pforams@mikrotax - Globigerinoides obliquus

Citation: Globigerinoides obliquus Bolli, 1957

Basionym: Globigerinoides obliqua Bolli, 1957

Synonyms:

Globigerinoides obliquus Bolli, 1957:113, pl. 25, figs. 10a-c [middle Miocene Globorotalia mayeri Zone, Lengua Fm., near Lengua Settlement, southern Trinidad].— Jenkins, 1971:177, pl. 21, figs. 613-615 [Pliocene-Pleistocene, Palliser Bay Section, Sample N165/554, New Zealand].—Kennett and Srinivasan, 1983:56, pl. 11, figs. 7-9 [middle Miocene Zone N9, DSDP Site 289, Ontong Java Plateau, western Pacific Ocean].—Spezzaferri, 1994:38, pl. 14, figs. 2a-c [lower Miocene Subzone N4b, ODP Site 709C, equatorial Indian Ocean].
Globigerinoides obliquus obliquus Bolli and Saunders, 1985, fig. 20(12) [holotype re-illustrated].
Globigerinoides fournieri Bermúdez, 1961:1228-1229, pl. 12, fig. 5a, 5b, [lower Miocene Globigerinita dissimilis Zone, Bissex Hill, Barbados].

[Spezzaferri et al. 2018]

Taxonomic discussion:

At the beginning of its range the last chamber of this species is only slightly oblique and compressed. It acquires the morphology typical of the holotype only during the Miocene starting from Zone M3 (Plate 9.6, Figs. 1-3). Kennett and Srinivasan (1983) and Chaisson and Leckie (1993) proposed G. altiaperturus as the ancestor of G. obliquus by lateral elongation of the aperture preceding the lateral compression of the chambers. This relationship is retained here.

Globigerinoides fournieri Bermúdez described from the Globigerinita dissimilis Zone is placed in synonymy with G. obliquus because its holotype (not shown) resembles the holotype of G. obliquus with the exception of the aberrant last chamber.

[Spezzaferri et al. 2018]

Distinguishing features:
Parent taxon (Globigerinoides): Supplementary apertures, with ruber/sacculifer-type spinose wall texture
This taxon: Obliquely compressed final chamber.

Description

Globigerinoides obliquus differs from other Globigerinoides with a similar outline (e.g., G. neoparawoodi) by having a more quadrangular profile due to the compressed oblique last chamber and generally ovate-reniform chambers in the last whorl instead of globular, and from G. bollii by its larger aperture as well as the oblique last chamber.

[Spezzaferri et al. 2018]

Low trochospiral consisting of about 3 whorls, quadrangular in outline and slightly lobate. Subspherical to ovate chambers; 4 in the last whorl gradually increasing in size. The last chamber is laterally compressed and oblique. Sutures depressed, straight to slightly curved on both sides. Umbilicus fairly open and deep. Primary aperture umbilical, medium-sized high and wide arch. One small to moderately high supplementary aperture is opposite to the primary aperture. [Spezzaferri et al. 2018]

Normal perforate, spinose, ruber/sacculifer-type wall. [Spezzaferri et al. 2018]

Maximum diameter of holotype 0.5 mm. [Spezzaferri et al. 2018]

Biogeography and Palaeobiology

Cosmopolitan, it is more common at middle and high latitudes. [Spezzaferri et al. 2018]

Chaisson and Ravelo (1997) described this species as mixed-layer dweller. Nikolaev and others (1998) identified a subsurface habitat niche from 25 to 75 m depth for the late Miocene and from 25 to 100 m depth for the Pliocene. [Spezzaferri et al. 2018]

Globigerinoides obliquus probably evolved from G. altiaperturus at the very end of Subzone M1b by developing lateral elongation of the aperture and compression of chambers. [Spezzaferri et al. 2018]

