Globoturborotalita labiacrassata


Classification: pf_cenozoic -> Globigerinidae -> Globoturborotalita -> Globoturborotalita labiacrassata
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 labiacrassata (Jenkins, 1965)
Rank: species
Basionym: Globigerina labiacrassata Jenkins, 1965
Synonyms:
Taxonomic discussion:

Jenkins (1965) described this species as possessing a finely pitted wall texture possibly merging into G. bulloides population at the end of its range. However, based on its ruber/sacculifer-type wall texture, it is clear that G. labiacrassata is not related to the G. bulloides group. Jenkins (1965) documented specimens within the population of labiacrassata with a ‘low arched aperture’ resembling G. connecta and displaying strong variation in the thickness of the rim bordering the aperture. Here we restrict the concept of G. labiacrassata to specimens that closely resemble the holotype; i.e. showing the lobulate profile, and a high arched open aperture bordered by a highly thickened rim. Little information was previously available on the ancestry of G. labiacrassata, which appears to be distinct from the G. woodi clade that lacks a thickened apertural rim. Identification of G. eolabiacrassata Spezzaferri and Coxall, n. sp., which also possesses a thickened apertural rim, provides an ancestral link to Eocene species of Globoturborotalita. [Spezzaferri et al. 2018]

Catalog entries: Globigerina labiacrassata

Type images:

Distinguishing features:

Like G. eolabiacrassata but with more lobulate profile and higher arched aperture.

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 labiacrassata is distinguished from the other 4 chambered Globoturborotalita including G. woodi, G. brazieri, G. cancellata, G. paracancellata and G. occlusa by its higher arched, symmetrical umbilical aperture, which is always bordered by a very thick rim. It differs from G. eolabiacrassata n. sp. (Plate 8.5) by its more lobulate profile and higher arched aperture. It differs from G. gnaucki by having only 4 chambers in the last whorl instead of 4½ and by the much thicker and more prominent rim bordering the aperture. [Spezzaferri et al. 2018]


Wall type: Normal perforate, spinose, ruber/sacculifer-type wall texture, the strong cancellation is often not visible because of calcitic overgrowth, an average of 22 pores/50 μm2 test surface area.

Test morphology: Low trochospiral, consisting of 2½ whorls, strongly lobulate in outline, 4 subglobular chambers visible in the last whorl on both sides, increasing slowly in size, sutures depressed, straight to slightly curved on both sides; umbilicus large and open, primary aperture umbilical, a symmetrical, rounded very high arch, bordered by a very thick rim. [Spezzaferri et al. 2018]

Size: Maximum diameter of holotype 0.50 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:4.0-4.0 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology


Geographic distribution: Dominant in the high southern hemisphere. It is recorded as being common in the South Atlantic and South Pacific Oceans (Spezzaferri, 1994), and very common in Australia and New Zealand (Jenkins, 1965). [Spezzaferri et al. 2018]

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

Phylogenetic relations: Globoturborotalita labiacrassata probably evolved from G. eolabiacrassata in the lower Oligocene through modifications to the final chamber that produced a more lobulate periphery, a more highly arched aperture and a thicker apertural rim. [Spezzaferri et al. 2018]

Most likely ancestor: Globoturborotalita eolabiacrassata - at confidence level 3 (out of 5). Data source: Spezzaferri et al. 2018.

Biostratigraphic distribution

Geological Range:
Notes: Jenkins (1965) identified the range of G. labiacrassata from the S. angiporoides angiporoides Zone (lower Oligocene, Zone O2) to the lower part of the G. dehiscens Zone (lower Miocene, upper part of Zone M1). Huber and Quillévéré (2005) record this species from the lower to middle Zone AO1 (around Zone O1/O2 boundary). Berggren and others (1995) and Huber (1991) have constrained from multiple sites the LAD of this species to the upper Oligocene (Chron C8n-C9n) and this biohorizon is used to define the AO3/AO4 biozone boundary in the most recent Antarctic Oligocene zonation scheme (Huber and Quillévéré, 2005). However, we note specimens resembling G. labiacrassata that can be traced up to Subzone M1b (Pl. 8.8, Figs. 10-15). [Spezzaferri et al. 2018]
Last occurrence (top): within M1b subzone (21.12-22.44Ma, top in Aquitanian stage). Data source: Spezzaferri et al. 2018 f8.1
First occurrence (base): within O2 zone (30.28-32.10Ma, base in Rupelian stage). Data source: Spezzaferri et al. 2018 f8.1

Plot of occurrence data:

Primary source for this page: Spezzaferri et al. 2018 - Olig Atlas chap.8 p.250

References:

Berggren, W. A. (1992). Paleogene planktonic foraminifer magnetobiostratigraphy of the southern Kerguelen Plateau (sites 747-749). Proceedings of the Ocean Drilling Program, Scientific Results. 551-568. gs

Berggren, W. A., Kent, D. V., Swisher, I. , C. C. & Aubry, M. -P. (1995b). A revised Cenozoic geochronology and chronostratigraphy. In, Berggren, W. A. , Kent, D. V. , Aubry, M. -P. & Hardenbol, J. (eds) Geochronology, Time Scales and Global Stratigraphic Correlations. SEPM (Society for Sedimentary Geology) Special Publication No. 54, 129-212. gs

Huber, B. T. & Quillévéré, F. (2005). Revised Paleogene planktic foraminiferal biozonation for the Austral Realm. Journal of Foraminiferal Research. 35: 299-314. 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

Jenkins, D. G. (1965b). Planktonic Foraminiferal zones and new taxa from the Danian to lower Miocene of New Zealand. New Zealand Journal of Geology and Geophysics. 8(6): 1088-1126. gs

Jenkins, D. G. (1971). New Zealand Cenozoic Planktonic Foraminifera. New Zealand Geological Survey, Paleontological Bulletin. 42: 1-278. gs

Nocchi, M., Amici, E. & Premoli Silva, I. (1991). Planktonic foraminiferal biostratigraphy and paleoenvironmental interpretation of Paleogene faunas from the subantarctic transect, Leg 114. Proceedings of the Ocean Drilling Program, Scientific Results. 114: 233-273. gs

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., 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(Chap 8): 231-268. gs

Stott, L. D. & Kennett, J. P. (1990). The Paleoceanographic and Paleoclimatic signature of the Cretaceous/Paleogene boundary in the Antarctic: Stable isotopic results from ODP Leg 113. Proceedings of the Ocean Drilling Program, Scientific Results. 113: 829-848. gs


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Globoturborotalita labiacrassata compiled by the pforams@mikrotax project team viewed: 17-11-2019

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