Which primate genus contains the siamang?

The primate genus that contains the siamang is Symphalangus.

The siamang is the largest member of the gibbon family, Hylobatidae, and its scientific name is Symphalangus syndactylus. The genus name distinguishes it from other gibbons placed in Hylobates, Hoolock, and Nomascus. Symphalangus currently contains only the siamang species.

Siamangs live in forests of Sumatra and the Malay Peninsula, including parts of Indonesia, Malaysia, and Thailand. Their name syndactylus refers to the partial webbing joining the second and third toes on each foot. They also have a large inflatable throat sac that amplifies their loud territorial calls.

A common mix-up is treating Symphalangus as the species name. In binomial nomenclature, Symphalangus is the genus, while syndactylus is the species epithet. The siamang is also a specialized brachiator: its long arms help it swing between branches, linking this question to the broader biology of gibbons.