Distinguishing features: It is distinguished from G. obliquus by its last chamber, which is less laterally compressed. It also has numerous supplementary apertures. It differs from G. conglobatus primarily by its wide, high aperture and inflated final chamber in adult specimens. An additional distinguishing feature is the coiling, which is tight and streptospiral in G. conglobatus and loosely coiled in G. eoconglobatus n. sp. [Stainbank et al. 2018] Discussion: To identify G. conglobatus we have strictly followed the ‘‘morphospecies’’ concept used in Wade et al. (2017, in press). We have defined it by a series of morphological characters that are shared with the holotype. Consequently, G. eoconglobatus n. sp., having different characters has been identified as a new morphospecies. Therefore, both G. conglobatus and G. eoconglobatus n. sp. may or may not represent true biological species. Forms similar to G. eoconglobatus n. sp. have been identified as G. conglobatus or its synonyms by several authors (e.g., Bé and Tolderlund 1971; Fordham 1979; Rillo 2016; Rillo et al. 2016). Yet, due to the lack of accompanying figures in the majority of publications, it is difficult to ascertain the true extent of this morphospecies distribution. Currently, based on this study and images from Rillo (2016) we can state it is found in the Indian and Pacific Oceans. [Stainbank et al. 2018] The species was not recognised in the synthesis of extant taxa of Brummer & Kucera (2022) who state - G. eoconglobatus is "considered to represent either an extinct form or a variant within the morphologically plastic G. conglobatus, because there is no evidence for the existence of more than one extant species of this lineage, as confirmed by genetic data of Morard et al. (2019). "
Catalog entries: Globigerinoides eoconglobatus
Type images:
holotype: G. eoconglobatus
holotype: G. eoconglobatus
paratype: G. eoconglobatus
paratype: G. eoconglobatus
paratype: G. eoconglobatus
paratype: G. eoconglobatus
paratype: G. eoconglobatus
paratype: G. eoconglobatus
paratype: G. eoconglobatus
x: G. eoconglobatus
x: G. eoconglobatus
x: G. eoconglobatus
x: G. eoconglobatusDistinguishing features:
Parent taxon (Globigerinoides): Supplementary apertures, with ruber/sacculifer-type spinose wall texture
This taxon: Like G. obliquus, but final chamber less laterally compressed.
Character matrix
| test outline: | Lobate | chamber arrangement: | Trochospiral | edge view: | Equally biconvex | aperture: | Umbilical |
| sp chamber shape: | Globular | coiling axis: | Low-moderate | periphery: | N/A | aperture border: | N/A |
| umb chbr shape: | Globular | umbilicus: | Wide | periph margin shape: | Broadly rounded | accessory apertures: | Sutural |
| spiral sutures: | Strongly depressed | umb depth: | Deep | wall texture: | Cancellate | shell porosity: | Macroperforate: >2.5µm |
| umbilical or test sutures: | Strongly depressed | final-whorl chambers: | 4-4 | N.B. These characters are used for advanced search. N/A - not applicable | |||
Aze et al. (2011) reported the evolution of G. conglobatus from G. obliquus in the Late Miocene. As such, it is inferred that G. eoconglobatus n. sp. evolved from G. obliquus in Subzone M13a and gives origin to G. conglobatus in Zone PL1.
Most likely ancestor:
Globigerinoides obliquus - at confidence level 3 (out of 5). Data source: Stainbank et al. 2018;.
Geological Range:
Notes: From Subzone M13a to Late Quaternary
Last occurrence (top): Non-extinct palaeontological taxon. Data source: Brummer & Kucera 2022: The morphotype occurs at the present day but is formed by the species G. conglobatus, so this taxon is not used by biologists
First occurrence (base): within M13a subzone (8.58-9.83Ma, base in Tortonian stage). Data source: Stainbank et al. 2018
Plot of occurrence data:
Primary source for this page: Stainbank et al. 2018
Aze, T., et al. (2011). A phylogeny of Cenozoic macroperforate planktonic foraminifera from fossil data. Biological Reviews. 86: 900-927. gs Bé, A. W. H. & Tolderlund, D. S. (1971). Distribution and ecology of living planktonic foraminifera in surface waters of the Atlantic and Indian Oceans. In, Funnell, B. M. & Riedel, W. R. (eds) Micropaleontology of Oceans. Cambridge Univ. Press, Cambridge, UK 105-149. gs Brummer, G-J. A. & Kucera, M. (2022). Taxonomic review of living planktonic foraminifera. Journal of Micropalaeontology. 41: 29-74. gs Fordham, B. G. (1979). A chronocladogeny and corresponding classification of Neogene planktic foraminifera with a documentation of morphotypes from two Pacific deepsea stratigraphic sections. PhD thesis, University of Queensland, Australia. -. gs Hemleben, C., Olsson, R. K., Premec Fucek, V. & Hernitz Kucenjak, M. (2018). Wall textures of normal perforate Oligocene planktonic foraminifera. 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 3): 55-78. gs Rillo, M. C. (2016). Dataset: Henry Buckley collection of planktonic foraminifera. Natural History Museum Data Portal (data.nhm.ac.uk). . -. gs Stainbank, S., Spezzaferri, S., Kroon, D., de Leau, E. S. & Rüggeberg, A. (2018). The Planktonic foraminifera Globigerinoides eoconglobatus n. sp. in a glacial–interglacial context: IODP359 Sites U1467 and U1468. Swiss Journal of Geosciences. 111(3): 511-522. gs References:
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Globigerinoides eoconglobatus compiled by the pforams@mikrotax project team viewed: 5-9-2026
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