pforams@mikrotax - Globanomalina luxorensis

Citation: Globanomalina luxorensis (Nakkady 1950)

Synonyms:

Anomalina luxorensis Nakkady, 1950:691, pl. 90: figs. 39-41 [upper Paleocene, Esna Shale, Abu Durba, Western Sinai, Egypt].—Nakkady, 1959:465, pl. 5: fig. 1a-c [upper Paleocene, Gabal Um Elghanayem, Kharga Oasis, Western Desert, Egypt].
Globanomalina luxorensis (Nakkady)._ Speijer and Samir, 1997:53 (partim, not pl. 1: fig. 6a-c), pl. 1: figs. 4a-5c [lower Eocene, 4a-c, Gebel Aweina, Egypt; 5a-c, Gebel Duwi, Egypt]; pl. 2: figs. 1a-4c [lower Eocene, 1a-c, Pyramidal Hill, Egypt; 2a-c, Darb Daga; 3a-4c, Gebel Aweina, Egypt].
Pseudohastigerina wilcoxensis (Cushman and Ponton).— Berggren, Olsson, and Reyment, 1967:278 (partim), text-fig. 2: d-f, m-r [lower Eocene Zone P6, Manasquan Fm., New Jersey].—Stainforth and others, 1975:243, fig. 99: 6a-c (reillustration of Berggren and others, 1967, text-fig. 2: p-r).—Stott and Kennett, 1990:560, pl. 5: figs. 5, 6 [lower Eocene Zone AP6, ODP Hole 690B, Maud Rise, Antarctic Ocean]. [Not Cushman and Ponton, 1932.]
Globorotalia (Turborotalia) chapmani (Parr).—Blow, 1979:1059 (partim, not pl. 116: fig. 2), pl. 116: figs. 1, 3-5 [lower Eocene Zone P7, Kilwa area, Tanzania]. [Not Parr, 1938.]
Globorotalia (Turborotalia) sp. Blow, 1979:1061, pl. 111: fig. 5 [lower Eocene Zone P7, Moogli Mudstones, Kagua, Papua] [recorded as ex interc G. (T.) chapmani and Pseudohastigerina wilcoxensis].

Taxonomic discussion: Globanomalina luxorensis has been a poorly known species since it was first described. This may, in part, be due to its limited occurrence and abundance in the stratigraphic record and, perhaps, to its having been overlooked or included in Globanomalina chapmani, Globanomalina ovalis Haque, 1956, or Pseudohastigerina wilcoxensis. Banner (1989) concluded that G. luxorensis could be separated from G. ovalis, although he earlier (Banner, 1982) had considered G. luxorensis as the senior synonym of G. ovalis He regarded G. luxorensis as the immediate ancestor of P. wilcoxensis. Recently, Speijer and Samir (1997) noted the association of G. luxorensis with the negative ∂13C excursion in the middle part of Zone P5 (of Berggren and others, 1995), which they suggested as the point for marking the boundary between the Paleocene and the Eocene in a Global Stratotype Section and Point (GSSP). However, they concluded, in contrast to Banner (1989), that G. ovalis was a junior synonym of G. luxorensis and found that in Egypt G. luxorensis was extremely rare below the ∂13C excursion. We would agree with Banner that the two species can be separated, but part of the confusion appears to be due to poor
preservation (see Banner, 1989) and to lack of sufficient specimens below the ∂13C excursion. Globanomalina ovalis is common in Zone P4 in southern India (Olsson and others, 1999), which suggests that the species was common in the Indian Ocean region, and records of the species in New Zealand indicate its widespread distribution in the late Paleocene.
Globanomalina ovalis usually has 5 chambers in the ultimate whorl in contrast to G. luxorensis which usually has 6-7 chambers in the ultimate whorl. Occasionally, 6-chambered forms and 5-chambered forms are found in assemblages of each species, respectively (see Speijer and Samir, pl 2, figs. 2a-c as an example). The chambers in G. ovalis in edge view are oval in shape, and wider than high. Because of this, the chambers tend to extend over the spiral side presenting a planispiral appearance and, as Banner (1989) noted, the spiral “side becomes incompletely evolute and slightly concave in shape” (p. 177). The aperture, however, only extends extraumbilically to the medium point of the axial periphery, in contrast to G. luxorensis where the aperture extends slightly over the axial periphery but not to the trace of the spiral suture. In edge view the chambers in G. luxorensis are more globular, equidimensional, or even slightly compressed. Given these morphological criteria the morphotype recorded as ex interc G. (T.) chapmani Parr and Pseudohastigerina wilcoxensis (Cushman and Ponton) by Blow (1979, pl. 111: fig. 5) is more appropriately placed in G. luxorensis rather than in G. ovalis (as recorded by Olsson and others, 1999). [Olsson & Hemleben 2006]

