Dentalina mutabilis

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Mynd: Guðmundur Guðmundsson

Dentalia mutabilis (Plesiotype-1 side view; from sample Bioice3280: depth 1692 m; bottom water temp. 2,85°C; loc. 62,8972°N, -15,9333°W Dec.Degr.)

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Mynd: Guðmundur Guðmundsson

Dentalia mutabilis  (Plesiotype-1 apertural view; from sample Bioice3280: depth 1692 m; bottom water temp. 2,85°C; loc. 62,8972°N, -15,9333°W Dec.Degr.)

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Mynd: Guðmundur Guðmundsson

Dreifing tegundar eftir dýpi, seltu og sjávarhita, innan þess breytileika sem allar sýnatökustöðvar ná yfir, sýnt sem heildarspönn lóðréttra ása. Gögn úr botndýraverkefninu „BIOICE“. (ENGLISH – Occurrence zone of the species within the range of water depth, temperature, and salinity, spanned by the "Bioice" samples; demarcated by respective y-axes.)

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Mynd: Guðmundur Guðmundsson

Hæð stöpla svarar til fjölda sýna þar sem tegundin er: fágæt (1-2 eintök); sjaldgæf (3-8 eintök); alltíð (9-32 eintök); algeng (>32 eintök). Gögn úr botndýraverkefninu (Bioice). (ENGLISH- Column height represents number of samples in bins where the species is: rare (1-2 specimens); occasional (3-8 specimens); common (9-32 specimens); and abundant (>32 specimens.) Data from the Bioice programme.)

Almennt

Dentalina mutabilis (Costa, 1855)

 

Nodosaria mutabilis – Costa, O.G. 1855. Foraminiferi fossili delle marne Terziarie di Messina. Roy. Accad. Sci. Napoli, Italica, vol.2, p.134, Pl.1, figs. 1a, 1c, 2a, 2c.

Nodosaria obliqua (not Linnaeus 1758) – Goës, A. 1894 (part). A synopsis of the Arctic and Scandinavian Recent Marine Foraminifera hitherto discovered. Kongl. Svenska Vetenskaps-Akademiens Handlinger, 25, no.9: p.70, plate 12, figs. 691-692 (only). – Cushman, J.A 1913, A Monograph of the Foraminifera of the Pacific Ocean, Smiths. Nat. Mus., p. 59. pl. 25, fig. 5. 

Dentalina flintii – Cushman, J.A. 1923 (description only; not pl. 14, fig. 1). The Foraminifera of the Atlantic Ocean. Smiths. Inst., Bull. 104, pt.4, Lagenidae, p. 85. – Jones, R.W., 1994. The Challenger Foraminifera, The Natural History Museum, London, Oxford Univ. Press: p. 76, Pl. 64, figs. 20-22.  Eiland, M. and G. Gudmundsson 2004. Taxonomy of some Recent Nodosariinae (Foraminifera) from the North Atlantic. Micropaleontolgy, vol. 50, no. 2, p.198, Pl.1, fig. O, Pl.2, fig. A.

Description: Test slender, nearly straight, and tapering into a long basal spine. Chamber arrangement uniserial; initial chambers only slightly inflated or flush, later successively more inflated. Sutures run transverse on lenght axis. Chamber height greater than width, nearly circular in cross section; number of chambers up to 16, often 10-14 in fully grown specimens. Aperture central, made of about 10 radiate slits of a strongly protruding and pointed crown. Wall is finely perforated, seems polylamellar. Surface covered with evenly sized costae, originating adjacent to the apertural crown, and running in nearly straight lines along the whole test; the costae may divide and fuse, usually over the sutures. The costae sometimes continue onto a distinct basal spine, and may winding around its axis. Length of largest specimen is 7 mm, but most are around 5 mm. About 320 specimens were picked from 81 of the 1031 Bioice samples that were checked for forams.

Diagnosis: Bears superficial resemblance to D. obliqua, but differs in that the test is much slenderer and nearly straight; chamber height is greater than chamber width. Aperture is central, not eccentric. The costae cover the apertural face and are in near direct continuation of apertural crown, wheras in D. mutabilis the costae never reach the apertural face, nor often the latest chambers.

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Útbreiðsla Dentalina mutabilis (Bioice samples, red dots; miscellaneous IINH samples, blue dots)

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