We describe the advertisement calls and color in life of Allobates sumtuosus (Morales 2002) based on specimens recorded and collected at its type locality in Reserva Biológica do Rio Trombetas, Brazilian Amazonia. We also improve the species diagnosis by adding information on states of characters frequently used in current Allobates taxonomy. Finally, we analyze genetic distances and the evolutionary relationships between typical A. sumtuosus and other Allobates species distributed in Brazil and along the Guiana Shield region using a fragment of the 16S rDNA mitochondrial gene. Based on this integrative analysis, we propose the synonym of Allobates spumaponens Kok & Ernst 2007 with A. sumtuosus and provide an updated geographic distribution of the species.