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Pentadinium netangei
From Fensome et al., 2019:
Pentadinium netangei Zhao Yunyun and Morzadec-Kerfourn, 1994, p.266,268, pl.1, figs.4a–c,5a–b,6a–b,7; pl.2, figs.4–8. Holotype: Zhao Yunyun and Morzadec-Kerfourn, 1994, pl.1, figs.4a–c. Age: Pleistocene.
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Original description (Zhao Yunyun & Morzadec-Kerfourn, 1994) translation PKB 2025:
PENTADINIUM NETANGEI NOV SP. : P1. 1, fig. 4-7 ; P1.2, fig. 4-8.
Derivatio nominis - in memory of Mr. Jean Baptiste Netange, donor to the Fondation de France.
Holotype - Leg 126, Site 791B, 801.01 m (sample 126-791B-44R-1, 31-33 cm, blade B, R40, fig. 6 P1. 1, fig. 4, deposited at the Institute of Geology of the University of Rennes.
Locus typicus - Leg 126, Site 791B, Izu Bonin Region.
Stratum typicum - Lower Pleistocene.
Diagnosis - Proximate to proximochorate cyst with a spherical to ovoid central shell. The wall is composed of an endophragm and a periphragm, generally in contact except at the level of the parasutures where the periphragm forms a fold (suturocavate). The parasutural fold is higher in the antapical region. The periphragm is microgranular. The 1' and 2', 3' and 4' paraplates are combined. The archaeopyle is formed by the loss of the 3' precingulate plate.
Description - This cyst of the genus Pentadinium is small, proximal to proximal, with a spherical to ovoid central shell. In polar view, it is circular to polygonal, in equatorial view, elliptical to polygonal. The wall is composed of an endophragm and a periphragm decorated with microgranules. The folds of the periphragm delimit the paraplates. The fold, wide at the base, creates a central cavity in the shape of an inverted V. The folds are high in the antapical region and, on the other hand, very reduced at the level of certain ventral and sulcal paraplates. In the apical region, paraplate 1' is combined with 2' and paraplate 3' combined with 4'. The delimitation between these combined plates r+2' and 3'+4', which are small, is marked by a low ridge not visible under an optical microscope. In the antapical region, the paraplate 1'"' is large and pentagonal in shape. The parasutural fold is two laws more developed in the antapical region. The cingulum, located in the middle of the cyst, is composed of five to six paraplates. The paratabulation is that of the genus Pentadinium: 4', 0a, 6", ?5-6c, 5'", lp, 0-1pv, 1"". The archaeopyle is precingulate 3".
Holotype Dimensions: Central shell diameter 28.8 µm; Total cyst length: 44.8 µm, Total cyst width: 35.2 µm, Antapical parasutural fold height: 12.8 µm, Apical parasutural fold height: 3.2 µm. Average dimensions of 13 measured specimens: Central shell diameter: 28.2 µm, Total cyst length: 45.8 µm, Total cyst width: 40.3 µm, Antapical parasutural fold height: 12.5 µm, Apical parasutural fold height: 5.4 µm.
Discussion - This cyst has been classified in the genus Pentadinium GERLACH emend BENEDEK et al. 1982 and not in the genus Impagidinium STOVER & EVITT, 1978 ~ because of the very clear detachment of the periphragm at the level of certain parasutures. This character allows it to be distinguished in particular from I. strialatum (WALL, 1967) STOVER & EVITT, 1978, I. pallidum BUJAK, 1984, I. velorum BUJAK, 1984 from which it also differs by the ornamentation. In Pentadinium netangei nov. sp., the granular ornamentation is present both on the central shell and on the folds of the periphragm, whereas in I. strialatum only the central shell is granular, the septal membrane is striated, in I. pallidum and L. velorum, the central body is smooth or chamois, the sutural membrane smooth. This new species is distinguished from the other species of the genus Pentadinium: P. laticinctum GERLACH, 1961 emend BENEDEK, GOCHT & SARJEANT, 1982 and P. lophophorum BENEDEK, 1972 emend BENEDEK, GOCHT & SARJEANT, 1982 by the height of the parasutural fold which reaches almost half the diameter of the central shell in the antapical region. P. netangei nov. sp. is also close to Pentadinium (?) circumstum (MORGENROTH, 1966) STOVER & EVITT, 1978 but is essentially distinguished by the presence of a true furrow.
