Symphalangus

Symphalangus is a monotypic genus of gibbons in the family Hylobatidae, containing the single species Symphalangus syndactylus, the siamang, native to the tropical rainforests of Sumatra and the Malay Peninsula in Indonesia, Malaysia and Thailand. As the largest living gibbon, it can stand up to a meter tall and weigh as much as 14 kilograms, and is distinguished by partially webbed second and third toes, reflected in its scientific name, and a large inflatable throat pouch used to amplify its calls. The species is divided into Sumatran and Malaysian subspecies, its fossil record dates to the Middle Pleistocene, and it is assessed as endangered.