Globigerinoides mitra

NB TAXA WHICH ORIGINATE IN THE OLIGOCENE ARE NOT INCLUDED YET
Classification: pf_neogene -> Globigerinidae -> Globigerinoides -> Globigerinoides mitra
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 mitra Todd 1957
Rank: species
Basionym: Globigerinoides mitra

Catalog entries: Globigerinoides mitra;

Type images:

Description


Diagnostic characters: Large, high trochospiral, spherical to subspherical chambers

Aperture: : Interiomarginal umbilical-extraumbilical large semi-circular opening. Supplementary sutural apertures on spiral side [Aze 2011, based on Kennett & Srinivasan 1983]


Wall type: Spinose; Cancellate [Aze 2011]

Test morphology: Test large , high spired, chambers spherical to suhspherical, three or four in the final whorl; sutures depressed, surface hummocky on earlier chambers but perforate on later chambers; primary aperture interiomarginal, umbilical, a large semicircular opening occupying most of the umbilical edge of the final chamber; small supplementary apertures at the intersection of the vertical sutures with the spiral sutures. [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); Pearson et al. (2001b)

Phylogenetic relations:

Gs. mitra is distinguished by its large test size, very high spire, and large, asymmetric primary aperture. Except for its distinct asymmetrically developed adult chambers, Gs. mitra is morphologically close to Gs. subquadratus and Gs. ruber and possibly is intermediate between them.
Saito et al. (1976) placed Gs. mitra under a new genus, Globicuniculus, stating that it lacks the characteristic elongate spines or the spine bases of the genus Globigerinoides. Todd (1957) described the form as being finely spinose, and thus generic differentiation is not justified on these grounds. However, the form exhibits distinctive smooth surface texture that may be significant taxonomically. [Kennett & Srinivasan 1983]

Biostratigraphic distribution

Geological Range:
Last occurrence (top): within N12 zone (11.79-13.41Ma, top in Serravallian stage). Data source: Kennett & Srinivasan 1983
First occurrence (base): within N6 zone (17.54-17.59Ma, base in Burdigalian stage). Data source: Kennett & Srinivasan 1983

Plot of occurrence data:

Primary source for this page: Kennett & Srinivisan 1983, p.76

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.

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.

Pearson, P.N. & others, (2001). Warm tropical sea surface temperatures in the Late Cretaceous and Eocene epochs. Nature, 413: 481-487.

Todd, R., (1957). Smaller foraminifera, in Geology of Saipan, Mariana Islands, Pt. J, Paleontology,. U.S. Geological Survey Professional Paper, 280-H: 265-320.


Globigerinoides mitra compiled by the pforams@mikrotax project team viewed: 23-5-2017

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