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Impletosphaeridium capitatum
Impletosphaeridium capitatum Fensome et al., 2009, p.38,39, pl.5, figs.m–p.
Holotype: Fensome et al., 2009, pl.5, fig.m.
Age: youngest occurrence, middle Campanian.
Original description (Fensome et al., 2009):
Impletosphaeridium capitatum sp. nov. (Plate 5, figs m-p)
HOLOTYPE. Plate 5, fig. m; from a cuttings sample at 1201- 1213 m (3940-3980 feet) in Demascota G-32 well; GSC type collection no. 130219, sample P9196, slide 09, co-ordinates 9.6 × 104.8, England Finder J48/0; maximum diameter of central body 32 μm, length of spines up to 5 μm. The age determined for the sample from which the holotype was recovered is Coniacian (Late Cretaceous); however, since it is a cuttings sample and no FAD has been determined for the species, the holotype is possibly a specimen caved down well from a younger stratum.
ETYMOLOGY. The epithet refers to the capitate distal endings of the processes.
DESCRIPTION. A species with a spheroidal to ovoidal, smooth central body and short, relatively fine but rigid, apparently solid, capitate processes.
SIZE. Maximum diameter of central body 29(30)32 μm, length of spines up to 5(6)7 μm.
AGE ON SCOTIAN MARGIN. LAD: middle Campanian (Late Cretaceous).
REMARKS. Impletosphaeridium williamsii is similar, but has a variety of process types, including acuminate and bifid; the processes of Impletosphaeridium capitatum are consistently capitate. Impletosphaeridium? tenuifilum has very delicate, readily bent processes.
Holotype: Fensome et al., 2009, pl.5, fig.m.
Age: youngest occurrence, middle Campanian.
Original description (Fensome et al., 2009):
Impletosphaeridium capitatum sp. nov. (Plate 5, figs m-p)
HOLOTYPE. Plate 5, fig. m; from a cuttings sample at 1201- 1213 m (3940-3980 feet) in Demascota G-32 well; GSC type collection no. 130219, sample P9196, slide 09, co-ordinates 9.6 × 104.8, England Finder J48/0; maximum diameter of central body 32 μm, length of spines up to 5 μm. The age determined for the sample from which the holotype was recovered is Coniacian (Late Cretaceous); however, since it is a cuttings sample and no FAD has been determined for the species, the holotype is possibly a specimen caved down well from a younger stratum.
ETYMOLOGY. The epithet refers to the capitate distal endings of the processes.
DESCRIPTION. A species with a spheroidal to ovoidal, smooth central body and short, relatively fine but rigid, apparently solid, capitate processes.
SIZE. Maximum diameter of central body 29(30)32 μm, length of spines up to 5(6)7 μm.
AGE ON SCOTIAN MARGIN. LAD: middle Campanian (Late Cretaceous).
REMARKS. Impletosphaeridium williamsii is similar, but has a variety of process types, including acuminate and bifid; the processes of Impletosphaeridium capitatum are consistently capitate. Impletosphaeridium? tenuifilum has very delicate, readily bent processes.