pforams@mikrotax - Fohsella robusta pforams@mikrotax - Fohsella robusta

Fohsella robusta


Classification: pf_cenozoic -> Globorotaliidae -> Fohsella -> Fohsella robusta
Sister taxa: F. paralenguaensis, F. lenguaensis ⟩⟨ F. robusta, F. lobata, F. fohsi, F. praefohsi, F. peripheroacuta, F. peripheroronda

Taxonomy

Citation: Fohsella robusta (Bolli, 1950)
taxonomic rank: species
Basionym: Globorotalia fohsi robusta
Synonyms:

Catalog entries: Globorotalia fohsi robusta

Type images:

Distinguishing features:
Parent taxon (Fohsella): G. peripheroronda - lenguaensis - fohsi - robusta lineage
This taxon: Like F. lobata but nearly circular outline and more convex umbilical 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


Morphology:
Test trochospiral, biconvex, umbilical side inflated , equatorial periphery almost circular; six to eight chambers in the final whorl; sutures on spiral side limbate, coalescing with the thick peripheral keel, on umbilical side radial; surface coarsely perforate; umbilicus open; aperture interiomarginal, extraumbilical-umbilical, a slit with an indistinct lip. [Kennett & Srinivasan 1983]

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

Character matrix
test outline:Circularchamber arrangement:Trochospiraledge view:Inequally biconvexaperture:Umbilical-extraumbilical
sp chamber shape:Crescenticcoiling axis:Lowperiphery:Single keelaperture border:Thin lip
umb chbr shape:Subtriangularumbilicus:Narrowperiph margin shape:Subangularaccessory apertures:None
spiral sutures:Raisedumb depth:Shallowwall texture:Smoothshell porosity:Macroperforate: >2.5µm
umbilical or test sutures:Weakly depressedfinal-whorl chambers:6-8 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology


Geographic distribution

Restricted to equatorial areas. [Kennett & Srinivasan 1983] Low latitudes [Aze et al. 2011, based on Kennett & Srinivasan (1983)]

[SCOR WG138]


Isotope paleobiology
Aze et al. 2011 ecogroup 3 - Open ocean thermocline. Based on light δ13C and relatively heavy δ18O. Sources cited by Aze et al. 2011 (appendix S3): Keller (1985); Hodell & Vayavananda (1993)

Phylogenetic relations
Gr. (F.) fohsi robusta, which is the end member of the Fohsella lineage, differs from Gr. (F.) fohsi lobata by its circular outline and more convex umbilical side. [Kennett & Srinivasan 1983]

Most likely ancestor: Fohsella lobata - at confidence level 4 (out of 5). Data source: Kennett & Srinivasan 1983, fig. 12.

Biostratigraphic distribution

Geological Range:
Last occurrence (top): within M9b subzone (11.79-13.13Ma, top in Serravallian stage). Data source: Kennett & Srinivasan 1983
First occurrence (base): at base of M9b subzone (0% up, 13.1Ma, in Serravallian stage). Data source: Wade et al. (2011), zonal marker

Plot of occurrence data:

Primary source for this page: Kennett & Srinivasan 1983, p.102

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. & Banner, F. T. (1966). The morphology, taxonomy and biostratigraphy of Globorotalia barisanensis LeRoy, Globorotalia fohsi Cushman and Ellisor, and related taxa. Micropaleontology. 12(3): 286-302. gs

Bolli, H. M. (1950a). The direction of coiling in the evolution of some Globorotaliidae. Contributions from the Cushman Foundation for Foraminiferal Research. 1(3&4): 82-89. gs

Hodell, D. A. & Vayavananda, A. (1993). Middle Miocene paleoceanography of the western equatorial Pacific (DSDP Site 289) and the evolution of Globorotalia (Fohsella). Marine Micropaleontology. 22: 279-310. gs

Keller, G. (1985). Depth stratification of planktonic foraminifers in the Miocene Ocean. In, Kennett, J. P. (ed.) The Miocene Ocean: Paleoceanography and Biogeography. GSA Memoir . 163: 1-337. gs

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

Wade, B. S., Pearson, P. N., Berggren, W. A. & Pälike, H. (2011). Review and revision of Cenozoic tropical planktonic foraminiferal biostratigraphy and calibration to the geomagnetic polarity and astronomical time scale. Earth-Science Reviews. 104: 111-142. gs


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Fohsella robusta compiled by the pforams@mikrotax project team viewed: 26-6-2024

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