Clavigerinella jarvisi


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

Taxonomy

Citation: Clavigerinella jarvisi (Cushman 1930)
Rank: Species
Basionym: Hastigerinella jarvisi
Synonyms:
Taxonomic discussion: Blow (1979) did not subdivide Clavigerinella based on chamber length, believing this character to be a function of growth stage and environmental factors, hence he placed C. jarvisi in synonymy with C. eocanica. Our observations of Clavigerinella from a number of sites (ODP Sites 865, 960, 1218, Kane 9-C) indicate that a C. jarvisi morphotype with long finger-like chambers can be distinguished from the moderately clavate form C. eocanica. Complete specimens of this species are extremely rare and it is usually recognised by the detached digitate adult chambers, which are easily recognized by the porous chamber surface and remnants of the apertural arch (Pl.8.2, Figs. 8, 9). We find no evidence for the presence of “roughened projections” representing spine bases as indicated by Cushman’s (1930) original description and find no link to the modern digitate form Hastigerinella digitata. [Coxall & Pearson 2006]

Catalog entries: Hastigerinella jarvisi;

Type images:

Short diagnosis: Final chambers elongate and slender, without terminal swellings

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 adult chambers of this species are significantly longer and more slender than in C. eocanica and C. caucasica and lack the terminal swellings of C. akersi. Clavigerinella jarvisi differs from “Clavatorellanazcaensis Quilty in the larger size and more regular pattern of size increase of the chambers in the final whorl. It is comparable to Cretaceous Clavihedbergella watersi but has less bulbous chambers and a non-pustulose wall. [Coxall & Pearson 2006]

Wall type: Usually smooth, normal perforate, sometimes weakly cancellate; possibly spinose in life. [Coxall & Pearson 2006]

Test morphology: Planispiral or pseudoplanispiral, evolute, biumbilicate or showing a slightly raised spiral side and very shallow umbilicus; 4- 4½ chambers in the final whorl; increasing rapidly in size as added, early chambers rounded, final 2-3 chambers rapidly elongating into slender, cylindrical fingers (digitate); distal chamber ends smooth and rounded or slightly tapered; equatorial high arched aperture, symmetrical or slightly asymmetrical, bordered by a broad imperforate lip; sutures shallow, straight, becoming curved in later stages, short compared to the overall chamber length. [Coxall & Pearson 2006]

Size: Up to 0.545 mm (Cushman, 1930). Detached chambers can be 0.4 mm, suggesting some specimens are as large as 1 mm. [Coxall & Pearson 2006]

Character matrix

test outline:Digitatechamber arrangement:Pseudoplanispiraledge view:Umbilico-convexaperture:Equatorial
umb chamber shape:Digitatecoiling axis:Lowperiphery:N/Aaperture border:Thick lip
sp chbr shape:Digitateumbilicus:Wideperiph margin shape:N/Aaccessory apertures:None
umbilical or test sutures:Weakly depressedumb depth:Shallowwall texture:Smoothshell porosity:Microperforate: <1µm
spiral sutures:Weakly depresseddiameter mm:0.545width mm:breadth mm:
final-whorl chambers:4.0-4.5

Biogeography and Palaeobiology


Geographic distribution: Worldwide in low and mid-latitudes. Rare in oligotrophic open ocean sections, occasionally common in upwelling assemblages. Based on the occurrence of common C. jarvisi (recorded as C. eocanica) together with radiolarian-rich sediments in Peru and Ecuador, Stainforth (1948) suggested this species thrived in the cold waters of northward flowing ex-polar currents. His
claim that this species is a strictly cold-water specialist cannot be substantiated, however, since it has never been found in polar regions. More likely, the occurrence of C. jarvisi was linked to western continental margin upwelling. [Coxall & Pearson 2006]
Aze et al. 2011 summary: Low to middle latitudes; based on Coxall & Pearson (2006)

Isotope paleobiology: No data available. [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: This species probably evolved from C. eocanica in uppermost Zone E7 by extension and tapering of the final chambers. [Coxall & Pearson 2006]

Biostratigraphic distribution

Geological Range:
Notes: Zone E7-E10. Last occurrence 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. 224

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.

Cushman, J.A., (1930). Fossil species of Hastigerinella. Contributions from the Cushman Laboratory for Foraminiferal Research, 6(1): 17-19.

Nuttall, W.L.F., (1930). Eocene Foraminifera from Mexico. Journal of Paleontology, 4: 271-293.

Stainforth, R.M., (1948). Description, correlation, and paleoecology of Tertiary Cipero Marl formation, Trinidad, B.W.I. Bulletin of the American Association of Petroleum Geologists, 32(7): 63-109.

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


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Clavigerinella jarvisi compiled by the pforams@mikrotax project team viewed: 21-10-2017

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