Catalog - Globigerina elburganica Catalog - Globigerina elburganica

CATALOG OF ORIGINAL DESCRIPTIONS: Globigerina elburganica Shutskaya 1970

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 -> Globigerina elburganica
Other pages this level: << < G. dinodensis, G. diplostoma, G. dissimilis, G. druryi, G. druryi decoraperta, G. dubia, G. dubia lakiensis, G. dubiata, G. dudrouensis, G. dutertrei, G. eamesi, G. edita, G. edita polycamera, G. eggeri, G. eggeriformis, G. elburganica, G. elevata, G. elongata, G. elongata Shutskaya, G. eocaena, G. eocaenica, G. eocaenica irregularis, G. esnaensis, G. euapertura, G. eugubina, G. eximia, G. exumbilicata, G. falconensis, G. fariasi, G. finlayi, G. fistulosa> >>

Globigerina elburganica

Citation: Globigerina elburganica Shutskaya 1970
taxonomic rank: Species
Described on page(s) : 83-85
Type specimens: holotype (fig. 1a-c), no 1238-1-62.
Type sample (& lithostrat): upper El'burgan Foratmion
Type age (chronostrat): Lower Paleocene, Mohnian, Globorotalia angulata Zone
Type locality: Along the Kuban River. Northern Caucasus, southern USSR
Type repository: probably deposited in the collections of the All-Union Scientific-Research Geological-Prospecting Petroleum Institute (VNIGNI), Moscow

Current identification:


Original Description

Translation from the Russian. - Test medium- sized (0.3-0.35 mm.). flattened dorsally, high ventrally, rounded-oval, co-efficient of elongation 1.1-1.2, coefficient of broadening mostly greater than 1.6. Structure of initial part rotaloicl, low-trochospiral, without a steplike transition from one plane to another, as in species of the Clobigerina edita group. Number of chambers in initial part 4-6. In the last whorl there are 31/2-4 chambers. Growth is gradual. The relationship between individual elements in the last whorl is as follows: a) width of penultimate chamber equal to or greater than that of last one, ratio 1-1.1; b) ratio of length of base of last chamber to its width 1.1-1.4. Height of last chamber equals height of the preceding part of the test. Chambers of last whorl spherical, surface of chambers inflated. Outline of last chamber on ventral side oval. Side surface of last chamber usually subquadrate. Chambers in last whorl arranged compactly. Intercameral sutures thin, deep. Umbilical depression narrow, deep. Outer margin coarsely festooned. Aperture umbilical, somewhat shifted toward the side relative to the center, covered by a flap. Perforation of the test is distinctly visible.

Extra details from original publication
Variation. - Together with gradually enlarging chambers (see tf. 1, 13, 14) chambers that expand unevenly are observed; the first is much smaller than the next one (see tf. 1, 15, 16). The sideward shift of the aperture relative to the center manifests itself differently: from a completely cen- tral aperture (tf. I, 15, 16) to one whose margin extends onto the peri- pheral margin of the test (tf. 1, 13, 14).

Comparison. - This species was erroneously referred to (Shutskaya, 1953. loc. cit. ) as Globigerina praebulloides. with which it has no features in common except for the rotaloid arrangement of the chambers in the initial part of the test. In the Globigerina varianta group it is closest to G. moskvini Shutskaya, from which it differs (Shutskaya, 1970, op. cit., table 1) by the low-trochospiral rather than flattened-trochospiral coiling or the whorls in the initial part of the test, the smaller number of chambers, their gradual enlargement and spherical shape, thin deep sutures, and umbilical aperture. The distinctive features of the species make it possible to identify it in the literature (see synonymy) also, demonstrating its broad geographic distribution.

References:

Shutskaya, E. K. (1953). Raschlenenie kubanskogo i elburganskogo gorizontov Severnogo Kavkaza po globigerinam:. Byulleten Moskovskogo Obshchestva Ispytateley Prirody Otdel Geologicheskiy. 28: 71-79. gs

Shutskaya, E. K. (1970a). Morphologic groups and descriptions of species of Globigerina and Acarinina in the lower Paleogene of the Crimea, the Caucasus Foreland, and western Central Asia. Trudy Vsesoyuznego Neftyanogo Nauchno-Issledovatel'skogo Geologo-Razvedochnogo Instituta (VNIGRI). 69: 79-113. gs


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Globigerina elburganica compiled by the pforams@mikrotax project team viewed: 14-12-2024

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