Globorotalia crassaformis

NB TAXA WHICH ORIGINATE IN THE OLIGOCENE ARE NOT INCLUDED YET
Classification: pf_neogene -> Globorotalidae -> Globorotalia -> truncatulinoides lineage -> Globorotalia crassaformis
Sister taxa: G. cavernula, G. crassaconica, G. crassaformis, G. crassula, G. excelsa, G. hessi, G. oceanica, G. pachytheca, G. ronda, G. tenuitheca, G. tosaensis, G. truncatulinoides, G. viola,

Taxonomy

Citation: Globorotalia crassaformis (Galloway & Wissler, 1927)
Rank: species
Basionym: Globigerina crassaformis
Synonyms:
Variants: NB Globorotalia crassaformis ronda Blow, 1969 and Globorotalia crassaformis viola Blow 1969 have also been considerd as variant but are now separaed as distinct species.
Taxonomic discussion: Globorotalia crassaformis oceanica Cushman and Bermudez, 1949 is considered a synonym by Kennett & Srinivasan 1983 (folowing Cifelli & Glacon 1979) - but Aze et al. (2011) regard it as a discrete species.

Catalog entries: Globigerina crassaformis; Globorotalia crassaformis hessi [not in catalog yet]Globorotalia crassaformis viola [not in catalog yet]

Type images:

Short diagnosis: No keel & flat spiral side

Description


Diagnostic characters: Low trochospiral, spiral side almost flat, umbilical side strongly convex

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

Coiling direction (in extant population): mixed with bias to dextral


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

Test morphology: Test low trochospiral, spiral side almost flat, umbilical side strongly convex, equatorial periphery slightly lobulate, subquadrate; axial periphery planoconvex, sub-acute to subrounded; chambers compressed, 4 in the final whorl, increasing rapidly in size; sutures on spiral side curved, depressed; on umbilical side almost radial, depressed; surface finely perforate, pustulate on umbilical as well as spiral side; umbilicus narrow, deep; aperture interiomarginal, extraumbilical-umbilical, a low-arched slit bordered by a lip. [Kennett & Srinivasan 1983]

Size: >250µm

Biogeography and Palaeobiology


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

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 Sources cited by Aze et al. 2011 (appendix S3): D. R. M. Stewart unpublished data

Phylogenetic relations: Gr. (T) crassaformis shows a wide range of variation in size, from rounded to keeled periphery, thin-walled to thick-walled test, and the degree of compactness. Different subspecific nomenclature such as oceanica Cushman and Bermudez, 1949; ronda Blow, 1969; viola Blow, 1969, and hessi Bolli and Premoli Silva, 1973, have been proposed to reflect these variations. All of these forms are characterized by four chambers in the final whorl and quadrate arrangement of quasi-scituline shaped chambers (Cifelli and Glacon, 1979), suggesting close phyletic relationships between them.
Gr. (T) crassaformis may have evolved from Gr. (T) crassula and is the ancestor of Gr. (T) tosaensis Takayanagi and Saito. [Kennett & Srinivasan 1983]

Biostratigraphic distribution

Geological Range:
Last occurrence (top): Extant Data source: present in the plankton (SCOR WG138)
First occurrence (base): near base of PL2 zone (12% up, 4.3Ma, 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).

Plot of occurrence data:

Primary source for this page: Kennett & Srinivisan 1983, p.146

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.

Blow, W.H., (1969). Late middle Eocene to Recent planktonic foraminiferal biostratigraphy. In: Bronnimann, P. and Renz, H.H. (Editors), Proceedings of the First International Conference on Planktonic Microfossils, Geneva, 1967, Leiden, Netherlands, pp. 380-381.

Bolli, H.M. & Premoli Silva, I., (1973). Oligocene to Recent planktonic foraminifera and stratigraphy of the Leg 15 sites in the Caribbean Sea. Initial Reports of the Deep Sea Drilling Project, 15: 475-497.

Cifelli, R. & Glacon, G., (1979). New Late Miocene and Pliocene occurrences of Globorotalia species from the North Atlantic; and a paleogeographic review. Journal of Foraminiferal Research, 9(3): 210-227.

Cushman, J.A. & Bermudez, P.J., (1949). Some Cuban species of Globorotalia. Contributions from the Cushman Laboratory for Foraminiferal Research, 25: 26-45.

Galloway, J.J. & Wissler, S.G., (1927). Pleistocene foraminifera from the Lomita Quarry, Palos Verdes Hills, California. Journal of Paleontology, 1(1): 35-87.

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


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Globorotalia crassaformis compiled by the pforams@mikrotax project team viewed: 24-9-2017

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AphiaID: 418113 Nomenclatural data on WoRMS
Go to Archive.is to create a permanent copy of this page - citation notes



AphiaID: 418113 Nomenclatural data on WoRMS
Go to Archive.is to create a permanent copy of this page - citation notes

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