Globigerinella roeglina


Classification: pf_cenozoic -> Globigerinidae -> Globigerinella -> Globigerinella roeglina
Sister taxa: G. adamsi, G. calida, G. radians, G. siphonifera, G. clavaticamerata, G. molinae, G. navazuelensis, G. obesa, G. praesiphonifera, G. pseudobesa, G. roeglina, G. megaperta, G. wagneri, G. sp.,

Taxonomy

Citation: Globigerinella roeglina Spezzaferri and Coxall, in Spezzaferri et al. 2018
Rank: species
Synonyms:
Taxonomic discussion:

Globigerinella roeglina is here established as a new species because its typical morphology is recurrent in the investigated samples and, although generally small, it does not seem to be a juvenile form. Rather it looks like the “base” morphology from which the extreme clavate species of Quiltyella (Q. nazcaensis, and Q. clavacella) evolve. This species shows a moderate intraspecific variability, with specimens characterized by a slightly radially elongated or smaller last chamber. The species was previously identified by Spezzaferri (1994) and informally called “Protentella sp.”. It is here attributed to the genus Globigerinella because of the typical wall texture and because of its tendency to a planispiral coiling mode, even if rarely reached. [Spezzaferri et al. 2018]

Catalog entries: Globigerinella roeglina,

Type images:

Distinguishing features: Like G. obesa but aperture higher and with thick rim, and last chamber slightly radially elongated

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 distinctive characters of G. roeglina are the thick rim bordering the aperture and the presence of a last slightly radially elongated chamber. It differs from G. obesa by the higher arched aperture bordered by the thick rim and from G. clavaticamerata by its less developed elongated last chamber and by the thick rim bordering the aperture instead of a small lip typical of G. clavaticamerata. [Spezzaferri et al. 2018]


Wall type: Spinose, spines are supported by spine collars, which coalesce to form ridges. Pore concentrations average 80 pores/50 μm2 test surface area and pore diameters average 1.5 μm.

Test morphology: Test low trochospiral consisting of 2 whorls, slightly tending to planispiral, lobulate in outline, chambers globular 4-5 in the last whorl, increasing rapidly in size, if present the last chamber may be either slightly radially elongated or smaller that the last chamber. Sutures are depressed, straight on both sides; the umbilicus is moderately small, open, enclosed by surrounding chambers, aperture an umbilical-extraumbilical high arch sometimes tending to move to completely extraumbilical, bordered by an imperforate and very thick rim. [Spezzaferri et al. 2018]

Size: Maximum diameter of holotype around 0.35 mm. [Spezzaferri et al. 2018]

Character matrix

test outline:Lobatechamber arrangement:Pseudoplanispiraledge view:Equally biconvexaperture:Umbilical-extraumbilical
sp chamber shape:Globularcoiling axis:Very lowperiphery:N/Aaperture border:Thick lip
umb chbr shape:Globularumbilicus:Wideperiph margin shape:Broadly roundedaccessory apertures:None
spiral sutures:Strongly depressedumb depth:Deepwall texture:Cancellateshell porosity:Macroperforate: >2.5µm
umbilical or test sutures:Strongly depressedfinal-whorl chambers:4.0-5.0 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology


Geographic distribution: Found at low latitudes in the Gulf of Mexico, tropical Indian Ocean and Paratethys sequences of Transylvania. [Spezzaferri et al. 2018]

Isotope paleobiology: Unpublished data of S. Spezzaferri indicate a deep water habitat for this species. [Spezzaferri et al. 2018]

Phylogenetic relations: Probably evolved from Globigerinella obesa in the upper lower Oligocene Zone O4. [Spezzaferri et al. 2018]

Most likely ancestor: Globigerinella obesa - at confidence level 3 (out of 5). Data source: Spezzaferri et al. 2018.
Likely descendants: Quiltyella clavacella;

Biostratigraphic distribution

Geological Range:
Notes: Sporadic occurrence from lower Oligocene Zone O4 to possibly lower/mid -Miocene Zone M5 (Spezzaferri, 1994). [Spezzaferri et al. 2018]
Last occurrence (top): within M5 zone (15.10-16.38Ma, top in Langhian stage). Data source: Spezzaferri et al. 2018
First occurrence (base): within O4 zone (28.09-29.18Ma, base in Rupelian stage). Data source: Spezzaferri et al. 2018

Plot of occurrence data:

Primary source for this page: Spezzaferri et al. 2018 - Olig Atlas chap.6 p.202

References:

Spezzaferri, S. (1994). Planktonic foraminiferal biostratigraphy and taxonomy of the Oligocene and lower Miocene in the oceanic record. An overview. Palaeontographia Italica. 81: 1-187. gs

Spezzaferri, S., Coxall, H. K., Olsson, R. K. & Hemleben, C. (2018a). Taxonomy, biostratigraphy, and phylogeny of Oligocene Globigerina, Globigerinella, and Quiltyella n. gen. 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: 179-215. gs

Srinivasan, M. S. & Kennett, J. P. (1974a). A planktonic foraminifer (Clavatorella) from the Pliocene. Journal of Foraminiferal Research. 4(2): 77-79. gs

van Eijden, A. J. M. & Smit, J. (1991). Eastern Indian Ocean Cretaceous and Paleogene quantitative biostratigraphy. Proceedings of the Ocean Drilling Program, Scientific Results. 121: 77-123. gs


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Globigerinella roeglina compiled by the pforams@mikrotax project team viewed: 20-7-2019

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