Upper Miocene Biostratigraphy: does Globorotalia conomiozea occur in the Messinian?
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G.H. Scott [1]
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[1] New Zealand Geological Survey, Lower Hutt, N.Z.
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- Localización: Revista española de micropaleontología, ISSN 0556-655X, Vol. 12, Nº. 3, 1980, págs. 489-506
- Idioma: inglés
- Texto completo no disponible (Saber más ...)
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Resumen
A representative sample of Globorotalia conomiozea Kennett and topotypes of G. miozea conoidea Walters from upper Miocene strata in New Zealand are described and compared with Messinian specimens from Falconara, Sicily. Similarity in the spiral shape of chambers suggests that the taxa shared ancestry in the Miocene plexus that developed from G. scitula praescitula Blow. However, chambers of Falconara specimens do not develop the marked conical form (axial orientation) of G. conomiozea and it is concluded that this taxon has been misidentified in some previous Mediterranean studies. Although Falconara shells resemble those of G. miozea conoidea from New Zealand, there are differences in the size of the aperture, prominence of the apertural lip, detailed shape of the ventral profile of chambers, and gross proportions of the shell. Character trends found in New Zealand populations are not seen in the morphologically stable populations from Falconara. The contrast in population histories and the morphological differences suggest that New Zealand and Falconara shells may represent separate lineages in the plexus. Falconara specimens are referred to G. mediterranea Catalano and Sprovieri. The appearance of the latter in Mediterranean strata is not related to the appearance of G. conomiozea in New Zealand strata.
