Scientists have identified a previously unknown frog species living in the seasonally flooded forests of the western Amazon. Named Adenomera varcena, the species adds to growing evidence that Amazonian biodiversity is even richer than it appears. The discovery also highlights the importance of cryptic diversity, in which animals that look nearly identical can actually belong to separate species. Researchers distinguished the new frog by combining several lines of evidence, including its DNA and distinctive call. The discovery grew out of field expeditions in the Upper Juruá River region of western Acre. Scientists surveyed forest fragments near the Moa and Crôa rivers, close to Cruzeiro do Sul. Confirming that the frog represented a new species required far more than simply examining its appearance. The team compared DNA data, recordings of its calls, body shape (morphology), habitat information, and specimens preserved in scientific collections.