Distinguishing features:
Parent taxon (Globanomalina): Very low trochospiral; 5-6 chambers in final whorl; chamber-shape variable.
Aperture interiomarginal, umbilical-extraumbilical, arch with narrow lip.
Wall smooth, normally perforate, pustules in some species.
This taxon: Test very low trochospiral. Chambers globular. Axial periphery rounded. Aperture arched, extending over axial periphery to spiral side, but not to the trace of the spiral suture.

Description

Test very low trochospiral, compressed, tightly coiled, oval in outline, slightly lobulate; chambers inflated, globular; in umbilical view normally 6 to 7 chambers in ultimate whorl, increasing rapidly in size, sutures moderately depressed, straight to slightly curved, umbilicus small, circular in shape; in spiral view 6 to 7, occasionally 5 or up to 8, chambers in ultimate whorl, increasing rapidly in size, sutures moderately depressed, straight to slightly curved, inner whorl of chambers depressed, evolute to partly involute; in edge view primary aperture an oval, umbilical extraumbilical high arch bordered by a narrow lip which extends slightly onto the spiral side but not to the spiral suture; test compressed with a rounded periphery; peripheral margin perforate. [Olsson & Hemleben 2006]

Smooth, normal perforate. [Olsson & Hemleben 2006]

Maximum diameter of holotype 0.25 mm, thickness 0.15 mm. [Olsson & Hemleben 2006]

Biogeography and Palaeobiology

Global in low to mid latitudes. [Olsson & Hemleben 2006]
Aze et al. 2011 summary: Low to middle latitudes; based on Olsson & Hemleben (2006)

Our data show relatively negative oxygen values that suggest a shallow habitat above the thermocline (R. K. Olsson, unpublished data). [Olsson & Hemleben 2006]
Aze et al. 2011 ecogroup 2 - Open ocean mixed-layer tropical/subtropical, without symbionts. Based on _¹³C lighter than species with symbionts; also with relatively light _¹⁸O. Sources cited by Aze et al. 2011 (appendix S3): Olsson & Hemleben (2006)

Globanomalina luxorensis evolved from G. ovalis by an increase of number of chambers in the final whorl, development of more globular equidimensional chambers, and by the migration of the aperture slightly over the axial periphery onto the spiral side. In turn, G. luxorensis gave rise to Pseudohastigerina wilcoxensis through the development of an equatorial aperture and a planispiral test. The species is the end-member of the Globanomalina imitata -G. ovalis-G. luxorensis lineage which led to the genus Pseudohastigerina. [Olsson & Hemleben 2006]

Biostratigraphic distribution

Geological Range:
Notes: Zone P5 to top of Zone E3. [Olsson & Hemleben 2006]
Last occurrence (top): at top of E2 zone (100% up, 55.2Ma, in Ypresian stage). Data source: Olsson & Hemleben 2006, fig14.1
First occurrence (base): in upper part of P5 zone (70% up, 56.3Ma, in Thanetian stage). Data source: Olsson & Hemleben 2006, fig14.1

Primary source for this page: Olsson & Hemleben 2006 - Eocene Atlas, chap. 14, p. 415

References:

Banner, F. T. (1982). A classification and introduction to the Globigerinacea. In, Banner, F. T. & Lord, A. R. (eds) Aspects of Micropaleontology (papers presented to Professor Tom Barnard). Allen and Unwin, London 142-239. gs

Banner, F. T. (1989). The nature of Globanomalina Haque, 1956. Journal of Foraminiferal Research. 19: 171-179. gs

Berggren, W. A., Olsson, R. K. & Reyment, R. A. (1967). Origin and development of the foraminiferal genus Pseudohastigerina Banner and Blow, 1959. Micropaleontology. 13(3): 265-288. gs

