Global stratigraphy, palaeobiogeography and palaeoecology of Albian-Maastrichtian pithonellid calcispheres: impact on Tethys configuration

This study reviews the stratigraphy, palaeobiogeography and palaeoecology o f some important Albian-Maastrichtian pelagic calcispheres: Bonetocardiella conoidea, Pithonella ovalis, P. perlonga, P. sphaerica and P. trejoi. It a lso presents a significant new data set on these organisms from the western South Atlantic Ocean. The group reached its acme simultaneously all over t he world during the highest Cretaceous sea level in late Albian to Coniacia n times. A strong association also existed between the maximum temperature and the salinity of the Tethyan water mass and the climax of these opportun istic microfossils. Their remarkable presence along the Brazilian and west African margins during the Albian, in association with other typical Tethya n pelagic biotic elements, indicates that during this period the northern S outh Atlantic was a long, narrow arm of the Tethys Sea. (C) 2000 Academic P ress.