End of a modern geological myth: there are no rudists in Brazil! Paleobiogeographic implications

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Data

2015-07-14

Autores

Granier, Bruno
Dias-Brito, Dimas [UNESP]

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ISSN da Revista

Título de Volume

Editor

Carnets Geologie

Resumo

Out of the few records of rudists from the Cretaceous strata of the South Atlantic coastal basins only two refer to Brazilian localities. However, petrographic analyses demonstrate that these shells should be assigned to Ostreids or to Pycnodontids rather than to Rudistids. More specifically, the domain considered herein, north of the Rio Grande Rise - Walvis Ridge barrier, was part of the warm-water tropical realm, but it was not part of the Mesogean domain because both Rudistids and Orbitolinas are missing. In addition, the scarcity of corals leads us to ascribe the taphonomic assemblage to the Chloralgal facies. Neither generalized hypersalinity or extreme sea-water temperatures seem to account for these biotic peculiarities. Instead, our alternative hypothesis favors the driving role played by oceanic circulation in the dispersal of the benthic organisms.

Descrição

Palavras-chave

Rudists, Ostreids, Pycnodontids, corals, Orbitolinids, calcareous algae, Cretaceous, Albian, Cenomanian, South Atlantic, Tethys, Mesogea, Chloralgal, paleobiogeography

Como citar

Carnets De Geologie. Brest Cedex 3: Carnets Geologie, v. 15, n. 9-11, p. 123-136, 2015.