Subbotina projecta


Classification: pf_cenozoic -> Globigerinidae -> Subbotina -> Subbotina projecta
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 projecta Olsson, Pearson, and Wade, in Wade et al. 2018
Rank: species
Synonyms:
Taxonomic discussion:

This species was referred to as “Subbotina sp. 2” in Wade and Pearson (2008). “Our specimens show clear spine holes indicating a spinose condition in life. The relatively free, loosely attached spherical chambers establish the relationship with other Subbotina species” rather than Dentoglobigerina (Pearson and Wade, 2015:16). [Wade et al. 2018]

Catalog entries: Subbotina projecta

Type images:

Distinguishing features:

Like S. tecta but with higher trochospiral coiling, wider, deeper, and squarer umbilicus; also the teeth are often elongate 

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 equatorial outline is in general diamond-shaped with chambers arranged in a cross. Subbotina projecta n. sp. is closely related to S. tecta “but is distinguished by its higher trochospiral coiling, wider, deeper, and generally more square umbilicus and detailed morphology of the teeth, which, although highly variable, can be quite elongate and are generally rimmed by a thin lip of constant thickness. It is distinguished from S. yeguaensis by its smaller size, more globular chambers, more incised umbilical sutures and by possessing true teeth rather than a broad, tapering lip” (Pearson and Wade, 2015:15). As seen in the synonymy list above, this morphotype has previously been attributed to Dentoglobigerina globularis (Bermúdez). However the SEMs of the holotype of globularis reveal a quite different general morphology, with more radially compressed and appressed chambers (see Chapter 11, this volume). [Wade et al. 2018]


Wall type: Cancellate, spinose ruber/sacculifer-type wall texture.

Test morphology: “Test large, globular, 10 to 13 chambers arranged in three whorls, in a moderately high trochospiral, lobate, oval in outline, chambers spherical to subspherical; in spiral view 3½- 4 globular, embracing chambers in final whorl, increasing gradually in size, sutures straight or gently curved, moderately incised; in umbilical view 3½ globular chambers, increasing moderately rapidly in size, sutures depressed to incised, straight, umbilicus wide, square, deep, aperture umbilical, usually with teeth projecting into umbilicus from one or more chambers. Teeth vary from small and triangular to narrow elongate projections, often with a distinct rim or lip around the edges of the tooth that connect with the apertural lip; in edge view chambers globular in shape, embracing, teeth leaning into the umbilicus” (Pearson and Wade, 2015:18). [Wade et al. 2018]

Size: Maximum diameter of holotype 0.50 mm. [Wade et al. 2018]

Character matrix

test outline:Lobatechamber arrangement:Trochospiraledge view:Equally biconvexaperture:Umbilical
sp chamber shape:Inflatedcoiling axis:Lowperiphery:N/Aaperture border:Tooth
umb chbr shape:Globularumbilicus:Wideperiph margin shape:Broadly roundedaccessory apertures:None
spiral sutures:Moderately depressedumb depth:Deepwall texture:Spinoseshell porosity:Finely Perforate: 1-2.5µm
umbilical or test sutures:Moderately depressedfinal-whorl chambers:3.5-4.0 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology


Geographic distribution: Probably restricted to low latitudes; currently known from the Gulf of Mexico, Indian Ocean (Tanzania), equatorial Pacific Ocean (ODP Sites 1218 and 803) and equatorial Atlantic Ocean (ODP Site 628). [Wade et al. 2018]

Isotope paleobiology: Multispecies stable isotope analysis from the lower Oligocene Zone O1 at Tanzania Drilling Project Site 12 indicates a positive δ18O signal consistent with a thermocline dwelling habitat (Wade and Pearson, 2008). [Wade et al. 2018]

Phylogenetic relations: Subbotina projecta n. sp. probably developed from S. tecta in the uppermost Eocene. [Wade et al. 2018]

Most likely ancestor: Subbotina tecta - at confidence level 2 (out of 5). Data source: Wade et al. 2018.

Biostratigraphic distribution

Geological Range:
Notes: Subbotina projecta n. sp. appears in the upper Eocene Zone E16 (Wade and Pearson, 2008 referred to as Subbotina sp. 2) and ranges through the Oligocene. Wade and others (2007) found specimens in upper Oligocene Zone O5, and Leckie and others (1993) have recorded specimens of Subbotina ? yeguaensis that are consistent with Subbotina projecta n. sp. in the uppermost Oligocene Zone O7 at ODP Sites 628 and 803. [Wade et al. 2018]
Last occurrence (top): within O7 zone (22.96-25.21Ma, top in Aquitanian stage). Data source: Wade et al. 2018 f.10.1
First occurrence (base): within E16 zone (33.90-34.68Ma, base in Priabonian stage). Data source: Wade et al. 2018

Plot of occurrence data:

Primary source for this page: Wade et al. 2018 - Olig Atlas chap.10 p.322

References:

Bermudez, P. J. (1961). Contribucion al estudio de las Globigerinidea de la region Caribe-Antillana (Paleoceno-Reciente). Editorial Sucre, Caracas. 1119-1393. gs :: ::

Blow, W. H. & Banner, F. T. (1962). The mid-Tertiary (Upper Eocene to Aquitanian) Globigerinaceae. In, Eames, F. E. , Banner, F. T. , Blow, W. H. & Clarke, W. J. (eds) Fundamentals of mid-Tertiary Stratigraphical Correlation. Cambridge University Press, Cambridge 61-151. gs :: ::

Gümbel, C. W. (1868). Beiträge zur Foraminiferenfauna der nordalpinen, älteren Eocängebilde oder der Kressenberger Nummulitenschichten. Abhandlungen der K. Bayerische Akademie der Wissenschaften, Cl. II,. 10(2): 579-730. gs :: ::

Leckie, R. M., Farnham, C. & Schmidt, M. G. (1993). Oligocene planktonic foraminifer biostratigraphy of Hole 803D (Ontong Java Plateau) and Hole 628A (Little Bahama Bank), and comparison with the southern high latitudes. Proceedings of the Ocean Drilling Program, Scientific Results. 130: 113-136. gs :: ::

Pearson, P. N. & Wade, B. S. (2015). Systematic taxonomy of exceptionally well-preserved planktonic foraminifera from the Eocene/Oligocene boundary of Tanzania. Cushman Foundation for Foraminiferal Research, Special Publication. 45: 1-85. 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. 62: 1-425. gs :: ::

Wade, B. S. & Pearson, P. N. (2008). Planktonic foraminiferal turnover, diversity fluctuations and geochemical signals across the Eocene/Oligocene boundary in Tanzania. Marine Micropaleontology. 68: 244-255. gs :: ::

Wade, B. S., Berggren, W. A. & Olsson, R. K. (2007). The biostratigraphy and paleobiology of Oligocene planktonic foraminifera from the Equatorial Pacific Ocean (ODP Site 1218). Marine Micropaleontology. 62: 167-179. gs :: ::

Wade, B. S., Olsson, R. K., Pearson, P. N., Edgar, K. M. & Premoli Silva, I. (2018a). Taxonomy, biostratigraphy, and phylogeny of Oligocene Subbotina. 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 10): 307-330. gs :: ::

Weinzierl, L. L. & Applin, E. R. (1929). The Claiborne Formation on the Coastal Domes. Journal of Paleontology. 3(4): 384-410. gs :: ::


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Subbotina projecta compiled by the pforams@mikrotax project team viewed: 7-7-2020

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