CATALOG OF ORIGINAL DESCRIPTIONS: Globigerina atlantisae Cifelli & Smith 1970

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 -> Globigerina -> Globigerina atlantisae
Other pages this level: << < G. anguliofficinalis, G. antarctica, G. antillensis, G. apertura, G. applanata, G. aptica, G. aquiensis, G. arabica, G. archaeobulloides, G. ariakensis, G. aspensis, G. aspera, G. asperula, G. atlantica, G. atlantis, G. atlantisae, G. aumalensis, G. ayalai, G. azerbaidjanica, G. baconica, G. bacuana, G. bakeri, G. balchanensis, G. baroemoenensis, G. baroemoenensis quadrata, G. bathoniana, G. baylissi, G. belli, G. bermudezi, G. bilobata, G. binaiensis, > >>

Globigerina atlantisae

Citation: Globigerina atlantisae Cifelli & Smith 1970
Rank: species
Type locality: North Atlantic
Type age: Recent - plankton
Type sample and level: not specified
Holotype Repository: USNM
Type & figured specimens: Plate 1: FIGURES 1, 2,3.

Linked specimens: USNM-179173 USNM-179172 USNM-179174

Current identification/main database link: Not linked - add to pf_cenozoic :: pf_mesozoic :: ?


Original Description
Test compressed, trochospiral, with a rounded, lobate periphery and a rather elliptical outline; chambers rapidly enlarging as added, usually between two and three whorls in the adult with between four and five chambers in the peripheral whorl and from four to five in the pre-peripheral whorl; number of chambers ranging from 8 to 14 in the entire test, usually 10 or 11; chamber shape appearing elongated along the axis of coiling on the spiral side, and perpendicularly to the periphery on the umbilical side, vertically compressed, especially in the peripheral whorl; sutures distinct, depressed, narrow, slightly curved to radial on the spiral side, more curved on the umbilical side, with the spiral suture following around the bases of the chambers of the peripheral whorl and meeting the radial sutures sometimes in a substellate pattern, otherwise lobate; spiral side of test either almost flat or with early whorls raised as a plane above the peripheral whorl (Plate 1: figure 2) ; aperture interiomarginal, umbilical-extraumbilical, a slit reaching close to the periphery, almost covered by the extended final chamber and small flap attached to the base of that chamber; wall finely perforate, finely hispid, thin; coiling direction both left and right, with left slightly predominant;

Size: maximum diameters of primary types 0.23-0.26 mm.

Extra details from original publication
Parker (1958) synonymized her form with Globigerina radians Egger on the basis of figures for this species given by Rhumbler (1909). The original figure is enigmatic, through it resembles Globigerinella aequilateralis superficially. Rhumbler (1909, p. 11) stated that the form figured by him as G. radians was obtained from Egger. Inspection of these figures reveals, however, that the chambers are not so elongate in the direction of coiling on the spiral side as are those of the present form or Parker's specimens, but instead are distinctly more lobulate. In this regard, they more closely resemble those of some Globigerinita iota Parker. The nature of the figures, although revealing a form similar to both G. iota and Globigerina atlantisae, new species, does not permit truly detailed comparison. Globigerina atlantisae, new species, most closely resembles G. quinqueloba egelida, new subspecies. It differs from the latter in its slightly greater curvature of the sutures. This difference is particularly apparent on the umbilical side. The chambers of G. atlantisae are more elongate along the axis of coiling on the spiral side of the test and less spherical (or subspherical) than those of G. quinqueloba egelida. Globigerina atlantisae also has fewer chambers (generally 10 to 11 in the adult test compared to 13 or 14 in G. quinqueloba egelida). In the peripheral whorl there are between four and five chambers instead of the four and a half to five found in G. quinqueloba egelida. Related to this is that there is a consistent difference in the peripheral outline between the two, with an indentation below and adjacent to the final chamber of G. atlantisae which is not present with G. quinqueloba egelida (Figure 10). The aperture of G. atlantisae usually is obscured by the final chamber's flap-like extension, while G. quinqueloba egelida shows this feature less commonly. Further, the aperture of G. atlantisae extends closer to the periphery. Both species are compressed, but G. atlantisae is generally more so, and also generally has a flatter spiral surface. With G. atlantisae specimens, chambers tend to occupy more nearly the same number of degrees of whorl (compared with other chambers of the same and other specimens) than is the case with G. quinqueloba egélida (Figure 11).

MEASUREMENTS. Sixteen specimens were selected to determine the relationship between chamber number and degrees of test volution in Globigerina atlantisae, new species (Figure 11). The maximum number of chambers recorded is 14, but most specimens contain 12 or fewer chambers. In all but four specimens the chambers occupy more than two but less than three full whorls. The four specimens consisting of less than two full whorls probably represent immature forms. Good consistency exists among specimens in growth pattern and they plot close to a straight line with a relatively small spread of points. The peripheral whorl contains between four and five chambers, which represents a slight decrease in rate of chamber addition from the previous 360° of volution (pre-peripheral whorl).

DISTRIBUTIONGlobigerina atlantisae, new species, is not common in Atlantis II material. It occurs at seven Atlantis 77-13 stations and one Atlantis II-9. It reaches a peak of 2 percent at station 21.

References:

Cifelli, R. J. & Smith, R. K. (1970). Distribution of planktonic foraminifera in the vicinity of the North Atlantic Current. Smithsonian Contributions in Paleobiology,. 4: -. gs


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Globigerina atlantisae compiled by the pforams@mikrotax project team viewed: 9-4-2020

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