pforams@mikrotax - Globorotalia challengeri pforams@mikrotax - Globorotalia challengeri

Globorotalia challengeri


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

Taxonomy

Citation: Globorotalia challengeri Srinivasan & Kennett 1981
Taxonomic rank: species
Basionym: Globorotalia challengeri Srinivasan & Kennett 1981
Synonyms:

Catalog entries: Globorotalia challengeri

Type images:

Distinguishing features:
Parent taxon (hirsuta lineage): G. scitula - juanai - margaritae - hirsuta lineage
This taxon: Like G. praescitula, but 5-5½ chambers in final whorl (vs 4½), more inflated chambers, and a more rounded periphery

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:

Low trochospiral, unequally biconvex, equatorial periphery lobate

Aperture: Interiomarginal umbilical-extraumbilical distinct arch with a prominent lip [Aze 2011, based on Kennett & Srinivasan 1983]


Morphology:
Test a fairly low trochospiral, unequally biconvex, equatorial periphery lobate, axial periphery rounded or with a tendency to become subangular, wall calcareous, thin, coarsely perforate , surface smooth; chambers twelve to fifteen, arranged in three whorls, 5 to 5½ chambers in the final whorl,which increases slowly in size; chambers strongly inflated especially in the later stage; rounded to ovate in shape; sutures on spiral side curved, depressed; on umbilical side slightly sinuous to radial, depressed; aperture a distinct arch, with a prominent lip, interiomarginal, umbilical-extraumbilical; coiling predominantly sinistral. [Kennett & Srinivasan 1983]

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

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:Broadly roundedaccessory apertures:None
spiral sutures:Weakly depressedumb depth:Shallowwall texture:Smoothshell porosity:Macroperforate: >2.5µm
umbilical or test sutures:Weakly depressedfinal-whorl chambers:5-5.5 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology


Geographic distribution

Temperate [Kennett & Srinivasan 1983] Middle latitudes [Aze et al. 2011, based on Kennett & Srinivasan (1983)]

[SCOR WG138]


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

Phylogenetic relations
This species differs from its ancestor, Gr. (G.) praescitula, in exhibiting 5 to 5½ rather than 4½ chambers in the final whorl, more inflated chambers, and a more rounded periphery. The species is also morphologically similar to Gr. (J.) mayeri but differs in being less elongate in equatorial profile and in exhibiting a distinctly low-arched aperture.
An evolutionary gradation was observed in DSDP Site 281 (Subantarctic) from Gr. (G.) praescitula in the latest Early Miocene to Gr. (H) challengeri in the early Middle Miocene. The morphological gradation largely involves an increase in the number of chambers, greater inflation of the test, and rounding of the periphery. The evolutionary change takes place over a period of about 2 my from the lower part of the Globorotalia miozea Zone (~18 Ma) to the base of the Orbulina suturalis Zone (16 Ma). [Kennett & Srinivasan 1983]

Most likely ancestor: Globorotalia praescitula - at confidence level 3 (out of 5). Data source: Kennett & Srinivasan 1983, fig 15; Stewart 2003 fig. 6.10; Aze et al. 2011, appendix 5.

Biostratigraphic distribution

Geological Range:
Last occurrence (top): within N15 zone (9.83-10.46Ma, top in Tortonian stage). Data source: Kennett & Srinivasan 1983
First occurrence (base): within N9 zone (14.24-15.10Ma, base in Langhian stage). Data source: Kennett & Srinivasan 1983

Plot of occurrence data:

Primary source for this page: Kennett & Srinivasan 1983, p.142

References:

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

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

Srinivasan, M. S. & Kennett, J. P. (1981b). Neogene planktonic foraminiferal biostratigraphy and evolution: equatorial to subantarctic, south Pacific. Marine Micropaleontology. 6: 499-533. gs


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Globorotalia challengeri compiled by the pforams@mikrotax project team viewed: 16-11-2025

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