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Selenopemphix armageddonensis
Selenopemphix armageddonensis De Verteuil and Norris, 1992
Holotype: De Verteuil and Norris, 1992, pl.1, figs.1-2; text-fig.4
Locus typicus: SE of Cobham Wharf, south bank of the James River, Virginia, USA
Stratum typicum: Late Miocene
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP
Selenopemphix armageddonensis de Verteuil and Norris, 1992. Diagnosis according to de Verteuil and Norris (1992, p.398-399), Small, pigmented, autophragmal, protoperidiniacean cysts, polar compressed with a circular to reniform outline. The epicyst bears a prominent apical horn 3-5 µm high but there are no antapical horns on the hypocyst. Seven intratabular precingular processes occur on the epicyst and five intratabular postcingular processes occur on the hypocyst; no other plate series bears processes. Processes are hollow, the size of each being constrained by the size of the plate it occupies. They are latispinous to taeniate and expand distally with margins that are extended and recurved in the plate of extension; extreme process margins are often denticulate. The archeopyle is broad, rounded, hexa intercalary, operculum free, and displaced on the left anterior dorsal surface. Size; equatorial diameter excluding processes: major 32-44 µm, minor 28-37 µm, process width 4-20 µm, height 4-7 µm
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Original diagnosis: de Verteuil and Norris, 1992, p. 398-399
Small, pigmented, autophragmal, protoperidiniacean cysts, polar compressed with a circular to reniform outline. The epicyst bears a prominent apical horn 3-5 µm high but there are no antapical horns on the hypocyst. Seven intratabular precingular processes occur on the epicyst and five intratabular postcingular processes occur on the hypocyst; no other plate series bears processes. Processes are hollow, the size of each being constrained by the size of the plate it occupies. They are latispinous to taeniate and expand distally with margins that are extended and recurved in the plane of extension; extreme process margins are often denticulate. The archeopyle is broad, rounded, hexa intercalary; operculum free, and displaced on the left anterior dorsal surface.
Original description: de Verteuil and Norris, 1992, p. 399
The cyst wall is psilate or scabrate with processes probably open proximally. Between processes the epicyst wall is concave and extends evenly to the apical horn. The cingulum is defined only as a concave fold between the precingular and postcingular processes; this feature is approximately 15-20 % of the major equatorial diameter in width. The sulcus may be indicated by a slight depression of the ventral surface in the cingular region.
Dimensions. Equatorial diameter excluding processes: major, 32(38)44 µm; holotype, 35 µm; minor, 28(30)37 µm; holotype, 30 µm. Processes: width, 4-20 µm; height, 4-7µm. Thirteen specimens measured.
Affinities:
de Verteuil and Norris, 1992, p. 399: S. armageddonensis differs from all other species of Selenopemphix in having a total of exactly 12 intratabular precingular and postcingular processes, one per plate, and no cingular or adcingular processes.
Holotype: De Verteuil and Norris, 1992, pl.1, figs.1-2; text-fig.4
Locus typicus: SE of Cobham Wharf, south bank of the James River, Virginia, USA
Stratum typicum: Late Miocene
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP
Selenopemphix armageddonensis de Verteuil and Norris, 1992. Diagnosis according to de Verteuil and Norris (1992, p.398-399), Small, pigmented, autophragmal, protoperidiniacean cysts, polar compressed with a circular to reniform outline. The epicyst bears a prominent apical horn 3-5 µm high but there are no antapical horns on the hypocyst. Seven intratabular precingular processes occur on the epicyst and five intratabular postcingular processes occur on the hypocyst; no other plate series bears processes. Processes are hollow, the size of each being constrained by the size of the plate it occupies. They are latispinous to taeniate and expand distally with margins that are extended and recurved in the plate of extension; extreme process margins are often denticulate. The archeopyle is broad, rounded, hexa intercalary, operculum free, and displaced on the left anterior dorsal surface. Size; equatorial diameter excluding processes: major 32-44 µm, minor 28-37 µm, process width 4-20 µm, height 4-7 µm
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Original diagnosis: de Verteuil and Norris, 1992, p. 398-399
Small, pigmented, autophragmal, protoperidiniacean cysts, polar compressed with a circular to reniform outline. The epicyst bears a prominent apical horn 3-5 µm high but there are no antapical horns on the hypocyst. Seven intratabular precingular processes occur on the epicyst and five intratabular postcingular processes occur on the hypocyst; no other plate series bears processes. Processes are hollow, the size of each being constrained by the size of the plate it occupies. They are latispinous to taeniate and expand distally with margins that are extended and recurved in the plane of extension; extreme process margins are often denticulate. The archeopyle is broad, rounded, hexa intercalary; operculum free, and displaced on the left anterior dorsal surface.
Original description: de Verteuil and Norris, 1992, p. 399
The cyst wall is psilate or scabrate with processes probably open proximally. Between processes the epicyst wall is concave and extends evenly to the apical horn. The cingulum is defined only as a concave fold between the precingular and postcingular processes; this feature is approximately 15-20 % of the major equatorial diameter in width. The sulcus may be indicated by a slight depression of the ventral surface in the cingular region.
Dimensions. Equatorial diameter excluding processes: major, 32(38)44 µm; holotype, 35 µm; minor, 28(30)37 µm; holotype, 30 µm. Processes: width, 4-20 µm; height, 4-7µm. Thirteen specimens measured.
Affinities:
de Verteuil and Norris, 1992, p. 399: S. armageddonensis differs from all other species of Selenopemphix in having a total of exactly 12 intratabular precingular and postcingular processes, one per plate, and no cingular or adcingular processes.