Chiloguembelina parallela

Classification: pf_cenozoic -> microperforate -> Chiloguembelinidae -> Chiloguembelina -> Chiloguembelina parallela
Sister taxa: C. cubensis, C. ototara, C. parallela, C. trinitatensis, C. wilcoxensis, C. crinita, C. subtriangularis, C. midwayensis, C. morsei, C. sp.,


Citation: Chiloguembelina parallela Beckmann 1957
Rank: Species
Basionym: Chiloguembelina parallela
Taxonomic discussion: The holotype of C. parallela (Pl.16.3, Figs. 11-12) shows the rapidly tapering test and centered, highly arched aperture that are characteristic of this species. Despite these distinctive features this species has not been reported outside of Trinidad, perhaps because it has been overlooked. [Huber et al. 2006]

Catalog entries: Chiloguembelina parallela;

Type images:

Short diagnosis: Differs from other chiloguembelinids by its short, thick test that tapers rapidly toward its base and its centrally located, symmetrical, high and narrow aperture.

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.


Diagnostic characters: Differs from other chiloguembelinids by its short, thick test that tapers rapidly toward its base and its centrally located, symmetrical, high and narrow aperture. [Huber et al. 2006]

Wall type: Microperforate, finely pustulose, lacking pore mounds or striae. [Huber et al. 2006]

Test morphology: Test short, rapidly tapering, periphery rounded rather than compressed; chambers biserial, increasing moderately in size, globular, sutures moderately depressed, slightly oblique toward apical axis; aperture a high, narrow, and symmetrical arch bordered by two parallel lateral flanges, occasionally covered by irregularly shaped terminal chamber. [Huber et al. 2006]

Size: Holotype (USNM 5780) length 0.12 mm, width 0.11 mm, breadth 0.07 mm. [Huber et al. 2006]

Character matrix

test outline:Subtriangularchamber arrangement:Biserialedge view:Equally biconvexaperture:Terminal
umb chamber shape:N/Acoiling axis:N/Aperiphery:N/Aaperture border:Thick flange
sp chbr shape:Inflatedumbilicus:N/Aperiph margin shape:Broadly roundedaccessory apertures:None
umbilical or test sutures:Moderately depressedumb depth:N/Awall texture:Finely pustuloseshell porosity:Microperforate: <1┬Ám
spiral sutures:N/Adiameter mm:0.12width mm:0.11breadth mm:0.07
final-whorl chambers:2.0-2.0

Biogeography and Palaeobiology

Geographic distribution: This species has not been reported outside of Trinidad. [Huber et al. 2006]

Isotope paleobiology: No data are available. [Huber et al. 2006]

Phylogenetic relations: According to Beckmann (1957), C. parallela probably descended from Chiloguembelina crinita during the early Eocene. [Huber et al. 2006]

Most likely ancestor: Chiloguembelina trinitatensis - at confidence level 4 (out of 5). Data source: Huber et al. 2006, f16.2.

Biostratigraphic distribution

Geological Range:
Notes: Lower Eocene Zone E3 to middle Zone E4. Beckmann (1957) suggested that C. parallela is a good index marker for the lower Eocene as it has a short range within the Globorotalia rex Zone in the upper Lizard Springs Fm. of Trinidad. [Huber et al. 2006]
Last occurrence (top): in mid part of E4 zone (50% up, 53.6Ma, in Ypresian stage). Data source: Huber et al. 2006, f16.2
First occurrence (base): within E3 zone (54.61-55.20Ma, base in Ypresian stage). Data source: Huber et al. 2006, f16.2

Plot of occurrence data:

Primary source for this page: Huber et al. 2006 - Atlas of Eocene Planktonic Foraminifera, chapter 16, p. 475


Beckmann, J.P., (1957). Chiloguembelina Loeblich and Tappan and related foraminifera from the Lower Tertiay of Trinidad, B.W.I. In: Loeblich, A.R., Jr. et al. (Editors), Studies in Foraminifera: U.S. National Museum Bulletin 215U.S. Government Printing Office, Washington, D.C., pp. 83-95.

Huber, B.T.; Olsson, R.K. & Pearson, P.N., (2006). Taxonomy, biostratigraphy, and phylogeny of Eocene microperforate planktonic foraminifera (Jenkinsina, Cassigerinelloita, Chiloguembelina, Streptochilus, Zeauvigerina, Tenuitella, and Cassigerinella) and Problematica (Dipsidripella). In: Pearson, P.N. et al. (Editors), Atlas of Eocene Planktonic Foraminifera, Cushman Foundation Special Publication 41. Cushman Foundation Special Publication.41 Allen Press, Lawrence, Kansas, pp. 461-508.


Chiloguembelina parallela compiled by the pforams@mikrotax project team viewed: 22-2-2018

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