pforams@mikrotax - Globoturborotalita labiacrassata

Citation: Globoturborotalita labiacrassata (Jenkins, 1966)

Basionym: Globigerina labiacrassata Jenkins, 1966

Synonyms:

Globigerina labiacrassata Jenkins, 1966:1102, fig. 8, no. 64-71 [lower Oligocene, Earthquake Section, Waitaki Valley, New Zealand].—Stott and Kennett, 1990:559, pl.7, fig. 1 [upper Oligocene Zone AP14a (= AO2, Huber and Quillévéré, 2005), DSDP Hole 690B, Maud Rise, South Atlantic Ocean].—Nocchi and others, 1991:pl. 5, figs. 11, 12 [Zone P22, upper Oligocene, ODP Site 703A, Kerguelen Plateau, southern Indian Ocean].—Berggren, 1992a:563, pl. 4, figs. 13, 14 [upper Oligocene ‘G. suteri Zone’ (= AO2 of Huber and Quillévéré, 2005), ODP Hole 749B, Kerguelen Plateau, southern Indian Ocean].
Globigerina (Globigerina) labiacrassata Jenkins.—Jenkins, 1971:151, pl. 16, figs. 474-484 [lower Oligocene, Earthquake Section, Waitaki Valley, New Zealand].
Zeaglobigerina labiacrassata (Jenkins).—Spezzaferri, 1994:33, pl. 6, figs. 2a-c [lower Oligocene Subzone P21a, DSDP Site 526A, South Atlantic Ocean].
Not Globoturborotalita labiacrassata (Jenkins).—Huber, 1991:pl. 5, fig. 16 [lower Oligocene, Zone AP14, ODP Site 744A, Kerguelen Plateau, southern Indian Ocean] (= G. eolabiacrassata n. sp.).
Not Zeaglobigerina labiacrassata (Jenkins).—Spezzaferri, 1994:33, pl. 4, fig.1a-c [lower Miocene, Subzone N4b, ODP Site 667A, equatorial Atlantic Ocean] (= G. eolabiacrassata n. sp.).

Taxonomic discussion:

Jenkins (1966) 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 (1966) 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]

Distinguishing features:
Parent taxon (Globoturborotalita): Trochospiral test with a single, large, open umbilical aperture. Cancellate wall. 4-4½ chambers in final whorl
This taxon: Like G. eolabiacrassata but with more lobulate profile and higher arched aperture.

Description

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]

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.

Maximum diameter of holotype 0.50 mm. [Spezzaferri et al. 2018]

Biogeography and Palaeobiology

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, 1966). [Spezzaferri et al. 2018]

No data available. [Spezzaferri et al. 2018]

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]

Biostratigraphic distribution

Geological Range:
Notes: Jenkins (1966) 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

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. 120: 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

Huber, B. T., Olsson, R. K. & Pearson, P. N. (2006). Taxonomy, biostratigraphy, and phylogeny of Eocene microperforate planktonic foraminifera (Jenkinsina, Cassigerinelloita, Chiloguembelina, Streptochilus, Zeauvigerina, Tenuitella, and Cassigerinella) and Problematica (Dipsidripella). 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 16): 461-508. gs O

Jenkins, D. G. (1966b). Planktonic foraminiferal zones and new taxa from the Danian to lower Miocene of New Zealand. New Zealand Journal of Geology and Geophysics. 8 [1965](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. (2018d). 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

test outline:	Lobate	chamber arrangement:	Trochospiral	edge view:	Concavo-convex	aperture:	Umbilical
sp chamber shape:	Globular	coiling axis:	Low	periphery:	N/A	aperture border:	Thick lip
umb chbr shape:	Globular	umbilicus:	Wide	periph margin shape:	Broadly rounded	accessory apertures:	None
spiral sutures:	Weakly depressed	umb depth:	Deep	wall texture:	Cancellate	shell porosity:	Macroperforate: >2.5µm
umbilical or test sutures:	Moderately depressed	final-whorl chambers:	4-4	N.B. These characters are used for advanced search. N/A - not applicable