CATALOG OF ORIGINAL DESCRIPTIONS: Globorotalia uncinata subsp. carinata El-Naggar 1966

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 -> Globorotalia -> Globorotalia uncinata carinata
Other pages this level: << < G. subconica, G. suterae, G. tadjikistanensis, G. testarugosa, G. tetracamerata, G. thebaica, G. tortiva, G. tosaensis, G. traubi, G. tribulosa, G. trichotrocha, G. trinidadensis, G. troelseni, G. truncatulinoides excelsa, G. uncinata, G. uncinata carinata, G. ungulata, G. velascoensis parva, G. wartsteinensis, G. whitei, G. wilcoxensis, G. wilcoxensis acuta, G. wilesi, G. woodi, G. youngi, G. zealandica, G. zealandica incognita, G. zealandica pseudomiozea,

Globorotalia uncinata carinata

Citation: Globorotalia uncinata subsp. carinata El-Naggar 1966
Rank: sub-species
Type locality: Holotype (fig. I a-d) and unfigured paratypes f rom approximately 11 2 meters above the base of the Gebel Owaina section (27°45'N 32°4 5.75'E), about 12 km. north of the Nile at El Maha mid. Esna-ldfu region, Upper Egypt.
Type age: Uppermost Middle Paleocene, Globorotalia angulata Zone, Globorotalia pusilla Subzone
Type sample and level: lower Owaina Shale. Rare.
Holotype Repository: London, UK; NHM
Type & figured specimens: holotype (fig. 1a-d) P.45634; unfigured paratypes) P.45635.

Linked specimens: London, UK; NHM (45635) London, UK; NHM (PM P 45634)

Current identification/main database link:


Original Description
Diagnosis. A Globorotalia uncinata with planoconvex test, thickened, nodose keel. imbricate dorsal side and rougher surface.

Description. - Test medium-sized, almost plano convex, coiled in a very low trochospire; dorsal side flat, imbricate: ventral side strongly protruding; equatorial periphery ovoid, distinctly lobate; axial periphery angular with a well-developed, very thick, heavily papillose or rather nodose keel; chambers, as seen on dorsal side, 15, arranged in 2½ dextrally coiled whorls; the initial ones are small, inflated and globigerine; the last whorl is composed of 6, relatively large, almost crescentic, overlapping chambers, which increase slowly in size in the early part and rapidly later; on the ventral side the chambers are 6, relatively large, strongly protruding, angular conical and increase rapidly in size towards the last chamber : sutures on the dorsal side curved, depressed in the early part, strongly curved, depressed later, although they are marked by the thick, papillose, marginal keel as it curves on the dorsal side encirc ling the periphery of each chamber; on the ventral side the sutures are almost straight, rad ial and strongly incised; umbilicus small, deep and open: aperture a low arch, interiomarginal, extraumbilical-umbilical; wall calcareous, perforate; surface rough, heavily papillose, with the roughness decreasing gradually towards the last chamber: the marginal keel is very thick, heavily papillose or even nodose.

Size: Dimensions of holotype: Maximum diameter 0.37 mm.: minimum diameter 0.24 mm.; thickness 0.21 mm.

Extra details from original publication
Main vanation. - Chambers 13-18, arranged in 2-3 tightly coiled whorls. Coiling is random. with a tendency to be sinistral (of 29 specimens studied, 12 coiled sinistrally). Chambers in the last whorl 5-6. rarely 7.

Remarks. - The tendency towards the development of a partial pseudo-keel was observed in specimens of G. uncinata uncinata Bolli from the Esna-Idfu region (e.g. El-Naggar. 1966,  pl. 19, fig. 2a-c) and can be seen on the holotype of Bolli (1957, pl. 17, figs. 13-15), this tendency was found to lead higher in the section to forms with very well-developed, thick, nodose keels, which are here described as G. uncinata carinata. This new subspecies is distinguished from G. uncinata uncinata Bolli, from which it is believed to have evolved, by its thick, nodose keel; flat, imbricate dorsal side; distinctly angular, axial periphery; angular conical chambers on the ventral side, and rougher surface.
The marginal keel in G. uncinata carinata is very peculiar; it is much thicker and rougher than any known keel in the genus Globorotalia. The well-developed rugosity does not allow one to see whether or not it is a true, imperforate keel, although it seems quite distinct from the rest of the test.""

References:

Bolli, H. M. (1957d). The genera Globigerina and Globorotalia in the Paleocene-Lower Eocene Lizard Springs Formation of Trinidad. 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: 61-82. gs V O

El-Naggar, Z. R. (1966). Stratigraphy and planktonic foraminifera of the Upper Cretaceous-Lower Tertiary succession in the Esna-Idfu region, Nile Valley, Egypt, U. A. R. Bulletin of the British Museum (Natural History) Geology. supplement 2: 1-291. gs


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Globorotalia uncinata carinata compiled by the pforams@mikrotax project team viewed: 19-9-2020

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