Rectoguembelina


Classification: pf_cenozoic -> Guembelitrioidea -> Heterohelicidae -> Rectoguembelina
Sister taxa: Rectoguembelina, Zeauvigerina
Daughter taxa: (blue => in age window 0-800Ma)
Rectoguembelina cretacea
Distinguished by its small, elongate biserial to uniserial test, usually with two to four uniserial chambers arranged in a rectilinear fashion and bearing a simple, terminal, round to oval-shaped aperture on a short neck.
Rectoguembelina sp.
Specimens which cannot be assigned to established species

Taxonomy

Citation: Rectoguembelina Cushman, 1932
Rank: Genus
Type species: Rectoguembelina cretacea Cushman, 1932.
Taxonomic discussion: Glaessner (1936) and Montanaro Gallitelli (1957) considered Rectoguembelina to be a junior synonym of Tubitextularia Sulc (type species = Pseudotextularia bohemica Sulc, 1929), whereas Loeblich and Tappan (1964, 1988) synonymized both of these genera under Bifarina Parker and Jones (type species = Dimorphina saxipara Ehrenberg, 1854). Comparison of the type species of Rectoguembelina with the type species of Bifarina and Tubitextularia, however, reveals significant differences. The holotype illustration of Dimorphina saxipara, which is a cross-sectional view, shows a tubular extension between the apertures of successive uniserial chambers (Loeblich and Tappan, 1988, pl. 491: fig. 4), and the apertures on the uniserial chambers of Pseudotextularia bohemica are described and illustrated as alternating from one side of the chamber to the other (Sulc, 1929, pl. 1: figs. 6-16); however, the uniserial apertures of R. cretacea lack any tubular extensions and are terminal in position. Rectoguembelina cretacea also differs from P. bohemica and D. saxipara by having a greater number of chambers, which are less globular and more distinctly biserial prior to the onset of the uniserial growth stage. Based on comparison of the type species, Tubitextularia is retained as a junior synonym of Bifarina, whereas Rectoguembelina is resurrected to accomodate the distinctly different R. cretacea.
The holotype and paratypes of Rectoguembelina texana Cushman and R. trinitatensis Cushman and Renz are more appropriately assigned to Bifarina because the biserial stage is only represented by two to four very globular chambers, the wall texture is hispid rather than smooth, and the apertures on the uniserial chambers alternate from one side to the other prior to the final chamber. Presently, R. cretacea is the only species placed in Rectoguembelina.
Rectoguembelina differs from Zeauvigerina by having several, rather than one, fully uniserial chambers following the biserial stage. The early ontogeny of both taxa are similar though, as the biserial chambers have an asymmetrically positioned aperture surrounded by a narrow, equidimensional lip. [Olsson et al. 1999]

Catalog entries: Rectoguembelina

Distinguishing features: Transition from biserial to uniserial portion of test very abrupt, occurring after first four or more pairs of biserial chambers, without an intervening interval of gradually increasing chamber overlap. Apertures on biserial portion interiomarginal with a small, narrow arch; apertures on uniserial chambers terminal, circular, and aligned in rectilinear fashion, without lip or toothplate. Wall calcareous, microperforate; surface smooth to finely pustulose.

NB These concise distinguishing features statements are used in the tables of daughter-taxa to act as quick summaries of the differences between e.g. species of one genus.
They are being edited as the site is developed and comments on them are especially welcome.

Description

Biogeography and Palaeobiology


Geographic distribution: Low to middle latitudes. [Olsson et al. 1999]

Biostratigraphic distribution

Geological Range:
Notes: Maastrichtian through Zone P2. [Olsson et al. 1999]
Last occurrence (top): near top of Danian Stage (85% up, 62.3Ma, in Danian stage). Data source: Total of range of species in this database
First occurrence (base): in mid part of Maastrichtian Stage (48% up, 69.2Ma, in Maastrichtian stage). Data source: Total of range of species in this database

Plot of occurrence data:

Primary source for this page: Olsson et al. 1999 - Atlas of Paleocene Planktonic Foraminifera, p. 93

References:

Cushman, J. A. (1932). Rectoguembelina, a new genus from the Cretaceous. Contributions from the Cushman Laboratory for Foraminiferal Research. 8(1): 4-7. gs V O

Ehrenberg, C. G. (1854). Mikrogeologie: Das Erden und Felsen schaffende Wirken des unsichtbar kleinen selbständigen Lebens auf der Erde. Leopold Voss, Leipzig. 1-374. gs

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

Loeblich, A. R. & Tappan, H. (1964b). Sarcodina, Chiefly "Thecamoebians" and Foraminiferida. In, Moore, R. C. (ed.) Treatise on Invertebrate Paleontology, Protista 2, pt. C. University of Kansas Press, Lawrence 1-900. gs

Loeblich, A. R. & Tappan, H. (1988). Foraminiferal Genera and Their Classification (Volume I-II). Van Nostrand Reinhold Co., New York. 1-1059. gs

Montanaro Gallitelli, E. (1957). A revision of the foraminiferal family Heterohelicidae. In: Studies in foraminifera; Part 1 - Planktonic foraminifera. 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: 133-154. gs V O

Olsson, R. K., Hemleben, C., Berggren, W. A. & Huber, B. T. (1999). Atlas of Paleocene Planktonic Foraminifera. Smithsonian Institution Press, Washington, DC. 1-252. gs

Sulc, J. (1929). Contributions à connaissance de la morphologie des foraminifères. Vestnìk Stàt. Geol. ustavu Ceskosl. Rep. 5: 142-149. gs


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Rectoguembelina compiled by the pforams@mikrotax project team viewed: 28-10-2020

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