Oxygénation des eaux etostracodes filtreurs: Application au Devonien-Dinantien

Abstract

In post-Palaeozozoic and modern oceans, it has been recently demonstrated that filter-feeding ostracods can beused to locate kenoxic events and to determine palaeo-oxygen levels. Our analysis shows that, of the Upper Paleozoic Ostracoda, the Palaeocopida, Metacopida, Platycopida, Kloedenellacea and the Paraparchitacea were filter-feeders. Our reconstructions for both dissolved oxygen and sea water temperatures in the Devonian and Lower Carboniferous, based upon the percentage of filter-feeders species, clearly depict the Upper Devonian Events in Western Europe: a time of low oxygen high temperatures and high filter-feeders into the Frasnian, the subsequent cooling and improved oxygenation into the Famennian and a glacial maximum marked by a low percentage of filter-feeders in the Lower Tournaisian. We propose some data to determine absolute values of oxygen rate in Upper Palaeozoic neritic environments.