Globanomalina australiformis


Classification: pf_cenozoic -> Globanomalidae -> Globanomalina -> Globanomalina australiformis
Sister taxa: G. australiformis, G. luxorensis, G. ovalis, G. imitata, G. planocompressa, G. planoconica, G. chapmani, G. pseudomenardii, G. ehrenbergi, G. compressa, G. archeocompressa, G. sp.,

Taxonomy

Citation: Globanomalina australiformis (Jenkins 1966)
Rank: Species
Basionym: Globorotalia australiformis
Synonyms:
Taxonomic discussion: The original description of this species by light microscope indicated a smooth, finely perforate wall, but SEM micrographs show a fine coating of pustule-like calcite covering the original wall. It is possible that this coating is of gametogenetic origin, but this possibility needs more study. The species has been reported only in southern latitude sites and may be biogeographically restricted. Blow (1979) suggested that G. australiformis may be a cool-water endemic form of the tropical Globorotalia troelseni Loeblich and Tappan morphotype due to its general morphologic similarity. Globorotalia troelseni (= G. chapmani Parr, 1938) is a 5-chambered species and does not possess the dense pustulose wall surface of G. australiformis. It would appear that G. australiformis arose independently as an endemic species in the southern high latitudes. Blow also placed specimens identified as Globorotalia elongata Glaessner, 1937a, by Loeblich and Tappan (1957a) from the Vincentown Formation of New Jersey and from the Velasco Shale of Mexico in synonymy with G. australiformis. Those specimens belong to G. chapmani. [Olsson et al. 1999]

Catalog entries: Globorotalia australiformis

Type images:

Distinguishing features: Test small. Final whorl with 4 low conical chambers and an acute axial periphery. Axial periphery imperforate, becoming thickened on the last chambers.

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: This small species is distinguished by having 4 low conical shaped chambers in the ultimate whorl and an acute axial periphery. The earlier chamber walls are covered by a fine, dense pustules which become more sparsely distributed on the penultimate and ultimate chambers. The axial periphery is imperforate for the most part and becomes thickened on the last one or two chambers. [Olsson et al. 1999]

Character matrix

test outline:Lobatechamber arrangement:Trochospiraledge view:Inequally biconvexaperture:Umbilical-extraumbilical
sp chamber shape:Inflatedcoiling axis:Lowperiphery:N/Aaperture border:Thick lip
umb chbr shape:Inflatedumbilicus:Narrowperiph margin shape:Broadly roundedaccessory apertures:None
spiral sutures:Strongly depressedumb depth:Deepwall texture:Smoothshell porosity:Finely Perforate: 1-2.5µm
umbilical or test sutures:Strongly 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: Southern middle to high latitudes (Figure 16). [Olsson et al. 1999]
Aze et al. 2011 summary: Southern middle to high latitudes; based on Olsson et al. (1999)

Isotope paleobiology: No data available. [Olsson et al. 1999]
Aze et al. 2011 ecogroup 3 - Open ocean thermocline. Based on light δ13C and relatively heavy δ18O. Sources cited by Aze et al. 2011 (appendix S3): this study

Phylogenetic relations: The origin of this species has not been traced. Jenkins (1965) notes that australiformis is closely related to many Paleocene smooth-walled species (of Globanomalina) and that it replaces G. pseudomenardii Bolli, 1957a, in the lower part of the Waipawan Stage. It would appear more closely related to G. imitata in having 4-4_ (mostly 4) chambers in the final whorl and in the dense pustulose wall surface observed in early chambers of this species (see Plate 4: Figures 12, 13, 16; Plate 36: Figures 8, 12). [Olsson et al. 1999]

Most likely ancestor: Globanomalina imitata - at confidence level 4 (out of 5). Data source: Olsson & Hemleben 2006, fig14.1.
Likely descendants: Turborotalia frontosa;

Biostratigraphic distribution

Geological Range:
Notes: Lower part of Waipawan Stage to the Porangan Stage; upper Subbotina triloculinoides Zone to the P. primitiva Zone (upper Paleocene to lower Eocene). [Olsson et al. 1999]
Last occurrence (top): in upper part of E9 zone (80% up, 43.4Ma, in Lutetian stage). Data source: Olsson & Hemleben 2006, fig14.1
First occurrence (base): near base of P5 zone (10% up, 57Ma, in Thanetian stage). Data source: Olsson et al. 1999, fig 5a

Plot of occurrence data:

Primary source for this page: Olsson et al. 1999 - Atlas of Paleocene Planktonic Foraminifera, p. 38

References:

Glaessner, M. F. (1937a). Planktonforaminiferen aus der Kreide und dem Eozän und ihre stratigraphische Bedeutung. Etyudy po Mikropaleontologiy, Paleontologicheskaya Laboratoriya Moskovskogo Gosudarstvennogo Universiteta. [Studies in Micropaleontology, Publications of the Laboratory of Paleontology, Moscow University]. 1(1): 27-46. 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. (1966b). Planktonic foraminiferal zones and new taxa from the Danian to lower Miocene of New Zealand. New Zealand Journal of Geology and Geophysics. 8: 1088-1126. gs

Loeblich, A. R. & Tappan, H. (1957b). Planktonic foraminifera of Paleocene and early Eocene Age from the Gulf and Atlantic coastal plains. In, Loeblich, A. R. , Jr. , Tappan, H. , Beckmann, J. P. , Bolli, H. M. , Montanaro Gallitelli, E. & Troelsen, J. C. (eds) Studies in Foraminifera. U.S. National Museum Bulletin. 215: 173-198. gs

Olsson, R. K., Hemleben, C., Berggren, W. A. & Huber, B. T. (1999). Atlas of Paleocene Planktonic Foraminifera. Smithsonian Institution Press, Washington, DC. 1-252. gs

Parr, W. J. (1938). Upper Eocene Foraminifera from Deep Borings in King's Park, Perth, Western Australia. Journal of the Royal Society of Western Australia. 24: 69-101. gs

Toumarkine, M. & Luterbacher, H. (1985). Paleocene and Eocene planktic foraminifera. In, Bolli, H. M. , Saunders, J. B. & Perch-Neilsen, K. (eds) Plankton Stratigraphy. Cambridge Univ. Press, Cambridge 87-154. gs


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Globanomalina australiformis compiled by the pforams@mikrotax project team viewed: 17-11-2019

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