CATALOG OF ORIGINAL DESCRIPTIONS: Globorotalia acostaensis Blow 1959

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 -> Globorotalia -> Globorotalia acostaensis
Other pages this level: G. acostaensis, G. acostaensis trochoidea, G. acrostoma, G. acrostoma partimlabiata, G. acutispira, G. adamantea, G. aequa bullata, G. africana, G. akersi, G. alamedillensis, G. albeari, G. almadenensis, G. amuria, G. andalusiana, G. anfracta, G. angulata abundocamerata, > >>

Globorotalia acostaensis

Citation: Globorotalia acostaensis Blow 1959
Rank: species
Type locality: near Pozon, eastern Falcon; Venzuela
Type sample and level: sample. No. RM 19791, auger line near Pozon, eastern Falcon
Holotype Repository: Washington; USNM
Type & figured specimens: Holotype; Plate 17, figures 106 a-c, deposited in U.S.N.M. collection, 625707.

Linked specimens: USNM-625708 USNM-625707 USNM-625708

Current identification/main database link: Neogloboquadrina acostaensis (Blow, 1959)


Original Description
Test low trochospiral; spire opening regularly but fairly rapidly, with 11-13 chambers composing the spire, usually with 5-6 chambers in the last whorl. Equatorial periphery strongly lobate, with the test appearing subcircular in equatorial profile; axial periphery rounded with the test appearing thick and parallel-sided in side view; chambers ovate or subspherical, generally inflated but not well separated; often the last chamber is much reduced in size compared with its predecessor, and it also occasionally becomes somewhat displaced towards the umbilical side (fig. 107, Pl. 17). Spiral side slightly convex, almost flat, or occasionally slightly concave due to the inflated nature of the chambers of the last whorl. Umbilical side generally slightly convex, with a small but usually deep umbilicus; sutures of the spiral and umbilical sides radial, depressed; aperture interiomargmal, umbihcal-extraumbihcal, arched, with a distinctive lip.

Size: Maximum diameter of holotype, 0.36 mm.

Extra details from original publication
Remarks: This form differs from Globorotalia mayeri Cushman and Ellison in having more inflated chambers, a thicker test, completely radial sutures, a more distinctive apertural lip, and a more rapidly opening spire. It differs from Globorotalia opima continuosa Blow, subsp. nov. in having more numerous and more inflated chambers in the last whorl, although transitional forms occur in the Globorotalia menardii menardii/Globigerina nepenthes Zone (lower part). It differs from Globigerina dutertrei d'Orbigny in having less globular and less well-separated chambers. The aperture of Globigerina dutertrei appears to be umbilical only in D'Orbigny's figures. The specimen figured by Wiseman and Ovey as Globigerina dutertrei (1950, Pl. 2, figs, la-c) shows an interiomarginal, umbilical- extraumbilical aperture with a distinct lip, and the writer believes this specimen to be identical with Globorotalia acostaensis.
Globorotalia acostaensis first appears after the extinction of Globorotalia mayeri.

Occurrence: Ranges from the Globorotalia menardii menardii/Globigerina nepenthes Zone to the Globigerina bulloides Zone, Pozon formation.

References:

Banner, F. T. & Blow, W. H. (1967). The origin, evolution and taxonomy of the foraminiferal genus Pulleniatina Cushman, 1927. Micropaleontology. 13(2): 133-162. gs

Blow, W. H. (1959). Age, correlation, and biostratigraphy of the upper Tocuyo (San Lorenzo) and Pozon Formations, eastern Falcon, Venezuela. Bulletins of American Paleontology. 39(178): 67-251. gs

Blow, W. H. (1969). Late middle Eocene to Recent planktonic foraminiferal biostratigraphy. In, Bronnimann, P. & Renz, H. H. (eds) Proceedings of the First International Conference on Planktonic Microfossils, Geneva, 1967. E J Brill, Leiden 380-381. gs


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Globorotalia acostaensis compiled by the pforams@mikrotax project team viewed: 18-2-2020

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