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Linked specimens: USNM-219456
Current identification/main database link:
The large test is a high trochospire of more than 10 subglobular chambers arranged in whorls of 3 chambers each. The initial portion of the trochospire is very tightly coiled and bluntly rounded so that the total number of whorls and chambers cannot be determined.
The cameral and spiral sutures are well incised. The outline of the test is somewhat lobate, as seen in side and in spiral view. The last-formed, arched aperture is situated at the intersection of the sutures between the ultimate, penultimate and antepenultimate chambers.The supplementary openings are also situated at the intersections of sutures. Each chamber of the ultimate and penultimate whorls has two sutural openings. The chambers increase rapidly in size from whorl to whorl.
Secondary sutural openings do not seem to occur in the chambers of the tightly coiled, early, elongate, trochospiral portion of the test. The principal arched aperture lies in a shallow umbilical depression. Its height is about 70 microns, and its width about 50 microns. It does not possess any lip, and its border is covered with strong individual, composite pustules.The calcareous wall is thick, pustulate and perforate. The scanning micrograph of the holotype Plate 13,Figure 1 shows that some of the tips of the isolated pustules of the final chamber are slightly eroded and expose minute rounded openings. On the earlier chambers the 4 to 6 large pustules surrounding a wall pore are basally and laterally fused, and form polygonal thick-walled compartments. Also on the earlier chambers the tips of the pustules are occasionally worn exposing minute openings which may represent canallike perforation of the pustules.
Size: The maximum diameter of the holotype, illustrated on Plate 13, Figure 1,is 425 microns. The holotype coils to the left. It is from Hole 64.1, Core 1, Section 5, 33-35 centimeters, Zone N. 7/N. 8, where it is associated with Globigerinoides subquadratus subquadratus Brönnimann,1954.
Extra details from original publication
Globigerinoides subquadratus subelongatus, n. subsp.,differs from Globigerinoides subquadratus subquadratus Brönnimann by its high trochospire. The other features of the test are identical. The form of the final aperture varies greatly from a typically high arch, occasionally with slightly inclined sides, to a low,broad arch (Plate 13, Figures 1, 2 and 5). In the same way that Globigerinoides subquadratus subquadratus is closely homeomorphic to Globigerinoides ruber (d'Orbigny), 1839, the new subspecies is homeomorphic to Globigerinoides elongatus (d'Orbigny),1826, which however closely shows only one supplementary sutural opening per chamber (Banner and Blow, 1960, pi. 3, Fig. lOa-c). The position of the final aperture in Globigerinoides elongatus Plate 13, Figure 3, from Hole 62.1, Zone N.21, is at the intersection of the suture of the ultimate chamber with that between the penultimate and antepenultimate chambers, hence identical with that in Globigerinoides subquadratus subelongatus, Plate 13, Figures 1 and 2,from Hole 64.1, Zone N. 7/N. 8.
The final chamber of Globigerinoides elongatus in the illustrated individual is strongly flattened and somewhat angular; the final aperture is a high elongate arch and the sides of the aperture converge toward the sutural intersection. This specimen agrees well with the lectotype of Globigerinoides elongatus designated by Banner and Blow (1960, ρl. 3, fig. 10 a c), from the Recent of the Adriatic Sea near Rimini, with the exception that the sides of the final apertures do not converge as strongly toward the sutural intersection as in our specimen.Parker (1967, pi. 22, fig. 2 4) illustrated as Globigerinoides ruber (d'Orbigny), specimens which we would assign to Globigerinoides elongatus. In Globigerinoides subquadratus subelongatus, the final opening tends more to be a broadly rounded arch whose sides do not form a pointed base.
The height of this arch, however, varies considerably from individual to individual. The apertural rim of Globigerinoides elongatus is also covered by pointed, isolated pustules,which expose the minute openings of canals. On the penultimate and earlier chambers the pustules fuse basally forming the funnel like depression already described for Globigerinoides subquadratus subelongatus. The scanning micrograph of the penultimate chamber of Globigerinoides elongatus, Plate 13, Fig ure 3 shows that the4 to 6 pustules surrounding a wall pore have tubular processes (= broken off spines),which are clearly isolated from the surrounding wall material and are incorporated in the wall only in the course of its thickening during growth.
Minute openings also occur on the interconnecting walls between the larger pustules. A paratype of Globigerinoides subquadratus subelongatus illustrated on Plate 13,Figure 2, possesses three arched apertures in the final chamber. The maximum diameter of four paratypes from Hole 64.1 ranges from 450 to 525 microns.
Globigerinoides subquadratus subelongatus compiled by the pforams@mikrotax project team viewed: 22-10-2020
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