pforams@mikrotax - Globanomalina archeocompressa pforams@mikrotax - Globanomalina archeocompressa

Globanomalina archeocompressa


Classification: pf_cenozoic -> Globanomalinidae -> Globanomalina -> Globanomalina archeocompressa
Sister taxa: G. australiformis, G. luxorensis, G. ovalis, G. imitata, G. planocompressa ⟩⟨ G. planoconica, G. chapmani, G. pseudomenardii, G. ehrenbergi, G. compressa, G. archeocompressa, G. sp.

Taxonomy

Citation: Globanomalina archeocompressa (Blow 1979)
Taxonomic rank: species
Basionym: Globorotalia (Turborotalia) archeocompressa
Synonyms:
Taxonomic discussion: This is the first species of the genus Globanomalina to appear in the earliest Danian. In morphology it is very similar to its ancestral species, Hedbergella holmdelensis Olsson, 1964. It differs, however, in that fine pustules are confined to the umbilical and inner spiral areas of the test rather than being sparsely distributed over the entire wall of the test as in H. holmdelensis. In early species of Globanomalina the chamber walls are smoother and generally free of numerous pustules. Pustules are more numerous on the chamber walls of G. pseudomenardii, but these are enhanced by gametogenesis. The possibility that the "pustules" in G. archeocompressa are of similar origin needs further investigation. The chambers are somewhat more inflated and the equatorial peripheral margin is more lobulate in H. holmdelensis. Another difference lies in the ontogeny of each species. Six to 7 chambers make up the
penultimate whorl in H. holmdelensis, a chamber arrangement typical of ancestral species of Hedbergella in the Cretaceous. In G. archeocompressa, the penultimate whorl is reduced to 5 chambers, which is typical of Globanomalina. The imperforate peripheral margin is a primary derived taxonomic character from H. holmdelensis and is present throughout the archeocompressa lineage. [Olsson et al. 1999]

Catalog entries: Globorotalia (Turborotalia) archeocompressa

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: 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.

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

Character matrix
test outline:Ovatechamber arrangement:Trochospiraledge view:Concavo-convexaperture:Umbilical-extraumbilical
sp chamber shape:Inflatedcoiling axis:Lowperiphery:N/Aaperture border:Thick flange
umb chbr shape:Inflatedumbilicus:Wideperiph margin shape:Moderately roundedaccessory apertures:None
spiral sutures:Moderately depressedumb depth:Shallowwall texture:Smoothshell porosity:Finely Perforate: 1-2.5µm
umbilical or test sutures:Moderately depressedfinal-whorl chambers:5-6 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology


Geographic distribution

Western equatorial Pacific Ocean, coastal Gulf of Mexico, and South Atlantic Ocean (DSDP Site 356). [Olsson et al. 1999]
Aze et al. 2011 summary: Western equatorial pacific, Gulf of Mexico, south Atlantic Ocean; based on Olsson et al. (1999)

Isotope paleobiology
No data available. [Olsson et al. 1999]
Aze et al. 2011 ecogroup 3 - Open ocean thermocline; based on comparison with other species of the genus.

Phylogenetic relations
This species evolved from Hedbergella holmdelensis in late Biochron P0. [Olsson et al. 1999]

Biostratigraphic distribution

Geological Range:
Notes: Upper Zone P0 to Zone Plb. Due to the very small size and rare occurrence of this species the upper range is not yet reliably established. [Olsson et al. 1999]
Last occurrence (top): at top of P1b subzone (100% up, 63.9Ma, in Danian stage). Data source: Olsson et al. 1999
First occurrence (base): in mid part of P0 zone (50% up, 66Ma, in Danian stage). Data source: Olsson et al. 1999

Plot of occurrence data:

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

References:

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

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


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Globanomalina archeocompressa compiled by the pforams@mikrotax project team viewed: 7-2-2025

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