Journal of Geological Society of India (Online archive from Vol 1 to Vol 78)

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On the Morphology and Wall Structure of Tritaxia prramldata Reuss from the Late Cretaceous-Early Tertiary Deposits of Pondicherry, South India


Affiliations
1 Department of Post-Graduate studies and Research in Geology, University of Mysore, Manasa-Gangotri, Mysore, India
2 Department of Geology, S. V. University, Tirupati, India
     

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Foraminiferal samples collected during a recent study of the Upper Cretaceous-Lower Tertiary deposits of Pondicherry area, South India, have yielded a large number of individuals of Tritaxia pyramidata Reuss. A detailed morphological and microwall structural study of these shells has been made. Such a study indicates a high degree of variation in the shell and apertural shapes. Contrary to the data provided by earlier workers, the wall structure in the specimens under examination, has revealed a two layered nature, the inner layer being formed of crystals of calcite. This new investigation demands reassessment of the taxonomic status of the form. Stratigraphically, Tritaxia pyramidata appears to be a high range species, being found distributed almost throughout the above formations.
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  • On the Morphology and Wall Structure of Tritaxia prramldata Reuss from the Late Cretaceous-Early Tertiary Deposits of Pondicherry, South India

Abstract Views: 178  |  PDF Views: 2

Authors

V. Venkatachalapathy
Department of Post-Graduate studies and Research in Geology, University of Mysore, Manasa-Gangotri, Mysore, India
P. Satyanarayana Rao
Department of Geology, S. V. University, Tirupati, India

Abstract


Foraminiferal samples collected during a recent study of the Upper Cretaceous-Lower Tertiary deposits of Pondicherry area, South India, have yielded a large number of individuals of Tritaxia pyramidata Reuss. A detailed morphological and microwall structural study of these shells has been made. Such a study indicates a high degree of variation in the shell and apertural shapes. Contrary to the data provided by earlier workers, the wall structure in the specimens under examination, has revealed a two layered nature, the inner layer being formed of crystals of calcite. This new investigation demands reassessment of the taxonomic status of the form. Stratigraphically, Tritaxia pyramidata appears to be a high range species, being found distributed almost throughout the above formations.