Pristimantis divnae — Los Amigos Rain Frog
I had difficulty tracking down even a guess for the ID of this frog. Dick Bartlett didn't recognize it, and couldn't find any description of a Pristimantis with the yellow at the top of the forelimbs. He contacted some Peruvian frog experts, who also could not come up with a potential match. However, a year later someone suggested that I look into Pristimantis divnae, which was described only a few years ago. I contacted the authors of the paper that described this species, and one of them, Dr. Edgar Lehr, was kind enough to write back and agree that my photo did look like that species. Without a more complete examination of the frog I don't know for sure (for example, the belly color & pattern is relevant to the ID), but that's my best guess for now.