the loss of paraplates 2a and 4". Size pericyst length 32-44 µm, width 27-40 µm, apical horn length less than 2 µm.
--------------------------------------------------
Original diagnosis: Bujak, 1994, p.???
Pericyst ovoidal with one small apical horn and one or two unequal antapical horns, the right always being strongly reduced. Endocyst ovoidal, and in contact with the periphragm except sometimes beneath the apical and antapical horns. Periphragm chagrinate to granulate with or without extremely low parasutural crests. When present these partially delimit a paratabulation of 4', 3a, 7", xc, 5''', 2''''. An archeopyle is always formed by the loss of paraplates 2a and 4". Dimensions. Pericyst length 32-44 µm, breadth 27-40 µm, apical horn length less than 2 µm.
Affinities:
Bujak, 1994, p.???: P. clithridium is distinguished from all other species of Phthanoperidinium except P. regalis by the formation of an archeopyle by the loss of paraplates 2a and 4". The mode of archeopyle forrnation is identical in P. clithridium and P. regalis which differ in their ornament. P. clithridium does not possess the penitabular ornament present on P. regalis and has less well-defined parasutural ornament. Rare specimens intergrade between these taxa, but the majority of specimens comprise distinct morphological populations, which have different palaeogeographic distributions in the North Sea (Bujak, pers. obs.). P. clithridium has not been recorded outside the North Sea region.