pforams@mikrotax - Chiloguembelina subtriangularis pforams@mikrotax - Chiloguembelina subtriangularis

Chiloguembelina subtriangularis

Classification: pf_cenozoic -> Guembelitrioidea -> Chiloguembelinidae -> Chiloguembelina -> Chiloguembelina subtriangularis
Sister taxa: C. adriatica, C. cubensis, C. andreae, C. ototara ⟩⟨ C. parallela, C. trinitatensis, C. wilcoxensis, C. crinita ⟩⟨ C. subtriangularis, C. midwayensis, C. morsei, C. sp.


Citation: Chiloguembelina subtriangularis Beckmann 1957
taxonomic rank: Species
Basionym: Chiloguembelina subtriangularis
Taxonomic discussion: This species is easily distinguished from other chiloguembelinids by its subtriangular test with a subangular periphery. [Olsson et al. 1999]

Catalog entries: Chiloguembelina subtriangularis

Type images:

Distinguishing features:
Parent taxon (Chiloguembelina): Test subtriangular in outline, biserial throughout or rarely with multiserial final chambers; aperture a simple arched opening at base of the final chamber, with a narrow rim on one margin and a broad collar or flange directed toward one of the flat sides of the test, lacking an infolded margin or internal plate. Rarely with multiple apertures.
This taxon: Test small, biserial with subangular periphery, subtriangular in side view. Chambers, slightly inflated,broadening though ontogeny, successive chambers slightly overlapping the previous one. Sutures nearly straight, at low angle with the growth axis. Aperture low, asymmetric arch with lip that narrows toward the center of the chamber. 

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.


Character matrix
test outline:Triangularchamber arrangement:Biserialedge view:Compressedaperture:Interiomarginal
sp chamber shape:Globularcoiling axis:N/Aperiphery:N/Aaperture border:Thin lip
umb chbr shape:Globularumbilicus:N/Aperiph margin shape:Subangularaccessory apertures:None
spiral sutures:Moderately depressedumb depth:N/Awall texture:Moderately pustuloseshell porosity:Microperforate: <1┬Ám
umbilical or test sutures:Weakly depressedfinal-whorl chambers:2-2 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology

Geographic distribution

Reported from the low to middle
latitudes worldwide. [Olsson et al. 1999]

Isotope paleobiology
No data available. [Olsson et al. 1999]

Phylogenetic relations
Beckmann (1957) suggested that C.
subtriangularis descended from C. midwayensis during the Paleocene. [Olsson et al. 1999]

Most likely ancestor: Chiloguembelina midwayensis - at confidence level 4 (out of 5). Data source: Olsson et al. 1999, f6.

Biostratigraphic distribution

Geological Range:
Notes: Zone Pic to Zone P3. [Olsson et al. 1999]
Last occurrence (top): within P3b subzone (60.73-61.33Ma, top in Selandian stage). Data source: Olsson et al. 1999
First occurrence (base): within P1c subzone (62.60-63.90Ma, 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. 92


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


Chiloguembelina subtriangularis compiled by the pforams@mikrotax project team viewed: 20-6-2024

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