pforams@mikrotax - Sphaeroidinella dehiscens

Citation: Sphaeroidinella dehiscens (Parker & Jones, 1865)

Basionym: Sphaeroidina bulloides var. dehiscens Parker & Jones, 1865

Variants:

Sphaeroidinella dehiscens immatura Cushman - phyletically primitive form [according to Kennett & Srinivasan 1983]
Sphaeroidinella ionica ionica Cita and Ciaranfi - phyletically primitive form [according to Kennett & Srinivasan 1983]
Sphaeroidinella dehiscens excavata Banner and Blow - phyletically advanced form [according to Kennett & Srinivasan 1983], regarded as a discrete species by Pearson (1995), but not by Brummer & Kucera (2022)

Distinguishing features:
Parent taxon (Sphaeroidinella): Like Sphaeroidinellopsis but with supplementary apertures
This taxon: monospecific

Description

Large, trochospiral, equatorial periphery ovoid or spherical with smooth secondary cortex

Aperture: Primary aperture interiomarginal umbilical two sutural supplementary apertures bordered by crenulated lip [Aze 2011, based on Kennett & Srinivasan 1983]

Coiling direction (in extant population): mixed

Test large, trochospiral compact, equatorial periphery broadly ovoid or spherical; chambers 3 in the final whorl , strongly inflated, subglobular, becoming increasingly embracing in the adult; sutures flush, covered by secondary thickening; primary surface coarsely perforate similar to Globigerinoides sacculifer (PI. 51, Fig. 2), which is covered by secondary thickening. The secondary covering reduced the external openings of the pores, thus rendering the surface a smooth and glossy appearance; umbilicus deep, irregular; primary aperture interiomarginal, umbilical, one or two sutural supplementary apertures present; apertures bordered by crenulated lip, which are extensions of the cortex. [Kennett & Srinivasan 1983]

Non-spinose; Cancellate with smooth cortex [Aze 2011]

Biogeography and Palaeobiology

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

In modern oceans a common, warm water, species [SCOR WG138]

Map of distribution from ForCenS database

Aze et al. 2011 ecogroup 3 - Open ocean thermocline. Based on light δ¹³C and relatively heavy δ¹⁸O. Sources cited by Aze et al. 2011 (appendix S3): Shackleton & Vincent (1978)

Sa. dehiscens evolved directly from Sphaeroidinellopsis paenedehiscens by developing a small, supplementary aperture at the chamber suture contact on the spiral side. By definition, this marks the change from Sphaeroidinellopsis to Sphaeroidinella and defines the base of Zone N19. [Kennett & Srinivasan 1983]

Molecular Genotypes recognised (data from PFR² database, June 2017), one genotype only from 6 sequences. Reference: André et al. 2014.

Most likely ancestor:
Sphaeroidinellopsis paenedehiscens - at confidence level 4 (out of 5). Data source: Kennett & Srinivasan 1983, fig 23..

Biostratigraphic distribution

Geological Range:
Last occurrence (top): Extant. Data source: present in the plankton (SCOR WG138)
First occurrence (base): near base of PL1 [Atl.] zone (12% up, 5.6Ma, in Messinian 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:

André, A., et al. (2014). SSU rDNA Divergence in Planktonic Foraminifera: Molecular Taxonomy and Biogeographic Implications. PLoS One. 9: e104641-. gs

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

Brady, H. B. (1884). Report on the Foraminifera dredged by H.M.S. Challenger, during the years 1873-1876. Report on the Scientific Results of the Voyage of H.M.S. Challenger during the years 1873-1876. 9 (Zoology): 1-814. gs

Brummer, G-J. A. & Kucera, M. (2022). Taxonomic review of living planktonic foraminifera. Journal of Micropalaeontology. 41: 29-74. gs

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

Lam, A. & Leckie, R. M. (2020a). Late Neogene and Quaternary diversity and taxonomy of subtropical to temperate planktic foraminifera across the Kuroshio Current Extension, northwest Pacific Ocean. Micropaleontology. 66(3): 177-268. gs

Loeblich, A. & Tappan, H. (1994). Foraminifera of the Sahul shelf and Timor Sea. Cushman Foundation for Foraminiferal Research, Special Publication. 31: 1-661. gs O

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

Parker, W. K. & Jones, T. R. (1865). On some foraminifera from the North Atlantic and Arctic Oceans, including Davis Straits and Baffin's Bay. Philosophical Transactions of the Royal Society of London. 155: 325-441. gs O

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

Shackleton, N. J. & Vincent, E. (1978). Oxygen and carbon isotope studies in Recent Foraminifera from the southeast Indian Ocean. Marine Micropaleontology. 3: 1-13. gs

Siccha, M. & Kucera, M. (2017). ForCenS, a curated database of planktonic foraminifera census counts in marine surface sediment samples. Scientific Data. 4(1): 1-12. gs

test outline:	Ovate	chamber arrangement:	Trochospiral	edge view:	Equally biconvex	aperture:	Umbilical
sp chamber shape:	Petaloid	coiling axis:	Low-moderate	periphery:	N/A	aperture border:	Thin flange
umb chbr shape:	Petaloid	umbilicus:	Wide	periph margin shape:	Broadly rounded	accessory apertures:	Sutural
spiral sutures:	Flush	umb depth:	Deep	wall texture:	Smooth	shell porosity:	Macroperforate: >2.5µm
umbilical or test sutures:	Weakly depressed	final-whorl chambers:	3-3	N.B. These characters are used for advanced search. N/A - not applicable

Sphaeroidinella dehiscens

Taxonomy

Description

Biogeography and Palaeobiology

Biostratigraphic distribution

References:

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