Globoconella conoidea


Classification: pf_cenozoic -> Globorotaliidae -> Globoconella -> Globoconella conoidea
Sister taxa: G. inflata, G. puncticulata, G. sphericomiozea, G. terminalis, G. pliozea, G. conomiozea, G. conoidea, G. miozea, G. panda, G. sp.,

Taxonomy

Citation: Globoconella conoidea (Walters 1965)
Rank: species
Basionym: Globorotalia miozea conoidea Walters 1965
Synonyms:
Variants:

Catalog entries: Globorotalia miozea conoidea, Globorotalia menardii miotumida, Globorotalia miotumida explicationis, Globorotalia (Globorotalia) iwaiensis

Type images:

Distinguishing features: Like G. miozea but much larger size, with more conical umbilical side, and tendency to develop a distinct keel

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: Low trochospiral, umbilical side strongly conical, distinct keel

Aperture: Interiomarginal umbilical-extraumbilical low distinct arch with indistinct rim [Aze 2011, based on Kennett & Srinivasan 1983]


Wall type: Non-spinose; Cancellate [Aze 2011]

Test morphology: Test relatively large, a relatively low trochospire consisting of 2½ to 3 whorls of slowly enlarging chambers, 4½ to 5 chambers in the final whorl; spiral side slightly convex, umbilical side highly conical; periphery bluntly rounded and thickened on early chambers, but on later chambers more sharply angled, with a narrow, cord like keel; sutures on spiral side strongly recurved, slightly raised, on umbilical side depressed, radial to slightly curved: Surface finely perforate, but earlier chambers show a progressive secondary thick- ening, especially on the periphery and on the umbilical surface. Umbilicus small, open; aperture interiomarginal, umbilical-extraumbilical, a low, distinct arch bordered by an indistinct rim. [Kennett & Srinivasan 1983]

Character matrix

test outline:Subcircularchamber arrangement:Trochospiraledge view:Planoconvexaperture:Umbilical-extraumbilical
sp chamber shape:Crescenticcoiling axis:Lowperiphery:Single keelaperture border:Thin lip
umb chbr shape:Subtriangularumbilicus:Narrowperiph margin shape:Subangularaccessory apertures:None
spiral sutures:Flushumb depth:Shallowwall texture:Smoothshell porosity:Macroperforate: >2.5µm
umbilical or test sutures:Weakly depressedfinal-whorl chambers:4.5-5.0 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology


Geographic distribution: Temperate to warm subtropical. [Kennett & Srinivasan 1983] Low to middle latitudes [Aze et al. 2011, based on Kennett & Srinivasan (1983)]

[SCOR WG138]


Isotope paleobiology: Aze et al. 2011 ecogroup 3 - Open ocean thermocline. Based on light ∂13C and relatively heavy ∂18O. Sources cited by Aze et al. 2011 (appendix S3): Schneider & Kennett (1996)

Phylogenetic relations: Gr. (G.) conoidea differs from Gr. (G.) miozea by its much larger size, by its much more conical umbilical side, and by its tendency to develop a distinct keel. [Kennett & Srinivasan 1983]

Most likely ancestor: Globoconella miozea - at confidence level 3 (out of 5). Data source: Kennett & Srinivasan 1983, fig. 13.
Likely descendants: Globoconella conomiozea;

Biostratigraphic distribution

Geological Range:
Last occurrence (top): within M13b subzone (6.14-8.58Ma, top in Messinian stage). Data source: Wei 1994 (age from fig.1 converted to modern zone)
First occurrence (base): within N9 zone (14.24-15.10Ma, base in Langhian stage). Data source: Kennett & Srinivasan 1983

Plot of occurrence data:

Primary source for this page: Kennett & Srinivasan 1983, p.112

References:

Aze, T. et al. (2011). A phylogeny of Cenozoic macroperforate planktonic foraminifera from fossil data. Biological Reviews. 86: 900-927. gs

Hayashi, H., Kurihara, Y., Horiuchi, S., Iwashita, T. & Yanagisawa, Y. (2003). Planktonic foraminifera biostratigraphy of the Miocene sequence in the Iwadono Hills, Central Japan: An Integrated approach. Palaios. 18: 176-191. gs

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

Schneider, C. E. & Kennett, J. P. (1996). Isotopic evidence for interspecies habitat differences during evolution of the Neogene planktonic foraminiferal clade Globoconella. Paleobiology. 22: 282-303. gs

Walters, R. (1965). The Globorotalia zealandica and G. miozea lineages. New Zealand Journal of Geology and Geophysics. 8: 109-127. gs

Wei, K. -Y. (1994b). Stratophenetic tracing of phylogeny using SIMCA pattern recognition technique: a case study of the late Neogene planktic foraminifera Globoconella clade. Paleobiology. 20(1): 52-65. gs


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Globoconella conoidea compiled by the pforams@mikrotax project team viewed: 18-9-2019

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