Biostratigraphic distribution

Geological Range:
Notes: From the top of Subzone M1b (Spezzaferri, 1994) to the Pleistocene (Kennett and Srinivasan, 1983). [Spezzaferri et al. 2018]
Last occurrence (top): in mid part of PT1a subzone (46% up, 1.3Ma, in Calabrian 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): within M1b subzone (21.12-22.44Ma, base in Aquitanian stage). Data source: Kennett & Srinivasan 1983

Primary source for this page: Spezzaferri et al. 2018 - Olig Atlas chap.9 p.284; Kennett & Srinivasan 1983, p.56

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. (1961). Contribucion al estudio de las Globigerinidea de la region Caribe-Antillana (Paleoceno-Reciente). Editorial Sucre, Caracas. (3): 1119-1393. gs

Bolli, H. M. & Saunders, J. B. (1985). Oligocene to Holocene low latitude planktic foraminifera. In, Bolli, H. M., Saunders, J. B. & Perch-Neilsen, K. (eds) Plankton Stratigraphy. Cambridge University Press, Cambridge, UK 155-262. gs

Bolli, H. M. (1957b). Planktonic foraminifera from the Oligocene-Miocene Cipero and Lengua formations of Trinidad, B.W.I. In, Loeblich, A. R. , Jr., Tappan, H., Beckmann, J. P., Bolli, H. M., Montanaro Gallitelli & E. Troelsen, J. C. (eds) Studies in Foraminifera. U.S. National Museum Bulletin . 215: 97-123. gs

Chaisson, W. P. & Ravelo, A. C. (1997). Changes in upper water-column structure at Site 925, late Miocene-Pleistocene: Planktonic foraminifer assemblage and isotopic evidence. Proceedings of the Ocean Drilling Program, Scientific Results. 154: 255-268. gs

Jenkins, D. G. (1971). New Zealand Cenozoic Planktonic Foraminifera. New Zealand Geological Survey, Paleontological Bulletin. 42: 1-278. 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

Lam, A. & Leckie, R. M. (2020a). Late Neogene and Quaternary diversity and taxonomy of subtropical to temperate planktic foraminifera across the Kuroshio Current Extension, northwest Pacific Ocean. Micropaleontology. 66(3): 177-268. gs

Nikolaev, S. D., Oskina, N. S., Blyum, N. S. & Bubenshchikova, N. V. (1998). Neogene-Quaternary variations of the ‘Pole-Equator’ temperature gradient of the surface oceanic waters in the North Atlantic and North Pacific. Global and Planetary Change. 18: 85-11. gs

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

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

Spezzaferri, S. (1994). Planktonic foraminiferal biostratigraphy and taxonomy of the Oligocene and lower Miocene in the oceanic record. An overview. Palaeontographia Italica. 81: 1-187. gs

Spezzaferri, S., Olsson, R. K. & Hemleben, C. (2018c). Taxonomy, biostratigraphy, and phylogeny of Oligocene to Lower Miocene Globigerinoides and Trilobatus. In, Wade, B. S., Olsson, R. K., Pearson, P. N., Huber, B. T. & Berggren, W. A. (eds) Atlas of Oligocene Planktonic Foraminifera. Cushman Foundation for Foraminiferal Research, Special Publication . 46(Chap 9): 269-306. gs

test outline:	Lobate	chamber arrangement:	Trochospiral	edge view:	Equally biconvex	aperture:	Umbilical
sp chamber shape:	Globular	coiling axis:	Low-moderate	periphery:	N/A	aperture border:	N/A
umb chbr shape:	Globular	umbilicus:	Wide	periph margin shape:	Broadly rounded	accessory apertures:	Sutural
spiral sutures:	Strongly depressed	umb depth:	Deep	wall texture:	Cancellate	shell porosity:	Macroperforate: >2.5µm
umbilical or test sutures:	Strongly depressed	final-whorl chambers:	4-4	N.B. These characters are used for advanced search. N/A - not applicable

Globigerinoides obliquus

Taxonomy

Description

Biogeography and Palaeobiology

Biostratigraphic distribution

References:

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