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Trioperculodinium sicula
From Fensome et al., 2019:
Trioperculodinium sicula Drugg, 1970b, p.820; text-figs.16F–G.
Holotype: Drugg, 1970b, text-figs.16F–G.
NOW Lingulodinium. Originally Trioperculodinium, subsequently (and now) Lingulodinium. NIA.
Locus typicus: Hinds County, Mississippi, USA
Stratum typicum: Oligocene
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Original description: Drugg, 1970, p. 820
The following comments are in addition to the generic description. For a diagram of the operculum see fig. 17C. The endophragm is smooth and is about 1 µm thick. The periphragm is 1 to 2 µm thick and is of a granular porous construction with a granulate surface. The processes are in the shape of tapering cones from 10 to 25 µm in length. The distal terminations are sharply pointed. The walls of the processes are thin and finely granulate. Occasionally a few short processes are scattered among the normal processes. The tract diameter ranges from 60 to 78 µm.
Affinities:
Drugg, 1970, p. 820: Trioperculodinium siculum Drugg resembles Lingulodinium machaerophorum (Deflandre and Cookson), Wall, 1967, to the extent that the processes are similar in form. The mode of archeopyle formation is entirely different. The archeopyle of T. siculum corresponds to Evitts" type 3P (Evitt, 1967, p. 43) and is the same as that of the cysts of the extant species Gonyaulax polyedra Stein (see Evitt, 1967, p. 43, pl. 6, figs. 13-19).
Trioperculodinium sicula Drugg, 1970b, p.820; text-figs.16F–G.
Holotype: Drugg, 1970b, text-figs.16F–G.
NOW Lingulodinium. Originally Trioperculodinium, subsequently (and now) Lingulodinium. NIA.
Locus typicus: Hinds County, Mississippi, USA
Stratum typicum: Oligocene
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Original description: Drugg, 1970, p. 820
The following comments are in addition to the generic description. For a diagram of the operculum see fig. 17C. The endophragm is smooth and is about 1 µm thick. The periphragm is 1 to 2 µm thick and is of a granular porous construction with a granulate surface. The processes are in the shape of tapering cones from 10 to 25 µm in length. The distal terminations are sharply pointed. The walls of the processes are thin and finely granulate. Occasionally a few short processes are scattered among the normal processes. The tract diameter ranges from 60 to 78 µm.
Affinities:
Drugg, 1970, p. 820: Trioperculodinium siculum Drugg resembles Lingulodinium machaerophorum (Deflandre and Cookson), Wall, 1967, to the extent that the processes are similar in form. The mode of archeopyle formation is entirely different. The archeopyle of T. siculum corresponds to Evitts" type 3P (Evitt, 1967, p. 43) and is the same as that of the cysts of the extant species Gonyaulax polyedra Stein (see Evitt, 1967, p. 43, pl. 6, figs. 13-19).