pforams@mikrotax - Acarinina sibaiyaensis

Citation: Acarinina sibaiyaensis El Naggar 1966

Basionym: Globorotalia sibaiyaensis

Synonyms:

Globorotalia sibaiyaensis El Naggar, 1966:235, pl. 23: fig. 6a-c [G. aequa/G. esnaensis Subzone, G. velascoensis Zone, Gebel Owaina section, Egypt].
Acarinina sibaiyaensis (El Naggar).—Kelly and others, 1996:424, fig. 2-1a-b [upper Zone P5, from within carbon isotope excursion of the Paleocene-Eocene Thermal Maximum, ODP Hole 865C, Allison Guyot, equatorial Pacific Ocean].—Kelly and others, 1998:159, figs. 5c, 9d-e [upper Zone P5, from within carbon isotope excursion of Paleocene-Eocene Thermal Maximum, ODP Hole 865C, Allison Guyot, equatorial Pacific Ocean].— Pardo and others, 1999:44, pl. 2: figs. 19-20.[Zone P5b, Kaurtakapy, Kazakhstan].
Acarinina aff. sibaiyaensis (El Naggar).—Pardo and others, 1999:44, pl. 2: figs. 17-18 [Zone P5b, Kaurtakapy, Kazakhstan].

Taxonomic discussion: This form, together with A. africana and Morozovella allisonensis, constitute an assemblage of small, morphologically distinct taxa that are characteristic of the temporally short (~200 kyrs) Paleocene Eocene Thermal Maximum. [Berggren et al. 2006]

Distinguishing features:
Parent taxon (Acarinina): Moderate to low trochospire; chambers ovoid, usually 4-6 in final whorl.
Wall muricate with pustules on umbilical shoulders;
This taxon: Numerous (5-9) chambers in final whorl, and almost planispiral test

Description

Diagnostic characteristics are the relatively large (5-9) number of chambers in final whorl, and the test coiled in a very low trochospiral (approaching planispiral) mode. [Berggren et al. 2006]

Planoconvex; generally
umbilico-convex, although some specimens approach being planispiral; peripheral margin round to subround; chambers inflated, subtriangular to round on both umbilical and spiral sides; approximately 12-14 chambers arranged in 3 whorls; gradual increase in chamber size throughout; sutures depressed and radial; primary aperture circular, arch-like opening with lip to well-developed flange, umbilical-extraumbilical position extending to peripheral margin.[Berggren et al. 2006]

Muricate, nonspinose, normal perforate. [Berggren et al. 2006]

Maximum diameter of holotype 0.29 mm, minimum diameter 0.19 mm, thickness 0.17 mm; our observations suggest that this form is typically <0.35 mm in maximum diameter. [Berggren et al. 2006]

Biogeography and Palaeobiology

Widely distributed throughout the (sub)tropics and temperate regions; common in the central equatorial Pacific (ODP Site 865), found in New Jersey Coastal Plain (Bass River), North Atlantic Ocean (ODP Site 1051), and also present in Tethyan sections of Europe (Alamedilla, Spain) and North Africa (Egypt). [Berggren et al. 2006]
Aze et al. 2011 summary: Low latitudes; based on Berggren et al. (2006b)

Inferred depth-habitat primarily shallow mixed-layer; carbon isotope signature exhibits strong covariance with shell size; overall stable isotopic signature is analogous to that of modern, symbiotic species (Kelly and others, 1998). [Berggren et al. 2006]
Aze et al. 2011 ecogroup 1 - Open ocean mixed-layer tropical/subtropical, with symbionts. Based on very heavy _¹³C and relatively light _¹⁸O. Sources cited by Aze et al. 2011 (appendix S3): Kelly et al. (1998)

Kelly and others (1996) suggested that this taxon evolved from Acarinina soldadoensis, but it shows much greater similarity with A. esnehensis which we suggest was the ancestor. Further flattening of the test produced the africana morphology (Kelly and others, 1998). [Berggren et al. 2006]

Biostratigraphic distribution

Geological Range:
Notes: Zone E1, restricted to carbon isotope excursion of the PETM. [Berggren et al. 2006]
The FAD of Acarinina sibaiyaensis marks the base of zone E1 / top of P5 (Wade et al. 2011)
Last occurrence (top): at top of E1 zone (100% up, 55.8Ma, in Ypresian stage). Data source: Eocene Atlas
First occurrence (base): at base of E1 zone (0% up, 56Ma, in Thanetian stage). Data source: zonal marker (Wade et al. 2011)

