Clavigerinella eocanica


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

Taxonomy

Citation: Clavigerinella eocanica (Nuttall 1928)
Rank: Species
Basionym: Hastigerinella eocanica
Synonyms:
Taxonomic discussion: Toumarkine and Luterbacher (1985) designated the specimen figured by Nuttall (1928) pl. 50: fig. 9 as the lectotype from three original illustrated cotypes. On recent examination of Nuttall’s Hastigerinella eocanica ( =Clavigerinella eocanica) cotype suite in the USNM collection (11 in total), however, no specimen could be found that exactly matched this illustration, although two are very similar (i.e., same number, orientation and length of chambers). Either the actual figured specimen is lost or the illustration is inaccurate. The SEM image illustrated as the probable lectotype of C. eocanica in this work (Pl.8.1, Figs. 10, 11) is the closest match among Nuttall’s cotypes to the illustration of the lectotype figured by Toumarkine and Luterbacher (1985). [Coxall & Pearson 2006]

Catalog entries: Eoclavatorella benidormensis; Hastigerinella eocanica;

Type images:

Short diagnosis: Clavigerinella eocanica is distinguished from all other clavigerinellids in having unmodified, smoothly rounded clavate chambers. It can be distinguished from its Miocene homeomorph Clavatorella bermudezi by the greater lateral compression and shell symmetry (along the equatorial plane), and fully equatorial position of the aperture. It differs from Parasubbotina eoclava in having better-developed clavate chambers, near planispiral coiling, and a higher-arched, equatorially positioned aperture. It differs from P. prebetica by the lower, near-planispiral coiling, greater lateral compression and possession of a high-arched, equatorial 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.

Description


Diagnostic characters: Clavigerinella eocanica is distinguished from all other clavigerinellids in having unmodified, smoothly rounded clavate chambers. It can be distinguished from its Miocene homeomorph Clavatorella bermudezi by the greater lateral compression and shell symmetry (along the equatorial plane), and fully equatorial position of the aperture. It differs from Parasubbotina eoclava in having better-developed clavate chambers, near planispiral coiling, and a higher-arched, equatorially positioned aperture. It differs from P. prebetica by the lower, near-planispiral coiling, greater lateral compression and possession of a high-arched, equatorial aperture. [Coxall & Pearson 2006]

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

Test morphology: Planispiral or pseudoplanispiral, evolute, laterally compressed biumbilicate or showing a subtly raised spiral side and very shallow umbilicus; 4-4½ rapidly enlarging chambers in the final whorl; early chambers rounded, final 2-3 adult chambers conspicuously elongated in to club-shaped (clavate) extensions; highly lobular peripheral outline; distal chamber ends smoothly rounded; equatorial high arched aperture, symmetrical or slightly asymmetrical, bordered by a smooth broad imperforate lip, relict apertural lips often present along sutures; sutures are shallow, straight, becoming curved in later stages, short relative to total chamber length. [Coxall & Pearson 2006]

Size: Maximum diameter 300-800 µm. [Coxall & Pearson 2006]

Character matrix

test outline:Digitatecoiling axis:N/Achamber arrangement:Pseudoplanispiralumbilicus:Wide
edge view:Hourglassumbilical or test sutures:Moderately depressedspiral sutures:Moderately depressedshell porosity:Finely Perforate: 1-2.5
wall texture:Cancellateaperture:Equatorialaperture border:Thick lipaccessory apertures:Relict
periphery:N/Aumb chamber shape:Digitatesp chbr shape:Digitateperiph margin shape:Narrowly rounded
umb depth:Shallowdiameter mm:0.30-0.80width mm:breadth mm:
final-whorl chambers:4.0-4.5

Biogeography and Palaeobiology


Geographic distribution: Clavigerinella eocanica is the most commonly encountered species of the genus and has been found in open ocean as well as marginal settings worldwide at mid-low latitudes. [Coxall & Pearson 2006]
Aze et al. 2011 summary: Low to middle latitudes; based on Coxall & Pearson (2006)

