Globorotalia crassaformis


Classification: pf_cenozoic -> Globorotaliidae -> Globorotalia -> truncatulinoides lineage -> Globorotalia crassaformis
Sister taxa: G. excelsa, G. pachytheca, G. cavernula, G. truncatulinoides, G. tosaensis, G. tenuitheca, G. hessi, G. ronda, G. crassaformis, G. viola, G. crassaconica, G. crassula,

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, and Globorotalia crassaformis hessi Bolli and Premoli Silva, 1973 have also been considered as variants but were separated as distinct species by Aze et al. (2011)
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 (Turborotalia) oceanica

Type images:

Distinguishing features: No keel & flat spiral side

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, 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

Character matrix

test outline:Subquadratechamber arrangement:Trochospiraledge view:Planoconvexaperture:Umbilical-extraumbilical
sp chamber shape:Subrectangularcoiling axis:Lowperiphery:N/Aaperture border:Thin lip
umb chbr shape:Subtriangularumbilicus:Narrowperiph margin shape:Subangularaccessory apertures:None
spiral sutures:Flushumb depth:Shallowwall texture:Smoothshell porosity:Macroperforate: >2.5µm
umbilical or test sutures:Weakly depressedfinal-whorl chambers:4.0-4.0 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology


Geographic distribution: Warm subtropical to temperate. [Kennett & Srinivasan 1983] Low to middle latitudes [Aze et al. 2011, based on Kennett & Srinivasan (1983)]

In modern oceans a common, warm water, species [SCOR WG138]


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): Stewart (2003).

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]

Most likely ancestor: Globorotalia crassula - at confidence level 2 (out of 5). Data source: Kennet & Srinivasan (1983). NB Stewart (2003 fig. 6.10) & Aze et al. (2011, appendix 5) derive G. crassaformis from G. cibaoensis, however this appears to be in large part due to their adopting an incorrect age for the base of G. crassaformis, hence we revert here to the interpretation of Kennett & Srinivasan (1983) .
Likely descendants: Globorotalia crassaconica; Globorotalia ronda; Globorotalia viola;

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 & Srinivasan 1983, p.146

References:

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

Blow, W. H. (1969). Late middle Eocene to Recent planktonic foraminiferal biostratigraphy. In, Bronnimann, P. & Renz, H. H. (eds) Proceedings of the First International Conference on Planktonic Microfossils, Geneva, 1967. E J Brill, Leiden 380-381. gs

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. gs

Brummer, G. J. A. & Kucera, M. (2014). SCOR/ICBP 138 taxonomy and key to species of modern planktonic foraminfera v2.1. Chart distributed at TMS FNG meeting Texel, The Netherlands, June 2014. 1-. gs

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. gs

Crundwell, M. P. (2018). Globoconella pseudospinosa, n. sp.: A new Early Pliocene planktonic foraminifera from the Southwest Pacific. Journal of Foraminiferal Research. 48(4): 288-300. gs

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

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

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

Loeblich, A. & Tappan, H. (1994). Foraminifera of the Sahul shelf and Timor Sea. Cushman Foundation for Foraminiferal Research, Special Publication. 31: 1-661. gs

Norris, R. D. (1998). Planktonic foraminifer biostratigraphy: Eastern Equatorial Atlantic. Proceedings of the Ocean Drilling Program, Scientific Results. 159: 445-479. gs

Postuma, J. A. (1971). Manual of planktonic foraminifera. Elsevier for Shell Group, The Hague. 1-406. gs

Stewart, D. R. M. I. (2003). Evolution of Neogene globorotaliid foraminifera and Micoene climate change. In, p269 (ed.) . Earth Sciences. 1-269. gs


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Globorotalia crassaformis compiled by the pforams@mikrotax project team viewed: 18-9-2019

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