Subbotina patagonica


Classification: pf_cenozoic -> Globigerinidae -> Subbotina -> Subbotina patagonica
Sister taxa: S. projecta, S. tecta, S. jacksonensis, S. corpulenta, S. eocaena, S. gortanii, S. crociapertura, S. yeguaensis, S. senni, S. roesnaesensis, S. utilisindex, S. angiporoides, S. minima, S. linaperta, S. patagonica, S. cancellata, S. hornibrooki, S. velascoensis, S. triloculinoides, S. triangularis, S. trivialis, S. sp.,

Taxonomy

Citation: Subbotina patagonica (Todd and Kniker 1952)
Rank: Species
Basionym: Globigerina patagonica
Synonyms:
Taxonomic discussion: Blow (1979) regarded Subbotina patagonica as a cold water species (high latitude) that was related to Subbotina angiporoides. Indeed, the coarsely cancellate sacculifer-type wall texture and compact test links a group of subbotinids that has its origin in the Danian species Subbotina cancellata (Blow). Subbotina patagonica has not been widely recorded in stratigraphic studies, so that its geographic range is not well known. Its occurrence in the lower Eocene of the London Clay and in Trinidad suggests a widespread distribution. Bolli (1957) illustrated a morphotype from Zone P4 in the Lizard Springs Formation, Trinidad that he identified as Globigerina linaperta Finlay. This morphotype (USNM P5032), here illustrated in SEM for the first time (Plate 6.15, Figs. 12, 16), has a coarsely cancellate sacculifer-type wall texture and is referable to S. patagonica. Subbotina patagonica has not been widely recorded by workers, although it is possible that references to S. linaperta in the lower Eocene refer to this species [Olsson et al. 2006]

Catalog entries: Globigerina patagonica

Type images:

Distinguishing features: Test compact, low trochospiral, with 3-3½ rapidly enlarging chambers. Aperture arched, semicircular. Wall texture coarsely cancellate, sacculifer-type.

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: Subbotina patagonica is distinguished by its compact, low trochospiral test with 3-3½ rapidly enlarging chambers, its arched, semicircular aperture and its coarsely cancellate sacculifer-type wall texture. [Olsson et al. 2006]

Wall type: Coarsely cancellate (sacculifertype wall texture), normal perforate, spinose. [Olsson et al. 2006]

Test morphology: Test very low trochospiral, globular, slightly lobulate in outline, chambers globular, embracing; in spiral view 3-3½ globular, embracing chambers in ultimate whorl, increasing rapidly in size, sutures slightly depressed, straight, ultimate chamber large, about½ the test size; in umbilical view 3-3½ globular, embracing chambers, increasing rapidly in size, sutures slightly depressed, straight, umbilicus very small, nearly closed, aperture umbilical, a rounded arch, bordered by a thickened rim that may display a lip, ultimate chamber large making up about½ the test; in edge view chambers globular in shape, embracing. [Olsson et al. 2006]

Size: Maximum diameter of holotype 0.32 mm, thickness 0.23 mm. [Olsson et al. 2006]

Character matrix

test outline:Subquadratechamber arrangement:Trochospiraledge view:Equally biconvexaperture:Umbilical
sp chamber shape:Globularcoiling axis:Very lowperiphery:N/Aaperture border:Thick flange
umb chbr shape:Globularumbilicus:Narrowperiph margin shape:Broadly roundedaccessory apertures:None
spiral sutures:Weakly depressedumb depth:Shallowwall texture:Spinoseshell porosity:Finely Perforate: 1-2.5µm
umbilical or test sutures:Weakly depressedfinal-whorl chambers:3.0-3.5 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology


Geographic distribution: There are two occurrences so far recorded in high latitudes locations of the southern hemisphere, and in other low-mid latitude locations. [Olsson et al. 2006]
Aze et al. 2011 summary: Cosmopolitan; based on Olsson et al. (2006a)

Isotope paleobiology: Recorded by Boersma and others (1987) from DSDP Holes 525A and 548A with relatively positive ∂18O indicating a deep planktonic habitat. This interpretation is supported by the boron isotope data of Pearson and Palmer (1999). [Olsson et al. 2006]
Aze et al. 2011 ecogroup 4 - Open ocean sub-thermocline. Based on very light δ13C and very heavy δ18O. Sources cited by Aze et al. 2011 (appendix S3): Pearson & Palmer (1999); Coxall et al. (2000)

Phylogenetic relations: Subbotina patagonica is derived from S. cancellata (Blow) by an increase in the rate of chamber inflation and, in turn, gives rise to S. linaperta in the early Eocene. [Olsson et al. 2006]

Most likely ancestor: Subbotina cancellata - at confidence level 0 (out of 5). Data source: Olsson et al. 2006 f6.2.
Likely descendants: Subbotina linaperta;

Biostratigraphic distribution

Geological Range:
Notes: Subbotina patagonica ranges from Zone P4 in Trinidad to Zone E8. Huber (1991) recorded a range in ODP Hole 738C from Zone AP6a to Zone AP7 (early to mid Eocene), which suggests that the species has a less extended range in Eocene high latitudes than in lower latitudes. [Olsson et al. 2006]
Last occurrence (top): within E8 zone (43.85-45.72Ma, top in Lutetian stage). Data source: Eocene Atlas
First occurrence (base): within P4b subzone (57.79-60.52Ma, base in Selandian stage). Data source: Eocene Atlas

Plot of occurrence data:

Primary source for this page: Olsson et al. 2006 - Eocene Atlas, chap. 6, p. 154

References:

Bolli, H. M. (1957a). Planktonic foraminifera from the Eocene Navet and San Fernando formations of Trinidad. In, Loeblich, A. R. , Jr. , Tappan, H. , Beckmann, J. P. , Bolli, H. M. , Montanaro Gallitelli, E. & Troelsen, J. C. (eds) Studies in Foraminifera. U.S. National Museum Bulletin. 215: 155-172. gs

Huber, B. T. (1991c). Paleogene and Early Neogene Planktonic Foraminifer Biostratigraphy of Sites 738 and 744, Kerguelen Plateau (Southern Indian Ocean). Proceedings of the Ocean Drilling Program, Scientific Results. 119: 427-449. gs

Murray, J. W., Curry, D., Haynes, J. R. & King, C. (1989). Palaeogene. In, Jenkins, D. G. & Murray, J. W. (eds) Stratigraphical Atlas of Fossil Foraminifera. Ellis Horwood Limited, Chichester 228-267. gs

Olsson, R. K., Hemleben, C., Huber, B. T. & Berggren, W. A. (2006b). Taxonomy, biostratigraphy, and phylogeny of Eocene Globigerina, Globoturborotalita, Subbotina, and Turborotalita. 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 6): 111-168. gs

Pearson, P. N. & Palmer, M. R. (1999). Middle Eocene seawater pH and atmospheric carbon dioxide concentrations. Science. 284: 1824-1826. gs

Todd, R. & Kniker, H. T. (1952). An Eocene foraminiferal fauna from the Agua Fresca shale of Magallanes Province, southernmost Chile. Cushman Foundation for Foraminiferal Research, Special Publication. no. 1: 1-28. gs


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Subbotina patagonica compiled by the pforams@mikrotax project team viewed: 22-10-2019

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