Catalog - Pseudogloborotalia

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Pseudogloborotalia

Citation: Pseudogloborotalia Haque 1956

Type species: Pseudogloborotalia ranikotensis Haque, 1956

Test trochoid, plano-convex, usually with a keeled periphery at the dorsal edges. Ventral side umbilicate, strongly convex, completely involute. Dorsal side flattened, evolute. Surface smooth. Wall calcareous, perforate, radial, hyaline. Aperture at the base of the last chamber between the periphery and the umbilicus, usually away from the former, ar:d opening into the latter. From Globorotalites Brotzen this genus is distinguished by the apertural character.

Family Globorotaliidae. Paleocene to Lower Eocene.

In 1927, Cushman erected a genus for rotaliid forms with typically cancellated test and the ventral aperture opening into the umbilicus. The genotype of that genus, Globorotalia, as designated by the author, is Pulvinulina menardii d'Orbigny var. tumida Brady, a biconvex, compressed, keeled, rotaliid with a thick cancellated surface and a ventral aperture at the base of the last chamber opening into the small umbilicus.

Cushman and Bermudez erected Truncorotalia in 1949, as a new subgenus of Globorotalia, for all the forms of Globorotalia with a flattened dorsal side, since the genotype of that genus shows a typically biconvex test. The subgenotype of Truncorotalia, as designated by the authors, is Rotalina truncatulinoides d'Orbigny. According to the description of the genus (1949, Cushman Lab. Foram. Res., Contr., vol. 25, pt. 2, p. 36) the surface of the test is ornamented by small papillae surrounding the umbilicus and fine granulations covering the earliest chambers on the dorsal side.

In the lower Ranikot [Paleocene] beds of the Nammal gorge, Pakistan, a group was found which bears a strong resemblance to Globorotalia, but the surface of the test is smooth and shiny throughout. The test is calcareous, rather coarsely perforate, and, like Globorotalia, is hyaline and built of radially arranged crystals of calcite. This laevigate form from the Nammal gorge is referred here to a new genus, Pseudogloborotalia.

The following species were included in the genus Pseudogloborotalia by Haque (1956):

Pseudogloborotalia khairabadensis Haque, 1956;
Pseudogloborotalia membranacea (Ehrenberg) = Planulina membranacea Ehrenberg, 1854;
Pseudogloborotalia paleocenica Hague, 1956;
Pseudogloborotalia ranikotensis Haque, 1956;
Pseudogloborotalia ranikotensis Hague var. oblonga Haque, 1956

References:

Haque, A. F. M. M. (1956). The smaller foraminifera of the Ranikot and the Laki of the Nammal gorge, Salt Range. Memoir of the Pakistan Geological Survey. 1: 1-300. gs

CATALOG OF ORIGINAL DESCRIPTIONS: Pseudogloborotalia Haque 1956

Pseudogloborotalia

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			Pseudogloborotalia guatemalensis Bermúdez 1961
			Pseudogloborotalia lomasha Singh and Kalia 1970
			Pseudogloborotalia pasionensis Bermudez 1961 = Morozovella pasionensis