provide the first adequate characterization of this taxon, to clearly illustrate the high degree of variability in this taxon (Shutskaya, 1958, 1970a), in particular, its distinctive high spire, and to transfer it to its appropriate home in the genus Acarinina. In fact, Morozova (1958, fig. 5), in a paper dealing with the morphologic characters important in the classification of Paleogene taxa of the Globigerinidea, observed that the microspheric generation among "globigerinids" typically possess a higher spire and more whorls of chambers than megalospheric forms, and she cited Globigerina subsphaerica Subbotina as a good illustration of this feature.
This taxon has been considered a junior synonym of Acarinina mckannai (White) by some workers (Hillebrandt, 1962; Krasheninnikov and Ponikarov, 1965; Stainforth et al., 1975; Berggren, 1977) because of their supposed similarity. The latter is distinguished by its significantly larger test, relatively low spire, and more evolute coiling pattern resulting in a wide and open umbilicus. In our material, A. mckannai stratigraphically appears somewhat higher/later than A. subsphaerica from which we suggest it is descended (cf. Stainforth
etal., 1975).
We note that moderately to high-spired morphotypes with
surficial morphology/ornament comparable to A. subsphaerica occur in upper lower to lower middle Eocene; these may represent a continuation of the late Paleocene acarininid radiation or an independent early Eocene radiation. This issue, however, is beyond the scope of this study. Similar high-spired acarinids, which we regard as synonymous with A. subsphaerica, have been described from middle Paleocene deposits in Azerbaizhan, Tadzhikistan, and the Crimea. These include Globoconusa quadripartitaformis Khalilov (1956), Acarinina falsospiralis Davidzon and Morozova (1964), and Acarinina microsphaerica Morozova (1967). Globigerina chascanona Loeblich and Tappan (1957a) is a small, very high-spired pustulose form, which we regard as an immature stage of A. subsphaerica. Both Blow (1979) and Huber (1991b) noted these small forms, which they placed in chascanona. Larger (adult) forms of A. subsphaerica have been identified in middle Paleocene coastal plain deposits from Alabama and New Jersey by Loeblich and Tappan as Globigerina spiralis Bolli. [Olsson et al. 1999]
Catalog entries: Globigerina subsphaerica, Globigerina chascanona, Globoconusa quadripartitaformis, Acarinina falsospiralis, Acarinina microsphaerica
Type images:Distinguishing features:
Parent taxon (Acarinina): Moderate to low trochospire; chambers ovoid, usually 4-6 in final whorl.
Wall muricate with pustules on umbilical shoulders;
This taxon: Test small, tightly coiled with strongly elevated spire; overall shape sub-sphaerical; umbilicus narro,w deep and surrounded by muricae; final chamber usually diminutive with an arched aperture.
Diagnostic characters:
Character matrix
test outline: | Lobate | chamber arrangement: | Trochospiral | edge view: | Inequally biconvex | aperture: | Umbilical |
sp chamber shape: | Crescentic | coiling axis: | Low | periphery: | N/A | aperture border: | N/A |
umb chbr shape: | Subtriangular | umbilicus: | Narrow | periph margin shape: | Broadly rounded | accessory apertures: | None |
spiral sutures: | Moderately depressed | umb depth: | Deep | wall texture: | Finely muricate | shell porosity: | Finely Perforate: 1-2.5µm |
umbilical or test sutures: | Moderately depressed | final-whorl chambers: | 5-6 | N.B. These characters are used for advanced search. N/A - not applicable |
Geographic distribution
Aze et al. 2011 summary: Cosmopolitan; based on Olsson et al. (1999)
Isotope paleobiology
Aze et al. 2011 ecogroup 1 - Open ocean mixed-layer tropical/subtropical, with symbionts; based on comparison with other species of the genus.
Phylogenetic relations
Most likely ancestor: Acarinina nitida - at confidence level 4 (out of 5). Data source: Olsson et al. 1999, fig5a.
