Globorotalia gigantea


Classification: pf_cenozoic -> Globorotaliidae -> Globorotalia -> hirsuta lineage -> Globorotalia gigantea
Sister taxa: G. hirsuta, G. theyeri, G. margaritae, G. juanai, G. bermudezi, G. scitula, G. praescitula, G. cibaoensis, G. gigantea, G. challengeri,

Taxonomy

Citation: Globorotalia gigantea Blow, 1959
Rank: species
Basionym: Globorotalia scitula gigantea
Taxonomic discussion: Not recognised by Kennett & Srinivasan (1983), but distingushed by Stewart (2003) and Aze et al. (2011). 

Catalog entries: Globorotalia scitula gigantea

Type images:

Distinguishing features: Like G. scitula but much larger (>0.5mm vs ca 0.3mm)

NB These concise distinguishing features statements are used in the tables of daughter-taxa to act as quick summaries of the differences between e.g. species of one genus.
They are being edited as the site is developed and comments on them are especially welcome.

Description


Diagnostic characters: Large, medium to low trochospiral, equatorial periphery slightly lobulate with keel-like rim

Aperture: Interiomarginal umbilical-extraumbilical low slit bordered by a pronounced lip [Aze 2011, based on Stewart 2003]


Wall type: Non-spinose; Smooth [Aze 2011]

Test morphology: Seprated from G. scitula by Blow (1959) on the basis of size "In general morphology this subspecies is similar to Globorotalia scitula scitula (Brady) but differs in being much larger. Two groups co-exist with mean diameters averaging 0.28 mm. and 0.54 mm. with few specimens greatly departing from the two means".

Character matrix

test outline:Lobatechamber arrangement:Trochospiraledge view:Inequally biconvexaperture:Umbilical-extraumbilical
sp chamber shape:Crescenticcoiling axis:Lowperiphery:N/Aaperture border:Thick lip
umb chbr shape:Subtriangularumbilicus:Narrowperiph margin shape:Narrowly roundedaccessory apertures:None
spiral sutures:Weakly depressedumb depth:Shallowwall texture:Smoothshell porosity:Macroperforate: >2.5µm
umbilical or test sutures:Weakly depressedfinal-whorl chambers:4.0-5.0 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology


Geographic distribution: Low to middle latitudes [Aze et al. 2011, based on D. R. M. Stewart unpublished data]

[SCOR WG138]


Isotope paleobiology: Aze et al. 2011 ecogroup 4 - Open ocean sub-thermocline. Based on very light ∂13C and very heavy ∂18O. Sources cited by Aze et al. 2011 (appendix S3): this study

Most likely ancestor: Globorotalia scitula - at confidence level 3 (out of 5). Data source: Stewart 2003 fig. 6.10; Aze et al. 2011, appendix 5.

Biostratigraphic distribution

Geological Range:
Last occurrence (top): within M13a subzone (8.58-9.83Ma, top in Tortonian stage). Data source: Stewart 2003; Aze et al. 2011
First occurrence (base): within M7 zone (13.77-14.24Ma, base in Langhian stage). Data source: Stewart 2003; Aze et al. 2011

Plot of occurrence data:

References:

Aze, T. et al. (2011). A phylogeny of Cenozoic macroperforate planktonic foraminifera from fossil data. Biological Reviews. 86: 900-927. gs

Blow, W. H. (1959). Age, correlation, and biostratigraphy of the upper Tocuyo (San Lorenzo) and Pozon Formations, eastern Falcon, Venezuela. Bulletins of American Paleontology. 39(178): 67-251. gs

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

Stewart, D. R. M. I. (2003). Evolution of Neogene globorotaliid foraminifera and Micoene climate change. In, p269 (ed.) . Earth Sciences. 1-269. gs


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Globorotalia gigantea compiled by the pforams@mikrotax project team viewed: 18-10-2019

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