Catalog - Globorotalia (Turborotalia) pseudopumilio

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.

Globorotalia (Turborotalia) pseudopumilio

Citation: Globorotalia (Turborotalia) pseudopumilio Brönnimann & Resig 1971

The very small test consists of about 11 to 12 chambers arranged in a flat trochospire with 5 subglobular chambers in the final whorl. The chambers of the initial whorl are minute and increase only little during growth. The five chambers of the final whorl are much larger than the previously formed ones and they increase gradually in size. In spiral view, the initial whorl is somewhat depressed in respect to the chambers of the final whorl. The early sutures are oblique,those between the chambers of the final whorl are ventrally and dorsally more or less radial and well incised so that the contour of the test is lobate. The chambers of the final whorl, which are either not compressed or only very slightly compressed in an axial direction, are equidimensional in a tangential and radial direction, as seen in spiral view. The ultimate chamber
is about 85 microns in radial diameter. The height of the final chamber is about 80 microns. The umbilical side shows a deep but small umbilicus of about 15 microns diameter. The aperture is an umbilical-extraumbilical arch, higher toward the periphery than toward the umbilicus. In side view the aperture is about 50 microns wide and is bordered by a narrow, thin-walled plate of 5 to 10 microns width. The calcareous wall is perforate and covered irregularly with bluntly rounded pustules of differing diameters which may fuse to form polygonal walls around the wall pores, of less than 1 to about 2 microns diameter, which are in the centers of low, funnel-like depressions. Scanning micrographs (Plate 43, Figures 4 and 5) exhibit pustules which are composites of numerous small units (crystallites) or small pustules. Some of them possess pinpoint-like openings in which fine spines rooted in the living specimens.

The maximum diameter of the holotype is about 187 microns, its axial height about 100 microns. The specimen coils to the right. It is illustrated on Plate 43, Figure 6 and comes from Hole 62.1, Core 6, Section 5, 15-17 centimeters, lower part of Zone N. 21.

In respect to gross morphology Globorotalia (T.)pseudopumilio, n. sp., seems to be related to Globorotalia (T.) pumilio Parker, 1962, which however is smaller, has at least six chambers in the final whorl, 5.5 to 7 according to Parker (1962, p. 238, pl. 6, fig. 2, 3),a brilliant, smooth surface and strongly oblique cameral sutures on the spiral side. The chambers of the final whorl of Globorotalia (T.) pumilio do not increase as rapidly in size, and the low-arched aperture is much smaller than in Globorotalia (T.) pseudopumilio. Furthermore, Parker's species has a more rounded outline than Globorotalia (T.) pseudopumilio which is rather elongate in spiral and umbilical outline.Topotypes of Globorotalia (T.) pumilio from CAP HG41, 0-1 centimeter, kindly donated by Frances L.Parker, with maximum diameters of about 125 to
150 microns, are rounded-lobate in spiral and umbilical outline, have a smooth brilliant surface, and an opaque wall. The specimens have 6 to 7 chambers in the ultimate whorl. The scanning micrograph (Plate 48,Figure 1) of the umbilical view of a specimen from CAPHG-41, 0-1 centimeter, permits the addition of the following morphologic data to Parker's excellent description:
The specimen, which coils to the left, possesses six chambers in the final whorl. The radial cameral sutures are well-incised and produce the lob ate outline. The umbilicus is small—about 3 to 4 microns in diameter—and deep. The aperture is a low elongate arch extending from the umbilicus toward the periphery without reaching it. There does not seem to be a discrete apertural rim. The surface of the chambers is minutely granular, almost smoothly brilliant, and toward the umbilical depression is covered by individual, minute pustules which are somewhat stronger on the oldest chamber of the final whorl than on the ultimate chamber. The topotypes are spirally rather flat and not convex as already mentioned by Parker (1962), and they correspond rather well with Parker's illustrations published in 1967 (pi. 18, fig. 5 a-c). In this aspect Globorotalia (T.) pumilio and Globorotalia (T.)pseudopumilio are very similar.
The height of the trochospire of paratypes of Globorotalia (T.) pseudopumilio ranges considerably. The initial coil, although always flattened, may be either depressed or slightly elevated in respect to the sub-globular chambers of the final whorl. The maximum diameter of the paratypes is around 200 microns. The number of chambers of the final whorl varies from 5 to 7. The direction of coiling of holotype and paratypes is to the right. Globorotalia (T.) pseudopumilio is associated almost throughout its range with Globorotalia (T.) planispira Brönnimann and Resig, n. sp., with which it has the multiple pustules in common.

References:

Brönnimann, P. & Resig, J. (1971). Brönnimann, P. & Resig, J. (1971). A Neogene globigerinacean biochronologic time-scale of the southwestern Pacific. Initial Reports of the Deep Sea Drilling Project. 7(2): 1235-1469. Initial Reports of the Deep Sea Drilling Project. 7(2): 1235-1469. gs O

CATALOG OF ORIGINAL DESCRIPTIONS: Globorotalia (Turborotalia) pseudopumilio Brönnimann & Resig 1971

Globorotalia (Turborotalia) pseudopumilio

References:

Add Comment

Comments