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Phthanoperidinium regalis
Phthanoperidinium regalis Bujak, 1994
Holotype: Bujak, 1994, pl.5, fig.6
Paratypes: Bujak, 1994
Locus typicus: North Sea, UK16/16a-3 well
Stratum typicum: section at 1689ft, Lutetian, Middle Eocene
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. An endocyst is rarely visible, but sometimes present beneath the apical horn. Periphragm chagrinate to granulate with parasutural rows of granulae, short spines, or low, irregular crests. These delimit a paratabulation of 4", 3a, 7", 6c, 5""", 2"""". Strongly developed penitabular rows or zones of similar ornament lie 1µm to 3µm inside the parasutures, except adjacent to the paracingulum where the parasutural and penitabular ornament merges. Archeopyle always formed by the loss of paraplates 2a and 4".
Dimensions. Pericyst length 37-46 µm, breadth 33-37 µm, apical horn length 2-3 µm.
Affinities:
Bujak, 1994, p.???: P. regalis is identical to P. geminatum Bujak in all respects except for the mode of archeopyle formation which comprises the loss of paraplate 2a in P. geminatum, and the loss of paraplates 2a and 4" in P. regalis. The stratigraphic ranges of the two taxa are also distinct. P. regalis has its last North Sea occurrence in Lutetian Subzone E5a of Bujak and Mudge, whereas P. geminatum ranges up into the Bartonian.
The mode of archeopyle formation is identical in P. regalis and P. clithridium which differ in their ornament. P. clithridium does not possess the penitabular ornament present on P. regalis and has less well-defined parasutural crests. Rare specimens intergrade between these taxa, but the majority of specimens assigned to the two taxa comprise populations with distinct palaeogeographic distributions in the North Sea (Bujak, pers. obs.). P. regalis has not been recorded outside the North Sea region.
Holotype: Bujak, 1994, pl.5, fig.6
Paratypes: Bujak, 1994
Locus typicus: North Sea, UK16/16a-3 well
Stratum typicum: section at 1689ft, Lutetian, Middle Eocene
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. An endocyst is rarely visible, but sometimes present beneath the apical horn. Periphragm chagrinate to granulate with parasutural rows of granulae, short spines, or low, irregular crests. These delimit a paratabulation of 4", 3a, 7", 6c, 5""", 2"""". Strongly developed penitabular rows or zones of similar ornament lie 1µm to 3µm inside the parasutures, except adjacent to the paracingulum where the parasutural and penitabular ornament merges. Archeopyle always formed by the loss of paraplates 2a and 4".
Dimensions. Pericyst length 37-46 µm, breadth 33-37 µm, apical horn length 2-3 µm.
Affinities:
Bujak, 1994, p.???: P. regalis is identical to P. geminatum Bujak in all respects except for the mode of archeopyle formation which comprises the loss of paraplate 2a in P. geminatum, and the loss of paraplates 2a and 4" in P. regalis. The stratigraphic ranges of the two taxa are also distinct. P. regalis has its last North Sea occurrence in Lutetian Subzone E5a of Bujak and Mudge, whereas P. geminatum ranges up into the Bartonian.
The mode of archeopyle formation is identical in P. regalis and P. clithridium which differ in their ornament. P. clithridium does not possess the penitabular ornament present on P. regalis and has less well-defined parasutural crests. Rare specimens intergrade between these taxa, but the majority of specimens assigned to the two taxa comprise populations with distinct palaeogeographic distributions in the North Sea (Bujak, pers. obs.). P. regalis has not been recorded outside the North Sea region.