pforams@mikrotax - Parasubbotina variospira

pforams@mikrotax - Parasubbotina variospira pforams@mikrotax - Parasubbotina variospira

Parasubbotina variospira

Classification: pf_cenozoic -> Globigerinidae -> Parasubbotina -> Parasubbotina variospira
Sister taxa: P. griffinae, P. eoclava, P. hagni, P. prebetica, P. inaequispira ⟩⟨ P. pseudowilsoni, P. variospira, P. varianta, P. pseudobulloides, P. aff. pseudobulloides, P. sp.

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Olsson_etal_99_pl23_f04_f06-7_f15.jpg
Olsson_etal_99_pl23_f05_f08_f13.jpg
Olsson_etal_99_pl23_f09-10_f16.jpg
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Taxonomy

Citation: Parasubbotina variospira (Belford 1984)

Taxonomic rank: species

Basionym: Globorotalia (Turborotalia) variospira

Synonyms:

Globorotalia (Turborotalia) variospira Belford 1984:18, pl. 24: figs. 15-17, pl. 25: figs. 1-7 [WABAG Sheet area, Papua, New Guinea].
Morozovella variospira (Belford).—Van Eijden and Smit, 1991:113, text-fig. 26A-D, pl. 5: figs. 1-8 [Zone P3, ODP Hole 758A/30X/CC; eastern Indian Ocean]. [Olsson et al. 1999]

Taxonomic discussion: Although described a decade ago, this species has been overlooked in studies of Paleocene planktonic foraminiferal faunas. This absence of attention is surprising because P. variospira is large and homeomorphic with the Neogene species Neogloboquardina dutertrei (d'Orbigny). Van Eijden and Smith (1992) drew attention to the distinct features of this large mid-Paleocene taxon and noted its globoquadrinid-like umbilical "teeth" that are unique among Paleocene species. Parasubbotina variospira overlaps for a short stratigraphic interval with Globanomalina pseudomenardii and early members of the acarininid radiation (nitida, mckannai, subsphaerica) within the lowermost part of Zone P4. [Olsson et al. 1999]

Catalog entries: Globorotalia (Turborotalia) variospira

Type images:

holotype: G. (Turborotalia) variospira
paratype: G. (Turborotalia) variospira
paratype: G. (Turborotalia) variospira
paratype: G. (Turborotalia) variospira

Distinguishing features:
Parent taxon (Parasubbotina): Very low trochospiral test, chambers increasing rapidly in size; aperture high-arched umbilical-extraumbilical aperture. At most 5 chambers in final whorl.
This taxon: Test large (0.4-0.7 mm), loosely coiled, with strongly lobulate outline. Any or all of the last 3-4 chambers with inwardly projecting umbilical teeth. Aperture interiomarginal, umbilical-extraumbilical arch; occasional secondary spiral apertures. Wall spinose and distinctly cancellate with large pore pits.

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

Diagnostic characters:

Large ( 0.4 to 0.7 mm in diameter), low to (less frequent) moderately high, loosely coiled trochospiral test with strongly lobulate outline; any or all of the last 3-4 chambers with inwardly projecting umbilical teeth, aperture an interiomarginal, umbilical-extraumbilical arch; loose coiling between chambers in the final whorl occasionally produces secondary spiral apertures with apertural lips, wall texture spinose and distinctly cancellate with large pore pits. [Olsson et al. 1999]

Character matrix
test outline: Lobate chamber arrangement: Trochospiral edge view: Planoconvex aperture: Umbilical-extraumbilical
sp chamber shape: Globular coiling axis: Moderate periphery: N/A aperture border: Teeth
umb chbr shape: Inflated umbilicus: Wide periph margin shape: Broadly rounded accessory apertures: None
spiral sutures: Strongly depressed umb depth: Shallow wall texture: Cancellate shell porosity: Finely Perforate: 1-2.5µm
umbilical or test sutures: Strongly depressed final-whorl chambers: 4-4 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology

Geographic distribution

This species has been observed at (sub)tropical sites in the Atlantic, Indian, and Pacific oceans. [Olsson et al. 1999]
Aze et al. 2011 summary: Low latitudes; based on Olsson et al. (1999)

