pforams@mikrotax - Globorotalia cavernula pforams@mikrotax - Globorotalia cavernula

Globorotalia cavernula


Classification: pf_cenozoic -> Globorotaliidae -> Globorotalia -> truncatulinoides lineage -> Globorotalia cavernula
Sister taxa: G. cavernula, G. truncatulinoides, G. tosaensis, G. tenuitheca ⟩⟨ G. hessi, G. ronda, G. crassaformis, G. viola ⟩⟨ G. crassaconica, G. crassula

Taxonomy

Citation: Globorotalia cavernula Bé, 1967
taxonomic rank: species
Basionym: Globorotalia cavernula
Synonyms:
Variants:
Taxonomic discussion: "Since its original description by Bé (1967b), G. cavernula has been elusive. Nevertheless, this species is retained because of the extensive documentation of its distinct morphology and relatively high abundance in the plankton claimed by the original author. The holotype indicates that the species is related to G. truncatulinoides, and the lack of occurrence records elsewhere indicates that it may be restricted to cold waters of the South Pacific. It is possible that G. cavernula refers to one of the known cryptic species of G. truncatulinoides (Quillévéré et al., 2013)." [Brummer & Kucera 2022]

Catalog entries: Globorotalia cavernula, Globorotalia crozetensis, Globorotalia petaliformis

Type images:

Distinguishing features:
Parent taxon (truncatulinoides lineage): G. crasula - crassaformis - tosaensis - truncatulinoides lineage, predominantly conicotruncate
This taxon: Like G. truncatulinoides but smaller, with very wide and open umbilicus, and smooth, finely perforate test.

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


Morphology:
Test small, very low trochospiral, spiral side almost flat, umbilical side distinctly convex; equatorial periphery ovate, slightly lobulate ; axial periphery sharply angled with thin keel; chambers angular to rhomboid, 5 to 6 in the final whorl, increasing rapidly in size, the final chamber showing a somewhat truncate shape. Sutures on both spiral and umbilical side curved and slightly depressed; surface smooth, finely perforate, few pustules on umbilical shoulder; umbilicus wide and deep, bordered by angled umbilical shoulder; aperture interiomarginal, umbilical-extraumbilical, a high rounded arch with a distinct rim.[Kennett & Srinivasan 1983]

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

Size:
>150µm

Character matrix
test outline:Subcircularchamber arrangement:Trochospiraledge view:Planoconvexaperture:Umbilical-extraumbilical
sp chamber shape:Crescenticcoiling axis:Lowperiphery:Single keelaperture border:Thick lip
umb chbr shape:Subtriangularumbilicus:Narrowperiph margin shape:Subangularaccessory apertures:None
spiral sutures:Weakly depressedumb depth:Shallowwall texture:Smoothshell porosity:Macroperforate: >2.5µm
umbilical or test sutures:Weakly depressedfinal-whorl chambers:5-6 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology


Geographic distribution

Temperate [Kennett & Srinivasan 1983] Middle latitudes [Aze et al. 2011, based on Kennett & Srinivasan (1983)]

In modern oceans a rare, cold water, species [SCOR WG138]

Map of distribution from ForCenS database

Isotope paleobiology
Aze et al. 2011 ecogroup 4 - Open ocean sub-thermocline; based on comparison with other species of the genus.

Phylogenetic relations
Gr. (T.) cavernula is distinguished from Gr. (T.) truncatulinoides by its smaller size, very wide and open umbilicus, and smooth, finely perforate test. This species appears to have evolved from Gr. (T.) truncatulinoides within the Quaternary. It closely resembles this species in having planoconvex test, rhomboid chambers, including the truncate final chamber, and an umbilical shoulder. [Kennett & Srinivasan 1983]

Most likely ancestor: Globorotalia truncatulinoides - at confidence level 3 (out of 5). Data source: Kennett & Srinivasan 1983, fig 16; Stewart 2003 fig. 6.10; Aze et al. 2011, appendix 5.

Biostratigraphic distribution

Geological Range:
Last occurrence (top): Extant. Data source: present in the plankton (SCOR WG138)
First occurrence (base): within PT1b subzone (0.00-0.61Ma, base in Ionian stage). Data source: Chaisson & Pearson (1997)

Plot of occurrence data:

Primary source for this page: Kennett & Srinivasan 1983, p.150

References:

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. (1967a). Globorotalia cavernula, a new species of planktonic foraminifera from the Subantarctic Pacific Ocean. Contributions from the Cushman Foundation for Foraminiferal Research. 18(3): 128-132. gs

Brummer, G-J. A. & Kucera, M. (2022). Taxonomic review of living planktonic foraminifera. Journal of Micropalaeontology. 41: 29-74. gs

Chaisson, W. P. & Pearson, P. N. P. (1997). Planktonic foraminifer biostratigraphy at Site 925: Middle Miocene–Pleistocene. Proceedings of the Ocean Drilling Program, Scientific Results. 154: 3-31. gs

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

Quillévéré, F. et al. (2013). Global scale same-specimen morpho-genetic analysis of Truncorotalia truncatulinoides: A perspective on the morphological species concept in planktonic foraminifera. Palaeogeography Palaeoclimatology Palaeoecology. 391: 2-12. gs

Siccha, M. & Kucera, M. (2017). ForCenS, a curated database of planktonic foraminifera census counts in marine surface sediment samples. Scientific Data. 4(1): 1-12. gs


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Globorotalia cavernula compiled by the pforams@mikrotax project team viewed: 24-2-2024

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