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Operculodinium azcaratei
Operculodinium azcaratei Troncoso and Doubinger, 1980
Holotype: Troncoso and Doubinger, 1980, pl.2, figs.1-2
Age: Maastrichtian-Danian
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Original description: [Troncoso and Doubinger, 1980] (translated from Spanish):
Operculodinium azcaratei sp. n.
Plate 2, figs. 1 and 2.
Diagnosis: Spherical cyst (ellipsoidal when deformed), with a smooth wall, decorated with spines equal to or less than 2u in length (exceptionally 3.5u), arranged in an intratabular-peritabular manner and often joined at the bases by more or less uninterrupted ridges. The apex of the spines is acute or slightly widened. The tabulation is partially reflected by the peritabular spines and ridges; only a few plates are discernible. The helicoidal cingulum is indicated by the spines and ridges of the pre- and postcingular plates, which are denser at that level. The sulcus is marked by the spines and ridges of the adjacent plates. Precingular archeopylon in the shape of a half-ellipse, apparently reflecting plate 3".
Holotype: SGO PmPb 1342/2 (P 52/4-P 53/3). Core 5, sample 2 between 907-902 m. Upper Chorrillo Chico Formation.
Holotype measurements: 52.8 x 57.8u.
Dimensions: 49-(59.6)-70u long by 48-(53.3)-70u wide (8 measurements).
Origin: between 914-902 m. Strasbourg 8169-8178. Chorrillo Chico Formation, upper part.
Main material studied: Strasbourg 8178'/1 (G 53-G 54); SGO PmPb 1345/1: (F 53/2). (0 45/1), (T 31/4-T 32/3).
Discussion and comparisons: Our specimens correspond perfectly to the genus Operculodinium Wall. However, they resemble Trichodinium castanea (Defl.) Clarke and Verdier, listed by those authors (1967), but lack apical differentiation, and the pre- and postcingular plates are discernible. Among the species in the genus Operculodinium, the closest species appears to be O. rarispinosum Cookson and Eisenack 1971 from the Middle Cretaceous of Australia, but comparison is difficult due to the brief description.
We dedicate this species to the Chilean palinologist Valeria Azcárate.
Holotype: Troncoso and Doubinger, 1980, pl.2, figs.1-2
Age: Maastrichtian-Danian
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Original description: [Troncoso and Doubinger, 1980] (translated from Spanish):
Operculodinium azcaratei sp. n.
Plate 2, figs. 1 and 2.
Diagnosis: Spherical cyst (ellipsoidal when deformed), with a smooth wall, decorated with spines equal to or less than 2u in length (exceptionally 3.5u), arranged in an intratabular-peritabular manner and often joined at the bases by more or less uninterrupted ridges. The apex of the spines is acute or slightly widened. The tabulation is partially reflected by the peritabular spines and ridges; only a few plates are discernible. The helicoidal cingulum is indicated by the spines and ridges of the pre- and postcingular plates, which are denser at that level. The sulcus is marked by the spines and ridges of the adjacent plates. Precingular archeopylon in the shape of a half-ellipse, apparently reflecting plate 3".
Holotype: SGO PmPb 1342/2 (P 52/4-P 53/3). Core 5, sample 2 between 907-902 m. Upper Chorrillo Chico Formation.
Holotype measurements: 52.8 x 57.8u.
Dimensions: 49-(59.6)-70u long by 48-(53.3)-70u wide (8 measurements).
Origin: between 914-902 m. Strasbourg 8169-8178. Chorrillo Chico Formation, upper part.
Main material studied: Strasbourg 8178'/1 (G 53-G 54); SGO PmPb 1345/1: (F 53/2). (0 45/1), (T 31/4-T 32/3).
Discussion and comparisons: Our specimens correspond perfectly to the genus Operculodinium Wall. However, they resemble Trichodinium castanea (Defl.) Clarke and Verdier, listed by those authors (1967), but lack apical differentiation, and the pre- and postcingular plates are discernible. Among the species in the genus Operculodinium, the closest species appears to be O. rarispinosum Cookson and Eisenack 1971 from the Middle Cretaceous of Australia, but comparison is difficult due to the brief description.
We dedicate this species to the Chilean palinologist Valeria Azcárate.