Biogeography of the Quaternary Molluscs of the Southwestern Atlantic Ocean

SERGIO MARTINEZ,; CLAUDIA DEL RÍO,; ALEJANDRA ROJAS

Springer Dordrecht Heidelberg New York London

Lugar: Londres; Año: 2013 p. 36

978-94-007-6054-7

The Quaternary comprises a brief lapse in the Earth?s history, and with a few exceptions, molluskan assemblages recovered from exposures along the coast of Southwestern South America (Southern Brazil, Uruguay, and Argentina) are essentially the same than those that inhabit the region today. However, minor changes are detected at regional scale, involving northwards latitudinal shifting in the geographic distributions of some species (?out of range? species). This can be specially assessed for the assemblages recorded in the central areas of the studied region. The fact that the number of recorded Holocene species is higher than the Pleistocene ones is explained as a sampling artifact. Multivariate analyses and, in a less extent, the richness and taxonomic diversity, show a latitudinal control overthe molluskan faunas, that could be attributed to the latitudinal temperature gradientcaused by the presence of the Brazilian and Malvinas (Falklands) currents and their confluence in the region.