ABSTRACT
After the definition of the basic biogeographical concepts, numerous questions arise. How can the observed biogeographical distributions be explained? What are the causal processes? How are the major geological processes involved in shaping the biogeographic distributions? Some of these questions may remain unanswered when the aims of the biogeographical study are not precisely defined. The aims can be expressed in terms of investigative pathways which apply to both the extraction and the explanation of biogeographical patterns, to the investigation of processes and to reconstruction of evolution and palaeogeography. Because the process is inferred from the pattern, we must take into account the limits and the constraints of palaeobiogeographic analyses.
