Taxon Concept provided by
  Home |   Search

Click on a letter below to get a list of species:
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z all
Clavigerinella columbiana Petters 1954 from: Pearson, P.N.Olsson, R.K.Hemleben, C.Huber, B.T.Berggren, W.A. (2006): Atlas of Eocene Planktonic Foraminifera. p. 1-513
.
Anonymous: Unedited TaxonConcept data
Notice: This catalogue page may contain unedited data.

Species Clavigerinella columbiana Petters 1954


Diagnosis / Definition:
Pearson et al. (2006):
DESCRIPTION. Type of wall: Uncertain because all the specimens we have examined are poorly preserved; it may have a higher pore density than is typical of the genus. Test morphology: Planispiral, involute, biumbilicate; 4-4 1/2 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. 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.
Discussion / Comments:
Pearson et al. (2006):
DISTINGUISHING FEATURES.- 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". 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). PHYLOGENETIC RELATIONSHIPS.- 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. STRATIGRAPIC RANGE.- Uppermost Zone E7-E10 (poorly constrained). 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 (1 979) comment that this species is particularly common in the Indo-Pacific region has not been substantiated. STABLE ISOTOPE PALEOBIOL0GY.- Clavigerinella colombiana registers high ò18O and low ò13C compared to other co-occurring planktonic species, indicating that it lived in a cold, 12C-rich water mass (Coxall, 2000).
Systematics:

35
 Ordo Foraminiferida
  Superfamilia Globigerinaceae
   Familia Hantkeninidae
    Genus Clavigerinella
     Species Clavigerinella columbiana
Synonym list:
Pearson et al. (2006):
1954 Hastigerinella colombiana Petters. - Petters : p.40 pl. 80; fig. 10a-b [middle Eocene, Asterigerina crassaformis zone, upper Carreto Fm., Colombia]
1955 Hastigerinella colombiana Petters. - Weiss : p.309 pl. 2; fig. 9-10 [middle Eocene, Talara, Chira, and Mirador Fms, Peru]
2006 Clavigerinella columbiana Petters. - Pearson et al. : p.220 pl. 8.2; fig. 9-13 (Pl. 8.2, Figs. 9-1 0: new SEMs of the holotype of Hastigerinella colombiana Petters)
Was used in synonym list of:
Specimen:
Cushman Collection - Smithsonian Museum of Natural History, Washington, D.C., Inventory number: USNM 64577
References:

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

Weiss,L. (1955):
Planktonic index Foraminifera of northwestern Peru . Micropaleontology Vol. 1(4) p. 301-308

Pearson,P.N.; Olsson,R.K.; Hemleben,C.; Huber,B.T. and Berggren,W.A. (2006):
Atlas of Eocene Planktonic Foraminifera. p. 1-513
Anonymous: Unedited TaxonConcept data
Creative Commons Attribution 2.5 License
This work is licensed under a Creative Commons Attribution 2.5 License.