Eocene_Atlas_pl09-11_fig17-19.jpg
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Eocene_Atlas_pl09-11_fig17-19.jpg
Eocene_Atlas_pl09-11_fig16.jpg
We question the high latitude records of forms cited under this name (see synonymy listing above); they do not appear to display the robust, inflated morphology characteristic of low latitude representatives, and indeed some of the forms are recorded from distinctly lower stratigraphic levels (Zone AP5 [which approximately correlates with Zone E2]) and contain only 3 chambers in the final whorl (Lu and Keller, 1993). [Berggren et al. 2006]
Catalog entries: Acarinina interposita
Type images:
paratype: A. interpositaDistinguishing features: Test with 4-4½ chambers in the final whorl, planoconvex with scalloped, lobulate peripheral margin; distinctly muricate; chambers umbilically inflated
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.
Wall type: Densely muricate on both sides, non-spinose; normal perforate. [Berggren et al. 2006]
Morphology: Low-trochospiral; relatively large, robust, test with embracing, appressed chambers; plano-convex, weakly lobate, circular outline, rounded periphery in edge view; 4-4½ chambers in final whorl, increasing slowly in size, generally globular; sutures depressed, radial, weakly curved; muricae more strongly developed on umbilical than on spiral side, short, thick muricae concentrated around umbilicus, which is narrow, deep; about 10-12 chambers in 2-3 whorls on spiral side; early chambers obscured by muricate texture, chambers of final whorl increasing slowly in size, essentially equidimensional; sutures radial, straight, only slightly depressed; muricae tend to concentrate along peripheral margin; in edge view planoconvex; profile of early chambers rounded, with flattening of ante- and/or penultimate chamber resulting in subacute margin; peripheral margin; aperture an umbilical-extraumbilical arch, bordered by thin lip, extending almost to peripheral margin. [Berggren et al. 2006]
Size: Diameter 0.35-0.55 mm, thickness 0.20-0.25 mm. [Berggren et al. 2006]
Character matrix
| test outline: | Subcircular | chamber arrangement: | Trochospiral | edge view: | Planoconvex | aperture: | Umbilical-extraumbilical |
| sp chamber shape: | Globular | coiling axis: | Low | periphery: | N/A | aperture border: | Thin lip |
| umb chbr shape: | Globular | umbilicus: | Narrow | periph margin shape: | Broadly rounded | accessory apertures: | None |
| spiral sutures: | Weakly depressed | umb depth: | Deep | wall texture: | Coarsely muricate | shell porosity: | Finely Perforate: 1-2.5µm |
| umbilical or test sutures: | Weakly depressed | final-whorl chambers: | 4.0-4.5 | N.B. These characters are used for advanced search. N/A - not applicable | |||
Geographic distribution: Occurs commonly in the Tethys (Egypt) and in the northern Caucasus. [Berggren et al. 2006]
Aze et al. 2011 summary: Tethys (Egypt) and in the northern Caucasus; based on Berggren et al. (2006b)
Isotope paleobiology: No data available. [Berggren et al. 2006]
Aze et al. 2011 ecogroup 1 - Open ocean mixed-layer tropical/subtropical, with symbionts. Based on very heavy δ13C and relatively light δ18O. Sources cited by Aze et al. 2011 (appendix S3): this study
Phylogenetic relations: This taxon seems to have been derived from A. soldadoensis and evolved into A. pentacamerata by an increase in the number of chambers in the whorl and a change in the spire height. [Berggren et al. 2006]
Most likely ancestor: Acarinina soldadoensis - at confidence level 4 (out of 5). Data source: Berggren et al. (2006) fig9.2.
Likely descendants: Acarinina pentacamerata;
Geological Range:
Notes: Zone E4 to Zone E6. [Berggren et al. 2006]
Last occurrence (top): within E6 zone (50.20-50.67Ma, top in Ypresian stage). Data source: Eocene Atlas
First occurrence (base): within E4 zone (52.54-54.61Ma, base in Ypresian stage). Data source: Eocene Atlas
Plot of occurrence data:
Primary source for this page: Berggren et al. 2006 - Eocene Atlas, chap. 9, p. 290
Berggren, W. A., Pearson, P. N., Huber, B. T. & Wade, B. S. (2006b). 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. gs V O Blow, W. H. (1979). The Cainozoic Globigerinida: A study of the morphology, taxonomy, evolutionary relationships and stratigraphical distribution of some Globigerinida (mainly Globigerinacea). E. J. Brill, Leiden. 2: 1-1413. gs Huber, B. T. (1991c). Paleogene and Early Neogene Planktonic Foraminifer Biostratigraphy of Sites 738 and 744, Kerguelen Plateau (Southern Indian Ocean). Proceedings of the Ocean Drilling Program, Scientific Results. 119: 427-449. gs V O Krasheninnikov, V. A., Serova, M. Y. & Basov, I. A. (1988). Stratigrafiya I planktonnyie foraminiferyi paleogena: vyisokikh shirot Tikhogo okeana. Trudy Geologicheskiy Institut Akademiya Nauk SSSR. 429: 1-120. gs Lu, G. & Keller, G. (1993). The Paleocene-Eocene transition in the Antarctic Indian Ocean: Inference from planktic foraminifera. Marine Micropaleontology. 21: 101-142. gs Stott, L. D. & Kennett, J. P. (1990). The Paleoceanographic and Paleoclimatic signature of the Cretaceous/Paleogene boundary in the Antarctic: Stable isotopic results from ODP Leg 113. Proceedings of the Ocean Drilling Program, Scientific Results. 113: 829-848. gs Subbotina, N. N. (1953). Foraminiferes fossiles d'URSS Globigerinidae, Globorotaliidae, Hantkeninidae. Bureau de Recherches Geologiques et Minieres. 2239: 1-144. gsReferences:
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Acarinina interposita compiled by the pforams@mikrotax project team viewed: 2-3-2021
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