Catalog - Trilobatus altospiralis

CATALOG OF ORIGINAL DESCRIPTIONS: Trilobatus altospiralis Spezzaferri, in Spezzaferri et al. 2018

This page provides data from the catalog of type descriptions. The catalog is sorted alphabetically. Use the current identification link to go back to the main database.

Higher levels: pf_cat -> T -> Trilobatus -> Trilobatus altospiralis
Other pages this level: T. altospiralis

Trilobatus altospiralis

Citation: Trilobatus altospiralis Spezzaferri, in Spezzaferri et al. 2018
Rank: Species
Type locality: South Atlantic Ocean, 30°08.36’ S, 03°08.28’E, water depth 1054 mbsf,
Type age (chronostrat): Lower Miocene, Subzone M1b
Type sample (& lithostrat): DSDP Sample 526A-27-1, 30-32 cm, foraminifer-nannofossil ooze.
Type specimens: Holotype (32498) and paratypes (32499 and 32500)
Type repository: Fribourg: Natural History Museum of Fribourg, Switzerland.

Current identification/main database link: Trilobatus altospiralis Spezzaferri, in Spezzaferri et al. 2018

Original Description

Type of wall: Normal perforate, spinose, sacculifer-type wall.

Test 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.

Size: Maximum length of holotype 0.37 mm, maximum width 0.32 mm.

Etymology: Named altospiralis for its characteristic high spiral side.

Extra details from original publication

DISTINGUISHING FEATURES. This species differs from T. primordius by having a high trochospire, up to 4 chambers in the last whorl, and slit-like primary and supplementary apertures. It differs from T. immaturus, T. praeimmaturus and T. trilobus by its very lobate outline, by having 3½-4 chambers in the last whorl and the very high spiral side.

DISCUSSION. Spezzaferri (1994) identified this species as Globigerinoides sp. 1.

PHYLOGENETIC RELATIONSHIPS. Trilobatus altospiralis evolved from Trilobatus primordius in the middle part of Subzone M1b.

STRATIGRAPHIC RANGE. Trilobatus altospiralis ranges from middle Subzone M1b to the middle Miocene Zones M13-M14 interval (Spezzaferri, 1994).

GEOGRAPHIC DISTRIBUTION. This species is more abundant at middle to high latitudes in the southern hemisphere (Spezzaferri, 1994).


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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