Madre Selva field station, Depto Loreto, Peru. January 14, 2013.
These frogs are very similar to the Gastrophryne species (and in the same family, Microhylidae) found back home in the United States, but just a little bigger. They blend in quite well with the leafy forest floor.
Peru 2013 Flickr album is here.
HerpMapper records for this species are here.