pforams@mikrotax - Chiloguembelina subtriangularis

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.

Olsson_etal_99_pl70_f01-3_f05-7.jpg

Taxonomy

Citation: Chiloguembelina subtriangularis Beckmann 1957

taxonomic rank: Species

Basionym: Chiloguembelina subtriangularis

Synonyms:

Chiloguembelina subtriangularis Beckmann, 1957:91, text-fig. 15 (39-42), pl. 21: fig. 5a,b [Paleocene, Globorotalia pusilla pusilla Zone, lower Lizard Springs Fm., Trinidad].—Said and Kerdany, 1961:331, pl. 2: fig. 6 [Paleocene, lower part of Esna Shale, Farafra Oasis, Egypt], [Olsson et al. 1999]

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:

holotype: C. subtriangularis
holotype: C. subtriangularis

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.

Description

Character matrix
test outline: Triangular chamber arrangement: Biserial edge view: Compressed aperture: Interiomarginal
sp chamber shape: Globular coiling axis: N/A periphery: N/A aperture border: Thin lip
umb chbr shape: Globular umbilicus: N/A periph margin shape: Subangular accessory apertures: None
spiral sutures: Moderately depressed umb depth: N/A wall texture: Moderately pustulose shell porosity: Microperforate: <1µm
umbilical or test sutures: Weakly depressed final-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:

Range-bar - range as quoted above, pink interval top occurs in, green interval base occurs in.
Triangles indicate an event for which a precise placement has been suggested
Histogram - Neptune occurrence data from DSDP and ODP proceedings. Pale shading <50 samples in time bin. Interpret with caution & read these notes
Taxon plotted: Chiloguembelina subtriangularis, synonyms included - Chiloguembelina subtriangularis;
See also space-time plot :: Samples map :: Parent: Chiloguembelina

Primary source for this page: Olsson et al. 1999 - Atlas of Paleocene Planktonic Foraminifera, p. 92

References:

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

Chiloguembelina subtriangularis compiled by the pforams@mikrotax project team viewed: 16-10-2024

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Short stable page link: https://mikrotax.org/pforams/index.php?id=100061 Go to Archive.is to create a permanent copy of this page - citation notes

test outline:	Triangular	chamber arrangement:	Biserial	edge view:	Compressed	aperture:	Interiomarginal
sp chamber shape:	Globular	coiling axis:	N/A	periphery:	N/A	aperture border:	Thin lip
umb chbr shape:	Globular	umbilicus:	N/A	periph margin shape:	Subangular	accessory apertures:	None
spiral sutures:	Moderately depressed	umb depth:	N/A	wall texture:	Moderately pustulose	shell porosity:	Microperforate: <1µm
umbilical or test sutures:	Weakly depressed	final-whorl chambers:	2-2	N.B. These characters are used for advanced search. N/A - not applicable