Catalog - Globorotalia challengeri Catalog - Globorotalia challengeri

CATALOG OF ORIGINAL DESCRIPTIONS: Globorotalia challengeri Kennett & Srinivasan 1981

This page provides data from the catalog of type descriptions. The catalog is sorted alphabetically. Use the current identification link to go back to the main database.


Higher levels: pf_cat -> G -> Globorotalia -> Globorotalia challengeri
Other pages this level: << < G. bouregregensis, G. broedermanni lodoensis, G. bullbrooki, G. bykovae, G. bykovae minoritesta, G. californica, G. californica Smith, G. canariensis minima, G. capdevilensis, G. cavernula, G. caylaensis, G. centralis, G. cerroazulensis cunialensis, G. cerroazulensis pomeroli, G. cerroazulensis possagnoensis, G. challengeri, G. chapmani, G. cibaoensis, G. cocoaensis, G. collactea, G. conica, G. conicotruncata, G. conomiozea, G. conomiozea mons, G. convexa, G. crassacarina, G. crassaconica, G. crassacrotonensis, G. crassaformis ronda, G. crassata aequa, G. crassula> >>

Globorotalia challengeri

Citation: Globorotalia challengeri Kennett & Srinivasan 1981
taxonomic rank: Species
Type specimens: Holotype (no. 320476) and four paratypes (no. 320477-320480)
Type age (chronostrat): Middle Miocene
Type locality: DSDP Site 281, Core 9, Section 6, 50 cm.
Type repository: Washington; USNM

Linked specimens: USNM-320479 USNM-320480 USNM-320478 USNM-320476 USNM-320477

Current identification/main database link: Globorotalia challengeri Srinivasan & Kennett 1981


Original Description

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 12-15, arranged in three whorls, 5 to 5½ chambers in the final whorl which increase 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, interio-marginal, umbilical-extraumbilical; coiling predominantly sinistral.

Extra details from original publication
Synonym: 1981 Globorotalia mayeri; Loutit, Mar. Micropale- ontol., 6(1): plate I, figs. 14-16 (non Cushman and Ellisor).

Remarks: The new species differs from its ancestor, G. praescitula in exhibiting five to five and one-half rather than four and one- half chambers in the final whorl, more inflated chambers and a more rounded periphery. The species is also morphologically similar to G. mayeri but differs in being less elongate in equatorial profile and in exhibiting a distinctly low-arched aperture.

Evolution: An evolutionary gradation was observed in Site 281 from G. praescitula in the latest Early Miocene to G. challengeri in the early Middle Miocene (Fig. 14). The upward gradation is recorded between Cores 12 and 9. The upward 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 m.y. from the lower part of the G. miozea Zone (~18 Ma) to the base of the Orbulina suturalis Zone (16 Ma).

 

References:


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Globorotalia challengeri compiled by the pforams@mikrotax project team viewed: 9-9-2024

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