Globoconella inflata Like Gr. (G.) puncticulata but <4 chambers in final whorl, greater test inflation, a broadly rounded periphery, and a larger, high-arched, aperture.
Globoconella conomiozea Like G. miotumida but more strongly vaulted umbilical side, and with 4-4¼ chambers in final whorl (vs. 4½-5).
Globoconella miotumida Like G. miozea but much larger size, with more conical umbilical side, and tendency to develop a distinct keel
Globoconella miozea Like G. praescitula but larger, more inflated test, 5 of chambers in final whorl (vs 4½), and more strongly developed secondary thickening and rugosity of the umbilical side
Globoconella panda Convex spiral side, flattened umbilical side, and a well developed peripheral keel
Globoconella sp. Specimens which cannot be assigned to established species
Taxonomic discussion: Bandy (1975) proposed the subgenus Globoconella for the globorotaliids having a high-arched aperture showing affinity to the Globorotalia miozea Finlay lineage. Srinivasan and Kennett (1981a, 1981b) emended the diagnosis of Globoconella Bandy and included in this lineage Gr. incognita, Gr. zealandica, Gr. praescitula, Gr. panda, Gr. miozea, Gr. conoidea, Gr. conomiozea, Gr. sphericomiozea, Gr. puncticulata, and Gr. inflata (Text Fig. 13). The evolution of Gr. (G.) incognita to Gr. (G.) miozea through Gr. (Globoconella) praescitula is considered by Srinivasan and Kennett (1981b) to represent one continuum rather than two parallel bioseries suggested earlier by Walters (1965). The Globoconella series is a major lineage in temperate areas and the most useful for biostratigraphic subdivision of that region. The continuum of forms in this lineage includes both keeled and nonkeeled and inflated and compressed forms. Most of the elements are thickwalled and thus dissolution resistant. In some cases, thin-walled forms have been designated as different species from thick-walled forms. For instance, we consider Globorotalia (Globoconella) miotumida to be a thin-walled form of Gr. (G.) conoidea. [Kennett & Srinivasan 1983] Wei(1987, 1994) document evolution in the lineage in detail.
Distinguishing features: Parent taxon (Globorotaliidae): Macroperforate, non-spinose This taxon: Globorotaliids having a high-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
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Biogeography and Palaeobiology
Geographic distribution The Globoconella series is a major lineage in temperate areas and the most useful for biostratigraphic subdivision of that region. Phylogenetic relationsGloborotalia (Globoconella) incognita, the earliest member of the lineage, evolved in the Early Miocene from an Oligocene globorotaliid stock. Judging from the stratigraphic ranges and morphological and surface ultrastructural characteristics, "Gr." nana seems to be the ancestral form of Globoconella. Jenkins (1971) and Srinivasan and Kennett (1981b) earlier suggested that its ancestry was from Neogloboquadrina continuosa. However, although N. continuosa is morphologically similar to Gr. (Globoconella) incognita, it gives rise to a different lineage. We no longer assign N. continuosa to Early Miocene forms for phylogenetic reasons. [Kennett & Srinivasan 1983]
NB G. miozea and G. panda are inferred to have evolved separately from Globorotalia praescitula, this makes Globoconella polyphyletic. [editor's comment - JRY 2021]
Most likely ancestor:Globorotalia - at confidence level 3 (out of 5). Data source: The oldest species, G. panda and G. miozea are both inferred to have evolved from Globorotalia praescitula.
Biostratigraphic distribution
Geological Range: Last occurrence (top): Extant. Data source: Total of ranges of the species in this database First occurrence (base): within N7 zone (16.38-17.54Ma, base in Burdigalian stage). Data source: Total of ranges of species in this database
Plot of occurrence data:
Range-bar - range as quoted above, pink interval top occurs in, green interval base occurs in.
Triangles indicate an event for which a precise placement has been suggested
Primary source for this page: Kennett & Srinivasan 1983 p. 103
References:
Bandy, O. L. (1975). Messinian evaporite deposition and the Miocene/Pliocene boundary, Pasquasia-Capodarso Sections, Sicily. In, Saito, T. & Burckle, L. H. (eds) Late Neogene Epoch Boundaries. American Museum Natural History Micropaleontology Press, New York 49-63. gs
Kennett, J. P. (1966). The Globorotalia crassaformis bioseries in north Westland and Marlborough, New Zealand,. Micropaleontology. 12: 235-245. gs
Malmgren, B. A. & Kennett, J. P. (1981). Phyletic gradualism in a Late Cenozoic planktonic foraminiferal lineage; DSDP site 284, southwest Pacific. Paleobiology. 7(2): 230-240. gs
Srinivasan, M. S. & Kennett, J. P. (1981a). A review of Neogene planktonic foraminiferal biostratigraphy: applications in the equatorial and south Pacific. SEPM Special Publication. 395-432. gs
Srinivasan, M. S. & Kennett, J. P. (1981b). Neogene planktonic foraminiferal biostratigraphy and evolution: equatorial to subantarctic, south Pacific. Marine Micropaleontology. 6: 499-533. 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. (1987). Multivariate morphometric differentiation of chronospecies in the late Neogene planktonic foraminiferal lineage Globoconella. Marine Micropaleontology. 12: 183-202. gs
Wei, K. -Y. (1994a). Allometric heterochrony in the Pliocene-Pleistocene planktic foraminiferal clade Globoconella. Paleobiology. 20: 66-84. 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
Globoconella compiled by the pforams@mikrotax project teamviewed: 10-12-2024
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/Globorotalia (Globoconella) conomiozea terminalis/Wei-1997-pl2-1-3.jpg)
