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Dapsilidinium duma
Dapsilidinium duma (Below, 1982c, p.28, pl.2, figs.9a–b,10a–b,11–12; text-fig.6a) Lentin and Williams, 1985, p.92. Holotype:
Below, 1982c, pl.2, figs.9a–b; Fauconnier and Masure, 2004, pl.19, figs.14–15. Originally Polysphaeridium,
subsequently (and now) Dapsilidinium. NIA. Age: Hauterivian–Albian.
Original description (Below, 1982) Translation PKB 2025:
Diagnosis: Spheroidal cyst consisting of a smooth endophragm and periphragm. Approximately 50-69 hollow, proximally closed, distally open appendages measure 1/3 to 1/2 the diameter of the central body. They exhibit a lateral habit but are slightly dilated basally. Fine hooks developed at the distal margin are bent back toward the central body. If these setae are absent, the distal end is oblate. The archaeolpyle corresponds to type A.
Note: The shape and number of appendages vary. In addition to slightly expanded, cylindrical appendages at the base, there are processes that taper slightly towards the distal end. In the forms from the Alb, this always bears numerous, fine hooklets bent back towards the central body. In the specimens from the upper Hauterive, these setae may be reduced in number, while their length increases. The appendages often end oblately. Both a reduction and a decrease in the number of appendages have been observed.
Dimensions: Holotype: diameter of the central body 40 µ, length of the appendages 12-15 µ, diameter of the appendages 2.5 µ; other specimens: diameter of the central body 34-42 µ, length of the appendages 9-20 µ, diameter of the appendages 1-3 µ.
Material: approx. 100 specimens.
Occurrence: Profile EB (20): Hauterivian, Barremian; Profile IAA (20): Bédoulien, Gargasia; Profile E (15): Alb; Profile Chicaoua I (18): Barremian.
Below, 1982c, pl.2, figs.9a–b; Fauconnier and Masure, 2004, pl.19, figs.14–15. Originally Polysphaeridium,
subsequently (and now) Dapsilidinium. NIA. Age: Hauterivian–Albian.
Original description (Below, 1982) Translation PKB 2025:
Diagnosis: Spheroidal cyst consisting of a smooth endophragm and periphragm. Approximately 50-69 hollow, proximally closed, distally open appendages measure 1/3 to 1/2 the diameter of the central body. They exhibit a lateral habit but are slightly dilated basally. Fine hooks developed at the distal margin are bent back toward the central body. If these setae are absent, the distal end is oblate. The archaeolpyle corresponds to type A.
Note: The shape and number of appendages vary. In addition to slightly expanded, cylindrical appendages at the base, there are processes that taper slightly towards the distal end. In the forms from the Alb, this always bears numerous, fine hooklets bent back towards the central body. In the specimens from the upper Hauterive, these setae may be reduced in number, while their length increases. The appendages often end oblately. Both a reduction and a decrease in the number of appendages have been observed.
Dimensions: Holotype: diameter of the central body 40 µ, length of the appendages 12-15 µ, diameter of the appendages 2.5 µ; other specimens: diameter of the central body 34-42 µ, length of the appendages 9-20 µ, diameter of the appendages 1-3 µ.
Material: approx. 100 specimens.
Occurrence: Profile EB (20): Hauterivian, Barremian; Profile IAA (20): Bédoulien, Gargasia; Profile E (15): Alb; Profile Chicaoua I (18): Barremian.