Likely descendants: Acarinina mckannai;
plot with descendants
Geological Range:
Notes: Subzone P4a. We have not found A. subsphaerica associated with P3b faunas in any of our material nor have we found it to occur above the middle part of Zone P4 at low latitudes. Indeed, it is the short and distinct stratigraphic range of this taxon that renders it so useful for subdivision of Zone P4. We recognize high-spired acarininids from the upper Paleocene at the high southern latitude ODP Site 690. (This taxon was recently recorded by Lu and Keller (1995) in younger stratigraphic levels at DSDP Site 577 (Shatsky Rise), northwestern Pacific Ocean and by Huber (1991b) at ODP Site 738, southwestern Kerguelen Plateau (southern Indian Ocean) near the Paleocene/Eocene boundary.) [Olsson et al. 1999]
Last occurrence (top): within E3 zone (54.61-55.20Ma, top in Ypresian stage). Data source: Olsson et al. 1999
First occurrence (base): within P4a subzone (60.52-60.73Ma, base in Selandian stage). Data source: Olsson et al. 1999
Plot of occurrence data:
Primary source for this page: Olsson et al. 1999 - Atlas of Paleocene Planktonic Foraminifera, p. 52
Berggren, W. A. & Norris, R. D. (1997). Berggren, W. A. & Norris, R. D. (1997). Biostratigraphy, phylogeny and systematics of Paleocene trochospiral planktonic foraminifera. Micropaleontology. 43(supplement 1): 1-116. Micropaleontology. 43(supplement 1): 1-116. gs Berggren, W. A. (1977a). 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. (ed.) Oceanic Micropaleontology. Academic Press, London 205-300. In, Ramsay, A. T. S. (ed.) Oceanic Micropaleontology. Academic Press, London 205-300. gs Berggren, W. A., Kent, D. V., Swisher, I. , C. C. & Aubry, M. -P. (1995b). Berggren, W. A., Kent, D. V., Swisher, I. , C. C. & Aubry, M. -P. (1995). A revised Cenozoic geochronology and chronostratigraphy. In, Berggren, W. A. , Kent, D. V. , Aubry, M. -P. & Hardenbol, J. (eds) Geochronology, Time Scales and Global Stratigraphic Correlations. SEPM (Society for Sedimentary Geology) Special Publication No. 54, 129-212. In, Berggren, W. A., Kent, D. V., Aubry, M. -P. & Hardenbol, J. (eds) Geochronology, Time Scales and Global Stratigraphic Correlations. SEPM (Society for Sedimentary Geology) Special Publication No. 54, 129-212. gs Blow, W. H. (1979). 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. E. J. Brill, Leiden. 2: 1-1413. gs Hillebrandt, A. , von (1962). Hillebrandt, A. , von (1962). Das Paleozän und seine Foraminiferenfauna im Becken von Reichenhall und Salzburg. Abhandlungen Bayerischen Akademie der Wissenschaften. Mathematisch-Naturwissenschaftliche Klasse, Neue Folge 108: 1-182. Abhandlungen Bayerischen Akademie der Wissenschaften. 108: 1-182. gs Krasheninnikov, V. A. & Ponikarov, V. P. (1965). Krasheninnikov, V. A. & Ponikarov, V. P. (1965). . . -. . -. gs Morozova, V. G. (1958). Morozova, V. G. (1958). K sistematike i morfologii paleogenovykh predstavitelei nadsemeistva Globigerinidea [Addition to the systematics and morphology of the Paleogene members of the Superfamily Globigerinidea]. Voprosyi Mikropaleontologii. 2: 22-52. Voprosyi Mikropaleontologii. 2: 22-52. gs Olsson, R. K., Hemleben, C., Berggren, W. A. & Huber, B. T. (1999). Olsson, R. K., Hemleben, C., Berggren, W. A. & Huber, B. T. (1999). Atlas of Paleocene Planktonic Foraminifera. Smithsonian Institution Press, Washington, DC. 1-252. Smithsonian Institution Press, Washington, DC. (85): 1-252. gs Shutskaya, E. K. (1958). Shutskaya, E. K. (1958). Variability in some lower Paleogene planktonic foraminifera from the northern Caucasus. Voprosyi Mikropaleontologii. 2: 86-90. Voprosyi Mikropaleontologii. 2: 86-90. gs Soldan, D. M., Petrizzo, M. R., Silva, I. P. & Cau, A. (2011). Soldan, D. M., Petrizzo, M. R., Silva, I. P. & Cau, A. (2011). Phylogenetic relationships and evolutionary history of the Paleogene genus through parsimony analysis. Journal of Foraminiferal Research. 41: 260-284. Journal of Foraminiferal Research. 41: 260-284. gs Stainforth, R. M., Lamb, J. L., Luterbacher, H., Beard, J. H. & Jeffords, R. M. (1975). Stainforth, R. M., Lamb, J. L., Luterbacher, H., Beard, J. H. & Jeffords, R. M. (1975). Cenozoic planktonic foraminiferal zonation and characteristics of index forms. University of Kansas Paleontological Contributions, Articles. 62: 1-425. University of Kansas Paleontological Contributions, Articles. 62: 1-425. gs O Subbotina, N. N. (1947). Subbotina, N. N. (1947). Danian and Paleogene foraminifera of the northern Caucasus. Vses Neft Nauchno-Issled Geol-Razved Inst. (VNIGRI), Microfauna of the oil fields of the USSR. 1947: 39-160. Trudy VNIGRI Mikrofauna USSR. 1947: 39-160. gs O Subbotina, N. N. (1953). Subbotina, N. N. (1953). Foraminiferes fossiles d'URSS Globigerinidae, Globorotaliidae, Hantkeninidae. Bureau de Recherches Geologiques et Minieres. 2239: 1-144. Bureau de Recherches Geologiques et Minieres. 2239: 1-144. gsReferences:
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Acarinina subsphaerica compiled by the pforams@mikrotax project team viewed: 15-5-2025
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