Banner's (1989) study clarified the taxonomic position of the genus Globanomalina and the type species ovalis. Banner correctly pointed out that as the number of chambers increase from 5 to 6 in the ultimate whorl the test becomes asymmetrically planispirally arranged. In addition, the aperture, which is a fairly high arch, bordered by a continuous, thin lip, migrates slightly onto the spiral side. The test walls are perforate throughout, and, although Banner described the wall as microperforate, we include G. ovalis in the normal perforate category, which contrasts with microperforate taxa (test walls with pore diameters 0.3-0.45 µm in diameter) of the Guembelitridae. As Banner (1989) pointed out in his study, Globigerina pseudoiota Homibrook (1958) should be regarded as a junior synonym of G. ovalis. The form illustrated by Blow (1979, pl.111 : fig. 5) as an intermediate between G. chapmani (Parr) and Pseudohastigerina wilcoxensis (Cushman and Ponton) is a smooth-walled, 6-chambered, nearly planispiral form that has an extraumbilical aperture extending slightly onto the dorsal side. We agree with Blow that this morphology is transitional to Pseudohastigerina, but that it is represented in the species G. ovalis. [Olsson et al. 1999]
Catalog entries: Globanomalina ovalis, Globigerina pseudoiota
Type images: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: 5-6 inflated chambers in the final whorl, very low coiling axis.
Character matrix
test outline: | Ovate | chamber arrangement: | Trochospiral | edge view: | Equally biconvex | aperture: | Umbilical-extraumbilical |
sp chamber shape: | Inflated | coiling axis: | Very low | periphery: | N/A | aperture border: | Thin lip |
umb chbr shape: | Inflated | umbilicus: | Wide | periph margin shape: | Broadly rounded | accessory apertures: | None |
spiral sutures: | Moderately depressed | umb depth: | Shallow | wall texture: | Smooth | shell porosity: | Finely Perforate: 1-2.5µm |
umbilical or test sutures: | Moderately depressed | final-whorl chambers: | 6-6 | N.B. These characters are used for advanced search. N/A - not applicable |
This species is a member of the inflated chamber, perforate walled lineage in Globanomalina. Globanomalina ovalis evolved from G. imitata in the upper part of Zone P4 by an increase in the number of chambers in the ultimate whorl from 5 to 6, a greater degree of inflation of the chambers, and the trend towards planispirality (see Plate 36: Figures 13-15). Although Berggren et al., 1967, and Banner, 1989, stated that G. ovalis derived from G. chapmani, there is a distinct difference in the wall texture between the two species that would appear to preclude a phylogenetic linkage. In the Pondicherry section of southeast India G. ovalis and G. imitata overlap morphologically. [Olsson et al. 1999]
Geographic distribution
Aze et al. 2011 summary: Northern and southern middle latitudes; based on Olsson et al. (1999)
Isotope paleobiology
Aze et al. 2011 ecogroup 2 - Open ocean mixed-layer tropical/subtropical, without symbionts; based on comparison with other species of the genus.
Phylogenetic relations
Most likely ancestor: Globanomalina imitata - at confidence level 4 (out of 5). Data source: Olsson & Hemleben 2006, fig14.1.
Likely descendants: Globanomalina luxorensis;
plot with descendants
Geological Range:
Notes: Zone P4c to Zone E1. [Olsson & Hemleben 2006]
Last occurrence (top): at top of E1 zone (100% up, 55.8Ma, in Ypresian stage). Data source: Olsson & Hemleben 2006, fig14.1
First occurrence (base): at base of P4c subzone (0% up, 57.8Ma, in Thanetian stage). Data source: Olsson et al. 1999, fig 5a
Plot of occurrence data:
Primary source for this page: Olsson et al. 1999 - Atlas of Paleocene Planktonic Foraminifera, p. 43
Banner, F. T. (1989). The nature of Globanomalina Haque, 1956. Journal of Foraminiferal Research. 19: 171-179. 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 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 Hornibrook, N. d. B. (1958). New Zealand Upper Cretaceous and Tertiary foraminiferal zones and some overseas correlations. Micropaleontology. 4: 25-38. 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. gsReferences:
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Globanomalina ovalis compiled by the pforams@mikrotax project team viewed: 7-2-2025
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