The extant Amphibia (Lissamphibia) comprise three distinguihable orders, each with a highly diverged body-plan: Anura (frogs and toads), Caudata (salamanders and newts) and Gymnophiona (caecilians). Currently, a timescale for the evolution of Amphibia, i.e. the divergence of the three orders and their families is considered one of the missing requirements for the construction of an evolutionary synthesis for Amphibia. Morphological as well as conventional molecular-systematic studies failed to solve this problem, and several paeontological, biogeographical and molecular studies have resulted into contradictory results. Complete resolution of the amphbian divergences may be obtained by means of identification of Rare Genomic Changes (RGC's), i.e. macro-mutations in the genomes of certain clades. Reliable estimation of dates, even in the absence of a molecular clock, are possible by analysing large datasets, using a recently developed Baysian approach. With this study, we try: (1) to determine phylogenetic relationships and to date the origin of large evolutionary lines within the Amphibia, (2) to formulate a biogeographical scenario by linking phylogenetic divergences to plate-tectonic events, and (3) to interprete the results in terms of the phylogenetic position of several fossil lines. A statistically fundated molecular phylogeny may reconcile the opinions of paleontologists, biogeographists and evolutionary biologists.