Globorotalia cibaoensis

NB TAXA WHICH ORIGINATE IN THE OLIGOCENE ARE NOT INCLUDED YET
Classification: pf_neogene -> Globorotalidae -> Globorotalia -> hirsuta lineage -> Globorotalia cibaoensis
Sister taxa: G. evoluta, G. gigantea, G. praemargaritae, G. primitiva, G. hirsuta, G. theyeri, G. margaritae, G. juanai, G. cibaoensis, G. scitula, G. challengeri, G. praescitula,

Taxonomy

Citation: Globorotalia cibaoensis Bermudez 1949
Rank: species
Basionym: Globorotalia cibaoensis
Synonyms:

Catalog entries: Globorotalia cibaoensis;

Type images:

NB The short diagnoses are used in the tables of daughter-taxa to act as quick summaries of the differences between e.g. species of one genus. They have initially been copied from the diagnostic characters/distinguishing features sections of the Eocene and Paleocene Atlases, they will be edited as the site is developed.

Description


Diagnostic characters: Low trochospiral, biconvex, equatorial periphery subquadrate

Aperture: : Interiomarginal umbilical-extraumbilical low arch bordered by a thin lip [Aze 2011, based on Kennett & Srinivasan 1983]


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

Test morphology: Test low trochospiral, biconvex, equatorial periphery subquadrate, axial periphery ovate, subrounded to subacute; 4 to 4½ inflated chambers in the final whorl, increasing rapidly in size as added; spiral sutures oblique, depressed , on umbilical side radial, depressed; surface finely perforate, on early chambers pustulose on umbilical as well as spiral ,side; umbilicus narrow; aperture a low arch bordered by a thin lip. [Kennett & Srinivasan 1983]

Biogeography and Palaeobiology


Geographic distribution: Tropical to temperate. [Kennett & Srinivasan 1983]

Isotope paleobiology: Aze et al. 2011 ecogroup 4 - Open ocean sub-thermocline. Based on comparison with other species of the genus

Phylogenetic relations: Gr. (H) cibaoensis is distinguished by its biconvex test with a rounded periphery, which sometimes becomes angular or narrowly keeled in the final chamber.
Gr. (H) cibaoensis descended from G. (H.) scitula in the Late Miocene and is a close relative of the Gr. ( H ) juanai-margaritae plexus. We believe it is the ancestor of Globorotalia crassula Cushman and Stewart, which evolved in temperate-Subantarctic areas during the latest Miocene and thence gave rise to the Gr. (T.) crassaformis to Gr. (T.) truncatulinoides lineage. We have observed gradation between Gr.(H) cibaoensis and Gr. (T.) crassula in DSDP Site 281 (Subantarctic area). [Kennett & Srinivasan 1983]

Most likely ancestor: Globorotalia scitula - at confidence level 3 (out of 5). Data source: Kennett & Srinivasan 1983, fig 15.

Biostratigraphic distribution

Geological Range:
Notes: The first appearance of Gr. (H.) cibaoensis provides a valuable biostratigraphic datum for correlation of Late Miocene-Pacific DSDP sequences close to the ∂C13 shift at 6.2 Ma.
Last occurrence (top): in upper part of PL1 [Atl.] zone (81% up, 4.6Ma, in Zanclean stage). Data source: Wade et al. (2011), additional event; position within zone determined by linear interpolation from data in table 1 of Wade et al. (2011).
First occurrence (base): in lower part of M13a subzone (35% up, 9.4Ma, in Tortonian stage). Data source: Wade et al. (2011), additional event; position within zone determined by linear interpolation from data in table 1 of Wade et al. (2011).

Plot of occurrence data:

Primary source for this page: Kennett & Srinivisan 1983, p.136

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.

Bermudez, P.J., (1949). Tertiary smaller foraminifera of the Dominican Republic. Contributions from the Cushman Laboratory for Foraminiferal Research special publication, 25: 1-322.

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


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Globorotalia cibaoensis compiled by the pforams@mikrotax project team viewed: 13-12-2017

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