Globigerinoides diminutus

NB TAXA WHICH ORIGINATE IN THE OLIGOCENE ARE NOT INCLUDED YET
Classification: pf_neogene -> Globigerinidae -> Globigerinoides -> Globigerinoides diminutus
Sister taxa: G. altiaperturus, G. conglobatus, G. diminutus, G. elongatus, G. extremus, G. mitra, G. obliquus, G. parawoodi, G. ruber, G. seigliei, G. subquadratus, G. tenellus, G. white,

Taxonomy

Citation: Globigerinoides diminutus Bolli, 1957
Rank: species
Basionym: Globigerinoides diminutus

Catalog entries: Globigerinoides diminuta;

Type images:

Description


Diagnostic characters: Small, trochospiral, equatorial periphery subquadrate

Aperture: Primary aperture interiomarginal umbilical small circular symmetrical arch. Supplementary sutural apertures on spiral side [Aze 2011, based on Kennett & Srinivasan 1983]


Wall type: Spinose; Cancellate [Aze 2011]

Test morphology: Test small, trochospiral, equatorial periphery subquadrate, chambers spherical in early stages, later becoming laterally compressed ; three chambers in the final whorl , increasing moderately in size; sutures on both spiral and umbilical side radial and depressed; surface distinctly cancellate; umbilicus small, primary aperture interiomarginal , umbilical small, almost circular symmetrically above the suture line of the two earlier chambers ; supplementary sutural apertures, generally two situated over the sutures of earlier chambers. [Kennett & Srinivasan 1983]

Biogeography and Palaeobiology


Geographic distribution: Tropical [Kennett & Srinivasan 1983]

Isotope paleobiology: Aze et al. 2011 ecogroup 1 - Open ocean mixed-layer tropical/subtropical, with symbionts. Based on very heavy ∂13C and relatively light ∂18O. Sources cited by Aze et al. 2011 (appendix S3): Keller (1985)

Phylogenetic relations: The position of the apertures symmetrically above the sutures between two earlier chambers, the subquadrate shape of the test, and the cancellate surface in both the Gs. diminutus and Gs. subquadratus suggest a close phylogenetic relationship between these two forms. Gs. diminutus is distinguished from Gs. subquadratus by its very small size and more compact test.
Possibly Gs. diminutus represents a tropical variant of Gs. subquadratus. [Kennett & Srinivasan 1983]

Biostratigraphic distribution

Geological Range:
Last occurrence (top): within N9 zone (14.24-15.10Ma, top in Langhian stage). Data source: Kennett & Srinivasan 1983
First occurrence (base): within N7 zone (16.38-17.54Ma, base in Burdigalian stage). Data source: Kennett & Srinivasan 1983

Plot of occurrence data:

Primary source for this page: Kennett & Srinivisan 1983, p.74

References:

Aze, T.; Ezard, T.H.G.; Purvis, A.; Coxall, H.K.; Stewart, D.R.M.; Wade, B.S. & Pearson, P.N.P., (2011). A phylogeny of Cenozoic macroperforate planktonic foraminifera from fossil data. Biological Reviews, 86: 900-927.

Bolli, H.M., (1957). Planktonic foraminifera from the Oligocene-Miocene Cipero and Lengua formations of Trinidad, B.W.I. In: Loeblich, A.R., Jr. et al. (Editors), Studies in Foraminifera: U.S. National Museum Bulletin 215. U.S. Government Printing Office, Washington, DC, pp. 97-123.

Keller, G., (1985). Depth stratification of planktonic foraminifers in the Miocene Ocean. In: Kennett, J.P. (Editor), The Miocene Ocean: Paleoceanography and Biogeography. GSA Memoir The Geological Society of America, Boulder, Colorado, pp. 1-337.

Kennett, J.P. & Srinivasan, M.S., (1983). Neogene Planktonic Foraminifera. Hutchinson Ross Publishing Co., Stroudsburg, Pennsylvania, 1-265 pp.


Globigerinoides diminutus compiled by the pforams@mikrotax project team viewed: 30-5-2017

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