The Indriidae are a family of strepsirrhine primates. They are medium- to large-sized lemurs, with only four teeth in the toothcomb instead of the usual six. Indriids, like all lemurs, live exclusively on the island of Madagascar.
Indriidae
Strepsirrhini or Strepsirhini is a suborder of primates that includes the lemuriform primates, which consist of the lemurs of Madagascar, galagos ("bushbabies") and pottos from Africa, and the lorises from India and southeast Asia. Collectively they are referred to as strepsirrhines. Also belonging to the suborder are the extinct adapiform primates which thrived during the Eocene in Europe, North America, and Asia, but disappeared from most of the Northern Hemisphere as the climate cooled. Adapiforms are sometimes referred to as being "lemur-like", although the diversity of both lemurs and adapiforms does not support this comparison.
Strepsirrhini
Early primates possessed adaptations for arboreal locomotion that enabled maneuvering along fine branches, as seen in this slender loris.
Notharctus, a type of North American adapiform, resembled lemurs but did not give rise to them.
The suborder Strepsirrhini was proposed by É. Geoffroy in 1812.