Globorotalia crassula


Classification: pf_cenozoic -> Globorotaliidae -> Globorotalia -> truncatulinoides lineage -> Globorotalia crassula
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 crassula Cushman & Stewart 1930
Rank: species
Basionym: Globorotalia crassula Cushman & Stewart 1930, in Cushman et al. 1930
Type species: (Truncorotalia)
Synonyms:
Variants:

Catalog entries: Globorotalia crassula, Globorotalia hirsuta aemiliana, Globorotalia crotonensis

Type images:

Distinguishing features: Like G. cibaoensis but with more nearly planoconvex test and more strongly angled 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: Very low trochospiral, spiral side almost flat, umbilical side convex
Aperture: Interiomarginal umbilical-extraumbilical low arch with lip [Aze 2011, based on Kennett & Srinivasan 1983]

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

Test morphology: Test very low trochospiral, spiral side almost flat, umbilical side convex; equa-torial periphery lobulate, subquadrate, axial periphery subacute to subrounded, peripheral thickening suggests presence of an imperforate keel; 4 chambers in the final whorl, uniformly in size as added, more inflated on umbilical side than on spiral side; sutures on spiral side curved and gently depressed, on umbilical side radial to curved and depressed; surface finely perforate, pustulate on early chambers; umbilicus narrow, aperture interiomarginal, umbilical-extraumbilical, a low arch with a lip. [Kennett & Srinivasan 1983]

Character matrix

test outline:Lobatechamber arrangement:Trochospiraledge view:Planoconvexaperture:Umbilical-extraumbilical
sp chamber shape:Crescenticcoiling 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: Temperate to warm subtropical. [Kennett & Srinivasan 1983] Low 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 very light ∂13C and very heavy ∂18O. Sources cited by Aze et al. 2011 (appendix S3): Shackleton & Vincent (1978)

Phylogenetic relations: Gr. (T.) crassula differs from Gr. (H.) cibaoensis by its more nearly planoconvex test and more strongly angled periphery. Blow (1969) distinguished less tightly coiled forms with lower umbilical vaulting as Gr. (T.) viola. He also considered that Gr. viola was essentially restricted to the tropics, while the closely related form, Gr. crassula, was restricted to the temperate areas. We consider that Gr. viola is probably no more than a tropical variant or subspecies of Gr. (T .) crassaformis.
Globorotalia aemiliana Colalongo and Sartoni, and Globorotalia crotonensis Conato and Follador are morphologically similar to Gr. (T.) crassula and probably represent no more than phenotypic variants or subspecies of this form.
Gr. ( T.) crassula may have evolved from Gr. (H.) cibaoensis in temperate-Subantarctic areas of the South Pacific and is the possible ancestor of Gr. (T.) crassaformis (Galloway and Wissler). At DSDP Site 281, we have observed gradation between Gr. (H.) cibaoesis and Gr. (T.) crassula. A possible ancestry between Gr. (T.) crassula and Gr. (T.) crassaformis is inferred. [Kennett & Srinivasan 1983]

Most likely ancestor: Globorotalia cibaoensis - at confidence level 3 (out of 5). Data source: Kennett & Srinivasan 1983, fig 16Stewart 2003 fig. 6.10; Aze et al. 2011, appendix 5.
Likely descendants: Globorotalia crassaformis;

Biostratigraphic distribution

Geological Range:
Last occurrence (top): within N21 zone (1.93-3.10Ma, top in Gelasian stage). Data source: Chaisson & Pearson (1997)
First occurrence (base): within N18 zone (5.20-5.72Ma, base in Messinian stage). Data source: Chaisson & Pearson (1997)

Plot of occurrence data:

Primary source for this page: Kennett & Srinivasan 1983, p.144

References:

Banner, F. T. & Blow, W. H. (1960a). Some primary types of species belonging to the superfamily Globigerinaceae. Contributions from the Cushman Foundation for Foraminiferal Research. 11: 1-41. 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

Cita, M. B. (1973). Pliocene biostratigraphy and chronostratigraphy. Initial Reports of the Deep Sea Drilling Project. 13: 1343-1379. gs

Cushman, J. A., Stewart, R. E. & Stewart, K. C. (1930). Tertiary foraminifera from Humboldt county, California. Transactions of the San Diego Society of Natural History. 6(2): 41-94. gs

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

Shackleton, N. J. & Vincent, E. (1978). Oxygen and carbon isotope studies in Recent Foraminifera from the southeast Indian Ocean. Marine Micropaleontology. 3: 1-13. gs


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

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