Blow (1979) considered that pseudotopilensis was the stem form of a lineage that led to Acarinina topilensis in the middle Eocene, and he named a new species, praetopilensis, for an intermediate morphology that first appears in Zone P9 (=E7 of this paper) and shows the beginnings of circum-cameral fusion of muricae that is more strongly developed in topilensis. [Berggren et al. 2006]
Catalog entries: Acarinina pseudotopilensis
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: Like A. wilcoxensis but with triangular to wedge- or cuneate-shaped chambers in the final whorl, disjunct (separation of) chamber margins and more densely muricate wall.
Diagnostic characters:
Morphology:
Wall type:
Character matrix
| test outline: | Subquadrate | chamber arrangement: | Trochospiral | edge view: | Planoconvex | aperture: | Umbilical-extraumbilical |
| sp chamber shape: | Inflated | coiling axis: | Low | periphery: | N/A | aperture border: | N/A |
| umb chbr shape: | Inflated | umbilicus: | Narrow | periph margin shape: | Broadly rounded | accessory apertures: | Sutural |
| spiral sutures: | Moderately depressed | umb depth: | Shallow | wall texture: | Coarsely muricate | shell porosity: | Finely Perforate: 1-2.5µm |
| umbilical or test sutures: | Moderately depressed | final-whorl chambers: | 4-4 | N.B. These characters are used for advanced search. N/A - not applicable | |||
Geographic distribution
Aze et al. 2011 summary: Low latitudes; based on Berggren et al. (2006b)
Isotope paleobiology
Aze et al. 2011 ecogroup 1 - Open ocean mixed-layer tropical/subtropical, with symbionts. Based on very heavy _13C and relatively light _18O. Sources cited by Aze et al. 2011 (appendix S3): Boersma et al. (1987)
Phylogenetic relations
Most likely ancestor: Acarinina wilcoxensis - at confidence level 4 (out of 5). Data source: Berggren et al. (2006) fig9.2.
Likely descendants: Acarinina boudreauxi; Acarinina mcgowrani; Acarinina quetra;
plot with descendants
Geological Range:
Last occurrence (top): within E7a subzone (48.31-50.20Ma, top in Ypresian stage). Data source: Eocene Atlas
First occurrence (base): within E1 zone (55.81-55.96Ma, 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. 305
Berggren, W. A. (1960). Some planktonic foraminifera from the Lower Eocene (Ypresian) of Denmark and northwestern Germany. Stockholm Contributions in Geology. 5: 41-108. gs Berggren, W. A. (1977a). 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. 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(Chap 9): 257-326. gs 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 Gohrbandt, K. (1963). Zur Gliederung des Palaeogen im Helvetikum nordlich Salzburg nach planktonischen Foraminiferen. Mitteilungen der Geologischen Gesellschaft in Wien. 56(1): 63-. gs Hillebrandt, A. , von (1962). Das Paleozän und seine Foraminiferenfauna im Becken von Reichenhall und Salzburg. Abhandlungen Bayerischen Akademie der Wissenschaften. 108: 1-182. gs Jenkins, D. G. (1971). New Zealand Cenozoic Planktonic Foraminifera. New Zealand Geological Survey, Paleontological Bulletin. 42: 1-278. gs 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. (1995). Planktic foraminiferal faunal turnovers in the subtropical Pacific during the Late Paleocene to Early Eocene. Journal of Foraminiferal Research. 25: 97-116. gs Luterbacher, H. P. (1975b). Planktonic Foraminifera of the Paleocene and Early Eocene, Possagno Section. Schweizerische Paläontologische Abhandlungen. 97: 57-67. 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 Reyment, R. A. (1960). Notes on some Globegerinidae, Globotruncanidae and Globorotalidae from the Upper Cretaceous and Lower Tertiary of western Nigeria. Records Geol. Survey Nigeria. 68-86. gs Samuel, O., Borza, K. & Kohler, E. (1972). Microfauna and lithostratigraphy of the Paleogene and adjacent Cretaceous of the Middle Vah Valley (West Carpathian). Geologicky Ustav Dionyza Stura, Bratislava. 1-264. gs 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. gs Soldan, D. M., Petrizzo, M. R. & Silva, I. P. (2014). Pearsonites, a new Paleogene planktonic foraminiferal genus for the broedermanni lineage. Journal of Foraminiferal Research. 44: 17-27. gs 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. gs O Subbotina, N. N. (1953). Foraminiferes fossiles d'URSS Globigerinidae, Globorotaliidae, Hantkeninidae. Bureau de Recherches Geologiques et Minieres. 2239: 1-144. gs 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, Tokyo. 4(4): 275-301, 218 figures, 273 aendices. gsReferences:

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Acarinina pseudotopilensis compiled by the pforams@mikrotax project team viewed: 12-11-2025
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