We analyzed the effects of ecological and historical factors on the anuran assemblage of a protected area with different ecotones located in northeastern Brazil. The 'tension' between habitats suggests that competition may drive niche structuring, even if space is more affected by phylogeny and diet is less influenced by it. We conducted sampling during the rainy season of 2023 using active and auditory searches. Historical factors exerted a greater influence on the spatial niche, indicating a predominance of adaptations from the Cretaceous. However, this influence was not significant, and there was no discernible structure in space, with no apparent tension between the different habitats. Several species exhibit habitat exclusivity, which may mitigate resource overlap due to their non-coexistence. Diet was standardized, likely because preys are more susceptible to seasonality and physical variations of each habitat. However, the phylogenetic influence on diet was quantitatively greater than ecological influence, primarily reflected through myrmecophagy, although it did not solely explain the results. Finally, we detected niche complementarity, with one dimension highly overlapped and another flexible, suggesting a possible coexistence strategy. The highly diverse plant composition of the area seems crucial for anuran richness, and future research should investigate other dimensions of the niche.