The giant aye-aye Daubentonia robusta.

Subfossils of a giant form of aye-aye are found at scattered sites in the south and southwest of the island of Madagascar, outside the known distribution of the living, or common, aye-aye. The subfossil aye-aye, named Daubentonia robusta, has massive, robust limb bones implying a species with a body weight 2.5-5 times as great as that of the living species. A mystery exists regarding how a species this large with the same specializations of teeth and manus as the living species could have existed in a xeric environment.