Dark Newtonia occurs in eastern Madagascar. Adults have grey-brown backs and pale, tan-tinged undersides, and the species uses low rainforest and nearby secondary growth.
Adults have grey-brown upperparts and white underparts tinged tan, with a black bill and golden-yellow eyes.
The account places it in the lower strata of low rainforest and nearby secondary growth in eastern Madagascar.
An extinction-risk assessment has not been added yet.