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.

Olig Atlas pl09-08 17-19.JPG
Olig Atlas pl09-08 13-15.JPG
Olig Atlas pl09-08 16.JPG
Olig Atlas pl09-08 20-22.JPG

Taxonomy

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

Rank: species

Synonyms:

Globigerinoides sp.1.—Spezzaferri, 1994:127, pl. 15, figs. 3a-c [lower Miocene Subzone N4a, DSDP Site 588C, South Pacific Ocean], figs. 4a-c [lower Miocene Subzone N4a, DSDP Site 516F, South Pacific Ocean].

Taxonomic discussion:

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

Catalog entries: Trilobatus altospiralis

Type images:

holotype: T. altospiralis
holotype: T. altospiralis
paratype: T. altospiralis
paratype: T. altospiralis
paratype: T. altospiralis
paratype: T. altospiralis

Distinguishing features: 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.

Description

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:	Lobate	chamber arrangement:	Trochospiral	edge view:	Equally biconvex	aperture:	Umbilical
sp chamber shape:	Globular	coiling axis:	High	periphery:	N/A	aperture border:
umb chbr shape:	Globular	umbilicus:	Wide	periph margin shape:	Broadly rounded	accessory apertures:	Sutural
spiral sutures:	Moderately depressed	umb depth:	Deep	wall texture:	Cancellate	shell porosity:	Macroperforate: >2.5µm
umbilical or test sutures:	Strongly depressed	final-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:

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
(NB There is no histogram as there are no occurrence records for the taxon in the Neptune database) Parent: Trilobatus

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

References:

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: 17-1-2021

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Short stable page link: http://mikrotax.org/pforams/index.php?id=104328 Go to Archive.is to create a permanent copy of this page - citation notes

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