Acarinina esnehensis


Classification: pf_cenozoic -> Truncorotaloididae -> Acarinina -> Acarinina esnehensis
Sister taxa: A. medizzai, A. collactea, A. pentacamerata, 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, > >>

Taxonomy

Citation: Acarinina esnehensis (Nakkady 1950)
Rank: Species
Basionym: Globigerina cretacea esnehensis
Synonyms:
Taxonomic discussion: As the description above indicates, clear distinction between esnehensis and the related taxa mckannai, soldadoensis and gravelli is difficult to achieve. Loeblich and Tappan (1957) expressed the view that esnehensis and gravelli are synonymous and junior synonyms of mckannai. As the result of a comparative examination of type material of these taxa at the British Museum (Natural History), London and the U .S. National Museum, Washington, Blow (1979, p. 1127-1128) agreed with the former view but distinguished esnehensis from mckannai on the basis of the following characters observable in mckannai: 1) much tighter coiling mode; 2) more “globigerine” initial coil; 3) posteriorly recurved (versus consistently radial) and more clearly incised dorsal intercameral sutures; 4) ventral intercameral sutures recurved on earlier part of last whorl to sinuous in the later part of the last whorl in addition to distinctly different stratigraphic ranges.
At the same time Blow (1979, p. 1129) was obviously at pains to distinguish consistently between esnehensis and soldadoensis, concluding that in view of the long stratigraphic persistence of transitional forms over the biostratigraphic interval of his Zone P5 (mid-part) to Zone P8b “Muricoglobigerina esnehensis (= M. gravelli) is little more than an environmentally induced ecophenotype of a basic soldadoensis genotype”. Nevertheless, he distinguished the two forms as separate species as do we here based on the set of distinguishing characters described above. [Berggren et al. 2006]

Catalog entries: Globigerina cretacea esnehensis, Globigerina dubia lakiensis, Globigerina gravelli,

Type images:

Distinguishing features: Like A. soldadoensis but with more (5-7 vs 4) of globular (vs tangentially elongate) chambers in final whorl; straighter, radial sutures on both sides of the (generally higher spired) test and a larger, deeper umbilicus.

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: This taxon is characterized by a muricate test of 5-6 (rarely 7) chambers arranged in a relatively loose (lax) coil resulting in an open and deep umbilicus, and moderate to strong lateral chamber compression (giving a subangulate appearance to the peripheral margin of some chambers). Muricae are well developed on the umbilical side but only weakly expressed (blunted) on the spiral side, the test being strongly cancellate. A small, weakly muricate chamber usually caps/bridges the junction between the first and last chambers of the final whorl and on the spiral side a smooth, virtually imperforate band (which appears to be a consistent distinguishing characteristic of this taxon) runs along the lower part of this diminutive chamber. This taxon is distinguished from Acarinina soldadoensis by having a greater number (5-7 vs 4) of globular (as opposed to tangentially elongate) chambers in the final whorl, straighter, radial sutures on both sides of the (generally higher spired) test and a larger, deeper umbilicus. [Berggren et al. 2006]

Wall type: Muricate, with strong concentration of muricae around umbilicus. [Berggren et al. 2006]

Test morphology: Low- to moderately high spired trochoid test; 5 (ranging up to 7) inflated chambers in last whorl, umbilicus open, deep and generally relatively wide; aperture low slit extending along margin of last chamber towards, but not reaching, periphery; no circumumbical muricate rim; sutures incised, radial to only slightly curved on umbilical and spiral sides of test; rounded margin(s) in edge view. [Berggren et al. 2006]

Size: Relatively large (to 0.5 mm maximum diameter); maximum diameter of holotype: 0.4 mm; thickness: 0.3 mm (Nakkady, 1950, p. 689). [Berggren et al. 2006]

Character matrix

test outline:Lobatechamber arrangement:Trochospiraledge view:Equally biconvexaperture:Umbilical
sp chamber shape:Inflatedcoiling axis:Moderateperiphery:N/Aaperture border:N/A
umb chbr shape:Inflatedumbilicus:Wideperiph margin shape:Moderately roundedaccessory apertures:None
spiral sutures:Moderately depressedumb depth:Deepwall texture:Moderately muricateshell porosity:Macroperforate: >2.5µm
umbilical or test sutures:Strongly depressedfinal-whorl chambers:5.0-7.0 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology


Geographic distribution: Widespread from (sub)tropical areas (Caribbean, New Jersey, Egypt) to austral (Hornibroook, 1958) and boreal (Berggren, 1960a) regions. Probably lumped with A. soldadoensis in some studies and thus an understanding of its real distribution remains muted. [Berggren et al. 2006]
Aze et al. 2011 summary: Low to high 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: Acarinina esnehensis probably evolved from A. soldadoensis in (lower) Zone P5. [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 sibaiyaensis; Pearsonites lodoensis;

Biostratigraphic distribution

Geological Range:
Notes: Zones P5 to Zone E6; particularly common in Zone E1 in association with the PETM excursion fauna in the Bass River section of coastal New Jersey and Egypt. [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 P5 zone (55.96-57.10Ma, base in Thanetian stage). Data source: Eocene Atlas

Plot of occurrence data:

Primary source for this page: Berggren et al. 2006 - Eocene Atlas, chap. 9, p. 289

References:

Berggren, W. A. (1960). Some planktonic foraminifera from the Lower Eocene (Ypresian) of Denmark and northwestern Germany. Stockholm University, Contributions to Geology. 5: 41-108. gs

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: 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

Bolli, H. M. (1957d). The genera Globigerina and Globorotalia in the Paleocene-Lower Eocene Lizard Springs Formation of Trinidad. In, Loeblich, A. R. , Jr. , Tappan, H. , Beckmann, J. P. , Bolli, H. M. , Montanaro Gallitelli, E. & Troelsen, J. C. (eds) Studies in Foraminifera. U.S. National Museum Bulletin. 215: 61-82. gs

Brönnimann, P. (1952e). Trinidad Paleocene and lower Eocene Globigerinidae. Bulletin of American Paleontology. 34(143): 1-34. gs

Haque, A. F. M. M. (1956). The smaller foraminifera of the Ranikot and the Laki of the Nammal gorge, Salt Range. Memoir of the Pakistan Geological Survey. 1: 1-300. gs

Hornibrook, N. d. B. (1958). New Zealand Upper Cretaceous and Tertiary foraminiferal zones and some overseas correlations. Micropaleontology. 4: 25-38. gs

Loeblich, A. R. & Tappan, H. (1957b). Planktonic foraminifera of Paleocene and early Eocene Age from the Gulf and Atlantic coastal plains. In, Loeblich, A. R. , Jr. , Tappan, H. , Beckmann, J. P. , Bolli, H. M. , Montanaro Gallitelli, E. & Troelsen, J. C. (eds) Studies in Foraminifera. U.S. National Museum Bulletin. 215: 173-198. gs

Nakkady, S. E. (1950). A new foraminiferal fauna from the Esna shales and Upper Cretaceous chalk of Egypt. Journal of Paleontology. 24(6): 675-692. gs

Pearson, P. N., Shackleton, N. J. & Hall, M. A. (1993). Stable isotope paleoecology of middle Eocene planktonic foraminifera and multi-species isotope stratigraphy, DSDP Site 523, South Atlantic. Journal of Foraminiferal Research. 23: 123-140. gs

White, M. P. (1928). Some Index Foraminifera of the Tampico Embayment Area of Mexico. Journal of Paleontology. 2(3): 177-215. gs


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Acarinina esnehensis compiled by the pforams@mikrotax project team viewed: 16-7-2019

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