Clavigerinella colombiana


Classification: pf_cenozoic -> smooth non-spinose -> Hantkeninidae -> Clavigerinella -> Clavigerinella colombiana
Sister taxa: C. akersi, C. caucasica, C. colombiana, C. eocanica, C. jarvisi,

Taxonomy

Citation: Clavigerinella colombiana (Petters 1954)
Rank: Species
Basionym: Hastigerinella colombiana
Synonyms:
Taxonomic discussion: Complete specimens are very rare; the holotype illustrated by Petters, and shown here in SEM for the first time, is one of very few that has been isolated more or less intact. The species is usually identified by the isolated, paddle-shaped chambers. A few complete species have been reported from the western equatorial Atlantic (Demerara Rise) (P. Sexton, pers. comm., 2004). [Coxall & Pearson 2006]

Catalog entries: Hastigerinella colombiana;

Type images:

Short diagnosis: Final chambers paddlewheel-like, i.e. flattened in side view, sub-triangular in edge view

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: Clavigerinella colombiana is differentiated from all other clavigerinellids by having sub-triangular chambers that are distinctly flattened in the anterior-posterior axis. Petters likened the form of the test to a “paddlewheel”. [Coxall & Pearson 2006]

Wall type: Uncertain because all the specimens we have examined are poorly preserved; it may have a higher pore density than is typical of the genus. [Coxall & Pearson 2006]

Test morphology: Planispiral, involute, biumbilicate; 4 - 4½ chambers in the final whorl, increasing rapidly in size as added; early chambers rounded, final 2-3 adult chambers radially elongate, distinctly flattened in the direction of coiling into subtriangular paddles, arranged perpendicular to the direction of coiling; individual chambers are wide at the distal ends, tapering to a narrow waist at the point of attachment; peripheral outline strongly lobulate; equatorial narrow arched aperture, symmetrical or slightly asymmetrical, bordered by an imperforate lip; sutures straight or curved, short compared to the total length of chambers. [Coxall & Pearson 2006]

Size: Maximum diameter of holotype 0.66 mm; minimum diameter 0.51 mm; maximum thickness (at periphery) 0.40 mm; minimum thickness (near umbilicus) 0.15 mm (Petters, 1954). Specimens reach up to 1 mm in diameter. [Coxall & Pearson 2006]

Character matrix

test outline:Lobatecoiling axis:N/Achamber arrangement:Planispiralumbilicus:Wide
edge view:Hourglassumbilical or test sutures:Weakly depressedspiral sutures:N/Ashell porosity:
wall texture:aperture:Equatorialaperture border:Thin lipaccessory apertures:None
periphery:N/Aumb chamber shape:Subtriangularsp chbr shape:N/Aperiph margin shape:Broadly rounded
umb depth:Shallowdiameter mm:0.51-0.66width mm:breadth mm:0.15-0.40
final-whorl chambers:4.0-4.5

Biogeography and Palaeobiology


Geographic distribution: Apparently worldwide, most common in continental margin settings and the equatorial Pacific. Not found in open-ocean oligotrophic assemblages. It was originally described from the same sample as Pseudoglobigerinella bolivariana. Blow’s (1979) comment that this species is particularly common in the Indo-Pacific region has not been substantiated. [Coxall & Pearson 2006]
Aze et al. 2011 summary: Cosmopolitan on continental shelf settings; based on Coxall & Pearson (2006)

Isotope paleobiology: Clavigerinella colombiana registers high ∂18O and low ∂13C compared to other co-occurring planktonic species, indicating that it lived in a cold, 12C-rich water mass (Coxall, 2000). [Coxall & Pearson 2006]
Aze et al. 2011 ecogroup 4 - Open ocean sub-thermocline. Based on very light δ13C and very heavy δ18O. Sources cited by Aze et al. 2011 (appendix S3): Coxall et al. (2000)

Phylogenetic relations: The evolutionary relationships of C. colombiana to other clavigerinellids is difficult to establish because of its sporadic occurrence. It probably evolved from C. eocanica in the latest early Eocene (E7) by lateral widening and flattening of the chambers in the direction of coiling. [Coxall & Pearson 2006]

Biostratigraphic distribution

Geological Range:
Notes: Uppermost Zone E7-E10 (poorly constrained).
[Coxall & Pearson 2006]
Last occurrence (top): within E10 zone (41.89-43.23Ma, top in Lutetian stage). Data source: Eocene Atlas
First occurrence (base): within E7 zone (45.72-50.20Ma, base in Ypresian stage). Data source: Eocene Atlas

Plot of occurrence data:

Primary source for this page: Coxall & Pearson 2006 - Atlas of Eocene Planktonic Foraminifera, chapter 8, p. 221

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, 1413 pp.

Coxall, H.K. & Pearson, P.N., (2006). Taxonomy, biostratigraphy, and phylogeny of the Hantkeninidae (Clavigerinella, Hantkenina and Cribrohantkenina). In: Pearson, P.N. et al. (Editors), Atlas of Eocene Planktonic Foraminifera, Cushman Foundation Special Publication 41. Allen Press, Lawrence, Kansas, pp. 213-256.

Coxall, H.K., (2000). Hantkeninid planktonic foraminifera and Eocene palaeoceanographic change. PhD Thesis, University of Bristol, unpublished, 264 pp.

Petters, V., (1954). Tertiary and Upper Cretaceous foraminifera from Colombia, S. A. Contributions from the Cushman Foundation for Foraminiferal Research, 5(1): 37-41.

Weiss, L., (1955). Planktonic index foraminifera of northwestern Peru. Micropaleontology, 1: 301-319.


Clavigerinella colombiana compiled by the pforams@mikrotax project team viewed: 29-5-2017

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