It is a forest mouse and was thought to be endemic to Ecuador but it is now known to have a wider distribution, being also present in part of Peru.

The dorsal pelage is short and dense and consists of a mixture of slender hairs with reddish or blackish tips and stouter spines of the same length that are darker at the tip, giving a grizzled appearance.

[4] The fur on the ventral surface has similar hairs and spines but they are a uniform grey colour.

Morphologically this species is very similar to the closely related Ucayali spiny mouse (Scolomys ucayalensis).

The nest often includes fibres from the undergrowth palm Lepidocaryum tenue and the litter size averages 2.5.