Globoturborotalita brazieri


Classification: pf_cenozoic -> Globigerinidae -> Globoturborotalita -> Globoturborotalita brazieri
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 brazieri (Jenkins, 1966)
Rank: species
Basionym: Globigerina brazieri Jenkins 1966
Synonyms:
Taxonomic discussion:

Jenkins (1965) and Chaproniere (1988) distinguished G. brazieri from G. woodi on the basis of the aperture, which in G. brazieri is higher arched, more rounded and resembles a reverse droplet, commonly higher than it is wide, and on the chambers in the last whorl that increase more rapidly in size in G. brazieri. Kennett and Srinivasan (1983) describe the aperture of G. brazieri as symmetrically placed over the sutures of the penultimate and antepenultimate chambers. Retained here in the species G. brazieri are specimens possessing an aperture tending towards a reverse droplet shape together, as documented in the paratypes of Jenkins (1965), with those with a more rounded aperture typical of the holotype. Although paratype 5 of Jenkins (1965) shows a bulla covering the aperture, this structure has not been observed in our material.

Jenkins (1965) suggested that G. brazieri evolved from G. woodi in the lower Miocene and identified the range of G. brazieri as restricted to the lower Miocene (from the Globoquadrina dehiscens Zone to the lower part of the Globigerina woodi connecta Zone = interval spanning Zones O7 to M1). However, Premoli Silva and Spezzaferri (1990) found this species occurring in Zone P20 in the Indian Ocean, and Spezzaferri (1994) recorded it in Subzone P21a in DSDP Holes 354 and 667A (equatorial Atlantic Ocean), 526A, 363 360, 516F (South Atlantic Ocean) and ODP Hole 709C (Indian Ocean). Thus, within our taxonomic and stratigraphic framework we suggest that G. brazieri was the ancestor of G. woodi and that G. brazieri evolved from G. paracancellata n. sp.

[Spezzaferri et al. 2018]

Catalog entries: Globigerina brazieri

Type images:

Distinguishing features: Like G. woodi but subquadrate test and aperture placed directly opposite the suture line

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 brazieri is distinguished from all 4 chambered Globoturborotalita, including G. woodi, by its high, symmetrical umbilical aperture, often circular or higher than wide, tending towards a reverse droplet shape. It differs from G. woodi also by its less lobulate and more compact subquadrate profile, but, as pointed out by Jenkins (1971), with a more rapid rate of chamber size increase in the final whorl. It also differs from G. cancellata by its less lobulate profile and the ruber/sacculifer-type wall texture instead of sacculifer-type, and from G. paracancellata n. sp. and G. occlusa by its subquadrate profile and the higher arched aperture. [Spezzaferri et al. 2018]


Wall type: Normal perforate, spinose, ruber/sacculifer-type wall texture with an average of 18 pores/50 μm2 test surface area. [Spezzaferri et al. 2018]

Test morphology: Low trochospiral, consisting of 3 whorls, subquadrate and poorly to moderately lobulate in profile, chambers subglobular; in spiral view 3½-4 subglobular, slightly embracing chambers in ultimate whorl, increasing rapidly in size, the last chamber may vary from slightly to strongly subquadrate, sutures depressed, straight to slightly curved; in umbilical view 3-3½ subglobular, slightly embracing chambers, increasing rapidly in size, sutures depressed, straight to slightly curved, umbilicus relatively wide, deep and open, enclosed by surrounding chambers, aperture umbilical, a symmetrical, rounded high arch, reverse drop-like with lower terminations joining at their base, it may be bordered by a thick rim. [Spezzaferri et al. 2018]

Size: Maximum diameter of holotype 0.45 mm. [Spezzaferri et al. 2018]

Character matrix

test outline:Subquadratechamber arrangement:Trochospiraledge view:Equally biconvexaperture:Umbilical
sp chamber shape:Globularcoiling axis:Low-moderateperiphery:N/Aaperture border:Thin 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:3.5-4.0 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology


Geographic distribution: Very common in Australia, New Zealand and Tasman Sea, it is also present and sometimes very abundant in the Gulf of Mexico, South Atlantic, Pacific and Indian Oceans. [Spezzaferri et al. 2018] Temperate to warm subtropical [Kennett & Srinivasan 1983] Low to middle latitudes [Aze et al. 2011, based on Kennett & Srinivasan (1983)]

Isotope paleobiology: Recent isotope data (Spezzaferri, unpublished) suggest a mixed-layer and shallow-water habitat for this species. [Spezzaferri et al. 2018] Aze et al. 2011 ecogroup 1 - Open ocean mixed-layer tropical/subtropical, with symbionts. Based on very heavy ∂13C and relatively light ∂18O. Sources cited by Aze et al. 2011 (appendix S3): this study

Phylogenetic relations: Globoturborotalita brazieri probably evolved from G. paracancellata by developing a more subquadrate profile and a higher but less wide, arched, and typically inverse drop-like, umbilical aperture. [Spezzaferri et al. 2018]

G. brazieri is distinguished from G. woodi by its subquadrate test and by the apertural placement directly opposite the suture line. Similarities in surface  ultrastructure and presence of morphologically transitional forms indicate that G. brazieri was derived from G. woodi. [Kennett & Srinivasan 1983, followed by Aze et al. 2011]

Most likely ancestor: Globoturborotalita paracancellata - at confidence level 2 (out of 5). Data source: Spezzaferri et al. 2018.
Likely descendants: Globoturborotalita woodi;

Biostratigraphic distribution

Geological Range:
Notes: This species has been observed from Zone O3 (Subzone P21a of Premoli Silva and Spezzaferri, 1990) in the Indian Ocean ODP Hole 709B to Zone M4? (Kennett and Srinivasan, 1983). According to Huber (1991) it disappears within Chron C6N at the Kerguelen Plateau. [Spezzaferri et al. 2018]
Last occurrence (top): within M4 zone (16.38-17.54Ma, top in Burdigalian stage). Data source: Kennett & Srinivasan 1983
First occurrence (base): within O3 zone (29.18-30.28Ma, base in Rupelian stage). Data source: Kennett & Srinivasan 1983

Plot of occurrence data:

Primary source for this page: Spezzaferri et al. 2018 - Olig Atlas chap.8 p.225; Kennett & Srinivasan 1983, p.43

References:

Blow, W. H. (1959). Age, correlation, and biostratigraphy of the upper Tocuyo (San Lorenzo) and Pozon Formations, eastern Falcon, Venezuela. Bulletins of American Paleontology. 39(178): 67-251. gs :: ::

Chaproniere, G. C. H. (1988). Globigerina woodi from the late Oligocene and early Miocene of southeastern Australia. Journal of Foraminiferal Research. 18: 105-115. gs :: ::

Huber, B. T. (1991). 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. (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 :: ::

Kennett, J. P. & Srinivasan, M. S. (1983). Neogene Planktonic Foraminifera. Hutchinson Ross Publishing Co., Stroudsburg, Pennsylvania. 1-265. gs :: ::

Premoli Silva, I. & Spezzaferri, S. (1990). Paleogene planktonic foraminifer biostratigraphy and paleoenvironmental remarks on paleogene sediments from Indian Ocean sites, Leg 115. Proceedings of the Ocean Drilling Program, Scientific Results. 115: 277-314. 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. (2018). 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 :: ::


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Globoturborotalita brazieri compiled by the pforams@mikrotax project team viewed: 12-7-2020

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