Catalog - Neogloboquadrina dutertrei andamanica

CATALOG OF ORIGINAL DESCRIPTIONS: Neogloboquadrina dutertrei andamanica Srinivasan & Azmi 1976

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 -> N -> Neogloboquadrina -> Neogloboquadrina dutertrei andamanica
Other pages this level: N. atlantica praeatlantica, N. dutertrei andamanica, N. dutertrei blowi, N. inglei, N. pachyderma dextralis

Neogloboquadrina dutertrei andamanica

Citation: Neogloboquadrina dutertrei andamanica Srinivasan & Azmi 1976
Rank: sub-species
Type sample (& lithostrat): Neill West Coast Fm., Silty mudstone member
Type age (chronostrat): Late Pliocene; G. toaensis tenuitheca zone
Type locality: Neill Island, Ritchie's Archipelago, Andaman Sea
Type repository: Bandaras; Geology Dept., Bandaras Hindu Univ.

Current identification:


Original Description

Test large, free, low, trochospiral, almost flat on spiral side, dextrally coiled, equatorial periphery lobate, axial periphery rounded, chambers angular to ovate, 10 to 14 arranged in about three whorls usually five to six in last whorl. Chambers increasing in size in last whorl somewhat irregular; last and penultimate chambers flattened and elongated toward umbilical side, with a steep umbilical face duture depressed, radial to slightly curved on umbilical side; wall calcareous, cancellate, similar to Neogloboquadrina duttertrei (d'Orbigny) usually with thin encrustations. The final and penultimate chambers have pitted microcrystalline surface whereas the early chambers on last whorl near the umbilical shoulder: show some secondary encrustation producing stellate tubercles (fig 5). Umbilicus fairly wide and deep; aperture a low arch, umbilical to extraumbilical, covered with a distinct pointed umbiical plate or tooth.

Size:
maximum diameter of holotype (fig. 4)~ 0.6 mm

Etymology:

Extra details from original publication

Remarks. - In the present work the views of Srinivasan and Kennett (1976)  concerning the eogloboquadrina plexus are followed.

In general appearance this subspecies resembles N. dutertrei, but is distinguished by having the chambers on last whorl, which are flattened and elongated towards the umbilical side with a steep umbilical face.

Specimens illustrated by Vincent, Frerichs and Heiman (1974) as Globoquadrina sp. A resemble Andaman Sea specimens and therefore are referable to this subspecies.


Editors' Notes

References:

Srinivasan, M. S. & Azmi, R. J. (1977). Contribution to the stratigraphy of Neill Island, Ritchie's Archipelago, Andaman Sea. In, Srinivasan, M. S. (ed.) Proceedings of the VI Indian Colloquium on Micropaleontology and Stratigraphy. Department of Geology, Banaras Hindu University, Varanasi 1-283. gs

Srinivasan, M. S. & Kennett, J. P. (1976). Evolution and phenotypic variation in the Late Cenozoic Neogloboquadrina dutertrei plexus. In, Takayanagi, Y. & Saito, T. (eds) Progress in Micropaleontology. American Museum of Natural History Micropaleontology Press, New York 329-355. gs

Missing or ambiguous references: Vincent et al. 1974;


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Neogloboquadrina dutertrei andamanica compiled by the pforams@mikrotax project team viewed: 26-11-2022

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Comments (1)

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Fran├žois

Neogloboquadrina dutertrei subsp. andamanica Srinivasan & Azmi, 1977 according to E&M

after the Andaman Sea. 1976 is the date of the Congress but the publication was issued in 1977 (still according to E&M)

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Jeremy Young (Tonbridge, UK)

corrected, thanks Jeremy

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