Isotope paleobiology: Clavigerinella eocanica has high ∂18O and low ∂13C indicating that it lived in a cold, deep possibly subthermocline habitat (Pearson and others, 1993; Coxall and others, 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): Pearson et al. (1993); Coxall et al. (2000)

Phylogenetic relations: This species evolved from Parasubbotina eoclava in Zone E7 by elongation of the chambers and lowering of the coil height to form a planispiral. It diversified shortly after its origin to produce a series of morphotypes including C. caucasica, which was the ancestor of Hantkenina. Detailed understanding of the relationship between C. eocanica and other clavigerinellids is lacking because of their sporadic geographic and stratigraphic occurrence. [Coxall & Pearson 2006]

Biostratigraphic distribution

Geological Range:
Notes: Upper Zone E7 to E16. This species is most characteristic of the lower middle Eocene, but has been observed ranging into the upper Eocene (Pearson and Chaisson, 1997). [Coxall & Pearson 2006]
Last occurrence (top): within E16 zone (33.90-34.68Ma, top in Priabonian 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. 222

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.

Bolli, H.M., (1957). Planktonic foraminifera from the Eocene Navet and San Fernando formations of Trinidad. In: Loeblich, A.R., Jr. et al. (Editors), Studies in Foraminifera: U.S. National Museum Bulletin 215. U.S. Government Printing Office, Washington, D.C., pp. 155-172.

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.; Pearson, P.N.; Shackleton, N.J. & Hall, M.A., (2000). Hantkeninid depth adaptation: An evolving life strategy in a changing ocean. Geology, 28: 87-90.

Coxall, H.K.; Huber, B.T. & Pearson, P.N., (2003). Origin and morphology of the Eocene planktonic foraminifera Hantkenina. Journal of Foraminiferal Research, 33: 237-261.

Cremades Campos, J., (1980). Eoclavatorella; nuevo genero de foraminifero planctonico del Eoceno inferior. . Cuadernos de Geologia Universidad de Granada, 11: 209-214.

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

Loeblich, A.R., Jr. & Tappan, H., (1957). Planktonic foraminifera of Paleocene and early Eocene Age from the Gulf and Atlantic coastal plains. In: Loeblich, A.R., Jr. et al. (Editors), Studies in Foraminifera, U.S. National Museum Bulletin 215. U.S. Government Printing Office, Washington, D.C., pp. 173-198.

Nuttall, W.L.F., (1928). Notes on the Tertiary Foraminifera of Southern Mexico. Journal of Paleontology, 2(4): 375-376.

Pearson, P.N. & Chaisson, W.P. (Editors), (1997). Late Paleocene to middle Miocene planktonic foraminifer biostratigraphy, Ceara Rise. Proceedings of the Ocean Drilling Program, Scientific Results, 154. Ocean Drilling Program, College Station, TX, 33-68 pp.

Pearson, P.N.; Shackleton, N.J. & Hall, M.A., (1993). Stable isotope paleoecology of middle Eocene planktonic foraminifera and multi-species isotope stratigraphy, DSDP Site 523, South Atlantic. Journal of Foraminiferal Research, 23: 123-140.

Saito, T.; Thompson, P.R. & Breger, D. (Editors), (1976). Skeletal ultra-microstructure of some elongate-chambered planktonic foraminifera and related species. Progress in Micropaleontology, Special Publication. Micropaleontology Press, The American Museum of Natural History, New York, 278-304 pp.

Toumarkine, M. & Luterbacher, H. (Editors), (1985). Paleocene and Eocene planktic foraminifera. Plankton Stratigraphy. Cambridge Univ. Press, Cambridge, 87-154 pp.


Clavigerinella eocanica compiled by the pforams@mikrotax project team viewed: 24-3-2017

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