Acarinina quetra

Classification: pf_cenozoic -> muricate non-spinose -> Truncorotaloididae -> Acarinina -> Acarinina quetra
Sister taxa: << < 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. pseudotopilensis, A. quetra, A. wilcoxensis, A. esnaensis, A. primitiva, A. coalingensis, A. nitida, A. strabocella, A. sp.,


Citation: Acarinina quetra (Bolli 1957)
Rank: Species
Basionym: Globorotalia quetra
Taxonomic discussion: Acarinina quetra is a distinctive form that with its cuneate chambers and peripheral concentration of muricae, bears a superficial
resemblance (in some instances) to the stratigraphically younger (middle Eocene) A. topilensis. [Berggren et al. 2006]

Catalog entries: Globorotalia quetra;

Type images:

Distinguishing features: This taxon is distinguished by its angular test whose chambers are loosely disposed sequentially to each other at ~ 90° and with a distinct, but discontinuous, peripheral muricocarina.

NB The short diagnoses are used in the tables of daughter-taxa to act as quick summaries of the differences between e.g. species of one genus. They have initially been copied from the diagnostic characters/distinguishing features sections of the Eocene and Paleocene Atlases, they will be edited as the site is developed.


Diagnostic characters: This taxon is distinguished by its angular test whose chambers are loosely disposed sequentially to each other at ~ 90o and with a distinct, but discontinuous, peripheral muricocarina. [Berggren et al. 2006]

Wall type: Moderately to strongly muricate with concentration of muricae along peripheral margin of last whorl, nonspinose, normal perforate. [Berggren et al. 2006]

Test morphology: Low trochospiral; test subquadrate, planoconvex; peripheral margin lobulate; chambers on umbilical side moderately inflated, flattened on spiral side; 4 broadly subtriangular chambers visible in umbilical view; anterior and posterior margins of last chamber flattened resulting in disjunct geometry with bordering chambers and conical apex of last chamber; sutures depressed/incised, curved to sinuous, radial; umbilicus relatively wide, deep; aperture an umbilical-extraumbilical, arch extending towards (but not to) the peripheral margin; 10-12 chambers in 2½ to 3 whorls on spiral side; chambers loosely disposed, meeting almost at right angles, increasing gradually in size; final chamber sometimes reduced in size; chambers lens-shaped, tangentially longer than radially broad in general, overlapping; sutures curved; discrete intercameral openings visible on some individuals (depending on preservation); planoconvex in edge view, final chamber distinctly anguloconical with high conical angle; periphery distinctly, but discontinuously, muricocarinate [Berggren et al. 2006]

Size: Maximum diameter of holotype 0.50 mm, thickness 0.38 mm. [Berggren et al. 2006]

Character matrix

test outline:Subquadratechamber arrangement:Trochospiraledge view:Planoconvexaperture:
umb chamber shape:Inflatedcoiling axis:Very lowperiphery:N/Aaperture border:N/A
sp chbr shape:Inflatedumbilicus:Wideperiph margin shape:Broadly roundedaccessory apertures:N/A
umbilical or test sutures:Moderately depressedumb depth:Deepwall texture:Coarsely muricateshell porosity:Finely Perforate: 1-2.5µm
spiral sutures:Moderately depresseddiameter mm:0.5width mm:breadth mm:0.38
final-whorl chambers:4.0-4.0

Biogeography and Palaeobiology

Geographic distribution: Widely distributed in (sub)tropical regions (Caribbean, Atlantic, Indo-Pacific, Tethyan/Mediterranean regions, North Caucasus) [Berggren et al. 2006]
Aze et al. 2011 summary: Low latitudes; 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: Descended from A. pseudotopilensis. [Berggren et al. 2006]

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

Biostratigraphic distribution

Geological Range:
Notes: Zone E3 (upper part) 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): in upper part of E3 zone (80% up, 54.7Ma, in Ypresian stage). Data source: Eocene Atlas

Plot of occurrence data:

Primary source for this page: Berggren et al. 2006 - Atlas of Eocene Planktonic Foraminifera, chapter 9, p. 310


Berggren, W.A., (1977). Atlas of Palaeogene Planktonic Foraminifera: some Species of the Genera Subbotina, Planorotalites, Morozovella, Acarinina and Truncorotaloides. In: Ramsay, A.T.S. (Editor), Oceanic Micropaleontology. Academic Press, London, pp. 205-300.

Berggren, W.A.; Pearson, P.N.; Huber, B.T. & Wade, B.S., (2006). Taxonomy, biostratigraphy, and phylogeny of Eocene Acarinina. In: Pearson, P.N. et al. (Editors), Atlas of Eocene Planktonic Foraminifera, Cushman Foundation Special Publication 41. Allen Press, Lawrence, Kansas, pp. 257-326.

Blow, W.H., (1979). The Cainozoic Globigerinida: A study of the morphology, taxonomy, evolutionary relationships and stratigraphical distribution of some Globigerinida (mainly Globigerinacea), 2. E. J. Brill, Leiden, 1413 pp.

Bolli, H.M., (1957). The genera Globigerina and Globorotalia in the Paleocene-Lower Eocene Lizard Springs Formation of Trinidad. In: Loeblich, A.R., Jr. et al. (Editors), Studies in Foraminifera, U.S. National Museum Bulletin 215. U.S. Government Printing Office, Washington, D.C., pp. 61-82.

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

Hillebrandt von, A., (1962). Das Paleozän und seine Foraminiferenfauna im Becken von Reichenhall und Salzburg. Bayerische Akademie der Wissenschaften Mathematisch-Naturwissenschaftliche Klasse, Abhandlungen, Neue Folge, 108: 1-182.

Snyder, S.W. & Waters, V.J., (1985). Cenozoic planktonic foraminiferal biostratigraphy of the Goban Spur Region, Deep Sea Drilling Project Leg 80. Initial Reports of the Deep Sea Drilling Project, 80: 439-472.

Stainforth, R.M.; Lamb, J.L.; Luterbacher, H.; Beard, J.H. & Jeffords, R.M., (1975). Cenozoic planktonic foraminiferal zonation and characteristics of index forms. The University of Kansas Paleontological Contributions, 62: 1-425.

Warraich, M.Y. & Ogasawara, K., (2001). Tethyan Paleocene-Eocene planktic foraminifera from the Rakhi Nala and Zinda Pir land sections of the Sulaiman Range, Pakistan. Science Reports of the Institute of Geosciences, University of Tsukuba, Section B = Geological Sciences, 22: 1-59.

Warraich, M.Y.; Ogasawara, K. & Nishi, H., (2000). Late Paleocene to early Eocene planktic foraminiferal blostratigraphy of the Dungan Formation, Sulaiman Range, central Pakistan. Paleontological Research, 4(4): 275-301, 18 figures, 3 appendices.


Acarinina quetra compiled by the pforams@mikrotax project team viewed: 22-3-2018

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