Berggren, W. A., Kent, D. V., Swisher, I. , C. C. & Aubry, M. -P. (1995b). A revised Cenozoic geochronology and chronostratigraphy. In, Berggren, W. A., Kent, D. V., Aubry, M. -P. & Hardenbol, J. (eds) Geochronology, Time Scales and Global Stratigraphic Correlations. SEPM (Society for Sedimentary Geology) Special Publication No. 54, 129-212. gs

Blow, W. H. (1979). The Cainozoic Globigerinida: A study of the morphology, taxonomy, evolutionary relationships and stratigraphical distribution of some Globigerinida (mainly Globigerinacea). E. J. Brill, Leiden. 2: 1-1413. gs

Cushman, J. A. & Ponton, G. M. (1932a). An Eocene foraminiferal fauna of Wilcox age from Alabama. Contributions from the Cushman Laboratory for Foraminiferal Research. 8(3): 51-72. gs

Haque, A. F. M. M. (1956). The smaller foraminifera of the Ranikot and the Laki of the Nammal gorge, Salt Range. Memoir of the Pakistan Geological Survey. 1: 1-300. gs

Nakkady, S. E. (1950). A new foraminiferal fauna from the Esna shales and Upper Cretaceous chalk of Egypt. Journal of Paleontology. 24(6): 675-692. gs

Nakkady, S. E. (1951). Zoning the Mesozioic-Cenozoic trasition of Egypt by the Globorotaliidae. Bulletin of the Faculty of Science. 45-58. gs

Nakkady, E. (1959). Biostratigraphy of the Um Elghanayem section, Egypt. Micropaleontology. 5: 453-472. gs

Olsson, R. K. & Hemleben, C. (2006). Taxonomy, biostratigraphy, and phylogeny of Eocene Globanomalina, Planoglobanomalina n. gen and Pseudohastigerina. In, Pearson, P. N., Olsson, R. K., Hemleben, C., Huber, B. T. & Berggren, W. A. (eds) Atlas of Eocene Planktonic Foraminifera. Cushman Foundation for Foraminiferal Research, Special Publication . 41(Chap 14): 413-432. gs O

Olsson, R. K., Hemleben, C., Berggren, W. A. & Huber, B. T. (1999). Atlas of Paleocene Planktonic Foraminifera. Smithsonian Institution Press, Washington, DC. (85): 1-252. gs

Parr, W. J. (1938). Upper Eocene Foraminifera from Deep Borings in King's Park, Perth, Western Australia. Journal of the Royal Society of Western Australia. 24: 69-101. gs

Speijer, R. P. & Samir, A. M. (1997). Globanomalina luxorensis, a Tethyan biostratigraphic marker of latest Paleocene global events. Micropaleontology. 43: 51-62. gs

Stainforth, R. M., Lamb, J. L., Luterbacher, H., Beard, J. H. & Jeffords, R. M. (1975). Cenozoic planktonic foraminiferal zonation and characteristics of index forms. University of Kansas Paleontological Contributions, Articles. 62: 1-425. gs O

Stott, L. D. & Kennett, J. P. (1990). The Paleoceanographic and Paleoclimatic signature of the Cretaceous/Paleogene boundary in the Antarctic: Stable isotopic results from ODP Leg 113. Proceedings of the Ocean Drilling Program, Scientific Results. 113: 829-848. gs

test outline:	Subcircular	chamber arrangement:	Trochospiral	edge view:	Compressed	aperture:	Umbilical-extraumbilical
sp chamber shape:	Inflated	coiling axis:	Very low	periphery:	N/A	aperture border:	Thin lip
umb chbr shape:	Inflated	umbilicus:	Narrow	periph margin shape:	Broadly rounded	accessory apertures:	N/A
spiral sutures:	Strongly depressed	umb depth:	Shallow	wall texture:	Smooth	shell porosity:	Finely Perforate: 1-2.5µm
umbilical or test sutures:	Strongly depressed	final-whorl chambers:	6-7	N.B. These characters are used for advanced search. N/A - not applicable

Globanomalina luxorensis

Taxonomy

Description

Biogeography and Palaeobiology

Biostratigraphic distribution

References:

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