Foot anatomy, climbing, and the origin of the Indriidae

Living indriids share a suite of derived osteological and myological features of the foot which are related to three of the most important components of their locomotor repertoire: climbing (primarily on vertical supports), vertical clinging, and leaping. However, the overall structure of the foot bones and musculature reflects the requirements for climbing more than any other behavior. All indriid subfamilies have postcranial morphologies and locomotor behaviors which are derived compared to the probable indriid-lemurid common ancestor. It seems most likely that the ancestral indriid was an "arboreal quadruped" (i.e. lemur-like), not a vertical clinger and leaper.