Planoglobanomalina pseudoalgeriana


Classification: pf_cenozoic -> Globanomalinidae -> Planoglobanomalina -> Planoglobanomalina pseudoalgeriana
Sister taxa: P. pseudoalgeriana, P. sp.,

Taxonomy

Citation: Planoglobanomalina pseudoalgeriana Olsson & Hemleben 2006
Rank: Species
Basionym: Planoglobanomalina pseudoalgeriana
Synonyms:
Taxonomic discussion: Planoglobanomalina pseudoalgeriana n. sp. is the type species for the new genus Planoglobanomalina. Blow referred morphotypes from a North Atlantc core to the Eocene/Oligocene planispiral genus Pseudohastigerina and stated that the genus had a polyphyletic origin, first appearing at the beginning of the Eocene and again in the early Eocene Zone P9. We
believe that Blow’s observations are correct in as much as we have observed a similar relationship in Zone E6 in the western North Pacific ODP Hole 865B and are the basis for this new species. Hillebrandt (1976) was first to illustrate this species (identified as P. micra) in Zone E7 from southeastern Spain. [Olsson & Hemleben 2006]

Catalog entries: Planoglobanomalina pseudoalgeriana

Type images:

Distinguishing features: Test loosely coiled, evolute, and compressed; 9-10 chambers in the final whorl, last three chambers showing a trend towards uncoiling.

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: The most distinguishing feature of Planoglobanomalina pseudoalgeriana n. sp. is the remarkable homeomorphy it shows with the upper Aptian planktonic foraminifer Globigerinelloides algerianus Cushman and ten Dam (1948) from which its name is derived. The test of P. pseudoalgeriana n. sp. is loosely coiled, evolute, and much compressed with 9-10 chambers in the ultimate whorl and with the last three chambers showing a trend towards uncoiling. Globanomalina is trochospiral, tightly coiled, has few chambers in the ultimate whorl, and an extraumbilical aperture confined to the umbilical side. [Olsson & Hemleben 2006]

Wall type: Smooth, normal perforate. Well-preserved specimens show smooth calcite overgrowths on the umbilical shoulders of chambers and similar irregular, discontinuous smooth bands on the test periphery. [Olsson & Hemleben 2006]

Test morphology: Test asymmetrical to fully planispiral, compressed, loosely coiled, evolute, oval in outline, chambers compressed, distinctly elongate; inner spire of chambers visible due to loose coiling, 9-10 chambers in ultimate whorl, increasing gradually in size last three chambers in ultimate whorl arranged in an uncoiling trend, sutures slightly depressed, straight to moderately curved, umbilicus moderate in size, circular in shape, apertural lips of ultimate chamber and previous chambers fuse to form a somewhat broad shelf that extends around the umbilicus, relict apertures present where apertural lips are not completely fused; in edge view primary aperture equatorial, asymmetric, an oval-shaped opening bordered by a broad lip, test much compressed with a pinched periphery which gives the chambers an ogyval shape. [Olsson & Hemleben 2006]

Character matrix

test outline:Ovatechamber arrangement:Planispiraledge view:Compressedaperture:Equatorial
sp chamber shape:Petaloidcoiling axis:Very lowperiphery:N/Aaperture border:Thick flange
umb chbr shape:Petaloidumbilicus:Wideperiph margin shape:Narrowly roundedaccessory apertures:Intralaminal
spiral sutures:Weakly depressedumb depth:Shallowwall texture:Smoothshell porosity:Finely Perforate: 1-2.5µm
umbilical or test sutures:Weakly depressedfinal-whorl chambers:9.0-10.0 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology


Geographic distribution: The occurrence of this species in southeastern Spain, Tanzania, North Atlantic Ocean, and at ODP Hole 865B, western North Pacific Ocean suggests that it was widespread in low to mid latitudes. [Olsson & Hemleben 2006]
Aze et al. 2011 summary: Low to middle 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: Planoglobanomalina pseudoalgeriana n. sp. evolved from Globanomalina planoconica in Zone E6. [Olsson & Hemleben 2006]

Most likely ancestor: Globanomalina planoconica - at confidence level 4 (out of 5). Data source: Olsson & Hemleben 2006, fig 14.1.

Biostratigraphic distribution

Geological Range:
Notes: Zone E6 to Zone E7b. [Olsson & Hemleben 2006 - but corrected following zonal definition change of Wade et al. 2011]
Last occurrence (top): in upper part of E7b subzone (80% up, 46.2Ma, in Lutetian stage). Data source: Olsson & Hemleben 2006, fig 14.1
First occurrence (base): in lower part of E6 zone (20% up, 50.6Ma, in Ypresian stage). Data source: Olsson & Hemleben 2006, fig 14.1

Plot of occurrence data:

Primary source for this page: Olsson & Hemleben 2006 - Eocene Atlas, chap. 14, p. 419

References:

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. & Ten Dam, A. (1948). Globigerinelloides, a new genus of the Globigerinidae. Contributions from the Cushman Laboratory for Foraminiferal Research. 24(2): 42-43. gs :: ::

Hillebrandt, A. , von (1976). Los foraminiferos planctonicos, nummulitidos y coccolitoforidos de la zona de Globorotalia palmerae del Cuisiense (Eoceno inferior) en el SE de Espana, (Provincias de Murcia y Alicante. Revista Española de Micropaleontología. 8(3): 323-394. gs :: ::

Howe, H. V. & Wallace, W. E. (1932). Foraminifera of the Jackson Eocene at Danville Landing on the Ouachita, Catahoula Parish, Louisiana. Bulletin of the Geological Survey of Louisiana. 2: 1-118. 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 :: ::


logo

Planoglobanomalina pseudoalgeriana compiled by the pforams@mikrotax project team viewed: 2-7-2020

Taxon Search:
Advanced Search

Short stable page link: http://mikrotax.org/pforams/index.php?id=100243 Go to Archive.is to create a permanent copy of this page - citation notes



Comments (0)

No comments yet on this page. Please do add comments if you spot any problems, or have information to share

Add Comment

* Required information
1000
Captcha Image
Powered by Commentics