Pentadinium netangei Zhao Yunyun and Morzadec-Kerfourn, 1994, p.266,268, pl.1, figs.4a–c,5a–b,6a–b,7; pl.2, figs.4–8. Holotype: Zhao Yunyun and Morzadec-Kerfourn, 1994, pl.1, figs.4a–c. Age: Pleistocene.
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Original description (Zhao Yunyun & Morzadec-Kerfourn, 1994) translation PKB 2025:
PENTADINIUM NETANGEI NOV SP. : P1. 1, fig. 4-7 ; P1.2, fig. 4-8.
Derivatio nominis - in memory of Mr. Jean Baptiste Netange, donor to the Fondation de France.
Holotype - Leg 126, Site 791B, 801.01 m (sample 126-791B-44R-1, 31-33 cm, blade B, R40, fig. 6 P1. 1, fig. 4, deposited at the Institute of Geology of the University of Rennes.
Locus typicus - Leg 126, Site 791B, Izu Bonin Region.
Stratum typicum - Lower Pleistocene.
Diagnosis - Proximate to proximochorate cyst with a spherical to ovoid central shell. The wall is composed of an endophragm and a periphragm, generally in contact except at the level of the parasutures where the periphragm forms a fold (suturocavate). The parasutural fold is higher in the antapical region. The periphragm is microgranular. The 1' and 2', 3' and 4' paraplates are combined. The archaeopyle is formed by the loss of the 3' precingulate plate.
Description - This cyst of the genus Pentadinium is small, proximal to proximal, with a spherical to ovoid central shell. In polar view, it is circular to polygonal, in equatorial view, elliptical to polygonal. The wall is composed of an endophragm and a periphragm decorated with microgranules. The folds of the periphragm delimit the paraplates. The fold, wide at the base, creates a central cavity in the shape of an inverted V. The folds are high in the antapical region and, on the other hand, very reduced at the level of certain ventral and sulcal paraplates. In the apical region, paraplate 1' is combined with 2' and paraplate 3' combined with 4'. The delimitation between these combined plates r+2' and 3'+4', which are small, is marked by a low ridge not visible under an optical microscope. In the antapical region, the paraplate 1'"' is large and pentagonal in shape. The parasutural fold is two laws more developed in the antapical region. The cingulum, located in the middle of the cyst, is composed of five to six paraplates. The paratabulation is that of the genus Pentadinium: 4', 0a, 6", ?5-6c, 5'", lp, 0-1pv, 1"". The archaeopyle is precingulate 3".
Holotype Dimensions: Central shell diameter 28.8 µm; Total cyst length: 44.8 µm, Total cyst width: 35.2 µm, Antapical parasutural fold height: 12.8 µm, Apical parasutural fold height: 3.2 µm. Average dimensions of 13 measured specimens: Central shell diameter: 28.2 µm, Total cyst length: 45.8 µm, Total cyst width: 40.3 µm, Antapical parasutural fold height: 12.5 µm, Apical parasutural fold height: 5.4 µm.
Discussion - This cyst has been classified in the genus Pentadinium GERLACH emend BENEDEK et al. 1982 and not in the genus Impagidinium STOVER & EVITT, 1978 ~ because of the very clear detachment of the periphragm at the level of certain parasutures. This character allows it to be distinguished in particular from I. strialatum (WALL, 1967) STOVER & EVITT, 1978, I. pallidum BUJAK, 1984, I. velorum BUJAK, 1984 from which it also differs by the ornamentation. In Pentadinium netangei nov. sp., the granular ornamentation is present both on the central shell and on the folds of the periphragm, whereas in I. strialatum only the central shell is granular, the septal membrane is striated, in I. pallidum and L. velorum, the central body is smooth or chamois, the sutural membrane smooth. This new species is distinguished from the other species of the genus Pentadinium: P. laticinctum GERLACH, 1961 emend BENEDEK, GOCHT & SARJEANT, 1982 and P. lophophorum BENEDEK, 1972 emend BENEDEK, GOCHT & SARJEANT, 1982 by the height of the parasutural fold which reaches almost half the diameter of the central shell in the antapical region. P. netangei nov. sp. is also close to Pentadinium (?) circumstum (MORGENROTH, 1966) STOVER & EVITT, 1978 but is essentially distinguished by the presence of a true furrow.