It is found in the island of Bioko (Equatorial Guinea) and in coastal Cameroon.

[2] The specific name newtonii honours Francisco Xavier Oakley de Aguiar Newton, a Portuguese botanist who collected in Africa in the 1880s.

Males shave hypertrophied forearms, dorsal spine on the distal edge of the metacarpal of the first finger, keratinised spicules on arms and tympanic borders, large thenar tubercle, and well-developed humeral crest.

Adults are found in and near streams (within two meters distance), but juveniles might occur away from water.

Specimens can be found on stream banks, rocks, or low in vegetation, but occasionally perched as high as 1.8 m (6 ft) above the water.