Isotope paleobiology

Parasubbotina variospira has a δ13C and δ18O signature similar to P. pseudobulloides, P. varianta, Subbotina triloculinoides, and Globanomalina compressa, but it typically has a heavier δ18O and more negative δ13C than coexisting Morozovella. [Olsson et al. 1999]
Aze et al. 2011 ecogroup 3 - Open ocean thermocline. Based on light _¹³C and relatively heavy _¹⁸O. Sources cited by Aze et al. 2011 (appendix S3): Olsson et al. (1999); Pearson et al. (2001a)

Phylogenetic relations

This species evolved from P. varianta by the development of a more loosely coiled test and inflated chambers. Both P. varianta and P. variospira share enlarged apertural flaps. These structures are restricted to the final chamber of P. varianta but are found on the last 3-4 chambers in the final whorl of P. variospira. [Olsson et al. 1999]

Most likely ancestor: Parasubbotina varianta - at confidence level 4 (out of 5). Data source: Olsson et al. 1999 f.5.

Biostratigraphic distribution

Geological Range:
Notes: Zone P3a to Zone P4 (lower part). [Olsson et al. 1999]
The LAD of Parasubbotina variospira marks the base of zone P4b / top of P4a (Wade et al. 2011)
Last occurrence (top): at top of P4a subzone (100% up, 60.5Ma, in Selandian stage). Data source: zonal marker (Wade et al. 2011)
First occurrence (base): at base of P3a subzone (0% up, 62.3Ma, in Danian stage). Data source: zonal marker (Wade et al. 2011)

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
Histogram - Neptune occurrence data from DSDP and ODP proceedings. Pale shading <50 samples in time bin. Interpret with caution & read these notes
Taxon plotted: Parasubbotina variospira, synonyms included - Parasubbotina variospira;
See also space-time plot :: Samples map :: Parent: Parasubbotina

Primary source for this page: Olsson et al. 1999 - Atlas of Paleocene Planktonic Foraminifera, p. 28

References:

Belford, D. J. (1984). Belford, D. J. (1984). Tertiary foraminifera and age of sediments, Ok Tedi-Wabag, Papua New Guinea. Australia Bureau of Mineral Resources, Geology and Geophysics Bulletin. 216: 1-52. Australia Bureau of Mineral Resources Geology and Geophysics, Bulletin. 216: 1-52. gs

Olsson, R. K., Hemleben, C., Berggren, W. A. & Huber, B. T. (1999). Olsson, R. K., Hemleben, C., Berggren, W. A. & Huber, B. T. (1999). Atlas of Paleocene Planktonic Foraminifera. Smithsonian Institution Press, Washington, DC. 1-252. Smithsonian Institution Press, Washington, DC. (85): 1-252. gs

van Eijden, A. J. M. & Smit, J. (1991). van Eijden, A. J. M. & Smit, J. (1991). Eastern Indian Ocean Cretaceous and Paleogene quantitative biostratigraphy. Proceedings of the Ocean Drilling Program, Scientific Results. 121: 77-123. Proceedings of the Ocean Drilling Program, Scientific Results. 121: 77-123. gs

Parasubbotina variospira compiled by the pforams@mikrotax project team viewed: 18-7-2025

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Short stable page link: https://mikrotax.org/pforams/index.php?id=100235 Go to Archive.is to create a permanent copy of this page - citation notes

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test outline:	Lobate	chamber arrangement:	Trochospiral	edge view:	Planoconvex	aperture:	Umbilical-extraumbilical
sp chamber shape:	Globular	coiling axis:	Moderate	periphery:	N/A	aperture border:	Teeth
umb chbr shape:	Inflated	umbilicus:	Wide	periph margin shape:	Broadly rounded	accessory apertures:	None
spiral sutures:	Strongly depressed	umb depth:	Shallow	wall texture:	Cancellate	shell porosity:	Finely Perforate: 1-2.5µm
umbilical or test sutures:	Strongly depressed	final-whorl chambers:	4-4	N.B. These characters are used for advanced search. N/A - not applicable