CATALOG OF ORIGINAL DESCRIPTIONS: Globigerina antarctica Keany & Kennett 1972
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.
Citation: Globigerina antarctica Keany & Kennett 1972Rank: speciesType specimens: tf. 3, no. 1-6; holotype (no. 6), no. 183690; and paratypes (nos. 1-5), nos. 183691-183695, respectively. Type age (chronostrat): Lower Pleistocene; and ranges throughout the stratigraphic section assignable to the Matuyama Reversed Polarity Epoch (0.7 to 2.43 million years BP).Type locality: U.S.N.S. ELTANIN core E 36-14, taken from a depth of 3054 meters at lat. 58°06' S., long. 150° 10' E., northern Antarctic Sea between Australia and Antarctica; holotype (no. 6) and one figured paratype (no. 1) from 500-502 cm. depth in the core; three figured paratypes (nos. 2-4), from 250-252 cm. depth: and one figured paratype (no. 5) from 520-522 cm. depth. Found in greatest abundances in cores taken immediately south of the Antarctic Convergence. Type repository: USNM;
Original Description Test of moderate size, moderately to highly lobulate with a low spire, fairly uniform increase in chamber size until the final chamber which is commonly the same size or smaller than the penultimate chamber. Mostly 4, occasionally 5 chambers in the final whorl; 12-14 in the test. Aperture is umbilical to extraumbilical in position and is a large arched opening, usually with a distinct lip. Test wall calcareous, perforate, often shiny (with light microscope). Surface of final chamber generally smoother and more shiny than earlier chambers which have rougher texture. Surface roughness more distinct when viewed with scanning electron microscope. Slight dominance of left-coiling forms.
Size: Dimensions. - Holotype (no. 6) greatest diameter 0.30 mm.; paratypes (nos. 1-5) greatest diameter 0.40 mm. Extra details from original publication Variability. - The most variable morphological features include the number of chambers in the final whorl (4 to 5) and the position of the aperture which ranges from umbilical to extraumbilical in position.
Remarks. - Similar to Globigerina bulloides but differs in being more lobulate, in having a distinct lip, smoother test wall and the tendency to have a smaller final chamber. Differs from Globigerina falconensis Blow in being less lobulate, in having a smoother test wall, and more highly arched aperture. lt differs from Globigerina parabulloides Blow in being less compact, more lobulate and in having a less uniformly arched and larger aperture. Both G. falconensis and G. parabulloides are of warmer-water habitat than G. antarctica. Distribution. This species has been found to range throughout the Matuyama, and has not been reported in sediments younger than the late Matuyama. It occurs in greatest abundances in cores immediately south of the Antarctic Convergence.
References:
Keany, J. & Kennett, J. P. (1972). Pliocene-early Pleistocene paleoclimatic history recorded in Antarctic-subantarctic deep-sea cores,. Deep-Sea Research. 19(8): 529-548. gs
Globigerina antarctica compiled by the pforams@mikrotax project teamviewed: 31-3-2023
_USNM-183690_holo2.jpg)
antarctica(G)_USNM-183690_holo2.jpg
Keany & Kennett 1972 DSR 03-01_02.jpg
Keany & Kennett 1972 DSR 03-04_05.jpg
Keany & Kennett 1972 DSR 03-06.jpg_USNM-183690_holo2.jpg)
antarctica(G)_USNM-183690_holo2.jpg
Keany & Kennett 1972 DSR 03-01_02.jpg
Keany & Kennett 1972 DSR 03-04_05.jpg
Keany & Kennett 1972 DSR 03-06.jpg
Comments
(0)