pforams@mikrotax - Globorotalia flexuosa pforams@mikrotax - Globorotalia flexuosa

Globorotalia flexuosa

Classification: pf_cenozoic -> Globorotaliidae -> Globorotalia -> tumida lineage -> Globorotalia flexuosa
Sister taxa: G. ungulata, G. flexuosa, G. tumida, G. plesiotumida, G. merotumida


Citation: Globorotalia flexuosa (Koch 1923)
taxonomic rank: species
Basionym: Pulvinulina tumida var. flexuosa Koch 1923
Taxonomic discussion: Brummer & Kucera (2022) consider G. flexuosa "to represent a morphological aberration as long as the name is applied on extant species" - however, it seems to have useful acme levels in the fossi lrecord -s ee discussion of stratigraphic range. 

Catalog entries: Pulvinulina tumida flexuosa

Type images:

Distinguishing features:
Parent taxon (tumida lineage): G. lenguaensis - merotumida - tumida - flexuosa lineage
This taxon: Like G. tumida, but anterior part of final chamber sharply bent toward the umbilicus.

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.


Test large , trochospiral, equatorial periphery oval to elongate; axial periphery acute with a heavy keel, anterior rim of the final chamber bent sharply toward umbilicus; chambers 6 to 7 in the final whorl , with the last chamber showing extreme elongation and infolding of the anterior part toward the umbilicus; spiral sutures limbate, raised, oblique merging with the keel, umbilical sutures sinuously radial, depressed; surface smooth, densely perforate, heavily pustulate on umbilical shoulders; umbilicus narrow , deep ; aperture interiomarginal, umbilical-extraumbilical, a low arch bordered by a platelike lip. [Kennett & Srinivasan 1983]

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

Character matrix
test outline:Ovatechamber arrangement:Trochospiraledge view:Inequally biconvexaperture:Umbilical-extraumbilical
sp chamber shape:Crescenticcoiling axis:Lowperiphery:Single keelaperture border:Thin flange
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:6-7 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology

Geographic distribution

Tropical. [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): D. R. M. Stewart unpublished data

Phylogenetic relations
Gr. (Gr.) tumida flexuosa is similar in all respects with Gr. (Gr.) tumida tumida except for the sharp bend of the anterior part of the final chamber toward the umbilicus.
Gr. (Gr.) tumida flexuosa differs from Globorotalia menardii neoflexuosa Srinivasan, Kennett, and Be in having narrower and more elliptical outline, less lobulate periphery, and a heavy keel. [Kennett & Srinivasan 1983]

Most likely ancestor: Globorotalia tumida - at confidence level 3 (out of 5). Data source: Kennett & Srinivasan 1983, fig 17;Stewart 2003 fig. 6.10; Aze et al. 2011, appendix 5.

Biostratigraphic distribution

Geological Range:
Notes: Upper part of Zone N18 to N21 (latest Miocene to Late Pliocene). [Kennett & Srinivasan 1983]
NB This range given by Kennett & Srinivasan is competely different to the end Pleistocene range given by Wade et al. (2011), based on Berggren et al. 1995 and ultimately Joyce et al. (1990).
Bolli & Saunders (1985, p.176) note that there is a late Pleistocene interval "largely characterized by the presence of Globorotalia tumida flexuosa as has been observed in numerous sections from the low latitude Atlantic realm. However, this subspecies is apparently controlled by environment rather than time (in low latitude Pacific sections it is present for only a brief interval in the Early Pliocene, as is the case in well Bodjonegoro-1. Java)."

Last occurrence (top): near top of PT1b subzone (89% up, 0.1Ma, in Tarantian stage). Data source: Wade et al. (2011), additional event; position within zone determined by linear interpolation from data in table 1 of Wade et al. (2011).
First occurrence (base): in lower part of PT1b subzone (34% up, 0.4Ma, in Ionian stage). Data source: Wade et al. (2011), additional event; position within zone determined by linear interpolation from data in table 1 of Wade et al. (2011).

Plot of occurrence data:

Primary source for this page: Kennett & Srinivasan 1983, p.158


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

Bé, A. W. H. & McIntyre, A. (1970). Globorotalia menardii flexuosa (Koch): An 'extinct' foraminiferal subspecies living in the northern Indian Ocean. Deep-Sea Research. 17: 595-601. gs

Berggren, W. A. et al. (1995a). Late Neogene chronology: New perspectives in high-resolution stratigraphy. Geological Society of America, Bulletin. 107(11): 1272-1287. gs

Brummer, G-J. A. & Kucera, M. (2022). Taxonomic review of living planktonic foraminifera. Journal of Micropalaeontology. 41: 29-74. gs

Joyce, J. E., Tjalsma, L. R. C. & Prutzman, J. M. (1990). High-resolution planktic stable isotope record and spectral analysis for the last 5.35 m.y: Ocean Drilling Program site 625 Northeast Gulf of Mexico. Paleoceanography. 5(4): 507-529. gs

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

Koch, R. (1923). Die jungtertiare Foraminiferenfauna von Kabu (Res. Surbaja Java). Eclogae Geologicae Helvetiae. 18: 342-357. gs

Stewart, D. R. M. I. (2003). Evolution of Neogene globorotaliid foraminifera and Miocene climate change. PhD thesis, Bristol University. 1-269. 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


Globorotalia flexuosa compiled by the pforams@mikrotax project team viewed: 18-7-2024

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