Globigerinella

NB TAXA WHICH ORIGINATE IN THE OLIGOCENE ARE NOT INCLUDED YET
Classification: pf_neogene -> Globigerinidae -> Globigerinella
Sister taxa: Beella, Globigerina, Globigerinella, Protentella, Globigerinoides, Globigerinoidesella, Globoturborotalita, Orbulina, Praeorbulina, Sphaeroidinella, Sphaeroidinellopsis, Trilobatus, Turborotalita, Catapsydrax, Clavatorella, Paragloborotalia, Orcadia,

Distinguishing features: Trochoid test becoming nearly planispiral, globular to ovate chambers, umbilical aperture, and fine spines covering the test

Daughter taxa (blue => in age window 0-300Ma)
Extant species
Near planispiral coiling & digitate chambers
Near planispiral coiling & spherical chambers
Near planispiral coiling & slightly radially elongate chambers
Trochospiral coiling & slightly radially elongate chambers
Miocene species
Initially trochospiral becoming planispiral in final whorl. 5 slowly enlarging chambers in final whorl;
Test low trochospiral; 4 rapidly enlarging chambers in the final whorl
Specimens which cannot be assigned to established species

Taxonomy

Citation: Globigerinella Cushman 1927
Rank: genus
Type species: Globigerina aequilateralis
Variants:
Taxonomic discussion: Cushman erected the genus Globigerinella for the forms with an initial trochoid test that later becomes nearly planispiral in the adult, globular to ovate chambers, umbilical aperture, and fine spines covering the test. Bolli et al. (1957) considered Globigerinella as junior synonym of Hastigerina Thomson. Bé (1969) discussed the surface ultrastructures (particularly the nature of spines) of Globigerinella and Hastigerina and concluded that these two genera are inseparable but later (Tolderlund and Bé, 1971) considered them as separate taxa. This latter view is followed here (compare also Parker, 1967; Saito et al., 1976, 1981). Globigerinella differs from Hastigerina in possessing simple rounded spines (in cross-section), which become triradiate only in later growth, as compared to the consistently triradiate spines of Hastigerina. The early members of Globigerinella (Ge. obesa, Ge. pseudobesa) resemble Jenkinsella in general test morphology but are distinguished primarily by their spinose surface ultrastructure. [Kennett & Srinivasan 1983]

Catalog entries: Globigerinella; Hastigerina (Bolliella);

Type images:

Distinguishing features: Trochoid test becoming nearly planispiral, globular to ovate chambers, umbilical aperture, and fine spines covering the test

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

Biogeography and Palaeobiology


Phylogenetic relations: The genus Globigerinella evolved from Globigerina (Gg.) praebulloides through Globigerinella obesa, the earliest member of the lineage in the Late Oligocene (Text Fig. 26). [Kennett & Srinivasan 1983]

Most likely ancestor: Globigerina - at confidence level 3 (out of 5). Data source: Kennett & Srinivasan 1983 p.234.

Biostratigraphic distribution

Geological Range:
Last occurrence (top): Extant Data source: Total of range of species in this database
First occurrence (base): near top of Chattian Stage (91% up, 23.5Ma, in Chattian stage). Data source: Total of range of species in this database

Plot of occurrence data:

Primary source for this page: Kennett & Srinivasan 1983, p.234

References:

Banner, F.T. & Blow, W.H., (1959). The classification and stratigraphical distribution of the Globigerinaceae. Palaeontology, 2(1): 1-27.

Chaproniere, G.C.H., (1991). Pleistocene to Holocene planktic foraminiferal biostratigraphy of the Coral Sea, offshore Queensland, Australia. BMR Journal of Australian Geology & Geophysics, 12: 195-221.

Cushman, J.A., (1927). An outline of a re-classification of the Foraminifera. Contributions from the Cushman Laboratory for Foraminiferal Research, 3: 1-105.

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


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Globigerinella compiled by the pforams@mikrotax project team viewed: 25-6-2018

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