"Explaining the causal mechanisms underlying the latitudinal gradient in species richness has long been a core objective for ecologists and biogeographers. The phylogenetic niche conservatism hypothesis (PNCH) is receiving increasing attention as a synthetic theory able to account not only for the high tropical richness of most taxa, but also for the exceptions to this pattern found in some groups. However, only a few studies have tested this hypothesis and, hence, the empirical support for PNCH as the primary driver of richness gradients at a large scale still remains limited. Because of the worldwide amphibian decline, large amounts of distributional, biological, phylogenetic and extinction risk data are increasingly available for researchers. Accordingly, PHYLONICHE will use a phylogenetically informed biogeographic approach to address a long-standing issue in ecology (i.e. why there are more species in the tropics?) and to explore the causal mechanisms underlying the global amphibian decline. Specifically, it will examine the following questions: (1) Do amphibian lineages tend to maintain their climatic niches over long evolutionary scales?;(2) is the observed global gradient in amphibian species richness a result of phylogenetically structured ecophysiological traits that limit the geographical distribution of species and clades?;(3) to what extent are older basal clades confined to the tropics and underrepresented in temperate regions, with younger derived clades showing higher species richness in extratropical regions?;(4) is there any relationship between a high degree of ecological specialization in terms of climatic niche breadth and higher extinction risk in amphibian species?;(5)which ecological factors and species biological traits are associated to a higher degree of extinction risk for amphibian species across the globe?;(6)which is the geographical location of areas with higher latent extinction risk for amphibian species at the global scale?"