Catalog - Pseudoguembelina

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.

Pseudoguembelina

Citation: Pseudoguembelina Bronnimann&Brown 1953

Type species: Guembelina excolata Cushman, 1926

Definition. - The tapering calcareous test is composed of biserially staggered, globular to subglobular chambers as in the genus Guembelina [Egger]. A pointed unlobulated initial end consists of minute chambers, followed by a lobated stage with considerably larger and more-inflated chambers. The chambers may become laterally compressed in the last stage. The principal aperture is an arched opening at the base of the inner margin of the ultimate chamber. In the lobated stage a minute accessory aperture is developed at the base near the median line on each side of each chamber. These apertures are covered by tiny valves or flaps. They are commonly damaged or filled with adherent matrix, and thus are not readily detected. Striations or costations (if present) are arranged longitudinally, following the contour of the chambers.
Family Heterohelicidae. Upper Cretaceous.

Diagnosis. - Guembelina s.str. resembles Pseudoguembelina but it does not exhibit accessory apertures. Textularia globulosa Ehrenberg, a smooth species, is the genoholotype of Guembelina. Ehrenberg (1840, p. 135) did not designate a type locality for this species, but among the localities mentioned are the Chalk of Gravesend, England, and Meudon in the Paris Basin. Cushman (1927, pp. 213-217) examined Ehrenberg's types in Berlin, and later figured (Cushman 1938, figs. 30-31) specimens from the Gravesend locality. No accessory apertures were mentioned, nor do the figures indicate that they may be present. Glaessner (1936) figured a specimen from the Paris Basin, but no accessory apertures were shown. Loeblich's figures (Loeblich 1951) of hypotypes from the Kemp clay, Navarro group (Maestrichtian) of Texas (U. S.G. S. Sta. 7638) are magnified 158 diameters, yet they do not reveal any features suggestive of accessory apertures. Specimens from the Upper Cretaceous of Cuba and from the Corsicana marl, Navarro group of Texas (U.S.G.S. Sta. 13832, same as Plummer Sta. 1048) have been identified by the writers as Guembelina globulosa (Ehrenberg). No accessory apertures have been observed in these specimens.

Striate species in which the presence of accessory apertures has not yet been verified are: Guembelina ultimatumida White, Guembelina planata Cushman, Guembelina semicostata Cushman, Guembelina carinata Cushman, Guembelina globocarinata Cushman, and others. The striate forms Guembelina plummerae Loetterle and Guembelina nuttalli Voorwijk differ from Guembelina s.str. not only in ornamentation but also in the development of the later stages. They should probably be allocated to another genus.

Cushman (1938), noted small depressed triangular areas between chambers of the smooth Gumbelina reussi Cushman and the striate Guembelina planata Cushman. These features may be interpreted as the flaps covering accessory apertures. However, an examination of type specimens should be made before further comments on this interpretation can be warranted.

Coiling is known in the initial stage in the microspheric form of several species of Guembelina, including the genoholotype Textularia globulosa Ehrenberg. Textularia striata Ehrenberg is the only species of Pseudoguembelina in which coiling has been observed.

The following species were included in the genus Pseudogumbelina by Bronnimann and Brown (1953):

Pseudoguembelina costulata (Cushman) = Guembelina costulata Cushman, 1938;
Pseudoguembelina excolata (Cushmanl = Guembelina excolata Cushman, 1926;
Pseudoguembelina palpebra Bronnimann and Brown, 1953;
Pseudoguembelina punctulata (Cushman) = Guembelina punctulata Cushman,1938;
Pseudoguembelina striata (Ehrenberg) =Textularia striata Ehrenberg 1840.

References:

Brönnimann, P. & Brown, N. K. (1953). Observations on some planktonic Heterohelicidae from the Upper Cretaceous of Cuba. Contributions from the Cushman Foundation for Foraminiferal Research. 4(4): 150-156. gs

Cushman, J. A. (1927e). Some characteristic Mexican fossil foraminifera. Journal of Paleontology. 1(2): 147-172. gs

Cushman, J. A. (1938). Cretaceous species of Guembelina and related genera. Contributions from the Cushman Laboratory for Foraminiferal Research. 14: 2-28. gs

Ehrenberg, C. G. (1840). Uber die Bildung der Kreidenfelsen und des Kreidemergels durch unsichtbare Organismen. Physik. Abh. (1838), Berlin. 59-147. gs

Glaessner, M. F. (1936). Die Foraminiferen gattungen Pseudotextularia und Amphimorphina. Problemy Paleontologii, Paleontologicheskay Laboratoriya Moskovskogo Universiteta. 1: 116-134. gs

Loeblich, A. R. (1951). Coiling in the Heterohelicidae. Contributions from the Cushman Foundation for Foraminiferal Research. 2: 106-110. gs

			Pseudoguembelina cornuta Seiglie 1959 = Pseudoguembelina palpebra
			Pseudoguembelina costellifera Masters 1976 = Pseudoguembelina costellifera
			Pseudoguembelina hariaensis Nederbragt 1991 = Pseudoguembelina hariaensis
			Pseudoguembelina kempensis Esker 1968 = Pseudoguembelina kempensis
			Pseudoguembelina leroyi Kavary in Kavary&Frizzell 1964 = Pseudoguembelina palpebra
			Pseudoguembelina palpebra Bronnimann&Brown 1953 = Pseudoguembelina palpebra
			Pseudoguembelina polypleura Masters 1976 = Pseudoguembelina palpebra
			Pseudoguembelina praehariaensis Tur&Huber in Huber et al. 2022a = Pseudoguembelina praehariaensis

CATALOG OF ORIGINAL DESCRIPTIONS: Pseudoguembelina Bronnimann&Brown 1953

Pseudoguembelina

References:

Add Comment

Comments