Pristimantis altamazonicus Amazonian Rain Frog
Some other names for this species:
Amazon Robber Frog, Upper Amazon Rain Frog
Madre Selva Biological Station, Loreto, PeruJanuary 12, 2014
Amazonian Rain Frog (Pristimantis altamazonicus)
This little frog was showing us just a teaser of its orange-red and black thigh flash colors. I think that these colors, in combination with the frog's general appearance, means that this is most likely Pristimantis altamazonicus. However, Dick Bartlett thinks it might instead be either P. martiae or P. orcus. We will never know for sure.

Here is a complete list of the herps I saw in the wild on my 2014 MT Amazon Expeditions trip.

Madre Selva Biological Station, Loreto, PeruJanuary 31, 2016
Amazonian Rain Frog (Pristimantis altamazonicus)
I believe the snout shape, eye color, placement of tubercles, and lack of tympanum mark this frog as Pristimantis altamazonicus, but as always with this set of frogs I can't be completely sure.

My Travelogues and Trip Lists page includes a complete list of the herps I saw in the wild on my 2016 MT Amazon Expeditions trip.

Santa Cruz Forest Reserve, Loreto, PeruFebruary 7, 2016
Amazonian Rain Frog (Pristimantis altamazonicus)
I spent a long time trying to identify numerous small Pristimantis frogs after this trip. Just to show that I'm not entirely guessing, here are my notes for this one:

"Pristimantis altamazonicus (reasonably tuberculate, general size & shape, toepad shape, thick scapular W mark, no tympanum, barring on lips and limbs, iris color, heel color. eyelid tubercles rule out croceoinguinis.)"

After all that, I fully expect someone to explain why this one isn't really P. altamazonicus. So go ahead.

Online references:
Printed references: