Globanomalina


Classification: pf_cenozoic -> Globanomalidae -> Globanomalina
Sister taxa: Globanomalina, Muricohedbergella, Planoglobanomalina, Pseudohastigerina, Turborotalia,
Daughter taxa: - divided into two main lineage groups and within these ordered by FO (blue => in age window 0-300Ma)
lineage group B - inflated chambers, perforate walls
Test small. Final whorl with 4 low conical chambers and an acute axial periphery. Axial periphery imperforate, becoming thickened on the last chambers.
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.
5-6 inflated chambers in the final whorl, very low coiling axis.
Test small. Final whorl with 4-4½ (rarely 5) inflated ovoid chambers. Aperture a high umbilical-extraumbilical arch with thin continuous lip.
5 chambers in the final whorl, increasing moderately in size. The chambers are more inflated than in G. archeocompressa and globular to ovoid.
lineage group A - compressed tests, imperforate margin
Test small highly compressed, with well-developed, thickened, imperforate peripheral margin. Final whorl with 5-6 (rarely 7) chambers, equatorial periphery rounded becoming lobulate. Aperture high umbilical-extraumbilical arch with thin, continuous lip.
Test compressed, periphery pinched with a thickened imperforate band. 5-6 rapidly enlarging chambers in final whorl.
Test spiroconvex with distinct keel & sharply-angled axial periphery. Umbilicus narrow. 5 (rarely 6) chambers in final whorl.
Test compressed, smooth-walled, chambers moderately increasing in size. Periphery pinched with a thickened imperforate margin (faint keel). 5-5½ chambers in final whorl.
Test small, 5 chambered, with moderately angular axial periphery, and with an imperforate peripheral margin that is moderately to strongly developed. Aperture a low, umbilical-extraumbilical arch, with a narrow well-defined lip.
Test very small (<130 µm), flattened, with the spiral side nearly flat. Axial periphery rounded with slightly conical chambers. Final whorl with 5-6, chambers that increase very gradually in size. Umbilicus shallow and broad, open to the previous chambers. Aperture umbilical-extraumbilical, broad, low arch with narrow lip.
Specimens which cannot be assigned to established species

Taxonomy

Citation: Globanomalina Haque, 1956
Rank: Genus
Type species: Globanomalina ovalis Haque, 1956
Synonyms:
Taxonomic discussion: Banner's 1989 study of Globanomalina clarified its taxonomic status, clearly distinguishing the genus from the planispiral Pseudohastigerina, which Loeblich and Tappan (1988) regarded as a junior synonym of this genus. Banner emended the genus to clearly separate it from Pseudohastigerina and discussed its evolutionary relationship with this genus. He, however, regarded Globanomalina as having a microperforate wall with low, bluntly margined perforation pits. His observations appear to be based on poorly preserved specimens with corroded and recrystallized walls. All of the species of Globanomalina included in this atlas are normal perforate. Banner's observation of perforation pits is, however, correct, but as he pointed out, they are not to be confused with a cancellate wall. Globanomalina is herein emended to include the smooth-walled species of the Paleocene, which are members of two distinct lineages, one with an imperforate margin that leads to the carinate species G. pseudomenardii and one with a perforate margin that leads to the planispiral genus Pseudohastigerina. [Olsson et al. 1999]

Catalog entries: Globanomalina; Pseudomenardella;

Type images:

Distinguishing features: 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.

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.

Description


Diagnostic characters: Test very low trochospiral with 12-15 chambers, with 5-6 chambers in ultimate whorl; chambers vary from globular to ovoid to low conical in shape. Aperture interiomarginal, umbilical-extraumbilical, a moderately high arch bordered by narrow lip that may broaden slightly towards umbilicus; aperture may extend slightly onto spiral side. Umbilicus small, generally deep. Wall normal perforate, smooth, but may be covered with pustule growth in some species, particularly in umbilical area. Peripheral margin either perforate, an imperforate band, or keeled. [Olsson et al. 1999]

Biogeography and Palaeobiology

Most likely ancestor: Muricohedbergella - at confidence level 3 (out of 5). Data source: Olsson et al. 1999 - fig 5a, discussion of G. archeocompressa.
Likely descendants: Planoglobanomalina; Pseudohastigerina; Turborotalia;

Biostratigraphic distribution

Geological Range:
Last occurrence (top): in upper part of Lutetian Stage (67% up, 43.4Ma, in Lutetian stage). Data source: Total of range of species in this database
First occurrence (base): within Danian Stage (61.61-66.04Ma, base in Danian stage). Data source: Total of range of species in this database

Plot of occurrence data:

Primary source for this page: Olsson et al. 1999 - Atlas of Paleocene Planktonic Foraminifera, p. 37

References:

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

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.

Loeblich, A.R. & Tappan, H., (1988). Foraminiferal Genera and Their Classification (Volume I-II)Van Nostrand Reinhold Co., New York, 1059 pp.

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


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Globanomalina compiled by the pforams@mikrotax project team viewed: 15-12-2018

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