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Impletosphaeridium machaeroides
Impletosphaeridium macheroides Stover and Hardenbol, 1994
Impletosphaeridium machaeroides sp. nov.
Plate 13, Figures 91a-92b
Description
Cysts skolochorate with subspherical, thin-walled central bodies bearing numerous nontabular processes that are nearly uniform in size and shape. Body wall and processes smooth, latter hollow, tapered, and acuminate distally; process length about one-third body diameter. Indications of paratabulation, including an archeopyle, absent.
Size: intermediate; overall diameter 55 to 60 Ám, body diameter 30 to 36 Ám, process length 12 to 14 Ám.
Comparison
The processes on Impletosphaeridium machaeroides resemble those on specimens of Lingulodinium machaerophorum (Deflandre and Cookson 1955) Wall 1967. However, the wall on L. machaerophorum is moderately thick and definitely two-layered with a granulate endophragm. In contrast, the wall of I. machaeroides is thin and smooth. A simple or compound precingular archeopyle, or an epicystal archeopyle is usually discernible on specimens of L. machaerophorum, whereas evidence of archeopyle formation is lacking on I. machaeroides.
Types
Holotype: Plate 13, figures 91a-b, Boom Composite Section sample at 52.35 meters (= Cored Reconnaissance Hole sample at a drill depth of 28.46 meters). Paratype: Plate 13, figures 92a b, Boom Composite Section sample at 36.11 meters, Kruibeke locality.
Occurrence
In the Boom Composite Section specimens of Impletosphaeridium machaeroides occur sporadically and rarely in the Putte Member of the Boom Formation between 31.71 and 60.90 meters.
Impletosphaeridium machaeroides sp. nov.
Plate 13, Figures 91a-92b
Description
Cysts skolochorate with subspherical, thin-walled central bodies bearing numerous nontabular processes that are nearly uniform in size and shape. Body wall and processes smooth, latter hollow, tapered, and acuminate distally; process length about one-third body diameter. Indications of paratabulation, including an archeopyle, absent.
Size: intermediate; overall diameter 55 to 60 Ám, body diameter 30 to 36 Ám, process length 12 to 14 Ám.
Comparison
The processes on Impletosphaeridium machaeroides resemble those on specimens of Lingulodinium machaerophorum (Deflandre and Cookson 1955) Wall 1967. However, the wall on L. machaerophorum is moderately thick and definitely two-layered with a granulate endophragm. In contrast, the wall of I. machaeroides is thin and smooth. A simple or compound precingular archeopyle, or an epicystal archeopyle is usually discernible on specimens of L. machaerophorum, whereas evidence of archeopyle formation is lacking on I. machaeroides.
Types
Holotype: Plate 13, figures 91a-b, Boom Composite Section sample at 52.35 meters (= Cored Reconnaissance Hole sample at a drill depth of 28.46 meters). Paratype: Plate 13, figures 92a b, Boom Composite Section sample at 36.11 meters, Kruibeke locality.
Occurrence
In the Boom Composite Section specimens of Impletosphaeridium machaeroides occur sporadically and rarely in the Putte Member of the Boom Formation between 31.71 and 60.90 meters.