Orbulina suturalis


Classification: pf_cenozoic -> Globigerinidae -> Orbulina -> Orbulina suturalis
Sister taxa: O. universa, O. suturalis, O. sp.,

Taxonomy

Citation: Orbulina suturalis Brönnimann, 1951
Rank: species
Basionym: Orbulina suturalis
Synonyms:
Taxonomic discussion: Not regarded as a discrete species by SCOR WG138

Catalog entries: Orbulina suturalis, Candorbulina universa

Type images:

Distinguishing features: final chamber not entirely enveloping earlier test

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: Almost spherical, final chamber not entirely enveloping earlier test

Aperture: Areal apertures supplementary apertures along sutures separating earlier and final chambers [Aze 2011, based on Kennett & Srinivasan 1983]


Wall type: Spinose; Hispid [Aze 2011]

Test morphology: Adult test almost spherical, final chamber not entirely enveloping the early part of the test. Tests show all gradations from a partly enveloped Globigerina to an almost completely enveloped one. In the adult stage, the Globigerina chambers are visible only as low, rounded projections from a general sphere; surface densely perforate; aperture areal distributed over the surface of final chamber. Supplementary apertures along sutures separating the final and earlier chambers. [Kennett & Srinivasan 1983]

Character matrix

test outline:Circularchamber arrangement:Envelopingedge view:Equally biconvexaperture:Umbilical
sp chamber shape:Inflatedcoiling axis:Moderateperiphery:N/Aaperture border:N/A
umb chbr shape:Inflatedumbilicus:Wideperiph margin shape:Broadly roundedaccessory apertures:Sutural
spiral sutures:Flushumb depth:Deepwall texture:Cancellateshell porosity:Macroperforate: >2.5µm
umbilical or test sutures:Strongly depressedfinal-whorl chambers:1.0-3.0 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology


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

[SCOR WG138]


Isotope paleobiology: Widely recorded as a photosymbiotic mixed-layer species but Aze et al. (2011) place it in ecogroup 3 - Open ocean thermocline. Based on light ∂13C and relatively heavy ∂18O. Sources cited by Aze et al. 2011 (appendix S3): D. R. M. Stewart unpublished data

Phylogenetic relations: O. suturalis is distinguished from Praeorbulina circularis, its immediate ancestor, by lacking the small apertures confined to the suture of the Globigerina stage and by the areal apertures over the surface. The initial evolutionary appearance of O. suturalis (Orbulina datum) has been recorded throughout the world and is taken to mark the base of the Middle Miocene. [Kennett & Srinivasan 1983]

Most likely ancestor: Praeorbulina circularis - at confidence level 4 (out of 5). Data source: Kennett & Srinivasan 1983, fig. 11.
Likely descendants: Orbulina universa;

Biostratigraphic distribution

Geological Range:
Last occurrence (top): within N21 zone (1.93-3.10Ma, top in Gelasian stage). Data source: Kennett & Srinivasan 1983
First occurrence (base): at base of M6 zone (0% up, 15.1Ma, in Langhian stage). Data source: Wade et al. (2011), zonal marker

Plot of occurrence data:

Primary source for this page: Kennett & Srinivasan 1983, p.86

References:

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

Brönnimann, P. (1951b). The genus Orbulina d'Orbigny in the Oligo-Miocene of Trinidad, B. W. I. Contributions from the Cushman Foundation for Foraminiferal Research. 2(4): 135+-. gs

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


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Orbulina suturalis compiled by the pforams@mikrotax project team viewed: 20-9-2019

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Short stable page link: http://mikrotax.org/pforams/index.php?id=104183 Go to Archive.is to create a permanent copy of this page - citation notes



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