pforams@mikrotax - Fohsella lobata

Citation: Fohsella lobata (Bermudez 1949)

Basionym: Globorotalia lobata Bermudez 1949

Synonyms:

Globorotalia (Fohsella) fohsi lobata [e.g. Kennett & Srinivasan 1983]
Globorotalia dominicana Bermudez - unnecessary new name prposed by Thalmann 1950

Distinguishing features:
Parent taxon (Fohsella): G. peripheroronda - lenguaensis - fohsi - robusta lineage
This taxon: Like F. fohsi but larger and with characteristic cockscomb-shaped peripheral margin

Description

Biconvex, low trochospiral, last few chambers distinctly lobulate with keel

Aperture: : Interiomarginal umbilical-extraumbilical slit with small flange-like lip [Aze 2011, based on Kennett & Srinivasan 1983]

Test low trochospiral, biconvex, equatorial periphery of the last few chambers distinctly lobulate; six to eight chambers of the final whorl, increasing rapidly in size, especially in their radial length, giving rise to a characteristic cockscomb outline; sutures on spiral side recurved, limbate coalescing into the peripheral keel, on umbilical side slightly curved to radial ; surface smooth, distinctly and uniformly perforate; umbilicus narrow; aperture interio-marginal, extraumbilical-umbilical, a slit with a small flangelike lip. [Kennett & Srinivasan 1983]

Biogeography and Palaeobiology

Restricted to equatorial areas. [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)

This species is distinguished from Gr. (F.) fohsi fohsi by its larger test size and typical cockscomb-shaped peripheral margin, a change that marks the base of Globorotalia fohsi lobata Zone of Bolli (1957).
Blow and Banner (1966) and Blow (1969) suggested that Gr. (F.) fohsi lobata and Gr. (F.) fohsi robusta may be phenotypic variants of a single form, but we consider them to be valid phylogenetic species. [Kennett & Srinivasan 1983]

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): within M9a subzone (13.13-13.41Ma, base in Serravallian stage). Data source: Wade et al. (2011), additional event; position within zone not given in table 1 of Wade et al. (2011).

References:

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

Bermudez, P. J. (1949). Tertiary smaller foraminifera of the Dominican Republic. Cushman Laboratory for Foraminiferal Research, Special Publication. 25: 1-322. 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

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

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

Miller, K. G. & Katz, M. E. (1987). Micropaleontology. 33(2): 97-149. gs

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

Thalmann, H. E. (1950). New names and homonyms in Foraminifera. Contributions from the Cushman Foundation for Foraminiferal Research. 1(3-4): 41-45. gs O

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:	Lobate	chamber arrangement:	Trochospiral	edge view:	Inequally biconvex	aperture:	Umbilical-extraumbilical
sp chamber shape:	Crescentic	coiling axis:	Low	periphery:	Single keel	aperture border:	Thin 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 lobata

Taxonomy

Description

Biogeography and Palaeobiology

Biostratigraphic distribution

References:

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