 Because of the similarities, Pachylemur is sometimes referred to as a giant ruffed lemur. In addition to the morphological similarities, molecular studies also support a close relationship. Based on studies of their DNA, Pachylemur and ruffed lemurs form the sister group relative to the rest of the lemurs in the family Lemuridae. This sister group itself forms a sister group with the clade (related group) containing brown lemurs (Eulemur), the ring-tailed lemur (Lemur), the greater bamboo lemur (Prolemur), and the lesser bamboo lemurs (Hapalemur).
