This langur is endemic to Siberut Island, Indonesia, and the current MDD treats it as a separate species. It lives in trees and is active by day, though field research dedicated to the species remains limited after its separation from related forms.
Its coat is dark, with a white mane-like fringe around the face and reddish-brown fur on the lower belly.
It lives in trees in primary and secondary rainforest and is active during the day. Reported foods include fruit and leaves. The account also notes that species-specific research remains sparse.
An extinction-risk assessment has not been added yet.