Pseudohastigerina wilcoxensis


Classification: pf_cenozoic -> Globanomalinidae -> Pseudohastigerina -> Pseudohastigerina wilcoxensis
Sister taxa: P. naguewichiensis, P. micra, P. sharkriverensis, P. wilcoxensis, P. sp.

Taxonomy

Citation: Pseudohastigerina wilcoxensis (Cushman & Ponton 1932)
Rank: Species
Basionym: Nonion wilcoxensis
Synonyms:
Taxonomic discussion: The concept of Pseudohastigerina wilcoxensis according to Berggren and others (1967) included morphotypes with an asymmetic aperture that extended extraumbilically over the axial periphery onto the spiral side to the trace of the spiral suture. These morphotypes contrast with other morphotypes where the aperture assumes an equatorial symmetric position, the test becomes planispiral and biumbilicate, and the aperture extends into the umbilicus on both sides. They also pointed out that the latter morphotypes often developed a bipartite division of the aperture at the axial periphery with paired symmetrical apertures present on both sides of the test. The asymmetric morphotypes were included in P. wilcoxensis to emphasize the transitional morphology between the proposed trochospiral ancestral species, Globanomalina chapmani (Parr, 1938), where the aperture does not extend onto the dorsal side. They emended the genus Pseudohastigerina, Banner and Blow, 1959 (type species Pseudohastigerina micra [Cole], 1927) to include the planispiral to slightly asymmetric morphotypes. Although Pseudohastigerina was originally described as having a planispiral test with an equatorial aperture that extended into the umbilicus on both sides, Banner and Blow emphasized the presence of asymmetrical imperforate portici, which they believed indicated a phylogenetic relationship with certain planktonic genera of the Cretaceous (e.g., Hedbergella, Globigerinelloides). Blow (1979) followed the concept of Pseudohastigerina set forth by Berggren and others (1967) and emended the genus to include tests with asymmetric to symmetric equatorial apertures and bipartite 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). The apertural lip was said (p. 1179) not to be a portical structure and that the genus was confined to the Paleogene. But Blow (1979) only provisionally accepted Pseudohastigerina as a valid genus because he was unsure of morphologic criteria that could be used to separate this genus from other planispiral genera in the Neogene (e.g., Hastigerina).
Using this definition for separating Pseudohastigerina from Globanomalina, Blow placed illustrations of two specimens identified by Berggren and others (1967) as P. wilcoxensis (text-fig. 2, d-e, p-r) in synonomy with Globanomalina chapmani because the apertures, although they extended slightly over the axial periphery, did not open into the spiral suture. Blow also placed Globanomalina luxorensis (Nakkady, 1950) in synonymy with G. chapmani as did Berggren and others (1967). Speijer and Samir’s (1997) study of the Globanomalina -Pseudohastigerina lineage in the circum-Mediterrean region recognized Nakkady’s species and noted that its first common occurrence was associated with the negative ∂13C shift in Zone E1 and emphasized its utility for biostratigraphic purposes. We concur with Speijer and Samir in that G. luxorensis can be separated from G. chapmani on the basis of a rounded axial periphery and an equatorial aperture that does not open into the trace of the spiral suture. And we concur with Speijer and Samir’s identification of text-fig. 2, d-e, p-r in Berggren and others, 1967 (the illustrations that Blow had identified as G. chapmani) as G. luxorensis. The study by Speijer and Samir has helped clarify the concept of G. luxorensis, which up to this point had been poorly known, being identified only in Egyptian deposits; indeed, Olsson and others (1999) still included this species as a junior synonym of G. chapmani. Nevertheless, Olsson and others (1999) pointed out that the lineage leading to Pseudohastigerina involved Globanomalina imitata (Subbotina, 1953) and Globanomalina ovalis (Haque, 1956) rather than G.
chapmani. Speijer and Samir (1997) considered G. ovalis a junior synonym of G. luxorensis and regarded G. chapmani as ancestral to G. luxorensis. See discussion under G. luxorensis for details on the Pseudohastigerina lineage. [Olsson & Hemleben 2006]

Catalog entries: Nonion wilcoxensis, Pseudohastigerina wilcoxensis globulosa, Globigerinella pseudovoluta, Hastigerina eocenica

Type images:

Distinguishing features: Test planispiral, smooth-walled test; chambers inflated globular, increase rapidly in size. Aperture, equatorial, single or bipartite, symmetrical.

