Catalog - Globorotaloides variabilis Catalog - Globorotaloides variabilis

CATALOG OF ORIGINAL DESCRIPTIONS: Globorotaloides variabilis Bolli 1957

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 -> G -> Globorotaloides -> Globorotaloides variabilis
Other pages this level: G. atlanticus, G. carcoselleensis, G. eovariabilis, G. falconarae, G. indigena anavenezuelana, G. indigena redissimilis, G. parvulus anasuteri, G. parvulus lateraliaperturus, G. quadrocameratus, G. suteri, G. suteri relizensis, G. trema, G. variabilis

Globorotaloides variabilis

Citation: Globorotaloides variabilis Bolli 1957
taxonomic rank: Species
Type specimens: Holotype ( P5657); figured paratypes ( P5658a-e) from the Globorotalia menardii zone, Lengua formation, road cutting, Concord area, Pointe-a-Pierre, Trinidad, sample Rz 502 (TTOC 65629).
Type locality: Holotype (USNM P5657) and figured paratypes (USNM P5658a-e) from the Globorotalia menardii zone, Lengua formation, road cutting, Concord area, Pointe-a-Pierre, Trinidad, sample Rz 502 (TTOC 65629).
Type repository: Washington; USNM

Linked specimens: USNM-5658 USNM-5657 USNM-5658 USNM-5658 USNM-5658 USNM-5658

Current identification/main database link: Globorotaloides variabilis Bolli, 1957

Original Description

Shape of test low trochospiral, biconvex; equatorial periphery lobate, in small specimens somewhat elongate; axial periphery subacute in immature specimens, rounded in mature specimens. Wall calcareous, perforate, surface very finely cancellate. Chambers subangular to ovate in early stage, later becoming ovate to spherical; about 15-18, arranged in 2-2½ whorls; the 5-7 chambers of the last whorl increase fairly rapidly in size. Sutures on spiral side distinctly curved in early stage, later becoming more radial, depressed; on umbilical side slightly curved in early stage, later becoming radial, depressed. Umbilicus fairly wide, open in immature specimens, in mature specimens partly or completely covered by a bulla-like chamber. Aperture a slit or low arch; interiomarginal, umbilicalextraumbilical in early stage, later becoming umbilical, which in the mature stage becomes covered by a bullalike chamber with one infralaminal aperture. Coiling random.

Largest diameter of holotype 0.45 mm.

Extra details from original publication
Stratigraphic range (in Cipero and Lengua formations) : Globorotalia fohsi barisanensis zone to Globorotalia menardii zone. Most typical and common in the Lengua formation.

Remarks: Globorotaloides variabilis, new species, is distinguished from G. suteri, new species, by having more compressed early chambers, more curved sutures and a greater number of chambers. It is likely that G. suteri, which is restricted to the lower and middle part of the Cipero formation, is the ancestor of G. variabilis, new species.


Bolli, H. M. (1957b). Planktonic foraminifera from the Oligocene-Miocene Cipero and Lengua formations of Trinidad, B.W.I. In, Loeblich, A. R. , Jr., Tappan, H., Beckmann, J. P., Bolli, H. M., Montanaro Gallitelli & E. Troelsen, J. C. (eds) Studies in Foraminifera. U.S. National Museum Bulletin . 215: 97-123. gs

Coxall, H. K. & Spezzaferri, S. (2018). Taxonomy, biostratigraphy, and phylogeny of Oligocene Catapsydrax, Globorotaloides, and Protentelloides. 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 4): 79-124. gs


Globorotaloides variabilis compiled by the pforams@mikrotax project team viewed: 18-4-2024

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