Acarinina boudreauxi


Classification: pf_cenozoic -> Truncorotaloididae -> Acarinina -> Acarinina boudreauxi
Sister taxa: << < A. aspensis, A. interposita, A. echinata, A. pseudosubsphaerica, A. alticonica, A. soldadoensis, A. cuneicamerata, A. angulosa, A. africana, A. sibaiyaensis, A. esnehensis, A. mckannai, A. subsphaerica, A. bullbrooki, A. punctocarinata, A. boudreauxi, A. rohri, A. topilensis, A. praetopilensis, A. mcgowrani, A. quetra, A. pseudotopilensis, A. wilcoxensis, A. esnaensis, A. primitiva, A. coalingensis, A. nitida, A. strabocella, A. sp.,

Taxonomy

Citation: Acarinina boudreauxi Fleisher 1974
Rank: Species
Basionym: Acarinina boudreauxi
Synonyms:
Taxonomic discussion: This taxon has rarely been used, but is nevertheless a distinctive form. Originally described from Zones P9 to P11 in the Arabian Sea area, it has recently been found at the same levels in Tanzanian drill cores (Pl.9.5, Figs. 13-16). Acarinina boudreauxi is clearly related to the A. bullbrooki group, particularly the matthewsae morphotype described by Blow (1979) (here considered conspecific with bullbrooki) but appears lower/earlier in the record, and provides a possible evolutionary link for that group with lower Eocene Acarinina pseudotopilensis. [Berggren et al. 2006]

Catalog entries: Acarinina boudreauxi

Type images:

Distinguishing features: Test anguloconical, tightly coiled with 4½-5 compressed chambers in fine whorl; straight radial sutures on the umbilical side; no muricocarina.

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: Acarinina boudreauxi is distinguished from A. interposita by the much tighter coil and more compressed chambers, and by having straight radial sutures on the umbilical side and an anguloconical test. Acarinina boudreauxi differs from A. punctocarinata by lacking a discontinuous muricocarina and typically being smaller; it differs from A. bullbrooki by its rounded profile and more slowly expanding chambers and the 4½-5 (as opposed to 4) chambers in the final whorl. [Berggren et al. 2006]

Wall type: Robust, heavily calcified, wall with blocky fused muricae. [Berggren et al. 2006]

Test morphology: Subcircular planconvex test, coiled in a low trochospiral with 4½ to 5 chambers in the final whorl. Chambers radially compressed and appressed with flat or slightly depressed sutures on a flat spiral side. Aperture umbilical-extraumbilical, a low arch. Ventral sutures straight, radial and depressed converging on a narrow, deep umbilicus. Periphery subacute. [Berggren et al. 2006]

Size: Maximum diameter of holotype 0.28 mm; thickness 0.21 mm. [Berggren et al. 2006]

Character matrix

test outline:Subcircularchamber arrangement:Trochospiraledge view:Planoconvexaperture:Umbilical-extraumbilical
sp chamber shape:Crescenticcoiling axis:Lowperiphery:N/Aaperture border:N/A
umb chbr shape:Subtriangularumbilicus:Narrowperiph margin shape:Subangularaccessory apertures:None
spiral sutures:Weakly depressedumb depth:Deepwall texture:Coarsely muricateshell porosity:Finely Perforate: 1-2.5µm
umbilical or test sutures:Moderately depressedfinal-whorl chambers:4.5-5.0 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology


Geographic distribution: Probably widespread; currently known only from the Indian Ocean. [Berggren et al. 2006]
Aze et al. 2011 summary: Probably widespread currently only known from Indian Ocean; 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: Possibly evolved from Acarinina pseudotopilensis and was ancestral to A. punctocarinata and A. bullbrooki. [Berggren et al. 2006]

Most likely ancestor: Acarinina pseudotopilensis - at confidence level 4 (out of 5). Data source: Berggren et al. (2006) fig9.2.
Likely descendants: Acarinina bullbrooki; Acarinina punctocarinata;

Biostratigraphic distribution

Geological Range:
Notes: Ranges from the lower Part of Zone E7 to within Zone E9. [Berggren et al. 2006]
Last occurrence (top): within E9 zone (43.23-43.85Ma, top in Lutetian stage). Data source: Eocene Atlas
First occurrence (base): in lower part of E7a subzone (20% up, 49.8Ma, 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. 266

References:

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

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

Fleisher, R. L. (1974a). Cenozoic planktonic foraminifera and biostratigraphy, Arabian Sea, Deep Sea Drilling Project, Leg 23A. Initial Reports of the Deep Sea Drilling Project. 23: 1001-1072. gs

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Acarinina boudreauxi compiled by the pforams@mikrotax project team viewed: 16-9-2019

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