Sphaeroidinellopsis kochi


Classification: pf_cenozoic -> Globigerinidae -> Sphaeroidinellopsis -> Sphaeroidinellopsis kochi
Sister taxa: S. paenedehiscens, S. kochi, S. seminulina, S. disjuncta, S. sp.,

Taxonomy

Citation: Sphaeroidinellopsis kochi (Caudri, 1934)
Rank: species
Basionym: Globigerina kochi Caudri, 1934
Synonyms:
  • Sphaeroidinella rutschi Cushman and Renz, [according to Kennett & Srinivasan 1983]
  • Sphaeroidinella multiloba, LeRoy  [according to Kennett & Srinivasan 1983]
  • Globigerina grimsdalei Keijzer [according to Kennett & Srinivasan 1983]

Catalog entries: Globigerina kochi, Sphaeroidinella rutschi, Sphaeroidinella multiloba, Globigerina grimsdalei

Type images:

Distinguishing features: Like S. seminulina but somewhat compressed trochospiral test with >3 chambers in final whorl.

NB These concise distinguishing features statements are used in the tables of daughter-taxa to act as quick summaries of the differences between e.g. species of one genus.
They are being edited as the site is developed and comments on them are especially welcome.

Description


Diagnostic characters: Large, compressed low trochospiral, equatorial periphery lobulate, chambers spherical to subspherical

Aperture: Umbilical large irregular opening with a thickened lip [Aze 2011, based on Kennett & Srinivasan 1983]


Wall type: Non-spinose; Cancellate [Aze 2011]

Test morphology: Test large, a compressed low trochospiral, equatorial periphery lobulate , axial periphery rounded; chambers subspherical to oval, 4 to 5 in the final whorl, sutures distinct, slightly depressed; surface smooth, very coarsely perforate, unthickened specimens distinctly cancellate (PI. 52, Fig. 1), umbilicus deep, aperture large, irregular opening into the umbilicus with a thickened lip. [Kennett & Srinivasan 1983]

Character matrix

test outline:Lobatechamber arrangement:Trochospiraledge view:Equally biconvexaperture:Umbilical
sp chamber shape:Globularcoiling axis:Lowperiphery:N/Aaperture border:Thick lip
umb chbr shape:Globularumbilicus:Wideperiph margin shape:Broadly roundedaccessory apertures:None
spiral sutures:Moderately depressedumb depth:Deepwall texture:Cancellateshell porosity:Macroperforate: >2.5µm
umbilical or test sutures:Strongly depressedfinal-whorl chambers:4.0-5.0 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology


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

[SCOR WG138]


Isotope paleobiology: Aze et al. 2011 ecogroup 3 - Open ocean thermocline. Based on light ∂13C and relatively heavy ∂18O. Sources cited by Aze et al. 2011 (appendix S3): this study

Phylogenetic relations: Ss. kochi is distinguished from Ss. seminulina seminulina by its somewhat compressed trochospiral test with more than three chambers in the final whorl.
Ss. kochi developed from Ss. seminulina in the Middle Miocene. The kochi morphotype exhibits a somewhat different stratigraphic range from Seminulina seminulina and therefore is probably phylogenetically distinct. [Kennett & Srinivasan 1983]

Most likely ancestor: Sphaeroidinellopsis seminulina - at confidence level 3 (out of 5). Data source: Kennett & Srinivasan 1983, fig 23.

Biostratigraphic distribution

Geological Range:
Last occurrence (top): near top of PL1 [Atl.] zone (87% up, 4.5Ma, in Zanclean 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): within N10 zone (13.77-14.24Ma, base in Langhian stage). Data source: Kennett & Srinivasan 1983

Plot of occurrence data:

Primary source for this page: Kennett & Srinivasan 1983, p.210

References:

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

Caudri, C. M. B. (1934). Tertiary Deposits of Soemba. H. J. Paris, Amsterdam. -. gs

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

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


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Sphaeroidinellopsis kochi compiled by the pforams@mikrotax project team viewed: 20-9-2019

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Short stable page link: http://mikrotax.org/pforams/index.php?id=104217 Go to Archive.is to create a permanent copy of this page - citation notes



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