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


Wall type: Smooth, normal perforate. [Olsson & Hemleben 2006]

Size: Maximum diameter of holotype 0.17 mm, thickness 0.09 mm. [Olsson & Hemleben 2006]

Character matrix

test outline:Subcircularchamber arrangement:Planispiraledge view:Equally biconvexaperture:Equatorial
sp chamber shape:Globularcoiling axis:N/Aperiphery:N/Aaperture border:Thin lip
umb chbr shape:Globularumbilicus:Narrowperiph margin shape:Broadly roundedaccessory apertures:Sutural
spiral sutures:Moderately depressedumb depth:Shallowwall texture:Smoothshell porosity:Finely Perforate: 1-2.5µm
umbilical or test sutures:Moderately depressedfinal-whorl chambers:6.0-7.0 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology


Geographic distribution: Global in mid to high latitudes. [Olsson & Hemleben 2006]
Aze et al. 2011 summary: Low to high latitudes; based on Olsson & Hemleben (2006)

Isotope paleobiology: No data available. [Olsson & Hemleben 2006]
Aze et al. 2011 ecogroup 2 - Open ocean mixed-layer tropical/subtropical, without symbionts. Based on δ13C lighter than species with symbionts; also with relatively light δ18O. Sources cited by Aze et al. 2011 (appendix S3): this study

Phylogenetic relations: Pseudohastigerina wilcoxensis evolved from Globanomalina luxorensis by a migration of the aperture over the axial periphery to the trace of the spiral suture, thereby developing an asymmetric planispiral test in early forms of P. wilcoxensis. In later forms of P. wilcoxensis the test becomes symmetrically planispiral and biumbilicate. The attainment of a planispiral test also leads to the development of symmetrically opposed bipartite apertures in some morphotypes of the species. Bipartite apertures are also seen in later species of Pseudohastigerina. [Olsson & Hemleben 2006]

Most likely ancestor: Globanomalina luxorensis - at confidence level 4 (out of 5). Data source: Olsson & Hemleben (2006) fig 14.1.
Likely descendants: Pseudohastigerina micra; Pseudohastigerina sharkriverensis;

Biostratigraphic distribution

Geological Range:
Notes: Base of Zone E2 to Zone E10. [Olsson & Hemleben 2006]
The FAD of Pseudohastigerina wilcoxensis marks the base of zone E2 / top of E1 (Wade et al. 2011)
Last occurrence (top): at top of E10 zone (100% up, 41.9Ma, in Lutetian stage). Data source: Olsson & Hemleben (2006) fig 14.1
First occurrence (base): at base of E2 zone (0% up, 55.8Ma, in Ypresian stage). Data source: zonal marker (Wade et al. 2011)

Plot of occurrence data:

Primary source for this page: Olsson & Hemleben 2006 - Eocene Atlas, chap. 14, p. 427

References:

Bandy, O. L. (1949). Eocene and Oligocene foraminifera from Little Stave Creek, Clarke County, Alabama. Bulletins of American Paleontology. 32(131): 1-210. gs

Banner, F. T. & Blow, W. H. (1959). The classification and stratigraphical distribution of the Globigerinaceae. Palaeontology. 2(1): 1-27. gs V O

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., Olsson, R. K. & Reyment, R. A. (1967). Origin and development of the foraminiferal genus Pseudohastigerina Banner and Blow, 1959. Micropaleontology. 13(3): 265-288. 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

Cushman, J. A. & Ponton, G. M. (1932a). An Eocene foraminiferal fauna of Wilcox age from Alabama. Contributions from the Cushman Laboratory for Foraminiferal Research. 8(3): 51-72. gs V O

Gohrbandt, K. H. A. (1967). Some new planktonic foraminiferal species from the Austrian Eocene. Micropaleontology. 13(3): 319-326. 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

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

Mallory, V. S. (1959). Lower Tertiary biostratigraphy of the California Coast Ranges. American Association of Petroleum Geologists, Tulsa, Oklahoma. 1-416. gs

McKeel, D. R. & Lipps, J. J. (1975). Eocene and Oligocene planktonic foraminifera from the Central and Southern Oregon Coast Range. Journal of Foraminiferal Research. 5(4): 249-269. 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

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. gs V O

Parr, W. J. (1938). Upper Eocene Foraminifera from Deep Borings in King's Park, Perth, Western Australia. Journal of the Royal Society of Western Australia. 24: 69-101. gs

Speijer, R. P. & Samir, A. M. (1997). Globanomalina luxorensis, a Tethyan biostratigraphic marker of latest Paleocene global events. Micropaleontology. 43: 51-62. 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 V O

Toumarkine, M. & Luterbacher, H. (1985). Paleocene and Eocene planktic foraminifera. In, Bolli, H. M. , Saunders, J. B. & Perch-Neilsen, K. (eds) Plankton Stratigraphy. Cambridge Univ. Press, Cambridge 87-154. gs

Wade, B. S., Pearson, P. N., Berggren, W. A. & Pälike, H. (2011). Review and revision of Cenozoic tropical planktonic foraminiferal biostratigraphy and calibration to the geomagnetic polarity and astronomical time scale. Earth-Science Reviews. 104: 111-142. 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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Pseudohastigerina wilcoxensis compiled by the pforams@mikrotax project team viewed: 22-10-2020

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