pforams@mikrotax - Trilobatus altospiralis

Trilobatus altospiralis

Classification: pf_cenozoic -> Globigerinidae -> Trilobatus -> Trilobatus altospiralis
Sister taxa: T. sacculifer, T. quadrilobatus, T. immaturus, T. trilobus ⟩⟨ T. bisphericus, T. sicanus ⟩⟨ T. altospiralis, T. praeimmaturus, T. primordius, T. subsacculifer, T. sp.


Citation: Trilobatus altospiralis Spezzaferri, in Spezzaferri et al. 2018
Rank: species

Taxonomic discussion:

Spezzaferri (1994) identified this species as Globigerinoides sp. 1. [Spezzaferri et al. 2018]

Catalog entries: Trilobatus altospiralis

Type images:

Distinguishing features:
Parent taxon (Trilobatus): Supplementary apertures and cancellate wall.
This taxon: Like T. primordius but with a high trochospire, up to 4 chambers in the last whorl, and slit-like primary and supplementary apertures.

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.


Wall type: Normal perforate, spinose, sacculifer-type wall.

Morphology: High to very high trochospiral consisting of about 2½ whorls. Subcircular to triangular or subtriangular profile, markedly lobate outline with globular chambers; 3½-4 chambers in the last whorl gradually increasing in size. Sutures strongly depressed, straight on both sides, umbilicus very narrow, almost absent and fairly deep. Primary aperture an umbilical very low arch tending to become an elongated slit. Sutural, slit-like to low arched supplementary apertures are placed over the sutures separating the last and the penultimate chambers and between the penultimate chamber and the inner spire. [Spezzaferri et al. 2018]

Size: Maximum length of holotype 0.37 mm, maximum width 0.32 mm. [Spezzaferri et al. 2018]

Character matrix
test outline:Lobatechamber arrangement:Trochospiraledge view:Equally biconvexaperture:Umbilical
sp chamber shape:Globularcoiling axis:Highperiphery:N/Aaperture border:-
umb chbr shape:Globularumbilicus:Wideperiph margin shape:Broadly roundedaccessory apertures:Sutural
spiral sutures:Moderately depressedumb depth:Deepwall texture:Cancellateshell porosity:Macroperforate: >2.5µm
umbilical or test sutures:Strongly depressedfinal-whorl chambers:3.5-4.0 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology

Geographic distribution: This species is more abundant at middle to high latitudes in the southern hemisphere (Spezzaferri, 1994). [Spezzaferri et al. 2018]

Isotope paleobiology: No data available. [Spezzaferri et al. 2018]

Phylogenetic relations: Trilobatus altospiralis evolved from Trilobatus primordius in the middle part of Subzone M1b. [Spezzaferri et al. 2018]

Most likely ancestor: Trilobatus primordius - at confidence level 3 (out of 5). Data source: Spezzaferri et al. 2018.

Biostratigraphic distribution

Geological Range:
Notes: Trilobatus altospiralis ranges from middle Subzone M1b to the middle Miocene Zones M13-M14 interval (Spezzaferri, 1994). [Spezzaferri et al. 2018]
Last occurrence (top): within M13 zone (6.14-9.83Ma, top in Messinian stage). Data source: Spezzaferri et al. 2018
First occurrence (base): within M1b subzone (21.12-22.44Ma, base in Aquitanian stage). Data source: Spezzaferri et al. 2018

Plot of occurrence data:

Primary source for this page: Spezzaferri et al. 2018 - Olig Atlas chap.9 p.289


Spezzaferri, S. (1994). Planktonic foraminiferal biostratigraphy and taxonomy of the Oligocene and lower Miocene in the oceanic record. An overview. Palaeontographia Italica. 81: 1-187. gs

Spezzaferri, S., Olsson, R. K. & Hemleben, C. (2018c). Taxonomy, biostratigraphy, and phylogeny of Oligocene to Lower Miocene Globigerinoides and Trilobatus. 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 9): 269-306. gs V O


Trilobatus altospiralis compiled by the pforams@mikrotax project team viewed: 21-9-2021

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Comments (1)

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Tatiana Pastro Bardola (Porto Alegre, Brazil)

Hi. On item Taxonomy I believe there is a little mistake:the DSDP site 516F is not in the South Pacific Ocean, but is in the South Atlantic Ocean, on Rio Grande Rise (Barker et al., Init.Repts.DSDP 72).

Jeremy Young (London, UK)

Tatiana - thank you for pointing that out, and I have corrected it now. Jeremy

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