Catalog - Globigerina (Eoglobigerina) balakhmatovae Catalog - Globigerina (Eoglobigerina) balakhmatovae

CATALOG OF ORIGINAL DESCRIPTIONS: Globigerina (Eoglobigerina) balakhmatovae Morozova, in Morozova & Moskalenko 1961

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 -> Globigerina (Eoglobigerina) -> Globigerina (Eoglobigerina) balakhmatovae
Other pages this level: G. (Eoglobigerina) balakhmatovae, G. (Eoglobigerina) bizkaiensis, G. (Eoglobigerina) eobulloides, G. (Eoglobigerina) hemisphaerica, G. (Eoglobigerina) pentagona, G. (Eoglobigerina) prebetica, G. (Eoglobigerina) taurica, G. (Eoglobigerina) tetragona, G. (Eoglobigerina) theodosica, G. (Eoglobigerina) trifolia

Globigerina (Eoglobigerina) balakhmatovae

Citation: Globigerina (Eoglobigerina) balakhmatovae Morozova, in Morozova & Moskalenko 1961
taxonomic rank: Species
Type specimens: 3513/1
Type sample (& lithostrat): argillite from the upper band of the Mogokh (Mogokhskiye) beds, Thirty well preserved and ten imperfect specimens.
Type age (chronostrat): Middle Jurassic. lower Bathonian, Globigerina (Conoglobigerina) dagestanica and Globigerina (Conoglobigerina) avarica Zone. Occurs also in the Upper Bajocian.
Type locality: Holotype from the village of Chokh; and found also in the village of Gunib, both in central Dagestan; and in the Gaurdak region, in Turkmenia; all in the USSR.
Type repository: Moscow, Russia; Museum of the Geological Institute of the Academy of Sciences

Current identification/main database link: Globuligerina balakhmatovae (Morozova in Morozova & Moskalenko, 1961)


Original Description

DiagnosisEoglobigerlna with a low spiral, consisting of two whorls. The first whorl comprises 3 to 5½ chambers and the final whorl contains 4 chambers. Wall thin, porous.
Description - Test small, low, its height approximately one-half the diameter. Spiral, formed by two whorls. The final whorl is two or three times higher than the first and consists of 4 rapidly increasing chambers which are slightly compressed along their height. The first whorl consists of 3 to 5½  chambers. Sutures between chambers weakly depressed, straight; those between the chambers of the first whorl sometimes slightly oblique. Aperture single, small, rounded, rimmed by a. narrow, weakly expressed lip. Wall thin, radiate, finely porous. Surface smooth, shiny or matte.

Size:
Greatest diameter 0.18-0.12mm; Smallest diameter 0.16-0.10, height 0.11-0.06mm

Extra details from original publication
Synonym: Globigerina sp. Balakhmatova, 1953, Vses. Nauchno-Issled. Geol. Inst.. Ser. Pal. Stat., Trudy, p. 88, pl. 1a-c.

Variability. - This species is distinctly dimorphic. Microspheric specimens have a multichambered initial whorl (pl. 1, figs. 1, 4) in megalospheric forms the initial whorl consists of three (pl.1, fig.5) or four chambers (pl. 1, fig. 9). The rate of increase of the chambers and the depression of the sutures vary with each generation. There are individuals with, four chambers in each, the initial and final whorl (fig. 5). 

Comparison. - An identical form was described by Balakhmatova from the Bajocian of Turkmenia under the name of Globigerina ex gr. bulloides d'Orbigny. As indicated by Balakhmatova, the studied Globigerinidae were separated from a rock in which was embedded Garantia sp., and partially from the rock embedded in the shell of that Ammonite. The identity of the Dagestanian representatives of this species with those from Turkmenia was established by means of comparison of our material with Balakhmatova's collection. It should only be noted that the Turkmenian specimens are a little larger than those from Dagestan, and are white in color, whereas individuals from central Dagestan are somewhat smaller and gray, in harmony with the gray color of the claystone in which they are embedded. The described species differs from Globigerina oxfordiana Grigelis, from the lower Oxfordian of Lithuania, in the closer arrangement of chambers and in that they increase more rapidly in size in the final whorl the small aperture of which is often poorly discernible; the multichambered final whorl; and the smaller size of the test. The Lower Cretaceous Globigerina hoterivica Subbotina and Globigerina cretacea Glaessner possess a larger number of whorls and chambers, and are smaller in size; the number of chambers in the first and the subsequent whorls is usually the same in both species.


Editors' Notes
content migrated from chronos

References:

Morozova, V. G. & Moskalenko, T. A. (1961). Планктонные фораминиферы пограничных отложений байосского и батского ярусов Центрального Дагестана (Северо-Восточный Кавказ) [Foraminiferes planctoniques des depots limitrophes du Bajocien et du Bathonien du Daghestan central (Nord-Est du Caucase)]. Voprosyi Mikropaleontologii. 5: 3-30. gs


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Globigerina (Eoglobigerina) balakhmatovae compiled by the pforams@mikrotax project team viewed: 14-10-2024

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Short stable page link: https://mikrotax.org/pforams/index.php?id=130302 Go to Archive.is to create a permanent copy of this page - citation notes



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Comments (2)

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Le Coze

I hope you will like the link

Morozova, V. G.; Moskalenko, T. A. (1961). Планктонные фораминиферы пограничных отложений байосского и батского ярусов Центрального Дагестана (Северо-Восточный Кавказ) - Foraminifères planctoniques des dépots limitrophes du Bajocien et du Bathonien du Daghestan central (Nord-Est du Caucase). Академия наук СССР Вопросы микропалеонтологии-Academy of Sciences USSR Questions of Micropaleontology. 5: 3-30., available online at http://www.ginras.ru/library/pdf/05_1961_voprosy_mikropaleontologii.pdf

It seems that the following species could be of some interest? (p. 25 fig. 6):

Globigerina (Conoglobigerina) gaurdakensis Balakhmatova & Morozova, 1961

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Jeremy Young(UK)

Thanks! The images will have to wait a while but i have got the basic species entry done now. species