pforams@mikrotax - Globorotalia ungulata

Citation: Globorotalia ungulata Bermúdez, 1961

Synonyms: Globorotalia (Globorotalia) ungulata Bermúdez, 1961 [e.g. Kennett & Srinivasan 1983]

Taxonomic discussion: Often ignored, but representing a necessary category to correctly assign specimens of the G. tumida–G. cultrata plexus. Applied consistently with current understanding by Saito et al. (1981) and Kennett & Srinivasan (1983). Specimen figured by Schiebel & Hemleben (2017) on plate 2.30 and figs. 1–3 represents G. ungulata, not G. tumida. Typified by a holotype from recent sediments and confirmed by molecular genetic data to be distinct, but related to G. tumida (Morard et al., 2015). [Brummer & Kucera 2022]

Distinguishing features:
Parent taxon (tumida lineage): G. lenguaensis - merotumida - tumida - flexuosa lineage
This taxon: Keel & lateral shell outline thickest on last chamber

Description

Small, umbilico-convex, equatorial periphery ovate with thin but distinct keel

Aperture: Interiomarginal umbilical-extraumbilical low arch covered by lip [Aze 2011, based on Kennett & Srinivasan 1983]

Coiling direction (in extant population): sinistral

Test small, umbilical side more highly vaulted than spiral , equatorial periphery ovate, slightly lobulate, axial periphery biconvex, with a thin but distinct keel; about 5 chambers in the final whorl increasing uniformly in size as added; spiral sutures limbate, slightly raised, oblique, merging with the keel on the periphery, on umbilical side almost radial, depressed; surface thin, densely perforate with circular pores and flat and smooth interpore area (PI. 36, Figs. 3, 4); umbilicus narrow; aperture a low arch at the base of the smooth apertural face, bordered by a lip ; interiomarginal umbilical-extraumbilical. [Kennett & Srinivasan 1983]

Biogeography and Palaeobiology

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

In modern oceans a common, warm water, species [SCOR WG138]

Map of distribution from ForCenS database

Aze et al. 2011 ecogroup 3 - Open ocean thermocline; based on comparison with other species of the genus.

This species resembles Gr. (Gr.) tumida tumida in test shape but is distinguished from it by its very thin, delicate and smooth, and finely perforate test. Lamb and Beard (1972) suggested that Gr. (Gr.) ungulata may be a shallow-water, thin-walled growth form of Gr. (Gr.) tumida tumida. [Kennett & Srinivasan 1983] Molecular Genotypes recognised (data from PFR² database, June 2017), one genotype only from 39 sequences. References: André et al. 2014; Seears et al. 2012.

Most likely ancestor: Globorotalia tumida - at confidence level 3 (out of 5). Data source: Kennett & Srinivasan 1983, fig 17; 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 N20 zone (3.10-4.37Ma, base in Zanclean stage). Data source: Chaisson & Pearson (1997)

References:

André, A., et al. (2014). SSU rDNA Divergence in Planktonic Foraminifera: Molecular Taxonomy and Biogeographic Implications. PLoS One. 9: e104641-. gs

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

Bermudez, P. J. (1961). Contribucion al estudio de las Globigerinidea de la region Caribe-Antillana (Paleoceno-Reciente). Editorial Sucre, Caracas. (3): 1119-1393. 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. (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

Lamb, J. L. & Beard, J. H. (1972). Late Neogene planktonic foraminifers in the Caribbean, Gulf of Mexico, and Italian stratotypes,. University of Kansas Paleontological Contributions, Articles. 57: 1-67. gs O

Loeblich, A. & Tappan, H. (1994). Foraminifera of the Sahul shelf and Timor Sea. Cushman Foundation for Foraminiferal Research, Special Publication. 31: 1-661. gs O

Morard, R., et al. (2015). PFR2: a curated database of planktonic foraminifera 18S ribosomal DNA as a resource for studies of plankton ecology, biogeography and evolution. Molecular Ecology Resources. 15: 1472-1485. gs

Saito, T., Thompson, P. R. & Breger, D. (1981). Systematic Index of Recent and Pleistocene Planktonic Foraminifera. University of Tokyo Press, Tokyo. 1-190. gs

Schiebel, R. & Hemleben, C. (2017). Planktic Foraminifers in the Modern Ocean. Springer-Verlag, Heidelberg. 1-358. gs

Seears, H. A., Darling, K. F. & Wade, C. M. (2012). Ecological partitioning and diversity in tropical planktonic foraminifera. BMC Evolutionary Biology. 12(54): 1-15. 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

test outline:	Ovate	chamber arrangement:	Trochospiral	edge view:	Inequally biconvex	aperture:	Umbilical-extraumbilical
sp chamber shape:	Crescentic	coiling axis:	Low	periphery:	Single keel	aperture border:	Thick lip
umb chbr shape:	Subtriangular	umbilicus:	Narrow	periph margin shape:	Subangular	accessory apertures:	None
spiral sutures:	Raised	umb depth:	Shallow	wall texture:	Smooth	shell porosity:	Macroperforate: >2.5µm
umbilical or test sutures:	Weakly depressed	final-whorl chambers:	5-5	N.B. These characters are used for advanced search. N/A - not applicable

Globorotalia ungulata

Taxonomy

Description

Biogeography and Palaeobiology

Biostratigraphic distribution

References:

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