Elphidium incertum

Elphidium incertum (Williamsom 1858)

Elphidium incertum (Williamson). Buzas 1966, p 585-594 pl 72 figs 1-6.
E. asklundi Brotzen 1943. Knudsen 1971, p 270 pl 1 figs 20,21.

Elphidium incertum 1

  • Side view, scale bar 0.1 mm.
  • Adult specimen.
  • Collected: Core L0987, NII Morgeo 1984, SW Kara Sea, 126 mwd, Holocene mud (50cm core depth)

Elphidium incertum 2

  • Apertural view, scale bar 0.1 mm.
  • Adult specimen.
  • Collected: summer 1991, RV Akademik Karpinski, Kara Sea (off northern tip of Novaya Zemlya), 20mwd

Elphidium incertum 3

  • Side view, scale bar 0.1 mm.
  • Juvenile specimen.
  • Collected: summer 1991, RV Akademik Karpinski, SW Kara Sea, 20mwd

Elphidium incertum 4

  • Side view, scale bar 0.1 mm.
  • Another juvenile specimen.
  • Collected: summer 1991, RV Akademik Karpinski, SW Kara Sea, 20mwd

Elphidium incertum 5

  • Enlarged apertural region of the above test.

Remarks:

A shallow-water foraminifer, typical of brackish, near-estuarine areas with salinities below 30‰. Morphology highly variable, which results in often confusing taxonomic references.

E.incertum can be distinguished by having 10 chambers in the last whorl and deep elongated slits in the sutures. The umbilicus is usually granulated and depressed. The aperture is not clear even under SEM because granulations cover the basal slit. Test wall is made of granular calcite and can appear translucent to opaque. Based on the granular test wall, this species may belong to genus Cribrononion (Hanssen & Lykke-Anderson 1976).

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