Globanomalina planocompressa


Classification: pf_cenozoic -> smooth non-spinose -> Hedbergellidae -> Globanomalina -> Globanomalina planocompressa
Sister taxa: G. archeocompressa, G. australiformis, G. chapmani, G. compressa, G. ehrenbergi, G. imitata, G. luxorensis, G. ovalis, G. planocompressa, G. planoconica, G. pseudomenardii,

Taxonomy

Citation: Globanomalina planocompressa (Shutskaya 1965)
Rank: Species
Basionym: Globorotalia planocompressa
Synonyms:
Taxonomic discussion: Although the original types are presumably lost, the meaning of this taxon seems clear from study of the Russian collections, and Blow's (1979) analysis of the species is followed herein. He based his analysis on the specimen figured by Loeblich and Tappan (1957a, pl. 40: fig. 5a-c), which became a paratype of this species when Shutskaya included this specimen in synonymy with her new species. Globanomalina planocompressa is the first member of the
planocompressa -imitata -ovalis lineage, a lineage characterized by inflated, perforate-walled chambers. [Olsson et al. 1999]

Catalog entries: Globorotalia planocompressa;

Type images:

Short diagnosis: The five chambers in the ultimate whorl increase moderately in size. The chambers are more inflated than in G. archeocompressa and globular to ovoid in shape. The pores which average 1 um at the narrowest point are evenly distributed in the chamber walls although some areas, especially on parts of the periphery, are imperforate. The wall ranges from 4 to 7 um in thickness.

NB The short diagnoses are used in the tables of daughter-taxa to act as quick summaries of the differences between e.g. species of one genus. They have initially been copied from the diagnostic characters/distinguishing features sections of the Eocene and Paleocene Atlases, they will be edited as the site is developed.

Description


Diagnostic characters: The five chambers in the ultimate whorl increase moderately in size. The chambers are more inflated than in G. archeocompressa and globular to ovoid in shape. The pores which average 1 um at the narrowest point are evenly distributed in the chamber walls although some areas, especially on parts of the periphery, are imperforate. The wall ranges from 4 to 7 um in thickness. [Olsson et al. 1999]

Character matrix

test outline:Circularcoiling axis:N/Achamber arrangement:Planispiralumbilicus:Narrow
edge view:Inequally biconvexumbilical or test sutures:Strongly depressedspiral sutures:Strongly depressedshell porosity:Finely Perforate: 1-2.5
wall texture:Smoothaperture:Umb.-extraumbilicalaperture border:Thin lipaccessory apertures:None
periphery:N/Aumb chamber shape:Inflatedsp chbr shape:Inflatedperiph margin shape:Broadly rounded
umb depth:Deepdiameter mm:0.45width mm:0.32breadth mm:-
final-whorl chambers:5.0-5.0

Biogeography and Palaeobiology


Geographic distribution: Known distribution in the northern hemisphere middle and low latitudes. [Olsson et al. 1999]
Aze et al. 2011 summary: Northern hemisphere and middle to low latitudes; based on Olsson et al. (1999)

Isotope paleobiology: Globanomalina planocompressa has ∂18O and 5'3C similar to Parasubbotina pseudobulloides, S. triloculinoides, and E. eobulloides. The species has distinctly more positive ∂18O and more negative ∂13C than Praemurica and Woodringina. [Olsson et al. 1999]
Aze et al. 2011 ecogroup 3 - Open ocean thermocline. Based on light δ13C and relatively heavy δ18O. Sources cited by Aze et al. 2011 (appendix S3): Olsson et al. (1999)

Phylogenetic relations: This species originates in Zone Pa from G. archeocompressa by the inflation of chambers and the loss of an imperforate peripheral margin. It, in turn, gives rise to G. imitata in Zone Pic. [Olsson et al. 1999]

Biostratigraphic distribution

Geological Range:
Notes: Upper Zone Pa to Zone Pic. [Olsson et al. 1999]
Last occurrence (top): within P1c subzone (62.60-63.90Ma, top in Danian stage). Data source: Olsson et al. 1999
First occurrence (base): within Pa zone (65.72-66.00Ma, base 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. 44

References:

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


Globanomalina planocompressa compiled by the pforams@mikrotax project team viewed: 29-5-2017

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