BENTHIC FOSSIL COMMUNITIES AROUND THE CRE TACEOUS TERTIARY BOUNDARY IN THE PYRENEES/

The study of continental and marine benthic communities of the Cretace ous/Tertiary transitional zone in the Pyrenees has shown, besides vari ous extinctions (clavatoraceae, larger foraminifera), a severe impover ishment of faunas and floras. These changes are analyzed among various benthic fossil groups of continental and shallow marine environments; then they are compared with changes in benthic deep sea ostracods ass ociated with mass extinction in planktonic assemblages, at the Cretace ous/Tertiary boundary, in order to have a better understanding of the ecological processes which have driven them.