- arranged by first occurrence (time control age-window is: 0-800Ma)
Pseudohastigerina naguewichiensis Test small, much compressed, circular in umbilical view. Chambers globular, increase very slowly in size, Adult tests appear coarsely perforate.
Pseudohastigerina micra Tests small, compressed, nearly circular in outline. Chambers globular, straight sutures, and rounded periphery in edge view. Aperture, high circular arch,with narrow, well-developed lip, frequently bipartite.
Pseudohastigerina sharkriverensis Test large, oval to quadrate; chambers much inflated, globular. Low chamber growth in final 3 chambers bipartite apertures common.
Pseudohastigerina wilcoxensis Test planispiral, smooth-walled test; chambers inflated globular, increase rapidly in size. Aperture, equatorial, single or bipartite, symmetrical.
Citation: Pseudohastigerina Banner&Blow, 1959taxonomic rank: GenusType species: Nonion micrus Cole, 1927Taxonomic discussion: Blow (1979) followed the concept of Pseudohastigerina set forth by Berggren and others (1967) who emended the genus to include tests with asymmetric to symmetric equatorial apertures. He drew (arbitrarily) the boundary between (Globorotalia = Globanomalina) and Pseudohastigerina “at the point where the primary aperture opens dorsally in direct continuation of the trace of the spiral suture” where “ a true planispiral coiling-mode can be said to have been attained” (p. 1060). This definition is followed here. In the transition from the ancestral Globanomalinaluxorensis (Nakkady) to the descendent Pseudohastigerinawilcoxensis the aperture is, at first, equatorially asymmetrical but becomes symmetrical as symmetrical planispiral tests evolve. All later species in the Pseudohastigerina lineage have symmetrical planispiral tests. Another feature which Berggren and others (1967) first pointed out is the development of bipartite apertures in some individuals. Blow also described this feature and emended it to the definition of Pseudohastigerina. [Olsson & Hemleben 2006]
Distinguishing features: Parent taxon (Globanomalinidae): Hedbergellids - trochospiral, mostly low trochospiral. Apertures of earlier formed chambers remain visible around the umbilicus. This taxon: Planispiral.
Aperture equatorial, sometimes bipartite, may be asymmetrical.
Wall smooth, normally perforate.
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
Biogeography and Palaeobiology
Phylogenetic relationsPseudohastigerina evolved from Globanomalinaluxorensis at the base of Zone E2 by the development of a symmetrical umbilical aperture and slightly asymmetric to fully planispiral test. In Zone E1 (within the CIE in the Bass River Borehole, New Jersey) in large populations of typical G. luxorensis; rare morphotypes exhibit a tendency towards planispirality but never develop a fully umbilical aperture and a biumbilical test. [Olsson & Hemleben 2006]
Pseudohastigerina evolved from Globanomalina luxorensis at the base of Zone E2 (Speijer and Samir, 1997; Berggren and Pearson, 2005; Olsson and Hemleben, 2006). [Pearson et al. 2018]
Most likely ancestor:Globanomalina - at confidence level 3 (out of 5). Data source: .
Biostratigraphic distribution
Geological Range: Notes: Base of Zone E2 to the top of Zone O1 (lower Oligocene). [Olsson & Hemleben 2006] Last occurrence (top): at top of O1 zone (100% up, 32.1Ma, in Rupelian stage). Data source: Total of ranges of the species in this database First occurrence (base): within E2 zone (55.20-55.81Ma, base in Ypresian stage). Data source: Total of ranges of species in this database
Plot of occurrence data:
Range-bar - range as quoted above, pink interval top occurs in, green interval base occurs in.
Triangles indicate an event for which a precise placement has been suggested
Primary source for this page: Olsson & Hemleben 2006 - Eocene Atlas, chap. 14, p. 420
References:
Banner, F. T. & Blow, W. H. (1959). The classification and stratigraphical distribution of the Globigerinaceae. Palaeontology. 2(1): 1-27. gs
Berggren, W. A. & Pearson, P. N. (2005). A revised tropical to subtropical Paleogene planktonic foraminiferal zonation. Journal of Foraminiferal Research. -. 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
Cole, W. S. (1927). A foraminiferal fauna from the Guayabal formation in Mexico. Bulletins of American Paleontology. 14(51): 1-36. gs
Miller, K. G., Aubry, M. -P., Khan, M. J., Melillo, A. J., Kent, D. V. & Berggren, W. A. (1985). Oligocene–Miocene biostratigraphy, magnetostratigraphy, and isotopic stratigraphy of the western North Atlantic. Geology. 13: 257-261. gs
Molina, E., Arenillas, I. & Pardo, A. (1999). High resolution planktic biostratigraphy and correlation across the Paleocene/Eocene boundary in the Tethys. Bulletin de la Société Géologique de France. 170: 521-530. gs
Olsson, R. K. & Hemleben, C. (2006). Taxonomy, biostratigraphy, and phylogeny of Eocene Globanomalina, Planoglobanomalina n. gen and Pseudohastigerina. 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 14): 413-432. gsO
Pearson, P. N., Olsson, R. K., Spezzaferri, S. & Leckie, R. M. (2018a). Taxonomy, biostratigraphy, and phylogeny of Oligocene Globanomalinidae (Turborotalia and Pseudohastigerina). In, Wade, B. S., Olsson, R. K., Pearson, P. N., Huber, B. T. & Berggren, W. A. (eds) Atlas of Oligocene Planktonic Foraminifera. Cushman Foundation for Foraminiferal Research, Special Publication . 46(Chap 14): 403-414. gs
Speijer, R. P. & Samir, A. M. (1997). Globanomalina luxorensis, a Tethyan biostratigraphic marker of latest Paleocene global events. Micropaleontology. 43: 51-62. gs
Pseudohastigerina compiled by the pforams@mikrotax project teamviewed: 6-10-2024
