Globoturborotalita paracancellata


Classification: pf_cenozoic -> Globigerinidae -> Globoturborotalita -> Globoturborotalita paracancellata
Sister taxa: G. tenella, G. rubescens, G. decoraperta, G. apertura, G. connecta, G. druryi, G. nepenthes, G. woodi, G. cancellata, G. occlusa, G. paracancellata, G. pseudopraebulloides, G. barbula, G. bassriverensis, G. brazieri, G. eolabiacrassata, G. euapertura, G. gnaucki, G. labiacrassata, G. martini, G. ouachitaensis, G. sp.,

Taxonomy

Citation: Globoturborotalita paracancellata Olsson and Hemleben, in Spezzaferri et al. 2018
Rank: species
Taxonomic discussion:

Blow and Banner (1962) derived “ Globigerinoides” from their subspecies Globigerina praebulloides occlusa. However, we do not retain here this lineage (see Chapter 9, this volume). According to our observations, the origin of the genus Trilobatus is preceded by morphotypes typified by Globoturborotalita paracancellata n. sp., which is hypothesized as the ancestral species.[Spezzaferri et al. 2018]

Catalog entries: Globoturborotalita paracancellata

Type images:

Distinguishing features:

Like G. cancellata but only 3½ chambers in the final whorl and final chamber forms about ½ the test. 

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:

Globoturborotalita paracancellata has a subbotinid-type morphology but differs in possessing a reticulate globoturborotalitid ruber/sacculifer-type wall and a thickened rim bordering the circular to moderately high arched aperture instead of a lip, as is typical of Subbotina. Globoturborotalita cancellata can be distinguished from G. paracancellata by having only 3½ chambers in the final whorl and a lower pore density than G. paracancellata. Globoturborotalita cancellata also has a generally smaller test. It differs from G. occlusa by the more open umbilical and higher arched aperture, bordered by a narrow rim that is absent in G. occlusa. It differs from G. woodi and G. brazieri by the lower arched aperture and by its 3½ chambers in the last whorl. G. connecta has a remarkably lower arched aperture. It differs from G. ouachitaensis also by its larger size and G. pseudopraebulloides Olsson and Hemleben n. sp. by having an apertural rim. [Spezzaferri et al. 2018]


Wall type: Normal perforate, spinose, ruber/sacculifer-type wall texture, an average of 17 pores/50 μm2 test surface area.

Test morphology: Low trochospiral, consisting of 3 whorls, globular, moderately lobulate profile, chambers globular; in spiral view 3½ globular, slightly embracing chambers in ultimate whorl, increasing rapidly in size, sutures depressed, straight; in umbilical view 3½ globular, slightly embracing chambers, increasing rapidly in size, sutures depressed, straight, umbilicus small, open, enclosed by surrounding chambers, aperture umbilical, a rounded arch, bordered by a thin thickened rim; in edge view chambers globular, slightly embracing, initial whorl of chambers flat. [Spezzaferri et al. 2018]

Size: Maximum diameter of holotype 0.43 mm, minimum diameter 0.32 mm, thickness 0.30 mm. [Spezzaferri et al. 2018]

Character matrix

test outline:Lobatechamber arrangement:Trochospiraledge view:Concavo-convexaperture:Umbilical
sp chamber shape:Globularcoiling axis:Lowperiphery:N/Aaperture border:Thick lip
umb chbr shape:Globularumbilicus:Wideperiph margin shape:Broadly roundedaccessory apertures:None
spiral sutures:Weakly depressedumb depth:Deepwall texture:Cancellateshell porosity:Macroperforate: >2.5µm
umbilical or test sutures:Moderately depressedfinal-whorl chambers:3.5-3.5 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology


Geographic distribution: Known so far in the western Atlantic Ocean and the U.S. Gulf Coast. Probably widespread in low to middle latitudes due to its ancestry to Trilobatus primordius. [Spezzaferri et al. 2018]

Isotope paleobiology: No data available. [Spezzaferri et al. 2018]

Phylogenetic relations: The species name paracancellata is chosen because it is believed that this species evolved from Globoturborotalita cancellata by a more rapid increase in chamber size and having 3½ chambers in the ultimate whorl and developing a ruber/sacculifer-type wall texture. [Spezzaferri et al. 2018]

Most likely ancestor: Globoturborotalita cancellata - at confidence level 3 (out of 5). Data source: .
Likely descendants: Globoturborotalita brazieri; Trilobatus primordius;

Biostratigraphic distribution

Geological Range:
Notes: The illustrated specimens on Plate 8.12 range from Zone O1 to Zone O6. We have identified the species in samples from the uppermost Eocene Zone E16. [Spezzaferri et al. 2018]
Last occurrence (top): within O6 zone (25.21-26.93Ma, top in Chattian stage). Data source: Spezzaferri et al. 2018
First occurrence (base): within E16 zone (33.90-34.68Ma, base in Priabonian stage). Data source: Spezzaferri et al. 2018

Plot of occurrence data:

Primary source for this page: Spezzaferri et al. 2018 - Olig Atlas chap.8 p.259

References:

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

Spezzaferri, S., Olsson, R. K., Hemleben, C., Wade, B. S. & Coxall, H. K. (2018c). Taxonomy, biostratigraphy, and phylogeny of Oligocene and Lower Miocene Globoturborotalita. 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: 231-269. gs


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Globoturborotalita paracancellata compiled by the pforams@mikrotax project team viewed: 21-8-2019

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