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Clavatorella nicobarensis Srinivasan & Kennett 1974 from: Srinivasan, M.S.Kennett, J.P. (1974): A planktonic foraminifer (Clavatorella) from the Pliocene . Journal of Foraminiferal Research Vol. 4 p. 77-79
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Species Clavatorella nicobarensis Srinivasan & Kennett 1974


Diagnosis / Definition:
Kennett & Srinivasan (1983):
Test small, outline deeply lobulate, coiled in low trochospire; spiral side evolute, umbilical side involute with moderately shallow umbilicus. The spire is mostly level or depressed below spiral surface of final whorl of chambers, giving false impression of biumbilicate, planispiral test; large specimens consist of nearly two whorls containing nine or more chambers with five (or rarely six) in final whorl; early chambers spherical to subspherical, with later chambers progressively more radially elongate; sutures essentially radial, slightly curved, and depressed; wall penetrated by closely spaced pores and surface roughened by cancellate ridges between pores and by irregular calcite growths on ridges; aperture simple, extending from the umbilicus to the periphery along base of final chamber, showing individual variation in height, and bordered by distinct, uniform, perforate lip throughout length; aperture does not extend across the periphery onto dorsal side.
Discussion / Comments:
Kennett & Srinivasan (1983):
Cl. bermudezi (Bolli) is most closely related to Cl. nicobarensis but differs in swollen extremities of later chambers, which are much more separated at their attenuated proximal ends. Also the wall surface of Cl. bermudezi (Bolli) is distinctly pitted. The former species also has similar depressed trochoid coiling and shallow umbilical depression and a comparably placed but more elevated aperture. It appears to be the direct ancestor of Cl. nicobarensis. Protentella prolixa Lipps differs in being planispiral and in having an equatorial symmetrical aperture.
Van Eijden & Smit (1991):
Remarks. A species indistinguishable from C. nicobarensis occurs in the uppermost Oligocene at Sites 757 and 758, although its reported range is upper Miocene-Pliocene.
Systematics:

3
 Classis Foraminifera
  Genus Clavatorella
   Species Clavatorella nicobarensis

32
 Ordo Foraminiferida
  Familia Globorotaliidae
   Genus Clavatorella
    Species Clavatorella nicobarensis
Synonym list:
Srinivasan & Kennett (1974):
1974 Clavatorella nicobarensis Srinivasan & Kennett. - Srinivasan & Kennett : p.78 pl 1 figs 1-13
Van Eijden & Smit (1991):
1974 Clavatorella nicobarensis Srinivasan & Kennett. - Srinivasan & Kennett : 74-79 pl. 1 figs. 1-13
1991 Clavatorella nicobarensis Srinivasan & Kennett. - Van Eijden & Smit : p.122 pl. 4, figs. 8-12
References:

Srinivasan,M.S. and Kennett,J.P. (1974):
A planktonic foraminifer (Clavatorella) from the Pliocene . Journal of Foraminiferal Research Vol. 4 p. 77-79

Kennett,J. and Srinivasan,M.S. (1983):
Neogene Planktonic Foraminifera - A Phylogenetic Atlas.

Van Eijden,A.J.M. and Smit,J. (1991):
Eastern Indian Ocean Cretaceous and Paleogene quantitative biostratigraphy.
In: Proceedings of the Ocean Drilling Program, Scientific Results Vol. 121 Eds: Weissel, J.Peirce, J.Taylor, E.Alt, J. p. 77-123
Anonymous: Unedited TaxonConcept data
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