Primary source for this page: Berggren et al. 2006 - Eocene Atlas, chap. 9, p. 318

References:

Berggren, W. A., Pearson, P. N., Huber, B. T. & Wade, B. S. (2006b). Berggren, W. A., Pearson, P. N., Huber, B. T. & Wade, B. S. (2006). Taxonomy, biostratigraphy, and phylogeny of Eocene Acarinina. In, Pearson, P. N. , Olsson, R. K. , Hemleben, C. , Huber, B. T. & Berggren, W. A. (eds) Atlas of Eocene Planktonic Foraminifera. Cushman Foundation for Foraminiferal Research, Special Publication. 41(Chap 9): 257-326. In, Pearson, P. N., Olsson, R. K., Hemleben, C., Huber, B. T. & Berggren, W. A. (eds) Atlas of Eocene Planktonic Foraminifera. Cushman Foundation for Foraminiferal Research, Special Publication . 41(Chap 9): 257-326. gs O

El-Naggar, Z. R. (1966). El-Naggar, Z. R. (1966). Stratigraphy and planktonic foraminifera of the Upper Cretaceous-Lower Tertiary succession in the Esna-Idfu region, Nile Valley, Egypt, U. A. R. Bulletin of the British Museum (Natural History) Geology. supplement 2: 1-291. Bulletin of the British Museum (Natural History). supplement 2: 1-291. gs

Kelly, D. C., Bralower, T. J., Zachos, J. C. & Premoli Silva, I. T. , E. (1996). Kelly, D. C., Bralower, T. J., Zachos, J. C. & Premoli Silva, I. T. , E. (1996). Rapid diversification of planktonic foramiifer in the tropical Pacific (ODP Site 865) during the late Paleocene thermal maximum. Geology. 24: 423-426. Geology. 24: 423-426. gs

Kelly, D. C., Bralower, T. J. & Zachos, J. C. (1998). Kelly, D. C., Bralower, T. J. & Zachos, J. C. (1998). Evolutionary consequences of the latest Paleocene thermal maximum for tropical planktonic foraminifera. Palaeogeography Palaeoclimatology Palaeoecology. 141: 139-161. Palaeogeography Palaeoclimatology Palaeoecology. 141: 139-161. gs

Pardo, A., Adatte, T., Keller, G. & Oberhänsli, H. (1999). Pardo, A., Adatte, T., Keller, G. & Oberhänsli, H. (1999). Paleoenvironmental changes across the Cretaceous-Tertiary boundary at Koshak, Kazakhstan, based on planktic foraminifera and clay mineralogy. Palaeogeography Palaeoclimatology Palaeoecology. 154: 247-273. Palaeogeography Palaeoclimatology Palaeoecology. 154: 247-273. gs

Wade, B. S., Pearson, P. N., Berggren, W. A. & Pälike, H. (2011). Wade, B. S., Pearson, P. N., Berggren, W. A. & Pälike, H. (2011). Review and revision of Cenozoic tropical planktonic foraminiferal biostratigraphy and calibration to the geomagnetic polarity and astronomical time scale. Earth-Science Reviews. 104: 111-142. Earth-Science Reviews. 104: 111-142. gs

test outline:	Lobate	chamber arrangement:	Pseudoplanispiral	edge view:	Equally biconvex	aperture:	Umbilical-extraumbilical
sp chamber shape:	Inflated	coiling axis:	Very low	periphery:	N/A	aperture border:	Thin lip
umb chbr shape:	Inflated	umbilicus:	Wide	periph margin shape:	Broadly rounded	accessory apertures:	None
spiral sutures:	Strongly depressed	umb depth:	Shallow	wall texture:	Moderately muricate	shell porosity:	Finely Perforate: 1-2.5µm
umbilical or test sutures:	Strongly depressed	final-whorl chambers:	5-9	N.B. These characters are used for advanced search. N/A - not applicable

Acarinina sibaiyaensis

Taxonomy

Description

Biogeography and Palaeobiology

Biostratigraphic distribution

References:

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