The distinctive spinose wall texture of Subbotina triangularis sets it apart from the trivialis -triloculinoides lineage and the cancellata -velascoensis lineage. Subbotina triangularis may be a stem form for a separate lineage that links with Eocene species, but this possibility has not been investigated. It may be linked with Globigerina praebulloides, which has a similar wall texture (compare Plate 2: Figures 14-16). [Olsson et al. 1999]
Catalog entries: Globigerina triangularis, Globigerina gerpegensis, Globigerina pseudotriloba Shutskaya, Globigerina uruchaensis
Type images:Distinguishing features:
Parent taxon (Subbotina): Low trochospiral, tripartite test, with 3-4 rapidly inflating, globular chambers in final whorl.
Umbilicus nearly closed by tight coiling.
Wall cancellate with spines at nodes of the ridges, +/- spine collars.
This taxon: Test triangular in umbilical view, axial periphery broadly rounded. 3½ loosely coiled chambers in final whorl. Final chamber low oval, often smaller than the one before. Umbilicus narrow, deep, sometimes obscured by final chamber. Aperture umbilical to slightly extraumbilical, with a thin, sometimes irregular lip. Wall cancellate, spinose.
Character matrix
test outline: | Triangular | chamber arrangement: | Trochospiral | edge view: | Inequally biconvex | aperture: | Umbilical |
sp chamber shape: | Globular | coiling axis: | Low | periphery: | N/A | aperture border: | Thick lip |
umb chbr shape: | Globular | umbilicus: | Narrow | periph margin shape: | Broadly rounded | accessory apertures: | None |
spiral sutures: | Strongly depressed | umb depth: | Deep | wall texture: | Cancellate | shell porosity: | Macroperforate: >2.5µm |
umbilical or test sutures: | Strongly depressed | final-whorl chambers: | 3-3.5 | N.B. These characters are used for advanced search. N/A - not applicable |
Geographic distribution
has a [Olsson et al. 1999]
Aze et al. 2011 summary: Low to middle latitudes; based on Olsson et al. (1999)
Isotope paleobiology
Aze et al. 2011 ecogroup 2 - Open ocean mixed-layer tropical/subtropical, without symbionts. Based on _13C lighter than species with symbionts; also with relatively light _18O. Sources cited by Aze et al. 2011 (appendix S3): D'hondt et al. (1994); Coxall et al. (2000)
Phylogenetic relations
Most likely ancestor: Subbotina trivialis - at confidence level 4 (out of 5). Data source: Olsson et al. 1999 f5a.
Likely descendants: Subbotina roesnaesensis;
plot with descendants
Geological Range:
Notes: Zone P2 to Zone P5, ? P6. [Olsson et al. 1999]
Last occurrence (top): within P5 zone (55.96-57.10Ma, top in Thanetian stage). Data source: Olsson et al. 1999
First occurrence (base): within P2 zone (62.29-62.60Ma, base in Danian stage). Data source: Olsson et al. 1999
Plot of occurrence data:
Primary source for this page: Olsson et al. 1999 - Atlas of Paleocene Planktonic Foraminifera, p. 30
Blow, W. H. (1979). The Cainozoic Globigerinida: A study of the morphology, taxonomy, evolutionary relationships and stratigraphical distribution of some Globigerinida (mainly Globigerinacea). E. J. Brill, Leiden. 2: 1-1413. gs Bolli, H. M. (1957d). The genera Globigerina and Globorotalia in the Paleocene-Lower Eocene Lizard Springs Formation of Trinidad. 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: 61-82. 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. (85): 1-252. gs Shutskaya, E. K. (1970a). Morphologic groups and descriptions of species of Globigerina and Acarinina in the lower Paleogene of the Crimea, the Caucasus Foreland, and western Central Asia. Trudy Vsesoyuznego Neftyanogo Nauchno-Issledovatel'skogo Geologo-Razvedochnogo Instituta (VNIGRI). 69: 79-113. gs Shutskaya, E. K. (1970b). Stratigrafiya, foraminifery i paleogeografiya nizhnego paleogena Kryma, predkavkaz'ya i zapadnoi chadsti srednei azii [Stratigraphy, Foraminifera and Paleogeography of the Lower Paleogene in the Crimea, Precaucasus and the Western Part of Central Asia]. Trudy Vsesoyuznego Neftyanogo Nauchno-Issledovatel'skogo Geologo-Razvedochnogo Instituta (VNIGRI). 70(1): 256-. gs Tjalsma, R. C. (1977). Cenozoic Foraminifera from the South Atlantic, DSDP Leg 36. Initial Reports of the Deep Sea Drilling Project. 36: 493-518. gs White, M. P. (1928). Some Index Foraminifera of the Tampico Embayment Area of Mexico. Journal of Paleontology. 2(3): 177-215. gs References:
Subbotina triangularis compiled by the pforams@mikrotax project team viewed: 14-10-2024
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