Abstract
Rudists have played a prominent role for settling the biostratigraphic subdivisions of the Tethyan Cretaceous carbonate platforms. The rudist biostratigraphic foundations have been established on both the evolution of morpho-functional elements which characterize the different families and the evolution of certain lineages. On of the main focus of modern researches has been the improvement of the Toucas biostratigraphic scale by a better definition of the rudist species. According to a first proposal by d'Orbigny, rudists have been used for the characterization of the Cretaceous stages, in addition to ammonites and foraminifera. Rudist evolution has been affected by short duration crises, which have deeply modified the composition in genera and species. New data obtained in Caribbean, Europe and Oman, give insights about the end Cretaceous demise of rudists. Rudists have been considered as palaeobiogeographic markers, giving valuable information for testing the plate tectonic and kinematic reconstructions. Their palaeobiogeographic distribution was probably driven by the larval reproduction, the geodynamic of the Tethyan margins and the oceanic circulation. The identification of the rudist palaeobiogeographic provinces and the assessment of the rudist endemism rate has led the establishment of relationships between provinces and the identification of palaeobiogeographic oceanic or continental barriers. Palaeobiogeographic isolation can be tested by the variations of rudist evolution rate during time. Global factors such as eustatic oscillations were able to monitor the inter-provincial faunal exchanges and, consequently, endemism.
