pforams@mikrotax - Clavatorella bermudezi

Citation: Clavatorella bermudezi (Bolli, 1957)

Basionym: Hastigerinella bermudezi Bolli, 1957

Distinguishing features:
Parent taxon (Clavatorella): low trochospiral test, later chanbers radially elongate and club shaped.
This taxon: Low trochospiral, lobulate, later chambers club-shaped

Description

Low trochospiral, lobulate later chambers club-shaped

Aperture: Umbilical-extraumbilical interiormarginal elongate arch bordered by a distinct lip [Aze 2011, based on Kennett & Srinivasan 1983]

Test low trochospiral, equatorial periphery very strongly lobulate; axial periphery broadly rounded; chambers initially spherical to ovate, the later ones becoming radially elongate and club shaped , increasing rapidly in size as added; sutures on spiral side slightly curved to radial, depressed; on umbilical side nearly radial, depressed; surface with uniformly distributed circular to subcircular, subhexagonal funnel-shaped pore pits (PI. 54, Fig. 2); umbilicus fairly wide; aperture interiomarginal, extraumbilical-umbilical, an elongate arch bordered by a distinct lip. [Kennett & Srinivasan 1983]

Biogeography and Palaeobiology

Tropical [Kennett & Srinivasan 1983] Low latitudes [Aze et al. 2011, based on Kennett & Srinivasan (1983)]

[SCOR WG138]

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 & Shackleton (1995); Coxall et al. (2000)

The surface ultrastructure of Cl. bermudezi is similar to that of Protentella prolixa (distinctly reticulate), but Cl. bermudezi has distinct trochospiral coiling and is larger.
Cl. bermudezi evolved from Globorotaloides hexagona by developing radially elongate, club-shaped chambers in the Early Miocene. [Kennett & Srinivasan 1983]

Most likely ancestor:
Globorotaloides hexagonus - at confidence level 3 (out of 5). Data source: Kennett & Srinivasan 1983, fig 24; Pearson 1995, p. 45.

Biostratigraphic distribution

Geological Range:
Last occurrence (top): near top of M7 zone (90% up, 13.8Ma, in Serravallian stage). Data source: Wade et al. (2011), additional event; position within zone determined by linear interpolation from data in table 1 of Wade et al. (2011).
First occurrence (base): in mid part of M5b subzone (45% up, 15.7Ma, in Langhian stage). Data source: Wade et al. (2011), additional event; position within zone determined by linear interpolation from data in table 1 of Wade et al. (2011).

References:

Aze, T., et al. (2011). A phylogeny of Cenozoic macroperforate planktonic foraminifera from fossil data. Biological Reviews. 86: 900-927. gs

Bolli, H. M. (1957b). Planktonic foraminifera from the Oligocene-Miocene Cipero and Lengua formations of Trinidad, B.W.I. In, Loeblich, A. R. , Jr., Tappan, H., Beckmann, J. P., Bolli, H. M., Montanaro Gallitelli & E. Troelsen, J. C. (eds) Studies in Foraminifera. U.S. National Museum Bulletin . 215: 97-123. gs

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. gs

Fox, L. R. & Wade, B. S. (2013). Systematic taxonomy of early–middle Miocene planktonic foraminifera from the equatorial Pacific Ocean: Integrated Ocean Drilling Program, Site U1338. Journal of Foraminiferal Research. 43: 374-405. gs

Kennett, J. P. & Srinivasan, M. S. (1983). Neogene Planktonic Foraminifera. Hutchinson Ross Publishing Co., Stroudsburg, Pennsylvania. 1-265. gs

Norris, R. D. (1998). Planktonic foraminifer biostratigraphy: Eastern Equatorial Atlantic. Proceedings of the Ocean Drilling Program, Scientific Results. 159: 445-479. gs O

Pearson, P. N. & Shackleton, N. J. (1995). Neogene multispecies planktonic foraminifer stable isotope record, Site 871, Limalok Guyot. Proceedings of the Ocean Drilling Program, Scientific Results. 144: 401-410. gs

Pearson, P. N. (1995). Planktonic foraminifer biostratigraphy and the development of pelagic caps on guyots in the Marshall Islands group. Proceedings of the Ocean Drilling Program, Scientific Results. 144: 21-59. gs

Postuma, J. A. (1971). Manual of planktonic foraminifera. Elsevier for Shell Group, The Hague. 1-406. gs

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

test outline:	Stellate	chamber arrangement:	Trochospiral	edge view:	Equally biconvex	aperture:	Umbilical-extraumbilical
sp chamber shape:	Elongate	coiling axis:	Very low	periphery:	N/A	aperture border:	Thin lip
umb chbr shape:	Elongate	umbilicus:	Wide	periph margin shape:	Moderately rounded	accessory apertures:	None
spiral sutures:	Weakly depressed	umb depth:	Shallow	wall texture:	Cancellate	shell porosity:	Macroperforate: >2.5µm
umbilical or test sutures:	Weakly depressed	final-whorl chambers:	4-5	N.B. These characters are used for advanced search. N/A - not applicable

Clavatorella bermudezi

Taxonomy

Description

Biogeography and Palaeobiology

Biostratigraphic distribution

References:

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