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Estudio cuantitativo de los foraminíferos planctónicos en el estratotipo del límite Eoceno/Oligoceno en Massignano (Apeninos, Italia)

1992; Issue: 12 Linguagem: Inglês

2173-6545

Concepción Gonzalvo, Eustoquio Molina Martínez,

Evolution and Paleontology Studies

The quantitative study of the planktic Foraminifera from the Eocene/Oligocene boundary stratotype at Massignano (Apennines, Italy) has been accomplished for the first time, This study allow us to establish the fauna/ changes in the assemblages, showing a progressive decline of the surface dwellers, which are the more tipicai Eocene species that disappear during the Late Eocene. The faunal change is gradual, it accelerates at the Eocene/Oligocene boundary, but there is not evidence of mass extinction. Nevertheless, these extinctions represent about 40% of the total species that lived during the Late Eocene and were partially replaced by oportunistic species. Besides, the quantitative study provides a base for a more rigorous biostratigraphy