pforams@mikrotax - Fohsella fohsi

Citation: Fohsella fohsi (Cushman & Ellisor, 1939)

Basionym: Globorotalia fohsi Cushman & Ellisor, 1939

Synonyms:

Globorotalia (Fohsella) fohsi fohsi [e.g. Kennett & Srinivasan 1983]
Globorotalia barisanensis LeRoy 1939 [see Blow & Banner 1966]

Distinguishing features:
Parent taxon (Fohsella): G. peripheroronda - lenguaensis - fohsi - robusta lineage
This taxon: Like F. praefohsi, but with a distinct keel throughout the entire final whorl.

Description

Biconvex, low trochospiral, equatorial periphery lobulate with distinct keel

Aperture: Interiomarginal umbilical-extraumbilical low arch with prominent lip [Aze 2011, based on Kennett & Srinivasan 1983]

Test low trochospiral, equatorial periphery slightly lobulate, axial periphery acute with a distinct keel throughout; umbilical side slightly more convex than spiral; chambers compressed, six to eight in the final whorl, increasing uniformly in size; sutures on spiral side curved and slightly raised, on umbilical side slightly curved to radial, depressed; surface smooth, uniformly perforate; umbilicus narrow; aperture interiomarginal, extraumbilical-umbilical, with a low arch, bordered by a lip. [Kennett & Srinivasan 1983]

Biogeography and Palaeobiology

Tropical to warm subtropical. [Kennett & Srinivasan 1983] Low latitudes [Aze et al. 2011, based on Kennett & Srinivasan (1983)]

[SCOR WG138]

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); Pearson & Shackleton (1995)

Gr. (F.) fohsi fohsi differs from its ancestor, Gr. (F.) praefohsi, in exhibiting a distinct keel throughout the entire final whorl, and from the more advanced forms, Gr. (F.) fohsi lobata and Gr. (F.) fohsi robusta, in its smaller size and usual lack of limbate sutures. This species grades into Gr. (F.) fohsi lobata by undergoing a rapid increase in size of successive chambers in radial length and a tendency to develop a cockscomb-shaped peripheral margin. [Kennett & Srinivasan 1983]

Biostratigraphic distribution

Geological Range:
Notes: The evolutionary first appearance of Gr. (F.) fohsi fohsi marks the base of Zone N12, or of Zone M9 of Wade et al. (2011)
Last occurrence (top): at top of M9 zone (100% up, 11.8Ma, in Serravallian stage). Data source: Wade et al. (2011), zonal marker
First occurrence (base): at base of M9 zone (0% up, 13.4Ma, in Serravallian stage). Data source: Wade et al. (2011), zonal marker

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

Cushman, J. A. & Ellisor, A. C. (1939). New species of foraminifera from the Oligocene and Miocene. Contributions from the Cushman Laboratory for Foraminiferal Research. 15: 1-14. 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

King, D. J., Wade, B. S., Liska, R. D. & Miller, C. G. (2020). A review of the importance of the Caribbean region in Oligo-Miocene low latitude planktonic foraminiferal biostratigraphy and the implications for modern biogeo- chronological schemes. Earth-Science Reviews. 202: 1-27. gs

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

Pearson, P. N. & Shackleton, N. J. (1995). Neogene multispecies planktonic foraminifer stable isotope record, Site 871, Limalok Guyot. Proceedings of the Ocean Drilling Program, Scientific Results. 144: 401-410. gs

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

test outline:	Ovate	chamber arrangement:	Trochospiral	edge view:	Inequally biconvex	aperture:	Umbilical-extraumbilical
sp chamber shape:	Crescentic	coiling axis:	Low	periphery:	Single keel	aperture border:	Thick lip
umb chbr shape:	Subtriangular	umbilicus:	Narrow	periph margin shape:	Subangular	accessory apertures:	None
spiral sutures:	Raised	umb depth:	Shallow	wall texture:	Smooth	shell porosity:	Macroperforate: >2.5µm
umbilical or test sutures:	Weakly depressed	final-whorl chambers:	6-8	N.B. These characters are used for advanced search. N/A - not applicable

Fohsella fohsi

Taxonomy

Description

Biogeography and Palaeobiology

Biostratigraphic distribution

References:

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